THE MINES ACT, 1952
Examination for Mine Manager’s Certificate of Competency under the Coal Mines
Regulation, 1957
FIRST CLASS
MINE MANAGEMENT, LEGISLATION & GENERAL SAFETY
Monday, the 20th December, 2004
Full Marks: 100
Time
: 3 Hours
Answer any Six Questions
(All questions carry equal marks)
Q.1.What do you understand by the term “flame proof equipment”? Draw a list
of instructions, responsibility for compliance and records that should be
maintained to ensure that flame proof features remain effective.
Ans:- Flame Proof Equipment:- Equipment enclosed in flameproof enclosure
is called flameproof equipment. Flameproof enclosure is an enclosure for
electrical machinery or equipments that will withstand (when the covers or
other access doors are properly secured) an internal explosion of the
inflammable gas or vapour which may enter or originate inside the
enclosure, without suffering damage and without communicating the
internal flammation ( or explosion) to the external inflammable gas or
vapour in which it is designed to be used ( through any joints or other
structural openings in the enclosures).
FLP equipment used in mines are of approved design and every part of such
equipment has standard specification. It becomes unsafe if it is not assembled,
installed, maintained and handled in the manner required. Purpose of an FLP
equipment is lost as soon as its original design, form of assembly and the
specifications are in any way tempered. This call for utmost care and caution in
maintenance of these equipments. Flameproof features of FLP equipment are
often found disturbed due to improper handling and poor maintenance. To avoid
this, the following are the list of instructions, responsibility for compliance and
records that should be maintained to ensure that flame proof features remain
effective:
(Clue- NSS CCWO SPCA FIAT BDO )
S.N.
Instructions
Responsibility
Nuts and bolts to be cleaned Electrician, Electrical
1
with petroleum gel before supervisor
and
refitting.
Engineer.
Studs, if broken, should not be Electrical supervisor
2
removed by drilling.
and Engineer.
Shrouds should be kept free Daily3
Electrician
from dirt and should not be WeeklyElectrical
damaged or removed.
Supervisor.
Monthly - Engineer.
Cast metal casings should be Electrical supervisor
4
examined for fractures and and Engineer.
cracks during installation and
shifting and also after roof fall.
Records
Record
to
be
maintained in the
register.
Every instance shall
be recorded.
Damages shall be
recorded.
To be recorded.
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Clearance of shaft glands and
all joints shall be checked
when ever motor is
dismantled.
Cracked and broken glass
winds and walls should be
replaced with fresh approved
glasses
complete
with
retaining rings.
Level of oil in oil immersed
equipment to be checked
frequently
Spares should be obtained
from original manufacturer.
Electrical supervisor To be recorded.
and Engineer.
Plug and socket connectors
and
coupler
should
be
examined for tightness and
overheating
Level of compound in sealing
boxes should be checked
regularly and particularly in hot
situation.
Armour glands should be
checked for its firm gripping
and
should
be
cleaned
frequently
Every flange joints should be
checked with fillers
To be recorded.
Electrician, Electrical To be recorded.
supervisor
and
Engineer
Electrical supervisor Checks with topping
and Engineer
up shall be recorded.
Electrician, Electrical
supervisor
and
Engineer
DailyElectrician
WeeklyElectrical
Supervisor.
Monthly- Engineer.
-do-
Replacements
be recorded.
shall
-do-
Daily- Electrician
To be recorded for all
MonthlyElectrical new installations.
Supervisor.
WeeklyElectrical Clearance shall be
Supervisor.
recorded.
Monthly- Engineer
Interlocks should be examined Weekly- Electrician.
He should repair or
frequently for broken & bent parts.
report for action.
No alteration in design of Electrician, Electrical
flameproof enclosures.
supervisor& Engineer
Terminal boxes to be kept free Electrician, Electrical Suitable entry in the
register
for
such
supervisor(Weekly)
from dust and moisture
cleaning jobs.
Bearing of switch spindles to DailyElectrician To be recorded.
Electrical
be regularly inspected and Weeklylubricated
Supervisor.
Monthly- Engineer
Doors, Covers, oil tanks DailyElectrician To be recorded in the
Electrical register
whenever removed, shall be Weeklywith
the
replaced correctly
Supervisor.
description of the
Monthly- Engineer
work.
Correct setting and checking of Electrician, Electrical Setting
shall
be
overload and earth leakage supervisor
and recorded.
trips to be ensured.
Engineer
Broken or missing bolts or set Electrical supervisor Every instance shall
screws should be replaced by and Engineer.
be recorded.
others of correct diameter,
thread, length, type of head
and quality of steel.
No cover of live FLP Electrician, Electrical
equipment should be opened supervisor
and
at any time.
Engineer
Q.2. A large mechanized opencast mine is being planned in a virgin area. Briefly
state and discuss the statutory notices that are to be sent and permissions/
relaxations to be obtained. What steps should be taken to select, recruit and
train the workman, staff and officers?
Ans: - The following are the various permission/exemption from statute for
opening a big O/C mine in a virgin area:
i) Notice of opening :- For opening any new O/C mine, the notice shall be
submitted in form I to the RIM, CIM, D.M. controller general IBM accompanied
by a plan showing the boundaries of the mine and other prominent and
permanent surface features.
ii) Communication of actual date of opening:- When mine has been opened,
owner/Agent/Manager shall forthwith communicate the actual date of opening
to CIM and RIM.
iii) Appointment of officials:- An intimation in form l shall be given to CIM and RIM
for appointment of officials.
iv) Appointment of deemed agent:- A statement showing names and designation
of every person authorized to act on behalf of the owner in respect of
management, control, supervision of direction of the mine shall be submitted to
CIM and RIM.
v) Exemption shall be applied for reduction the number of U/Ms / ACMs, Surveyors,
as these are based on the production of the mine and not on extent of mine &
machinery deployed, from the relevant statute.
vi) Exemption is required for bench height/ bench slope (bench geometry).
vii) Exemption /permission shall be required under from CIM for gradient of roads
steeper than 1 in 14 at any place of the mine.
viii) Permission to work within 45m of any public building or permanent structure not
belonging to owner is required from CIM.
ix) Permission/exemption for temporary storage of explosives near the mine shall be
obtained.
x) Exemption for not using cartridge in open cast mines( use of bulk explosives)
xi) Exemption for blasting more than 120 shorts in a shift in O.C. Mines.
xii) Permission for max. charge/hole as per requirement of the mine taking into
account the require blasted material to fulfill the target.
xiii)Permission/exemption/ approval for new blasting technique from CIM/RIM so that
flying fragments from blasting can’t project beyond a distance of 10m from the
place of firing.
xiv)
a) Notice is to be given under IER for size and type of apparatus together
with such particulars which may be required by the inspector.
b) 7 days notice to inspector for new installation in the mine.
xv)Exemption/permission is to be applied for any voltage other than specified
voltage.
xvi)Permission is required for using flexible cable with equipment in O/C mines and
length of cable more than 300m.
xvii)Permission for using more than one type of explosives in the same hole is
needed.
xviii)Prime and column charge if different, permission is required.
xix)If buildings / structures exists within 50m of site of blasting, permission from
CIM/RIM is required.
Selection, recruitment and training of workmen, staff and officers:For selection, recruitment & training of manpower for running a big open cast
mine, we assume the following conditions:Conditions assumed:Coal Production
=
2.0 m.te
OBR
=
6.0 mm3
Average S.R.
=
1: 3
Thickness of Seam =
20m
Thickness of OB
=
60m
Gradient of seam =
1 in 10
No of coal benches =
2
“
OB benches =
5
Height & width coal bench =
10m, 30m
Height & Width of OB “
=
12m ,30m
Under the assumed conditions, we need the under mentioned equipment and
manpower:
Requirement of Equipment & Manpower
a) Equipment Nos. Operators
Officers, supervisors & Helpers
Electric rope shovel (4.6m3) 05 15
Mining
- 15
Dumper(35T)
30 90
Electircal
- 12
Dozer (135KW)
03 09
Mechanical - 12
Drills ( 250mm)
04 12
Personnel &
Motor Grader (100KW)
01 02
Finance
- 10
Roller (25T)
01 02
Agent
- 01
Scrapper (11m3)
01 02
Manager
- 01
Pick up van
01 03
ACM
- 08
Explosive Van
01 02
S.O.
- 01
Light vehicles
04 08
G.Maz.
- 30
Water Sprinkler
01 03
Surveyors
- 02
Mobile crane
01 03
Trg.Officers - 03
Ambulance
01 03
Med.Officer - 01
Instructors - 06
Drilling &
Blast.Gang - 15
Tripman/
Dumpman - 02__
154
119
To run a big open cast mine in safe and efficient manner in order to fulfill the
production target, deployment of skilled and trained manpower is first and
foremost necessity.
Selection and recruitment is the process of discovering manpower by
disseminating information about the nature of vacancies and the education and
skills required for its performance. As a result, persons who possess the requisite
qualifications and skill, submit their applications for selection and appointment.
Introduction of a new technology demands new skills for which suitable
manpower has to be found either by recruiting people from outside or by
selecting people from within the industry and training them to suit the needs.
There is a close link between manpower planning and recruitment.
Source of Recruitment:There are a number of sources from which skilled
or unskilled manpower may be recruited. These are:
1. Employment Exchange:- The mine management has to send its specific
needs for manpower requirement mentioning the minimum qualifications and
experience desired. The Employment Exchange makes preliminary screening
from the names of the persons registered and forwards the same to the
requisitioning authority.
2. From Existing Employees:- By designing the training schemes and
manpower development plans for upgrading skills, mine management can meet
the bulk of its semi skilled and skilled manpower demand from its own resources.
3. Recruitment from Institutions:- Recruitment Officers team from an industry
make a round of visits to the universities, colleges and polytechnics. They meet
the students, counsel them about the job opportunities in their firm and recruit
suitable students.
4. Advertisement:- This is the process by which senior and more experienced
people are found.
After selection and recruitment of workmen, staffs and officers, initial / basic training shall be
imparted to them in the following manner:-
i) Training of workers and supervisorsSl.
No.
1
2
3
i.
ii
iii
iv.
v.
vi
vii
viii
ix.
x.
Categories of
workers/staffs
Surface
workers
Duration
of
training
12
Course content
Organisation/lmine details, safety policies, role & function
of ISO, Institution of SC & WMI, mine environment,
dangers from fire, medical attention etc.
O/C workers
18
Method of mining, coal seams and geology, haul road &
geometry, HEMM, traffic rules, code of practices, safety &
other apparatus, use of explosives, shelter etc.
Special categories of workers & supervisors
Drillers
36
Type of drills with specification and details, type of drill
bits and its use, drilling pattern, safety during drilling and
marching, routine check up and maintenance etc.
Blasting crew
36
Drilling and blasting concept, types of explosives and
accessories, importance of free face, code of practice for
safe handling, storage, transport and use of explosives,
fly rocks, fragmentation, ground vibration, danger zone
etc.
Dumper
60
Type of dumpers, functioning of dumpers and its safety
Operators
devices, service and parking brakes, fire protection etc.
Shovel
60
Type of shovels, functioning of hoist, crowd, swing and
Operators
propel system, code of practices, fire in HEMM and its
fighting.
Dozer
60
Dozers & its function, transmission and hydraulic system,
Operators
steering / brake / final drive etc
Fitters
&
72
Various types of HEMM & other machinery, tools and its
Mechanics
use, measuring instruments, lubrication, bearings etc.
Electricians
96
HEMM & other machinery, electrical tools, measuring
instruments, type of motors and its use, cables and
conductors, transformers, circuit breakers, earthing, semiconductor devices etc.
Auto
90
Types of transportation machinery, motors and its use,
Electricians
transformer/batteries /dynamo, generator, alternator,
control box, AVA etc.
Electrical
18
Electrical layout, AC&DC, load, voltage drop, power
supervisors
factor, transformer, DG sets, important provisions of IER
etc.
Sub-ordinate
Coal seams & geology, duties & responsibilities of
supervisory
Supervisors, mining methods, mine plan & section, traffic
officials
rules, safe code of practices of machinery etc.
ii) Training of Officers –
(a) Induction/ Orientation training – Such type of training is imparted to newly
recruited officers in order to make them familiar with the organisation and its
structure, service conditions, duties, responsibilities and rights, career growth,
social security, medical facilities etc. The duration of course is generally one
week and the training is generally in-house.
(bi) Medical Officer associated with PME should be imparted proper training in
occupational health and use of ILO classification.
(c) Supervision & Management Course – One month extensive training is
imparted at Central Staff training College for developing officers through inter
company management development programme as a continuous process.
d) Special training facilities: - Special training related to introduction of special
mining techniques and methods such as scraper mining, continuous mining,
surface mining etc is imparted to officers engaged in mining operation. The
duration of training is generally one week.
e) External training facilities:- In-house training facilities are not adequate to
meet all the training needs of the industry. Following external training facilities
are given to officers:- Refresher and improved courses in technology at technical institution.
- Management courses at administrative Staff training College.
- Specialized technical skills and advanced management courses outside the
country.
- Seminars and workshops organized by professional bodies like institution of
Engineers, Mine Managers association, educational institution etc.
Q..3.Answer the following:
a. What should be the syllabus for pre-employment training for workers for
an underground mine? What is the need for refresher training?
b. State the differences in statutory provisions relating to haulage and
winding ropes?
Ans:-a) As per statutory provision under MVTR1966, Pre-employment/basic/initial
training should be imparted to workers of an u/g mine for 12 days under direct
personal supervision of trainers. But as per recommendation of National tripartite
workshop on Revised Modules for vocational training in mines held in 1999 at
DGMS, U/G workers should be imported 48 days ( Theory – 10 days , on the job
28 days & Feed back – 2 days) pre-employment/initial training.
Syllabus for Pre-employment training for u/g workers:A) Theoretical training 1) General –
i. Details of mine/organisation, types of jobs etc.
ii. Organisation structure – company, area, mine etc
iii .Departments/ sections/ units etc & their function.
iv. Service conditions, personnel matters, disciplinary proceedings.
v. Safety policy of company, company objectives, mine objectives, individual
objectives.
vi. ISO and need of workers participation in safety management, Role of
DGMS.
vii. Duties of workmen
viii.General Service condition & facilities to be provided.
2) Specific –
i. General idea about the coal seams, formation of coal, types of associated
rocks, geological disturbances etc.
ii. Different type of mining – O/C & U/G Mining, multi-seam workings etc.
iii. Different type of outlets – Shaft /Incline/drift, second outlet
iv. Mining methods- Board & Pillar, Longwall, SDL / LHD / Continuous miners
district, Development working, Depillaring (caving, stowing method.)
v. Strata control – Type of supports, method of support, RMR/ SSR, Timber,
roof bolts, roof stitching, powered support. Hydraulic support, safe erection
and withdrawal of supports.
vi. Mine Ventilation & Environmental monitoring–
Quantity & quality of air, Natural & artificial ventilation, MMV, booster &
auxiliary fans, ventilation stoppings. Monitoring of mine gases and their
detection. Effect of inflammable & noxious gases etc.
vii. Dust & noise hazardCoal dust, its formation, hazards (health and explosion), dust control
measured, noise problems and control measures.
viii. Equipment, lighting, telecommunication and signaling – Face pumps, cap
lamps, drills, CCM, FLP apparatus, earthing etc.
ix. Dangers of inundation – Common accidents due to inundation &
preventive measures, emergency responses in case of inundation etc.
x. Dangers due to spontaneous heating / fire – System of workings on
panels, precaution against spontaneous / fire etc
xi. Mines Rescue & Recovery work- Provision of rescue room, rescue station,
rescue tracings etc.
xii.Mine Transport- Haulage and winding installation, safety devices,
conveyors etc.
xiii. Dangers from Explosives- Explosives and detonators, reserve station,
taking shelters, misfired shots etc.
Need of refresher trainingRefresher training is needed to make the workmen safety concern and to
restrict them to do unsafe acts & unsafe habits. Over a period of time, people
forget / de-learn what they have learned earlier. Hence, relearning / refresher
training is essential in order to sharpen the knowledge and skill of the workmen.
No amount of safety regulations or technological advances in safety devices
can pay dividends unless we train or retrain our workers and supervisors, who,
together with equipment and capital, form the total system in a mine.
No training programme is complete unless it is given in repetitive dozes over a
continuous period of time, in the form of refresher training.
Refresher training of workmen is an important factor in the performance &
safety improvements. Events, which affect performance & safety (bad habits)
must be eradicated, Technical competence should not be assured to ensure
competence in safe working. It is a psychological fact that some 90% of the
knowledge of the safe working, learned mechanically forgotten within hours.
Furthermore, where there is no practical experience, the rate of forgetfulness is
accelerated.
Recognizing the need for safety education to enable the mine workers to
prepare them to face the challenges of mining, MVTR were framed in 1966.
These rules provide for initial, refresher & specialized training to mine workers.
As per rule 8 of MVTR 1966, refresher training are to be imparted in the
following manner:Sl.
No.
1
2
3
Category of workmen
Re-employed workers after break of
service of one year or more:
a. On surface & OC workers
b. for UG Workers in gassy mines
c. for UG Workers in non-gassy mines
Already employed workers in gassy
mines.
Duration of
course (no.
of lectures)
Remarks
Training within one
month of employment.
03
15
09
06
Already employed workers categories 09
(a) & (c) as above.
All persons to be
trained during the 1st
year.
At least 1/5th of the
total
number
of
persons
in
each
category to be trained
each year.
However, in tripartite workshop on training, the following recommendations
have been made:
Category of workers
Refresher Training (days)
1. Surface workers
06
2. O/C
“
06
3. U/G
‘
12
4. Specific categories of O/C
Workers/supervisors
9-12
5. Specific categories of U/G
Workers/supervisors
6-12
Refresher training helps in improved quality of work, reduction in accidents,
increase in production and productivity & high morale. MVTR requires refresher
training for persons already employed and also for persons who return to work
after absence from work for a period exceeding one year
. The safety consciousness is an inherent and natural instinct present in all
creatures and is more prominent in human beings. Due to different social and
environmental setup and repetitive nature of jobs, this instinct is subdued in our
work force.
Our task is to sharpen its natural instinct which can be best done by well
designed and well implemented refresher training programme. Sharpening of
the instinct will make safe working methods a natural habit. By enacting laws
and their strict enforcement, we can bring compliance not commitment. It is
needless to mention that performance through commitment is far superior,
qualitativly and quantitativly to compliance by force or fear.
Ans: b) The differences in statutory provisions relating to haulage and winding ropes
are tabulated below:Sl.
No.
Parameters /
particulars
1
Construction
2
Splicing
3
Factor of Safety
4
Life of rope
5
Drum/ rope ratio
Haulage
Rope
Winding Rope
Need not be made of Except in a sinking shaft less
cold
drawn
steel than 80m in depth, every
wires.
winding rope shall be made
of cold drawn steel wires &
the gauge of the wire used in
construction of such rope
shall be suited to dia of
drums, pulleys and sheaves
of the winding installation.
Splicing can be done
No spliced rope shall be
used.
FOS not specified in Static factor of safety shall
the statute. However, not be less than 10 as per
FOS of new haulage statutory provision
ropes
for
material
hauling should be at
least 9. For man riding
installations it should
be at least 10.
No specified life.
Specified statutory life not
more than 3½ Yrs.
Not specified. However 100
it should be 80 as
recommended
by
DGMS
Q.4.Write short notes on the following:
a. Statutory provisions relating to working near mine boundaries, their
rationale and adequacy.
b. Functions of Committee under Section 12 of the Mines Act.
c. Statutory provisions relating to supply and use of dust respirators.
d. Fly rocks in opencast mines, their causes and prevention.
Ans:- a) Statutory provisions relating to working near mine boundaries,
their rationale and adequacy- Following are the statutory provisions while
working near mine boundaries.
1) The owner, agent or manager of a mine, shall before the commencement of
any mining operation give notice in form l to CIM, controller (IBM), DM and a
copy thereof shall be submitted to RIM with a plan showing the mine
boundaries. This notice shall be so given as to reach the persons concerned at
least one month before the commencement of any mining operation.
2) The surveyor shall record in a bound paged book kept for the purpose, the
full facts when workings of the mine have approached to about 75 m from the
mine boundary.
3)a) i. The surface plan and the u/g plan shall show the settled boundary of the
mine or where the boundary is in the dispute, the boundaries claimed by the
owner of the mine and the owner of the adjacent mine. If complete leasehold
can’t be shown on the same plan, an additional key plan on any other suitable
scale showing such boundaries and the outline of the workings shall also be
maintained.
ii. The u/g plan shall also show the workings, and all features as prescribed in
above clause, both above and below ground of all adjacent mines as are situated
within 60m, measured on any plane, of the boundaries claimed by the owners of
the mine.
b) The owner, agent and manager of every mine shall as soon as its workings
extend to within 60m of the settled boundary with an adjacent mine (or where the
boundary is in dispute within 60m of the boundary claimed by the owner of the
adjacent mine) inform the owner, agent or manager of such mine about the fact
of such extension.
4. Statutory precautions are required to be taken as in case of multi section and
contiguous working.
5. a) Every mine shall have fixed boundaries and these shall not be changed
except with the express permission in writing of CIM. If the boundary of a mine is
changed, a plan showing the new boundary shall be submitted within 7 days.
b) No workings shall be made within a distance equal to half the distance of
pillar (length) corresponding to the depth of the seam being worked, of the
boundary of any mine. No workings shall be made within the aforesaid distance
from the boundary claimed by the owner of the adjacent mine (disputed
boundary) until the dispute has been settled.
Provided that where work is done in more than one seam, the barrier kept at the
boundary, shall, as far as practicable, be vertically coincident and of the same
dimension.
c) The CIM may, permit the workings of any mine or part thereof to extend
within any shorter distance than what is statutory laid down above or may require
that the said workings shall not extend further than a specified distance.
6. Prior approval of the CIM should also be obtained whenever it is intended to
cross boundaries and/ or 15m statutory barrier of between two adjacent mine
under the control of different managers after the amalgamation etc.
7. Where the workings of any seam for any reason, may extended or get
extended within any shorter distance than laid down in 5(c) the CIM may by an
order in writing, require the owner to construct such protective works within
such time as he may specify in the order.
8. If the adjoining mine is water logged, permission under Req. 127 is required.
Statutory provisions in respect of working near mine boundary are not adequate.
In my opinion, the following additional provisions should be incorporated in the
statute:
i) When the workings reached within 60m of a mine boundary, a fresh corelation and joint survey should be made to ensure that the plan is
correct.
ii) Every mine plan should be connected with at least two points of
national grid so as to have a fixed geographical position so far as the
boundary is concerned.
iii) For making a co-relation survey as aforesaid, instrument supplied by
owner only should be used.
iv) It must be ensured that the surveyor checks the accuracy of the
instrument and if necessary carryout the necessary adjustments.
v) The regulation should also provide that if the workings of any mine get
extended to any shorter distance from the boundary as required under
regulation, it shall be the duty of owner, agent and manager to report
about the same immediately to RIM and CIM in writing.
vi) Reg. 107(2) requires the barrier in different seams should inter-alia be of
the same dimensions. As dimension includes height also, the law should
specify that the barrier should be of same width and length as falls of
roof adjacent to the barrier pillar in a seam may make the height of the
pillar greater than what should not be allowed in other seams.
vii) The law should provide that if one of the mines adjacent to the common
barrier between two mines have been caved and got water logged,
extraction of pillars near the mine boundary in the other mine should be
so conducted that the lines representing the angle of draw due to caving
in two mines do not interest at a point which is at a lower level than the
water level. Inrush of water may take place in the working mine due to
coalescence of the goaves above the point of intersection as aforesaid.
Ans. b) Functions of Committee under Section 12 of the Mines ActFunctions of Committee:
i) To consider proposals for making rules and regulations (not bye laws)
and to make appropriate recommendations to the central Govt.
ii) To enquire into such accidents or other matter as may be referred to it by
the Central Govt. from time to time and make reports thereon and
iii) To hear and decide such appeals or objections against notices or orders
issued under the statute.
Ans:- 4(c)- Statutory provisions relating to supply and use of dust
respirators- Reg.123 of CMR’1957 stipulates that the average concentration of
airborne respirable dust in mine air shall not be more than 3mg/m3 of air in case
of coal seam or where SiO2 is less than 3% and 15/ % of SiO2, if Si02 is more
than 5%.
When the dust survey results indicate that the concentration of air borne
respirable dust at any place in a mine exceeds the permissible limit as mentioned
above, immediate steps shall be taken by the mine management to minimize the
emission of dust and to notify the DGMS. If, the average concentration of
respirable dust in a series of 5 samples taken in 7 successive normal working
shifts during the subsequent month exceeds 11/2 times the permissible limit, the
relevant operations causing excessive dust shall cease till the dust concentration
is well below the permissible limit as established by fresh dust sampling.
In case of non-functioning of dust control mechanism of any machinery/
equipment, operation of such machinery / equipment shall cease and shall not be
resumed until the defects have been rectified.
In a work situation, wherein it is technically not feasible to reduce the respirable
dust concentration below permissible limit or during the time period necessary to
install and commission any device or to institute any new work practice for dust
prevention or suppression, the following steps shall be taken:
 remote operation of machinery / equipment
 job rotation of workmen.
However, in case of failure of above steps, the owner, agent or Manager shall
provide dust respirators in sufficient numbers to the workmen free of cost for
their use. The mine management shall also provide for
 regular cleaning & disinfecting of dust respirators
 maintaining dust respirators in efficient working order
 through training of workmen in the need for and correct use of respirators.
It is obligatory on the part of all the workman to whom dust respirators provided
shall wear the same.
Ans: d) Fly rocks in opencast mines, their causes and prevention- Fly-rock is a
rock which is unexpectedly propelled from a blast site well beyond normal
expectations. It occurs when explosive energy in the form of gas expansion
energy is vented into the atmosphere and propels the rock in front of it. All blasts
more or less produces fly-rocks. Fly-rocks also increase air blast. Due to crater
effect, it can travel in any direction and throw of fly-rock depends upon local
geological conditions and blast parameters.
Apart from being physically dangerous, fly-rock is economically
undesirable
and causes delay and litigation. Fly rock is an indicator of
inefficient utilization of explosive energy as the energy goes waste in
propelling rock fragment to undesirable distances. If any open cast mine
resorting to heavy blasting in hard rock is situated in within a few kilometers of
airdrome, special permission for blasting may be required from air port
authorities so that no blasting takes place when a plane is about to take off or
land.
Causes of flyrock:(i) Poor blast design like use of large diameter blast holes for small benches,
variation in burden due to over break or toe, drilling deviation, inadequate burden
and too close spacing.
(ii) Improper charging and firing – High specific charge, concentration of free
flowing slurries at the bottom of holes, inadequate length of stemming column,
improper size of stemming material, top initiation and simultaneous firing.
(iii) Presence of major geological discontinuities such as faults, weak planes,
cracks, bedding planes, mud seams, open fractures, open joints etc.
iv) Poor blast site control.
v) Presence of loose stones at the blast site.
vi) Presence of water in the blast holes.
vii) Improper profile of bench.
viii) Less cohesion and adhesion of rock bed.
ix) Speed and direction of wind.
x) Presence of uncharged holes in the vicinity of charged holes.
Control of flyrocks:(i) Accuracy in the interpretation of the geology of the area.
(ii) Proper blast design according to the site conditions.
(iii) Monitoring of loading of explosives.
(iv) Deck charging in weak rock in between hard rocks.
(v) Muffle blasting in populated areas.
(vi) Ensuring that with the stemming material boulders do not fall into the hole.
Such boulders act as missiles and are thrown over very long distances.
(vii) While charging explosive in watery holes, it is to be ensured that it settles
down and des not float.
(viii) Use of Nonel’s
Q.5. a) State and discuss statutory provisions relating to taking shelter while
blasting in opencast mine. How would you ensure adequate shelter when
there are private hutments and public road within the danger zone?
b) In an underground mine, the Overman has reported probable explosion
in a mechanized development district and 16 persons missing. Draw a list
of actions, in order of priority that you would take to deal with the
emergency and rescue/recover the missing persons.
Ans:- (a) :- Following are the statutory provisions relating to taking shelter while
blasting in opencast mine :
i) In an open cast working, the shot firer shall not charge or fire a shot
a) unless all persons other than his assistants has taken proper shelter. He
shall also take suitable steps to prevent any person approaching the shot and
shall himself take adequate shelter along-with his assistants.
b) unless sufficient warning by efficient signals is given over the danger
zone, i.e. within a radius of 300m from the place of firing.
However, DGMS in statutory permission instructs the mine management to
treat the danger zone for 500m in any direction from the place of firing.
c) two persons are posted, one each in either direction at the two extreme
points of public road / railway falling within danger zone to warn the
passengers with efficient system of telecommunication or other approved
means.
ii) If permanent building / structure not belonging to owner lies within the danger
zone, the aggregate max. charge in all the holes fired at one time shall not
exceed 2Kg. However DGMS may permit the charges to fired at a time in
excess of 2 Kg.
If blasting is done with delay detonators and there is a delay of at least half a
second between successive shots fired, a maximum charge of 2kg. can be
used in each hole.
If there is surface structure within 50m of place of firing no blasting shall be
done except with written permission from DGMS.
In case of big open cast mines, adherence of these provisions are nor
practicable hence, is exemption required from DGMS.
iii) Adequate shelters shall be provided against flying fragments or missiles.
In order to ensure adequate shelter when there are private hutments and public
road within the danger zone, the following steps shall be taken:i) Marking & identification of danger zone:-Before any blasting is done in
Opencast workings the danger zone (a radius of 500 m) is marked on the
surface plan of the mine and also identified on the ground.
ii) System of warning & posting of guards:-Based on the features/structures
within the danger zone, decide upon the scheme of warning people within the
said zone and ensuring their safety. The number of guards to be deployed for
the purpose may be decided on the needs of the situation.
Guards must be posted at all points of entry into the danger zone so that no
one can unknowingly enter the dangerous area.
iii) Education:- Educating the people about danger zone, hazards from blasting
and the need to take proper shelter at the time of blasting. Evolve a fool proof
method of warning them about impending blast as well as that of informing
them about cessation of danger from blasting. A powerful siren could be used
for the purpose. But the difference between ‘Danger Signal and All Clear’
signal should be made clear to all concerned.
Persons working in the adjoining pits, either in the same mine or a neighboring
mine must be adequately warned before commencing blasting operations.
iv) Selection of spot for shot firing:-A suitable spot should be selected for firing
shots. From this place the shot firer should be able to communicate with all the
guards deployed for ensuring that no person remains within his danger zone
without due protection from projectiles. A Walkie-Talkie communication between
the shot firer and guards would be desirable.
v) Taking shelter - The blasting in-charge must ensure that all those within the
danger zone have taken proper shelter before the blast is initiated.
vi) Use of substantially built shelters- All those who must remain within the
danger zone at the time of blasting should take shelter in substantially built
shelters. Buildings with thatched roofs, or asbestos or filed roofs, or wooden
structures or mine tubs may not be able to withstand the force of projectiles.
Shelters should be of strong construction to be effective.
vii) Controlled Blasting: - The blast must be muffled in a manner that flying
fragments cannot project beyond a distance of 10m; or shots should be fired by
controlled blasting technique with nonels or electronic detonators..
viii) The above drill is necessary in addition to.
a) careful planning of pattern and sequence of blast holes
b) correct charging and stemming of holes.
c) proper sequence of blasting using short delay detonators, where necessary.
Ans:b)- Action plan to deal with emergency arising out of possible
explosion in a mechanized ug district:
An exact procedure to be followed in such a situation is difficult to state as it will
depend on the possible site of the explosion, the distance of my district from
that site, the layout of the mine, the nature of ventilation system and the extent
of explosion. Telephonic communications are invariably disrupted after an
explosion and I cannot expect guidance from others.
Normally a gas explosion is sometimes followed by a second one and keeping
this in mind my line of action will be as follows:i) Sending word to all explosions in bye to come to my district.
ii) Counting all the workers to see if any person is missing or still inbye.
iii) Explaining to the workers, the gravity of the situation and the need to
keep cool without losing heart. To keep up their morale, I would quote
examples of previous gas explosions in other mines where men had
survived.
iv) Assuming that my district is ventilated by an independent split which is not
affected by the products of explosion such as smoke, fumes, afterdamp
coal dust-laden air current, I shall decide to escape by the intake air
route. A level headed strong man should form the rear guard and all the
men will travel together.
v) If en-route, there are signs of violence resulting in roof fall, jamming of the
route with tubs, broken steel arches etc., I shall take another route to
reach an unaffected seam or another district away from the possible site
of explosion. The main idea is to avoid any route where after dump may
be present and for this reason a return airway will be avoided.
vi) If my district happens to be on the return side of the explosion, smoke,
fumes, coal dust laden air will enter my district with the ventilating air and I
shall then have to escape via the return airway. Before escaping, the
ventilation will be stopped by erecting brattice cloth to arrest travel of
oncoming air mixed with after dump, smoke, fumes, dust etc.
vii) If the workers are provided with self rescuers, I shall ask them to wear
the self rescuers before passing through a zone containing afterdamp. If
self rescuers are not provided and the return route is also affected by after
dump and roof falls, the only course for me will be to retreat in bye and
stay in the air which is still unpolluted by after damp. The air will be
conserved by erection of brattice / stoppings and by short- circuiting the
ventilation. If compressed air pipes are available in the district, I would turn
on the compressed air assuming the surface compressors to be still
running. To conserve the cap lamp current, practically all the lamps will be
switched off and if flame safety lamps are provided they will be dimmed.
The air trapped in the district behind brattice stoppings will last a long time
and perhaps for a few days.
The party then has to visit for the arrival of the rescue team.
Q.6. What could be the occupational health problems with increasing
mechanization? What steps should be taken to guard against the same.
Ans: Occupational Health:- Occupational health is essential preventive
medicine. According to the joint ILO/WHO Committee,” Occupational health
should aim at the promotion and maintenance of the highest degree of physical,
mental and social well-being of workers in all occupations, the prevention among
workers of departures from health caused by their working condition, the
protection of workers in their employment from risk resulting from factors adverse
to health, the placing and maintenance of the worker in an occupational
environment.
In modern times Occupational Health may be defined as the state of
physical, mental, social and spiritual well being of all workmen at all kind of
workplaces and not merely absence of sickness and infirmity.
The health of a worker not only depends on facilities of housing, water, sewage
and waste disposal, nutrition and education but also on occupational
environment.
Need for Mechanization:For sustainable development of our country, coal is to be produced to meet the
energy demand. This could be possible only by increasing mechanization in both
u/g as well as in open cast mines using high capacity equipment / machines.
To ensure ever increasing production needs with safety standards, introduction
of intense mechanization compatible to the geo-mining requirement is quite
necessary.
Occupational Health HazardsThere is no profession which is free from occupational hazards. Out of the
accepted hazardous professions mining is considered to be one in the top list.
Increasing mechanization in mines may lead to occupational health hazards to
the workmen.
The occupational hazards in mining depend on: Mineral being worked
 Geological formation
 Technique employed
 Standards of health and sanitation
 Living environment
Following are the occupational health hazards /problems with increasing
mechanization vis-à-vis preventive measures against the same:1. Physical
2. Chemical
3. Mechanical
1) Physical Hazardsa) Dust Hazards- Dust pollution is a predominant problem associated in mining
operations. In coal as well as metalliferous mining activities involving drilling,
blasting, crushing, transportation, dumping of Ore etc., are closely associated
with high levels of air borne coal and other metal dust including asbestos and
exposure to crystalline silica (free silica), Inhalation and retention in excessive
amount of such dust over the length of time may lead to serious respiratory
health problems including pneumoconiosis.
Preventive measuresTo guard against dangers of coal dust, the following precautions shall be
taken:-
i) The concentration of airborne reparable dust shall not be more than 3 mg /m3
of air, when Si02 <5% & not more than 15
if Si02 > 5%.
%of Si02
ii) Air borne dust survey shall be conducted in prescribed manner at prescribed
interval and record shall be maintained.
iii) If the concentration of dust in mine workings exceeds the permissible limit,
immediate necessary steps shall be taken to minimize the emission of dust. If
needed, the relevant operation(s) causing excessive dust shall cease.
iv) Mine management shall provide dust respirators in sufficient number free of
cost to concerned work person for use in dusty atmosphere.
v) Every working face and the floor, roof and sides of every roadway or airway
within 50m shall be washed down to prevent accumulation of dust and shall be
kept wetted.
vi) Water spraying arrangement shall be made and maintained within 90m of
working faces.
vii) Complete set of picks with proper size shall be fitted in cutter head.
viii) The speed of cutter head shall be maintained such as to prevent formation
of dust.
ix) Water spray system shall be maintained in good working order to prevent
formation and propagation of dust.
x) The spray nozzles shall be kept regularly cleaned.
xi) Pyrite band of igneous rock shall be avoided to cut by machine.
xii) Cutting of coal shall not be commenced until water spray starts with proper
pressure and quantity.
xiii) Cutting of coal at the face by Coal Cutter shall not be commenced or carried
out unless water spraying arrangement at the cutting picks is provided and
maintained in good working order.
xiv) Suitable mechanism to interlock the operation of water spraying and cutting
shall be provided and maintained at all time in the Coal Cutter.
xv) Screening and sorting plant should be located beyond 80m from down cast
shaft, incline or other openings being used as intake.
xvi) Tubs and conveyors are to be maintained in good condition.
xvii) Workers may be protected by remote operations, job rotation or by
using
dust protectors.
b) Noise Hazards- One of the important physical hazards which mining workers
are exposed to, due to use of modern machinery is high intensity noise in
different working areas of the mines. Continuous exposure to high intensity noise
can cause a serious occupational illness called noise induced hearing loss
(NIHL) which is due to irreversible damage to the highly sensitive internal
auditory organ. It not only has a detrimental effect on auditory machinery and
nervous system but it also affects other organ systems adversely.
Preventive measures- These include:
 Providing enclosure or barriers to noisy machines/ attenuating screen.
 Damping by layers of soft or elastic materials.
 Fitting silencers and noise absorbers
 Isolating men from source by means of acoustic enclosures.
 Ensuring that machine is balanced.
 Proper mounting of machines/flexible mounting.
 Use of ear protection devices such as ear plugs, ear muffs, helmets and other
sophisticated ear-protectors.
 Selection of suitable machine


Proper maintenance of machine i.e. lubrications, spare parts managements.
Noise mapping of various work places in the mine premises based on the
various machines being used in concerned mines along with personal noise
dosimetry of individual, workmen exposed to noise level above 85 db(A).
c) Vibration- Workers using different machinery like pneumatic drills, excavators,
dozers, dumpers, SDLs, LHD, surface miners, conveyor etc are exposed to high
degree of whole body and segmental vibration during their entire shift of working,
over a period of time. Exposure to whole body vibration can cause either
permanent damage, or disturb both the central as well as peripheral nervous
system. Daily exposure to hand arm vibration over a number of years can also
cause permanent physical damage resulting in white finger syndrome.
Preventive measures against vibration:- These include:
 Mounting of machine on sound foundation, if necessary on vibration isolators
or dampers.
 Installing the machine on inertia block with a damping sand-witch between it
and the building foundations.
 Vibration studies of various mining machinery.
d) Heat & Humidity- The common physical hazard in our industry is high
temperatures and the workers are often exposed to it. The direct effect of heat
causes hyperpyrexia, heat exhaustion, syncope, cramps, burns, heat stroke etc.
While the indirect effects are decreased efficiency, increased fatigue, enhanced
accident rates.
Preventive measures- To guard against the dangers from heat & humidity,
sufficient quantity of fresh air should be ensured in the mine working as per
statutory provisions in order to clear away smoke and steam, to dilute
gases(inflammable or noxious) to harmless proportion, to provide air containing
sufficiency or oxygen and to prevent excessive rise of temperature or humidity
likely to be harmful to health of persons.
e) Light – The workers may be exposed to the risk of poor illumination. The
acute effects are eye strain, headache, eye ache, lachrymation, eye fatigue and
conjection. The chronic effects lead to “Miner’s nystagmus”.
Preventive measures- Adequate lighting arrangement shall be provided in order
to prevent glare or eye strain.
2) Chemical Hazards- The chemical hazards are on the increase with the
introduction of newer and complex chemicals. The chemical agents act on three
ways, direct contract / local action, gas poisoning / inhalation and metal
poisoning.
a) Direct contract / local action – It is usually in the form of dermatitis, ulcers,
boils etc. The acidic water, machine oil or other chemical substances which come
in direct contact with skin are the responsible factors.
b) Gas poisoning/ inhalation- Gas exposure is a common hazards, noxious
gasses like CO, CO2, Nitrous fumes are common sources of inhalation poisoning.
These cause irritation to eyes, headache, giddiness, vomiting, broncho-spasm,
dyspnoea, cynosis, hyposixa, pulmonary oedema and finally death depending
upon severity and duration of exposure.
c) Metal poisoning- Many metals such as Mn, Hg, Pb, Cr, Br etc. due to their
harmful chemical properties cause tremendous adverse effects on miners health.
Preventive measures- Adequate steps should be taken to guard against gas
and metal poisoning.
3) Mechanical Hazards- The main cause of health hazards due to application of
large scale high capacity Shovels, SDLS, LHDs, Drag Lines, Drills etc are:

Faulty structure of seats of the machinery.

Wrong posture of the employees while handling the machinery.

Faulty ways of lifting and handling heavy equipments.
Preventive measures- Ergonomic assessment of all latest machines, before their
introduction into mining operation should be made.
In addition to the above, the following additional measures should also be taken
to guard against occupational health hazards due to increasing mechanization:
1) IME & PME of workmen as per provision of statute.
2) IME should be made mandatory for all mining employees whether permanent,
temporary or contractual, before they are engaged in any mining job.
3) The frequency of PME should be brought down from existing 5 yrs to 2 yrs for
the mining employees above 45 yrs of age.
4) Each mechanized mine should engage at least one qualified medical officer
for every 500 employees and thereafter, one for every 1000 employees.
5) One of the medical examinations of every person should be arranged within
one year of his superannuation.
6) Standards IME & PME shall be suitably modified in order to ensure early
diagnosis of diseases caused due to employment in mines.
7) Special tests should be included in the PME for employees exposed to
specific health hazard.
8) Setting up structured occupational health services.
9) Potability test of drinking water supplied to the mine employees, to be made
mandatory once in a year irrespective of its source, the sample of water to be
collected from the points of consumption.
10) Occupational health survey of workmen as per provision of statute.
Q.7. Write short notes on the following:
a. Risk Management.
b. Effectiveness of Safety Committee.
c. Statutory provisions relating to Rescue Rooms.
d. Condition for use of trolley wire locomotive below ground.
Ans:-a) Risk Management:Risk management as a tool for development of good health and safety
management system is a break through in the traditional strategy as it differs
from the existing one by involving the entire staff in the realization of safety
improvement programme with responsibility and accountability sharing
proportionately with the decision making authority.
As per recommendation of 9th conference on safety in mines, Risk management
plans shall be prepared on the basis of risk assessment and implemented in the
identified mines. Risk Management is a logical and systematic application of
management policies, procedures and practices to the tasks of identifying,
analyzing, assessing, treating and monitoring risk with any activity,
process or equipment etc.
It is the pro-active process, where a particular process or operation is
examined in detail so as to identify potential hazards and threats, which if not
addressed, could cause an accident or incident. Controls or combination of
controls are identified, which if implemented, ensure safety. It aims to improve
the understanding of the potential for the accidents, their possible consequences
and the adequacy of controls.
Objectives of risk management:
To reduce the likelihood and impact of mishaps of all kinds.

To reduce the inherent potential for major accidents which could injure or
kill many people.

To limit the damage to the environment

To ensure desired production, productivity and profitability.
Fundamentals of risk management:
Understanding of what could happen and how

Real and visible commitment to managing the risks.
Risk Management process/Elements of risk managementRisk management consists of following steps:i) Establishment of context – It is important to clarifya) the nature of risks which the organisation is concerned about (people,
equipment, environment, production etc.)
b) resource limitations of the organisation
c) the attitudes within the organisation.
ii) Identification of hazards:- Hazard identification is a critical step of risk
assessment, presuming what is not identified cannot be actively managed.
iii) Analysis of risks: - Analysis of risks entails understanding the nature of the
hazards which exist, the nature of the existing controls and barriers and
assessing the likelyhood of occurrence of hazards and the severity of the
consequences of those hazards.
iv) Assessment and prioritization of risks:- It is the process used to determine
risk management priorities by evaluating and comparing the level of risks against
predetermined standards, forget risk levels or either criteria. All risks can not be
totally eliminated at once. Ranking the major contributors and planing appropriate
improvement on the principle of “do first things first and then move to the next”
should be adopted.
v) Treatment of risk:- It is selection and implementation of appropriate options
for dealing with risk. It consists of identification and evaluation of treatment
options as well as preparation and implementation of treatment plans.
vi) Monitoring and review:- An essential part of any rise management
programme is monitoring of performance compared with the standards and the
plans and review of the standards. The success of the programme needs to be
reviewed periodically by consideration of :
 the degree of completion of the listed tasks (inputs)
 the performance of the mine in relation to the defined criteria (outputs)
Applicability / Need of risk management:In principal, a systematic risk management/ assessment should be undertaken
whenever there is:
i) a mine which has not previously undertaken a formal risk management
exercise.
ii) a disaster/ dangerous occurrence has occurred and management wishes to
act effectively to prevent a recurrence.
iii) a modification in procedure is planned which could affect safety.
iv) a new equipment/ extensively modified equipment is purchased or
equipment/machine is to be modified.
v) an established method or mining operation is to be modified.
Ans: b) Effectiveness of Safety Committee- For improvement of functioning of
the safety committee, the following steps may be taken:
1) The members of the safety committee should be given orientation training
on different aspects of mining as well as in communication skills etc.
In order that the members of the safety committee discharge their functions
meaningfully and become more relevant to the safety needs of the mining
industry, a need based pre-designed training schedule should be developed
for the members who are workmen or subordinate supervisory officials.
The training programme may consist of 10 lectures/demonstrations, sessions
of a not less than 2 hour duration each supplemented by visits to mines,
workshop etc. A suitable syllabus should be drawn by the individual mine
management to suit the local conditions and local work practices.
2) For the safety committee meetings, 60% of the total membership should
constitute a quorum provided that if a meeting is postponed due to lack of
quorum, the next meeting may be held irrespective of quorum.
3) Before a S/C meeting is held, a suitable agenda should be prepared by the
secretary by soliciting information from workers and other members of the
committee.
4) During any meeting, the status of implementation of the recommendations
of the previous meeting should be discussed first before taking up discussions on
the prepared agenda.
5) During discussions in a S/C meeting, the workers representatives should be
encouraged to participate in the discussion. In fact discussions should not be
dominated by officers of the company. The members should not only be
encouraged to initiate the discussions but also to substantially participate in the
discussions so that they feel themselves important with regard to safety
management of the mine.
6) A scheme may be initiated for making special award to any members who
makes any constructive suggestions for improving safety in mines.
7) Senior officials of the company as well as officers from DGMS should attend
some of the meetings so that the workers may appreciate the importance
attached to such meetings.
Once in a year the meeting of the safety committee should be attended by the
senior officials of the Area. Such meetings should review the recommendations
made during the year by the safety committee together with the status of
implementations of the recommendations.
8) At the area level annual review of the functioning of S/C of all the mines of
Area should be made by the G.M. Such meetings should be attended by
G.M.(Safety), W.I. (Mining). Workmen’s representatives of the S/C, the Secretary
and the Chairman of S/C. An officer from the DGMS may also attend the review
meeting.
9) In order to prevent the S/C meeting becoming mere rituals, monitoring of the
S/C should be done by officers of higher level of mine management.
10) In order that the S/C can serve as a forum for communication of messages of
safety & occupational health matters, based on the deliberations in the S/C
meeting, the members of different categories of workers may be allowed to visit
districts of the mine within a suitable time schedule prepared by the manager of
the mine for communication messages to the workers in general.
11) Occupational health physician should be a member of the S/C where he
could contribute to the health education of the workers.
12) Manager being the Chairman of the S/C does not have enough time to
devote. Moreover, deliberation under him becomes difficult for the subordinate
officers. Therefore, it is suggested that some other officials who is relatively free
but smart enough to conduct such work, shall be given the responsibility.
13) Some of the important officials of the adjoining mines should be included
in the safety committee so that their opinions are also considered because safety
of the mine has to do a lot with the condition of the adjoining mine.
14) In the safety committee. Doctors, Welfare Officers and Surveyors should also
be made a committee member.
15) There should be provision for recording of the discussions taking place in
the safety committee.
16) The members of the safety committee should visit surface and underground
workings on a fixed day in every month with a view to meet the workers on the
spot and talk with them on the matters of safety, invites suggestions on the safety
and check general safety standard.
17) Examination and enquiry of all types of accident and incidents by S/C.
18) Unit/department –wise safety committees to be constituted under overall
control of the main safety committee.
19) Action taken report on rectification of the deficiencies to be prepared by the
official concerned within 7 days of the committee meeting and compilation of the
status of rectification by the Area Safety Officer.
20) Status of rectification of deficiencies pointed out in the safety committee
meeting to be assessed a day or two before the next safety committee meeting.
21) Tenure of Safety Committee to be made 2 years.
22) Training and refresher training of safety committee members..
Ans:c) Statutory provisions relating to Rescue Rooms:Refer to Q.No.7(b)(2nd class 2005)
Ans:- (d) Condition for use of trolley were locomotive below ground- While
using trolley-wire locomotives belowground, the following condition shall
apply :
i. General- As far as practicable, the surface of every length of roadway shall
be kept even, firm, well- drained and in a condition which is not conducive to
skidding.
ii. Approval for use:- No trolley- wise locomotives shall be used below ground
unless it is a type approved by CIM and equipped with a “ dead man
control” The maximum voltage, the character of current and the electrotechnical details of every installation shall be approved by electrical
Inspector of Mines. Control levers of the locomotives shall be so arranged
that the lever cannot be accidentally removed when the power is on.
iii. Gradient- No locomotives shall run on any length of roadway, the gradient of
which exceeds 1 in 6.
iv. Transport rule:- The manager of a belowground mine shall frame transport
rules for safe operation / movement of locomotives and submit a copy to
DGMS for approval and enforce the same in the mine.
v. Clearance:- The following minimum clearance should be ensured:
a) On the side of the track opposite to the manholes – 0.3m
(b) Where there is total minimum clearance of less than 2m, safety stations
shall be provided at intervals of 30m and they shall be clearly marked.
v. Height of trolley wires- The height of the trolley wire above the top of the
rails shall not be less than 2.0 m
vii. Support & electrical protection of trolley wires and feeders:(a) It shall be supported from efficient insulators at suitable spacing and
doubly insulated from the anchorage of the suspension device.
(b) It shall be protected collectively by an automatic circuit breaker.
(c) Trolley wire shall be of adequate current carrying capacity and having xsectional area not less than 0.53 cm2 and breaking load not less than 2000
kg.
(d) All trolley lines shall be sectionalized every 800m by placing a switch in
the line.
(e) All branch trolley lines shall be provided with a frog and switch at a point
where they leave the main line, by which the branch line can be
disconnected.
(f) At every shunting place, crossing and approach, conspicuous light signals
shall be provided.
viii. Rail Track:(a) It shall be of adequate X-sectional area & be so connected together by
welding, fish plates and so efficiently bonded across all joints that electrical
resistance of a joint between two successive rails does not exceed the
resistance of one rail of normal length.
(b) Two rails of the same track shall be connected by cross-bonding of good
conductance at intervals not exceeding 200m in approved manner by a
conductor having X-sectional area not less than that of any trolley wire
conductor over the track.
(c) The negative track rails shall be electrically and mechanically continuous
and be effectively connected to the negative terminal of the generator or
converter by insulated copper conductors of adequate current carrying
capacity.
(d) Drawbars and axles of the locomotives shall be bonded.
(e) Trolley wires and the rail return shall be so constructed and maintained
that during the working of the system, sparking between the loco wheels and
the rails is minimized.
ix. Safety devices:-Trolley wire locomotive shall be provided with
(a) an efficient automatic braking system of non-inflammable material.
(b) a suitable parking brake permitting satisfactory emergency braking
(c) a speedometer
(d) an efficient distance indicator
(e) an efficient head light
(f) an approved portable lamp for emergency
(g) a mechanically operated device like gong hammer capable of giving
adequately audible warning signal.
(h) at least two portable fire extinguishers
(i) an ergonomically designed seat for the driver.
x. Examination & maintenance – For proper functioning & maintenance of the
system, the following examination & maintenance scheme/schedule shall be
prepared and ensured by manager:(a) Shift-wise examination.
(b) Daily examination
(c) Weekly examination
(d) Monthly examination
Q.8. The management of a large opencast mine has entrusted the work of
removal of overburden to a contractor. Deployment of contractor’s trucks
and workers for removal of overburden has led to increase of accidents.
Discuss the reasons for increase in accidents and suggest preventive
measures.
Ans:- Increased demand of coal has necessitated large amount of Coal /OB
handling in the mine. The O/C activities have thus been under immense
pressure to boost production and achieved required target and hence OBR jobs
are being increasingly carried out by engaging contractors trucks and workers.
Analysis of accidents in O/C reveals that:
 Approximately 33% of accidents take place while reversing vehicles in dump
yard / coal benches.
 60-70% of the victims were either driver or Khalashi of the vehicles deployed
by the contractors.
 No basic or specialized training were imparted to the contractors workers
before engaging them in the mine.
Risk to contractors workers –
 Workers are purely temporary or migratory in nature and not well conversant
with mining activities or laws. In many cases, no formal or informal training is
imparted as required.
 Contractor’s workers are having more risk taking attitudes as earnings are
directly connected with output.
 Safety is considered as a cost components by the contractors.
 Contractors have little commitment for ensuring safety and health condition of
the work force.
Reasons for increase in accidents due to deployment of contractors trucks
and workers for removal of OB & preventive measures to reduce such
accidents:
i) Unskilled, negligent and unauthorized driving / riding of trucks.
Preventive measuresa) Contractors shall submit the list of drivers (whose antecedents he believes
are good) along with their valid licenses for verification and record by Engineer
and issue of authorization by Manager/PO(Agent). No such driver should be
allowed without verification of license/authorization.
b) No helper/any – unauthorized person shall be allowed to travel in tipping
trucks. Trained trip man/helpers shall be provided at the loading and unloading
point and for the miscellaneous jobs at key positions. Unauthorized riding in
vehicles shall make both the driver and/or the unauthorized person traveling
liable to punishment.
c) Manager shall take all appropriate steps including his authority of
punishment to ensure prohibition of unauthorized driving/riding.
ii) Non road-worthiness of trucks and non-fitting of various safety devices
in the trucks.
Preventive measuresa) All contractual/ hired machinery engaged in the mine shall be
audited/inspected by a team consisting of mine officials and contractors
technical personnel for their suitability before engaging in the mine.
b) Fitness of all the vehicle/machines including AVA shall be checked under the
supervision of Colliery Engineer.
c) Fitness certificates of all vehicles shall be checked by the Colliery Engineer
and proper records shall be maintained.
d) After the checking of the vehicles and fitness certificates the Engineer shall
recommend for the issue of valid pass for vehicles/machines to the
Manager/Project Officer.
e) No contractors vehicle/machines shall be allowed inside mine premises
without valid pass issued by Manager/Project Officer(Agent) of the Colliery.
f) If any vehicle is found defective, the same shall not be allowed inside the
mine, unless the defect has been rectified and vehicles certified to be fit by the
Colliery Engineer in writing.
g) The time of incoming and outgoing contractors vehicles in the command area
should be recorded in a register at the check post.
h) Contractors equipment are to be checked by a competent person of the mine
periodically.
i) Regular checking of braking systems of trucks including parking brakes. Fail
safe brake should be used.
j) An audiovisual back up alarm system which adjusts itself to the surrounding
noise level maintaining minimum 5 dB(A) above the noise level may be used in
the trucks, which should be actuated automatically during reversing.
iii) Not following traffic rules and code of practice for movement of
vehicles.
Preventive measuresa) Code of traffic rules, dumping practices, signaling and communication shall be
framed and implemented.
b) Escape lane or escape road shall be provided wherever there are chances of
over speeding or roll back of vehicles in motion.
c) Separate roads/lanes for HEMMs and contractors tipping trucks and for
pedestrians shall be provided.
d) One way traffic should be adopted for movement of vehicles.
iv) Uncontrolled fleeting and over crowding of vehicles.
Preventive measuresa) Sufficient dumping place shall be ensured by the Manager to avoid over
crowding.
b) Sufficient level space shall be provided on ramps close to unloading point for
unloading, reversing and authorized parking.
c) Dumping and manual loading shall not be allowed at the same place.
d) No vehicle shall be parked along slope/gradient. If, it is unavoidable, hand
brakes shall be applied firmly, engine stopped, the vehicle kept in gear and stop
blocks against the wheels used.
e) Adequate level parking place should be created near loading / unloading
points.
v) Improper open pit / dump slope design:
Preventive measuresa) The height, width and slope of benches should be maintained as per statute
and conditions imposed by DGMS.
b) OB dump should be designed taking into consideration the natural angle of
repose of dump materials.
vi) Inadequate illumination.
Preventive measuresProper illumination is a key to better and safe working environment. Adequate
lighting arrangement as per provision of statute shall be provided and maintained
for proper lighting of open cast workings.
vii)Improper and unsafe haul road and dump yard.
Preventive measuresHaul road & dump yard shall be designed properly taking into consideration the
engineering parameters and shall also be maintained in good condition.
viii) Lack of knowledge of mine lay out, mine working including system of
working among the contractors workers.
Preventive measuresa)All persons engaged at any work within the mines premises through
contractors must receive relevant training and other job related briefings.
b) Compulsory training programme on the basics of mining layout & system of
working encompassing traffic rule should be arranged by management, proper
vigilance should be observed, so that contractor could engage no one in the mine
premises without imparting training.
ix) Lack of training & frequent change of workers by contractor.
Preventive measuresa) Before commencement of work against work order, contractor shall give to the
manager a list of his workers/supervisors to be trained as per VT rules and new
VT module.
b) Persons required to be trained, shall be sent for training by Manager.
c) A list of trained workers already available with the contractors shall be
furnished to the Manager.
d) Strict guidelines should be enforced by management to discourage & stop the
frequent retrenchment of workers by contractors.
x) Lack of competent supervision during loading and transportation of OB.
Preventive measuresStatutory supervision of contractual operation by departmental competent
persons to be ensured by Manager/Project Officer.
xi) Deployment of workers on overtime.
Preventive measuresContractors workers should not be allowed to work beyond permitted hours
without permission of management.
The responsibility of contractors works safety is a shared one. Work can be
contracted but risks can not. Under the circumstances, mine management,
contractors and contractors workers have to play their active roles and to
shoulder individual responsibilities for ensuring safety of contractors workers. As
per recommendation of 10th safety conference, following measures should be
taken for ensuring safety of contractors workers.
1. Managements responsibility i) Ensuring that contractor’s arrangements for health & safety management are
consistent with those of the principal employer.
ii) Ensuring that contract shall preferably be for longer periods so that there is an
adequate scope for management of safety by contractors.
iii) Ensuring that contractor provides fit – for – purpose machinery, operators and
other staffs and provided with written safe work procedures.
iv) Monitoring of all activities of contractors to ensure that they are complying with
all the requirements of the statutes and safety system.
2. Contractor’s responsibilitiesi) Preparing written safe operating procedure for the work to be carried out,
including risk assessment and safe method to deal with the risk and providing a
copy of SOP to the person designated by mine owner who shall be supervising
the contractor’s work.
ii) Keeping the SOP up-to-date and providing a copy of changes to the
designated person.
iii) Ensuring that all work is carried out in accordance with the statute and SOP
and deploy adequate qualified and competent persons for the jobs.
iv) All persons deployed by contractors for working in the mines shall undergo
vocational training, IME & PME.
3) Contractors workers responsibilitiesi) An employee shall take reasonable care for health and safety of persons who
are at his place of work or who may be affected by his acts and omissions.
ii) An employee shall cooperate with his employer or other persons in supervision
of his work to enable compliance with requirement of the statute.
Morning Session
THE MINES ACT, 1952
Examination for Mine Manager’s Certificate of Competency under the Coal Mines
Regulation, 1957
SECOND CLASS
MINE MANAGEMENT, LEGISLATION & GENERAL SAFETY
Monday, the 20th December, 2004
Full Marks: 100
Time
: 3 Hours
Answer any SIX Questions
(All questions carry equal marks)
Q.1. Write provisions in respect of the following:(a) Appointment of rescue trained persons in mines and their disposition
etc.
(b) Fresh air base
(c) Duties of manager in emergency.
Ans:-a) Appointment of rescue trained persons in mines and their
disposition etc:Refer to Q.No.3 (b) (2nd Class 2007)
Ans:-(b) Fresh air basei) As soon as possible, fresh air base(s) shall be established in fresh air as near
to the irrespirable zone(s) as safety permits.
ii) If F.A.B. is belowground, it shall be connected to surface by telephone or if
F.A.B. is on the surface it shall be connected to shaft bottom by telephone.
iii) Except in emergency, rescue trained persons shall not proceed beyond any
place where FAB is to be established until there have been provided at such
base.
 One qualified medical practitioner and one rescue trained person.
 A spare rescue team.
 One or more reviving apparatus, oxygen revivers etc.
 First aid box and stretcher
 CO detector
 A hygrometer and
 Two flame safety lamps.
iv) Whenever men are already at work beyond the FAB, there shall be provided
at the base as soon as possible the persons, apparatus and equipment as
mentioned in (iii) above
It is recommended that telephone, O2 cylinder, mechanical resuscitators and
food stuffs should also be provided at fresh air base.
A good FAB underground should possess the following features: It should be located at a well ventilated place.
 There should be scope for quick advance / retreat.
 The roofs should be properly dressed and supported
 Sufficient space should be available for the rescue team to prepare/
moved about / retreat, and for the stocking of the first aid and medical
facilities.
The following persons may also be made available at the FAB as early as
possible:


In-charge of the affected area and his assistants.
Mechanics & Helpers.
Ans:- c) Duties of manager in emergency:Speed & efficiency are the main requirements for handling an emergency. This
calls for a fast and efficient team working under able leadership. First few hours
are vital after an emergency has set in, to contain loss of human lives and
property.
The following are the statutory provisions in Mines Rescue Rules 1985 in respect
of duties of manager in emergency.
i) On receiving information of any emergency, the manager shall immediately:
 inform rescue station or rescue room serving the mine.
 summon rescue trained persons employed in the mine
 inform the management of adjacent mines for rescue/ help.
 inform the management of rescue station regarding the nature of
emergency.
 summon medical assistance: and
 send information to Regional Inspector of Mines.
ii) All rescue and recovery work shall be conducted under the control,
supervision and direction of the manager. However, in case of major
emergency, the manager shall take guidance from an expert group consisting
of senior official of management, representative from D.G.M.S., concerned
rescue station and recognized trade unions in taking decisions regarding rescue
and recovery.
Q.2.Discuss
problems of high-wall and spoil dump stability and the
precautions to be
taken in deep mechanized opencast mine using
dragline.
Ans: - Problems of high-wall
In an open cast mine deploying draglines, the height of benches may go beyond
50m but in Indian condition it is restricted within 40m. The common dragline
bench height ranges from 30m for draglines having bucket capacity 24m3 with a
boom length 96m. To manage such high walls in case of dragline benches is a
very difficult task and some times becomes a potential hazard for safety due to
failure of benches.
The angle of slope of bench plays a vital role in stability of benches. The angle of
slope of bench should be either equal to or less than the angle of repose of
bench rock. The angle of slope depends upon the plane of weakness,
orientation of bedding plane, hydro-geological condition of the strata etc. The
slope failure is due to mainly by a slow progress of rotational shear, mechanical
properties of rock like cohesion, angle of internal friction, pore water pressure,
seepage forces, tension crack etc. The bench slope may failed in following ways:
 Plane failure
 Wedge failure
 Circular failure
Causes of bench slope failurei)
Dynamic loading caused by plying HEMM, heavy blasting, earthquakes
etc.
ii)
Presence of water in the rock mass
iii)
Decrease in cohesion & angle of internal friction of high wall material
iv)
Floor sliding due to presence of aquifer.
v)
Improper bench geometry
Precautions to be taken against high wall:i)
Bench Design: - Design of bench geometry on the basis of sound
scientific technique.
ii)
Supporting of slopes:- Supporting of high wall slopes may control the
failure of slopes,. The high wall slopes may be supported by bolting,
anchoring, shotcreting etc.
iii)
Proper drainage system- Surface drainage arrangement, deep drainage
system, vertical bore holes, horizontal toe drains, horizontal drainage adits
etc. should be provided and maintained for stability of high wall slope.
iv)
De-watering of slopes - Dewatering of slopes also called
depressurization, reduces water- pressure components and also improves
the properties of rock-mass.
v)
Re-excavation/re-shaping- This method of slope stabilization removes
extra material to form shorter benches. This ensures a stable slope. Such
type of stabilization work is adopted when support measures are not likely
to be effective.
By taking above pre-cautionary measures, the problems of high wall due to its
slope failure may be tackled.
Problems of spoil dump stabilitySafe, property designed and scientifically engineered slope is essential
requirement for stability of spoil dump. The benefit of an open pit operation
largely depends on the use of the steepest slopes possible which should not fail
during its life. However, excessive steeping may result into slope failure leading
to loss of production, extra stripping costs to remove failed material, reforming of
benches, rerouting of haul roads and production delays.
Factors influencing spoil dump stability are:a) Soil dump geometry
i) Height of spoil dump :- Slope stability generally decreases with increasing
height of spoil dump as the shear stresses within the spoil mass increases due to
added weight and may exceed the shear strength of the spoil material.
ii) Slope of spoil dump :- Low slope angle minimizes the adverse effects of
increasing spoil height. Long terms stability is achieved by re-sloping the face of
piles between 26º-28º .
iii) Zonation in spoil dump :- The zonation of the spoil material results in
different strength and density material results in different strength through the
spoil pile which can control this failure surface and influence the nature and
extent of spoil stability.
b) Presence of Water:- It adversely affects the dump stability by changing the
material strength and influencing the pore water and seepage forces.
c) Climate :- The total precipitation, frequency of thunderstorms or heavy
rainfall and seasonal precipitation affects the ground water conditions and
drainage through spoil dump and reduces the stability of spoil dump.
d) Foundation of dump :- Nature of foundation strata and its slope angle is to
be found very carefully as it affects the stability of dump. The maximum
permissible foundation slope can be determined by the following relation:tan θ= tanβ/F, where θ = slope angle of foundation
β = friction angle between the base of the
pile and its foundation.
F = desired factor of safety.
e) Geotechnical Parameter:- Shear strength of foundation material should be
greater than shear strength of material comprising soil dump.
f) Mining equipment and mining method.
g) Drainage :- It affects the ground water condition and pore water pressure
and hence stability of dump. The surface water must be prevented from entering
spoil dump and the foundation with the help of proper drainage.
h) Blasting:- The fragmentation of O.B. rocks affects the initial particle size of
spoil material. The well graded fragment size may allow a denser packing and
thereby increases density and strength of spoil material.
Precautions to be taken against likely failure of spoil dump:To ensure stability of spoil dump, the following precautions should be taken
i) Design of slope - The rock mass behind each slope is unique. To design
proper slopes for each case of rock formation, the geological data, rock strength
formation, ground water data and pressure is required.
Slopes have to be designed by qualified and competent rock mechanics
engineers after taking into consideration the factors influencing the slope stability.
ii) Slope stabilization:When safety factor of a slope is found to be
inadequate, it needs to be stabilized. The method for this are:a) External Support
b) Removal of water from the slope
c) Removal of material which is likely to slip.
External support is given by retaining walls (in soil slopes) as a temporary
measure, provided the wall is higher than the slope and its foundation is below
the expected slip surface. Such walls are practicable only in case of short slopes.
Rock-bolding with pre-tensioning and with or without shotcreting is a fairly
permanent measure, in rock slopes. The bolt must extend beyond the failure
surface.
Removal of water from the slopes reduces water pressure components and
also improves the properties of rockmass.
The third method of slope stabilization is removal of material to form shorter
benches or re-grading the slope. This is adopted when support measures are not
likely to be effective.
iii) Drainage- The excavated pit must be provided with an effective garland drain.
The benches should have an effective toe drains. All the drains should be kept
clear of debris and effective for the free flow of water.
iv) Controlled blasting:Un-controlled blasting results in rough uneven
contours, over breaks, overhangs and extension of tension cracks in the slope.
Poor blasting causes opening between various weak planes, which result in loss
of resultant cohesion between them. It also results into shattering of the slope
mass well behind the desired location and consequently allowing earlier
infiltration of surface water, which leads to un-favourable ground water pressures
and related problems.
These detrimental after effects, due to poor blasting, can be checked by one of
the most experimented controlled blasting methods known as “ Pre-spliting
Blasting Technique” in order to minimize the damage of the slope mass forming
the ultimate pit slope.
v) Slope monitoring – It is essential to detect any instability well in advance so
that any damage to men and animals can be avoided. If any instability is
detected in the early stage then it can be stabilized by applying the suitable
remedial measures. The active monitoring system permits early and confident
decision making by management both for safety purpose and for optimum
excavation sequencing.
Tension cracks are the first sign of slope instability. The development of any
tension cracks on the different benches formed in weak slope material should be
observed. Tension cracks should be filled with weathered laterite and sealed with
clay to prevent the entry of water, which may cause failure.
Q.3.An accident had occurred in an open cast mine due to run over by a
dumper being driven in reverse. One worker received fatal injuries. Write a
report of enquiry of the accident bringing out contraventions, responsibility
and suggestions to prevent similar accident in future. Assume your own
conditions.
Ans:-
Enquiry Report
Ref.No………………………
Date………...
To,
The Manager,
“ A “ OCP
Sub:- Enquiry report in respect of fatal accident involving
1 worker in A-open cast working due to run over by a
dumper being driven in reverse.
Dear Sir,
As desired vide your letter no………………… dt…………… I am enclosing
herewith the detailed enquiry report in respect of fatal accident in A-O/C working
due to run over by a dumper being driven in reverse indicating the cause and
circumstances attending to the accident, contraventions of statutory provisions,
responsibilities and suggestions to prevent similar accident in future in Annex.l . I
am also enclosing the accident plan showing the site of accident along-with
photo graphs.
Yours faithfully,
Encl: As above.
( A.C.M. )
“A” OCP
Annexure - l
Detailed Enquiry Report
Assumption of Conditions:A OCP is being worked in lll seam 10m thick, dipping at 1 in 7 with shovel
– dumper combination using deep hole blasting after obtaining statutory
permission for extraction of pillars by OC method from DGMS.The seam is
extensively developed in 2 sections in past on the pattern of B/P method of
mining. The depth of working from the surface is about 50m. There are 3
benches in OB and 2 benches in Coal. The Coal & OB are being removed by
hiring agency.
I _______________, ACM, A OCP inspected the place, where this
accident occurred and enquired into the cause and circumstances connected
with the same.
1) Introduction & information :- The accident occurred in A OCP of M/s……. on
……… at about 3.45 A.M. in 3rd / night shift causing death of 1 person working as
maintenance helper of M/s. ……….. the hiring agency engaged for removal of
Coal & OB. I received information about the accident at about 4.30 A.M. when I
was in my residence.
2) Background information:The depillaring permission was obtained for
extraction of developed pillars by open cast method with shovel – dumper
combination using deep hole blasting. The usual practice at A OCP was to
expose the developed coal pillars by removing OB, extract the pillars and then
Coal & OB transported to coal stock and OB dump respectively.
3) Occurrence of accident:- At about 3.45 A.M., one of the worker’s noticed
that a person was slipping on the sand on OB bench & dumper operator was
driving the dumper in reverse and the dumper run over the sleeping worker.
4) Cause of Accident:- After inspection of site of accident, recording of
statements of co-workers and other officials it was revealed that accident
occurred due to the following reasons:i) Careless driving of dumper by dumper operator who was deployed on
overtime.
ii) Sleeping of person / maintenance helper while on duty.
5) Contraventions of statutory provisions:- In my opinion, the following
statutory provisions were contravened:
i) Reg. 38(6) of CMR,1957 – The maintenance helper of M/s. …… engaged by
hiring agency was sleeping on OB bench while he was on duty.
ii) Reg. 95A of CMR,1957- Negligence on duty by dumper operator as he
carelessly driven the dumper in reverse direction in contravention of conditions
imposed by DGMS in statutory permission.
6)Responsibilities:- Enquiry into the accident revealed that if the dumper
operator was operating the dumper carefully & maintenance helper was not
sleeping, the accident could have been averted.
The following persons are considered responsible for the accident:i) ACM- In contravention of provisions of reg. 95A and 42 of CMR 1957, the ACM
failed to effectively implement the conditions imposed by DGMS for safe driving
of dumpers.
ii) Overman- In contravention of provisions of reg. 95A and 43 of CMR 1957, the
Overman failed to effectively implement the conditions imposed by DGMS for
safe driving of dumpers as well as allowing the maintenance helper to sleep
while on duty.
iii) Dumper Operator- He failed to follow the instructions given by senior officials.
iv) Maintenance Helper- He failed to obey the regulation 38(6) of CMR,1957 as
well as instructions of his superiors.
7) Suggestions to prevent similar accident in future:In my opinion, the following suggestions should be implemented in order to
avoid repetition of similar accidents in future:
i) Manpower -Adequate nos. of dumper operators should be appointed keeping
in view factors like absenteeism, leave etc. in order to avoid deployment of
dumper operator on overtime.
ii) Avoidance of overtime duty.- Work on overtime should be avoided..
iii) Selection of Operators- Operators should be selected from amongst persons
possessing requisite qualifications. The selection process should comprise a
test to check driving / operating skill, aptitude, health and oral examination of the
candidate by a competent selection committee.
viii) Training and re-training- Operators should be imparted proper training and
retraining for their development and strict adherence of safety rules.
Q.4.Draw a code of practice for deployment of side discharge Loaders in a depillaring
district in which a 5.0m thick seam is being extracted in two lifts in conjunction
with hydraulic sand stowing.
Ans:- Refer to Q.No.7 (2nd class 2007)
Q.No.5.Discuss the various reasons for accident due to inundation. Suggest steps for
prevention of such accidents.
Ans: The history of Coal Mining in India has witnessed several disasters /
accidents due to inundation both from surface sources as well as u/g sources of
water.
The following are the various reasons for accidents due inundation vis-à-vis
preventive measures to avoid such accidents:-
Sl.No. Cause of accidents
A.
Due to surface source of water
i
Entry of water into mine workings through
openings of mine (shaft / incline/ goaf /
borehole etc) which are at lower level than
the HFL of any river/ nallah etc.
2
Low cover and pot holing under river or
low lying areas where water can
accumulate.
3
Collapse of unstable workings whether
the cover is low or comparatively high but
capable of producing wide cracks on the
surface.
4
Subsidence under rivers, tanks, lakes or
water accumulated in low lying areas.
5
Obstruction in the course of water and
water entering through mine openings
Preventive measures
a) Ensuring mine opening
above 3m of known HFL
of the area.
b)Diversion of river or
provision
of
suitable
embankment.
c) Fixing warning level ,
danger
level
and
withdrawal level
at a
suitable site.
d) Checking of protective
measures regularly.
a) Seeking and obtaining
permission from CIM while
making mine workings
beneath and within 15m of
bank of river, stream,
nullah,lake,tank etc.
b)
Inspection
and
examination of protective
measures envisaged and
enforced to provide adeq
uate protection against
danger of inrush of water.
a) Supporting the roof by
steel girders & stabilizing
the workings by packing
with
incombustible
materials.
b) Providing dams out bye
of
the
packing
in
appropriate case.
a) No extraction of pillars
under low lying areas by
caving method.
b) Providing drains around
subsided areas.
a) Avoiding constricting
the water course on the
which are apparently at higher level.
6
Fault planes, fissures connected with
river lake, canal etc. may cause inrush of
water.
7
Failure of embankment
8
Water accumulated against stoppings/
deposits of quarry debris in galleries
exposed in quarries.
9.
Where a mine threatened with danger of
inundation is worked in rainy season
without taking safety measures.
downstream
side
or
erecting dams across the
course for pumping water.
b) Avoiding choking of
culverts etc by debris and
checking water courses for
ensuring
unobstructed
flow of water during rainy
season.
a) Leaving a barrier of atleast 7.5m against such
fissures/disturbances and
crossing
at
minimum
number
of
essential
points.
b) Driving galleries with
advance boreholes.
c) Plugging boreholes
effectively when in –flow of
water cannot be stopped.
a)
The
embankment
should
be
of
right
dimension for streams.
b) It should be such as to
contain the water against
features to be protected.
Water should be not by
pass the embankment at
any point.
c) The side facing water
shall be pitched with stone
and brick masonry set in
cement mortar.
d) It should be built with
proper materials and well
compacted to prevent
leaking or breaches.
Barriers against quarries
shall be at least one pillar
in thickness to avoid
dangers.
Otherwise
accumulation of water
against such barriers shall
be avoided.
To guard against sudden
release of large quantity of
water from dams on the
upstream side or due to
heavy rains on the upper
reaches of the river,
effective liaison shall be
maintained with the dam
authorities.
Adequate
advance warning arrange
ments for monitoring rains
in the upper reaches of the
river
and
re-flashing
warning sufficiently in
advance shall also be
provided.
B.
1
2
3
Due to underground source of waterInundation from accumulation of water
in the same seam:
a) Inadvertent connection of active
workings with water body either due to
unknown thickness of barrier or presence
of thin barrier.
b) Connection of active workings with
water logged workings along a fault plane.
a) Maintenance of correct
water danger plan &
surveyor’s report when
water is 75m away.
b) Maintenance of Plans
correctly
showing
geological disturbances &
c) Failure of a dam holding a body of spot levels at the ends of
water.
workings.
c) Ensuring design of
d) Impounding of water against stoppings
water dam based on
and their bursting.
engineering parameters.
d) All stoppings against
which
water
can
accumulate
shall
be
provided with suitable
drain pipes.
Inundation from waterlogged upeer a)
Maintenance
of
seam or section:
accurate
plans,
a) Boreholes, staple pits, drifts connected submission of AMPs and
with water logged upper seam/section.
maintenance of surveyor’s
report book.
b) Collapse of roof under waterlogged
b) Dewatering the top
workings.
seam
workings
and
stabilization of unstable
workings in the lower
c) Extracting pillars beneath waterlogged
seam if possible.
workings.
c) Dewatering of water
body may be done by
pumps, boreholes etc. The
fact that the workings are
free from water must be
ascertained with reason
able certainty.
Danger of water accumulated in a lower a) 60m barrier shall be left
seam
against any borehole or
staple connecting active
workings in upper seam
with water logged lower
seams.
4
Transference of danger
Statutory
provisions
a) Thin barrier on connection with a mine stipulated in statute must
vulnerable to inundation from surface be followed strictly.
water.
b)
Non-superimposition
of
barriers
between two mines.
c) Intentional flooding
Under the circumstances mentioned
above, transference of danger due to
water may take place from one mine to
another.
Q.6 State provisions of IER 1956 regarding the following:(a) Voltage limits.
(b) Precautions where gas exits.
(c) Care of flexible cable.
Ans:- a) Voltage limits:- Energy shall not be transmitted into a mine at a
voltage exceeding 11 KV and shall not be used therein at a voltage exceeding
6.6 KV.
However, this shall be subjected to following limitations:Maximum Voltage
(a) Hand- held portable apparatus125V
(b) Electric lighting (i) u/g (phase to phase); 125V
(ii) o/c mines and surface of mines 250V
(phase to phase)
(Neutral point shall be connected with earth)
(c) Portable hand lamps u/g.
30V
(d) Circuits for remote control or inter-locking of apparatus
30V
(e) In fixed plants if bolt type plug is used
650V
Ans:- b) Precautions where gas exits
Ref. to Q.No. 5(d) ( 2nd Class 2007)
Ans- c) Care of flexible cable: - Flexible trailing cables are highly vulnerable to
damage. Manual handling should be avoided as far as possible by use of
properly designed, installed and maintained cable reeling or handling devices.
Where manual handling is unavoidable, the following precautions should be
taken:
1) Where flexible cable is not required to move, it should be effectively
supported and protected against physical damage by roof/side fall, shot firing,
crushing by moving machinery or tubs.
2) Machine operators and cable men should be trained in safe operation and
handling of trailing cables.
3) Handling live trailing cables should be considered a specialized job to be done
by competent persons. They should be properly trained and authorized.
4) Where flexible cable is joined with the main cable, a switch shall be provided
which is cable of entirely disconnecting supply from the flexible cable.
5) Flexible cable shall be connected to the gate end box and the machine by
suitable and properly constructed connectors. For HV machines, bolted type
connectors shall be used.
6) Flexible cable shall be examined periodically by the person authorised to
operate the machine. It shall be examined at least once in each shift by the
competent person. Damaged or defective cable shall be replaced by good one
immediately. No flexible cable with a temporary joint shall be used.
7) Supply of energy shall be disconnected whenever the cable is not in use and it
shall be removed from the face to a safe and secure place.
8) Arrangements shall be made to prevent energizing of flexible cable by
unauthorized persons.
9) Guidelines for repair and maintenance should be laid down considering
manufacturers instructions, relevant BIS standards and skill of workmen
incorporating the following :-




Provision of well equipped workshop in terms of manpower & equipment /
appliances
Provision of procedure for location of puncture in the outer sheath,
detection of faults between conductors, drying out of cable, check on
insulation resistance during vulcanization.
Condition for replacement of cable.
Periodical checking of insulation resistance and maintenance of records.
Q.7. Write short notes on:(a) Nominated owner
(b) Compensatory day of rest
(c) Pattern of holes while approaching waterlogged workings.
(d) Support of freshly exposed roof.
Ans:- a)Nominated Owner:- Section 76 of Mines Act’1952 stipulates the
provisions in respect of nominated owner and empowers a firm or an association
of persons or a joint stock company to nominate any of its partners, members or
directors, respectively or managers to assume the responsibility of the owner of
the mine. In case of mine owned by Govt., officers authorised by the Govt. will be
the nominated owner.The nominated person must be a resident of India, and
must either be actually in charge of the management or hold the largest number
of shares in such firm, association or company.
In large companies, all persons on the Board of Directors do not look after the
day to day management of the company. Such persons should not be held guilty
of contravening any provision of the law. Therefore the Act has made a provision
for nominating an owner who can even be a manager of the firm or association or
company.
A notice to this effect is required to be sent to CIM in form l accompanied by a
certified copy of the resolution of the Board of Directors of the company and a
written consent of the concerned Director for acceptance of such nomination.
In case of non-appointment of nominated owner, every Director / partner /
member / manager of the company / firm / association is liable to the
responsibilities / punishment of the owner of the mine.
Such partner, member, director or manager nominated as owner shall so long as
he continues to so reside and be in charge or holds the largest no of share be
deemed to be the owner of the mine unless a notice in writing canceling his
nomination or starting that he has ceased to a partner, member, director or
manager is received by CIM.
Hence, the person who is nominated by the management to take the
responsibilities of provisions of statute as owner is known as nominated owner
which is given below:Owner (Management)
Nominated Owner (Provision)
1. Firm or other association any partners or members
of individual
2. Company
3.Government
authority
any directors or managers
or
local Any officers or person authorized
by the Govt. or such local
authority.
Ans:-(b) Compensatory day of rest..
A Person can be deprived of his weekly days of rest either under one of following
eventualities:
i) an emergency involving serious risk to the safety of the mine or of person
employed therein.
ii) an accident, whether actual or apprehended.
iii) any act of God.
iv) any urgent work to be done to machinery, plant or equipment.
or, as a result of exemption granted by the Central Government in exercise of
powers conferred by section 83(1).
If a person is deprived of his weekly days of rest, he shall be given a
compensatory day of rest, equal in number to the days of rest which he has been
deprived off, within the same month or within the next two months. These
compensatory days of rest shall be so spaced that in any one week not more
than 2 such days shall be allowed to any one person.
In the event of a person being discharged or dismissed, the number of
compensatory days of rest due to him shall not be reckoned as part of any period
of notice to which he is entitled under any rule, award, agreement or contract of
service, and he shall be allowed such compensatory days of rest before the date
of his discharge or dismissal.
On or before the last day of every month a notice shall be displayed outside the
office of the mine showing the list of all persons, who have not been allowed
compensatory days of rest during that month and the dates on which the
compensatory days of rest will be allowed to them in the following two months.
A register of compensatory days of rest is also to be maintained in Form F of the
mines rules 1955.
Ans:- (c) Pattern of holes while approaching waterlogged workings.
Pattern of holes commonly depends on:
 condition of strata
 head of water in the old workings
 reliabilities of old plans
In order to approach a waterlogged area of a mine, which is not easily
approachable, boring is practiced. Ordinary long hole boring is not of any help as
the danger of inrush is imminent. The advance bore holes must be driven by
safety boring machine/burnside boring machine. This machine achieves safe
boring with water under control, and enables the water to be drained out under
control when tapped.
Reg.127 of CMR.1957 stipulates that CIM’s permission shall be obtained when a
working is to be advanced within 60m (shortest distance) of any waterlogged
workings.
Workings shall be advanced strictly as per the approved plan, in approved
method and as per the conditions laid down by DGMS in the permission letter.
There shall be no variation from the approved method unless such variation is
against approved by CIM. For getting permission, information regarding outline,
depth of workings, proposed method and layout, presence of geological
disturbances and other particulars shall be acquired and submitted to DGMS with
two copies of plans and sections.
The height & width of workings shall not exceed 2.4m and there shall be
maintained at-least one central bore hole, sufficient flankholes on each side
and bore holes above and below the working, at a maximum intervals of 5m.
All boreholes shall be
drilled sufficiently close
to each other to ensure
that the advancing face
will not accidentally hole
through into water
logged workings and
shall be constantly
maintained at a sufficient
distance in advance of
the workings and such
distance shall not be
less than 3m. The
typical pattern of holes
while approaching
waterlogged workings
have been shown in the
adjacent figure.
The simplest arrangement is to bore two central boreholes driven in advance and
the flank bore holes should be arranged to cross one and other by driving them
alternatively at 22½º & 45º . To set off the flank boreholes accurately , a central
line should be marked along the heading and the direction of the hole obtained
with a triangular frame of wood giving the correct angle. The length of holes must
be governed by condition such as nature of the seam, reliability of plans and the
expected pressure of water.
All these operations shall be carried out under direct supervision of competent
person, who shall also maintain the record of bore holes alongwith its pattern.
This record shall be countersigned by the manager every day.
Also a plan and section of workings approaching waterlogged workings showing
the above particulars, shall be prepared and maintenance and brought up to date
at-least once in every 15 days.
The advance of minimum 3m must be constantly maintained even after blasting,
so depth of boreholes should take into consideration advance desired to be
maintained.
During drilling advance bore holes, the following precautions shall be taken: area near the face to be well supported before the starting of operation.
 machine to be supposed on timbers or steel girders to withstand the
weight when the machine is under pressure of water.
 proper ventilation & good lighting
 provision of safety lamps & automatic gas detectors to detect CH4, SO2
etc.
 provision of escape route.
Ans:-d) Support of freshly exposed roof: - A majority of roof fall accidents
occur close to working faces, where the freshly exposed roof is not kept
supported. The conventional roof supports are often dislodged during blasting
and thus about 3m – 4m zone behind the advancing force practically remains
unsupported. To control accidents in this vulnerable zone, some quick setting
supports which will not be affected by blasting.
The fifth Conference on Safety in Mines recommended that no worker shall be
permitted to work under unsupported roof that has been freshly exposed.
As per Xth safety conference, suitable steps are to be taken by the mining
company to inculcate a culture of no work at a face till the roof is supported by
roof bolts upto at-least .6m from the face.
The importance of support of freshly exposed roof arises because of the
following:i) The maximum percentage of accidents occur due to falls of roof.
ii) A majority of the roof fall accidents occur close to the working face.
iii) With each advance of the face, roof is exposed, the nature of which cannot by
any means be assessed or foreseen.
iv) Apart from exposure of week planes in the roof, bed separation commences
as soon as the roof is exposed. Bed separation extends gradually upwards and
causes roof falls in stages.
v) Once bed separation takes place heavy supports will be necessary to hold
the loose strata.
In order to be effective the supports designed for freshly exposed roof shall have
inter-alia the following characteristics:
i) They should not be easily dislodged during blasting.
ii) They should have adequate strength keeping in mind that the thickness of
roof fall normally varies from 15 to 80 cms.
iii) They shall be amenable to quick setting so that the roof can be secured
before loading of coal commences after blasting.
iv) They shall be portable and acceptable to the workmen.
vi) The cost of such supports should not be prohibitive.
As per regulation 108 of CMR 1957, freshly expose roof shall be supported
systematically. Managers of every below ground mines shall frame and
implement the SSR in their mines.
Keeping the above in view, the following methods of supports may be adopted
for the support of freshly exposed roof in development galleries and depillaring
areas.
A. Support of freshly exposed roof in development galleries.
In development galleries the following methods of supports for freshly exposed
roof may be adopted depending on the prevailing conditions at the faces:1) Crossbar supports fixed on Clamps
2) Screw type props with crossbars set over them
3) Bamboo/Wooden Bolts.
4) Recoverable Bolts.
5) Hydraulic Props with link bars.
6) Triangular Screw Type cogs.
7) Rock bolting with quick setting cement.
Pal committee/Expert group recommends that, in general, extended use of roof
bolting as a method of support should be adopted for support of freshly exposed
roof. The committee has recommended the following system supports for freshly
exposed roof:
Recommended support System for freshly exposed roof (upto 10m from
the face)
Roof (Class)
Description of bolding system
a) Yielding steel arches under
high stress condition.
b) Rigid steel arches under
moderate stress condition.
2.Poor Roof ( Class (a) Point anchored (mechanical
Conventional Supports
1. Very Poor
Roof(Class V)
Cross bars on steel
IV)
3.Fair Roof(Class
III)
or grouted with quick setting
resin) bolts for immediate tension, to be fully grouted soon
afterwards. W-straps where
necessary.
(b) Full column grouted bolts
with quick setting grout.
(a)Combination bolts as at (a)
above.
(b) Full column grouted bolts
with quick setting grout.
(c) Recoverable bolts.
4. Good Roof
(Class ll)
(a) Recoverable bolts.
(b) Full column grouted bolts.
5 Very Good Roof
(Class l)
No support except for spot
bolting in disturbed areas.
chocks or hydraulic
props with minimum 5te
setting load.
(a) Light duty hydraulic
props.
(b) Steel Props
(c) Triangular shocks at
junctions
(d) Safari supports
(a) Steel props
(b) Safari supports
B. Support of freshly exposed roof in depillaring areas:
Supports for the depillaring areas need special considerations so that they may
be withdrawn safely and easily. Further, such supports should not interfere with
the cavability of roof when extraction is being done with caving method. Keeping
these points in mind, the following types of supports may be used for supporting
the freshly exposed roof:
 Screw type props
 Three legged screw type cogs
 Recoverable bolts
Q.8.Draw up a suitable scheme of training and facilities to be provided under Mines
Vocational Training Rules 1966 for a large mechanized underground mine having
Longwall Workings.
Ans:- Conditions assumed :i. Mining parameters
Mine Outlet
: A pair of inclines
Production
: 1.0 mill. te/year
Thickness of seam
: 3.5 to 4.0m
Height of extraction
: 3 to 3.5 m
Depth of working
: 60 m
Gradient of seam
: 1 in 20
Mode of Coal getting
: By highly mechanized longwall system.
Panel length
: 860 m
Face length
:120m
Face span
:4.5 m
Roof
: sandy shade & sand stone
Floor
:
-doii. Face equipment
Coal cutter- Shearer (double ended ranging drum)
Face support – 4 legs hydraulic chock (Powered support)
Face conveyor – Armored Flexible conveyor ( 760 tph.)
Loader – Stage loader (760 tph)
Power pack with feed pump
Lump breaker, Gate belt, boost pump
Deployment of manpower:-Assuming that the L/W face is operated in two shifts
for production and one shift is kept for maintenance. Manpower are deployed on
the concept of all men all job. The requirement of manpower in mechanized L/W
working shall be as follows:a. Mine officials
Shifts
Designation
I
II
III
Total
i)) Mining Sirdar/Overman
1
1
1
3
ii) Foreman/Foreman incharge
1
1
2
4
iii)Engineer
1
1
0
2
iv)ACM
2
1
1
4
5
4
4
13
b) Operators & OthersShearer operators
2
2
2
6
Face crew
18
18
18
54
Mech. Fitter & helper
2
2
2
6
Elec. fitter & Helper
2
2
2
6
Gale belt operator
1
1
1
3
General mazdoor/ Others
2
2
2
6
Total
27
27
27
81
G.Total
32
31
31
94
Training Scheme:The training scheme for the persons mentioned above must incorporate the
following:
 Categorisation of workers - i) no. of batches ii) course content & its
duration
 Type of training to be imparted
 Type of training Centers
 Manpower
 Equipment
 Records
For imparting training to workmen, supervisors and officers, a full fledged
training organisation ( Group training centre as well as Mechanized Long-wall
training centre) must be available as per following details:Training Organisation
Manpower
Building accommodation
with furniture
* Principal
Lecture hall
* Suptt.
Training gallery
* Training Officer GT Chamber
* Instructors
Other Stores
* Accountant
Work shed
* Stenographer
Model Room
* Clerks
* Fitters/Electricians
* Lab assistant
* Scientific Asstt. Etc.
Training Aids
Record maintenance
Equipment
Appliances & tools
Samples
Supplies
For training of above persons, a well equipped & well furnished training centre
having adequately trained, qualified and experienced training officers, as well as
trainers from various aspects of operations is to be established. For this purpose,
L/W mechanized training centre set-up as per recommendation of safety
conference may be utilized for imparting training. The training centre should have
adequate accommodation for model room, discussion hall, record room, canteen,
model aids, equipments, video etc. The total training programme is divided as
follows:Training Scheme
↓
↓
↓
Statutory
Non-Statutory
↓
↓
↓
↓
Workers Supervisor Executives
i)Training for Longwall crew:- As per statutory provisions contained in MVTR’
1996, all persons to be employed in u/g mine shall be imparted initial / basic
training for 24 days including 12 days training under direct personal supervision
of trainers. They shall also be imparted refresher training for 15 days within one
month of re-employment after break of service of one year or more.
However, as per recommendation of National tripartite workshop on Revised
Modules for vocational training in Mines held in 1999, Longwall Crew, mine
officials & other workman shall be imparted training as per the proposed new
training modules given below:-
(a) Type & duration of training
Type of training
Duration of training
Initial
Refresher
Theoretical class room training
22
05
On the job practical training
24
06
Feed back training/oral test
02
01
(b) Course Content:-Training to L/W face crew should include – Basic concept
of L/W mining, different types of machines and statutory provisions, concept of
ventilation, support of gate rods, different types of support and their use, support
at face, roof bolting and anchorage testing, fundamental and maintenance of
hydraulic machines, familiarization of tools used for maintenance of L/W
machinery, concept of different types of pumps, precautions against inflammable
and noxious gasses, concepts of power supports, chain and belt conveyors,
examination of machinery & writing of statutory reports, salvaging of longwall
equipment, procedure to support in case of cavity formation, dust & gas hazards
(health & explosion) importance of leg-pressures, its monitoring and leakage.
(ii) Training of mine offcialsa) Sub-ordinate Supervisory officials:
Type of training
Duration of training ( days) Course content/syllabus
Initial
Refresher
Mining & Geology, safety
Theoretical
11
5
policy, ISO, causes of
On Job
6
3
accident & preventive
Feedback
1
1
measures, cost of accidents,
enquiry into the accidents,
workman’s inspection S.C.role / function, duties and
responsibilities of supervisors
mining methods, exam. of
workings, emergency plan,
mine plan etc.
b) Electrical supervisor
Type of training
Duration of training ( days)
Course content/syllabus
Initial
Refresher
Theoretical
11
5
Electrical layout, AC & DC, PF,
On Job
6
6
Ohm’s law, load calculation,
Feed Back
1
1
voltage drop, transformer, circuit
breakers,
isolators,
Cables,
method of earthing, capacitors &
its use, reports and records
maintenances of electrical plan,
IR, resistance testing etc. FLP &
intrinsically safe equipment, first
aid, electric shock etc.
iii) Fitters/ Mechanics
Initial
Theoretical
24
On Job
28
Feed Back
2
Refresher
5
various type of m,/c used in u/g, tools
6
and tackles, duties, maintenance
1
schedule & preventive maintenance,
different types of FLP motors used
belowground, tensioning &
alignment methods of chain
conveyors and different types of
rollers used with belt conveyor,
statutory provision regarding use
of m/c, dangers from fires in hydraulic
system in different m/c. and their
maintenance, dangers from mine gas,
action in case of emergency.
.
Electrician
Type of training
Theoretical
On Job
Feed Back
Duration of training ( days)
Initial
24
28
2
Refresher
5
6
1
Course content/syllabus
Various types of electrical
machine used in u/g,
duties of electrician,
provision of IER and its
applicability in mines,
dangers due to electricity
and use of personnel
protective equipment,
testing & measuring
instruments, LT & HT
switchgears and panels
common causes of faults &
repairs
in
electrical
machines, earthing and
earth pit maintenance,
electrical
signaling
&
telecommunication, cable
lying, jointing & protection,
electrical layout plan, FLP
enclosure & intrinsically
safe circuit, Testing of
inflammable
gas
with
flame safety lamp &
maintenance, permit to
work system etc.
Other facilities to be provided:
Training allowances

Accommodation/fooding

Reading materials

Certificate of competency
Afternoon Session
THE MINES ACT, 1952
Examination for Mine Manager’s Certificate of Competency under the Coal Mines
Regulation, 1957
FIRST CLASS
MINE MANAGEMENT, LEGISLATION & GENERAL SAFETY
Monday, the 19th December, 2005
Full Marks: 100
Time
: 3 Hours
Answer any Six Questions
(All questions carry equal marks)
Q.1.What are the objectives of convening the National Safety Conferences?
Briefly state major recommendations made by it till date and their impact
on legislation and status of safety in mining industry?
Ans – Safety in mines has remained as a vital necessity of our mineral
development. Indian legislation related to mines safety remained as most
comprehensive corpus encompassing every aspect of mining operations. One of
the best forums at the national level for all those associated with mining
operations has been mines safety conference.
National Safety Conference:- National conference on safety in mines is a
tripartite forum at the national level for deliberation on issues connected
with safety and health in mines.
In the conference, the employer’s representatives, the Trade Unions
representatives, the Govt. represented by the Ministry of Labour and
Employment/DGMS, various administrative ministries/ department and state
Govt. and Associated Institutions, Professional bodies, Academic and Research
Institute, Service Associations etc take part. This is an event of great
importance which brings together the policy formulators, planners and
experts in mining technology, officers of law enforcement machinery,
representatives of mining industry, trade unions and workers.
Objectives of convening the National Safety Conferences:i)
To discuss/ review the status of safety in mines.
ii)
To dwell upon the emerging safety issues in mines by different stake
holders of the country to identify the thrust areas for improvement in
the safety standards in Indian mines.
ii)
To review the status of safety in mining and adequacy of existing
measures in improving working conditions in mines in a spirit of mutual
co-operation.
iv)
To suggest measures for further improvement in safety, welfare and
health of mine workers.
v)
To think, reflect and critically analyse as to how safe mining operations
can be combined with production of minerals.
vi)
To play vital role in shaping the safety and health policies of the mining
industry.
Safety Conference was first started in the year 1958 following a disaster
(explosion) in Chinakuri Colliery in Eastern India and subsequently eight more
conferences were held in the years 1966, 1973,1978,1980,1986,1988,1993 &
2000.
Many of the recommendations of the safety conferences have been
absorbed in statute by making suitable amendments and by the DGMS
circulars where as some have been incorporated in management’s safety
policies and practices.
The major recommendations of various safety conferences vis-a- vis its
impact on legislation and status of safety in mining industry are tabulated below:Safety
Conference
i) 1st (1958)
2nd July
(1966) to
review a
fresh the
entire
position
regarding
safety in
mines.
Major recommendation
i) Detailed specification of standard of
ventilation, illumination and tracks.
ii) Specification of standards of
accuracy of mine plans, carrying out of
important surveys and preparation &
maintenance of water danger plan.
iii) Organisation for dust treatment
Impact on legislation &
status of safety in mines.
Technical instructions have
been issued by DGMS for
strict compliance in order to
ensure safety in mines.
Some
recommendations
have been incorporated in
statute.
v) Appointment of safety officers in
large and / or gassy mines.
v) Provision of experienced manager in
large mines.
vi) All technical instructions should be
routed through the manager and to
enable him to devote more attention to
the safety matters; he should be
relieved of non-technical obligation.
CMRI’1957 amended in
1965 in which appointment /
qualification of safety officer
in mine were specifically
defined.
DGMS advised the mining
industry
that persons
having experience more than
5 years after obtaining
Managers
certificate
of
competency
should
be
appointed as Manager.
vii) Constitution of Pit safety committee.
PSC constituted
mine.
in
each
viii) Introduction of scheme for training MVTR’s
1966
frammed
of all new entrants to mining & re- incorporating provision of
refresher course for mine workers
basic training to new entrants
and refresher training to
mine workers with a view to
make them aware of the
dangers of working in mines
so that they can work safely.
i)
Compulsory
installation
of CMR 1957 were amended in
mechanical ventilators in all mines, the year 1967,1971 and
provision of safety lamps, conduction 1972 to
provide the
of gas survey.
following:
ii) Greater association of workers in 1967- To provide for use,
safety matters.
supply and maintenance of
iii) Suitable vocational training, specially footwear, helmets and other
for the surveying and engineering staff. protective equipment.
iv) Formation of more rescue station
1971 i) Installation of fan made
compulsory
ii)Lamp checker’s certificate
introduced
3rd (July
1973)
i) Treatment of workmen at the cost of
management with full pay and
provision of suitable alternative job,
who is rendered unfit as a result of an
occupational disease/injury
ii) Issue of Identity cards to all mine
workers.
4th(Dec’1978)
No Recommendation
5th Dec’ 1980 i) Well defined Safety Policy in the
fields of health & safety of its
employees and establishment of
institution of ISO
ii) Amendment of Mines Act 1952 to
give statutory backing to the institution
of PSC and Work-men’s Inspector. 
iii) No worker to be permitted to work
under unsupported freshly exposed
roof.


iii)Appointment of V.O.
iv) Duties of S.O.& V.O.
v) Quantity and velocity of air
specified.
1972 –
i) Procedure for classification
of coal seems according to
their degree of gassiness.
ii)Appointment
&
Qualification of shot firers &
fixing of max no. of shots in a
round.
Mines rules,1955 amended
in 1978 to include a new
chapter on medical exami
nation of persons employed
or to be employed in mines
and to prescribe the medical
standards of fitness
Mines rule 1955 amended in
1980 to provide for issue of
identity tokens to all persons
employed in mine.
For ensuing safety in mines,
CMR1957
were
further
amended in 1978 regarding
systematic supports and
CIM’s approval for certain
equipment and materials.
AIso IER, were amended in
1980
for
requirements
regarding the use of FLP
apparatus & intrinsically
safe circuit.
Incorporated in management
policies and practices for
ensuring safety in mines.
Mines Act were thoroughly
amended in 1983 in-corporating following provisions::
i)Safety
&
occupational
health survey by DGMS.
ii)Duties & responsibilities of
Owner, Agent & Manager.
iii)Constitution of committee
at national level.
Mines rules 1955 amended
for inclusion of a new chapter
on P.S.C &.W.I.

CMR amended in 1985
incorporating provision for
appointment
of
deemed
agent, fixed mine boundary ,
preparation of emergency
6th (Jan’
1986)
i) Formulation of support plan for
support of roof, sides, back and hang
wall in consultation with strata control
cell, CMPDIL & Safety Committee
ii) Conduction of fresh survey to
connect the mines to national grid and
check survey to ensure accuracy of
mine plans.
iii) Preparation of ventilation scheme
to achieve the stipulated standards
w.r.t. mine environment and facilities of
continuous monitoring of environment,
conduction of dust survey at regular
intervals.
7th (Dec’88 )
8th (May
1993)
iv) Selection, appointment and training
of operators and drivers of HEMM
as well as steps for preventing
unauthorized riding on dumpers &
trucks.
i) Framing of suitable code of traffic
rules for regulating the movement of
HEMM and suitable code of practice for
the prevention of injuries to persons
engaged in tipping, dumping and
loading operations.
plan, compulsory use of self
rescuer in u/g mines.
CMRI 1957 were amended in
a major way in 1990. The
important amendments arei) SSR have been modified
indicating the use of roof
bolts, hydraulic chocks &
powered supports.
ii)Provision regarding setting
and withdrawal of support
have been detailed.
iii)Requirement regarding the
qualification
and
appointment of VO revised.
iv)Permissible
limit
and
sampling procedure for air
borne
respirable
dust
prescribed and precautions
against dust elaborated.
v)Coursing of air upto 4.5m
of face.
Included in Management
policies and practices.
Guidelines have been issued
by DGMS in the form of
technical circulars for framing
and enforcement of traffic
rules for movement of HEMM
and code of procedure for
prevention of injury to
persons.
ii) Design & maintenance of haul Incorporated
in
roads.
management policies and
practices.
iii) Creation of well equipped properly
staffed department on O.H.S. in mining For proper health care and
companies and for group of mines.
detection of occupational
iv) Infrastructure, scheme and functions diseases, PME centres have
of OHS
been established & is functi
oning effectively
v) Training and education in first aid
and OHS
i) Framing of SSR based on RMR, Roof bolting has been
introduction of roof bolting as primary introduced as a means of
support system.
integrated support system in
ii)
Establishment
of
adequate u/g mines for securing roof
arrangement,
organisation
and and sides.
infrastructure facilities for carrying out Guideline has been issued
dust survey.
by DGMS for conducting air
9th
(Feb,2000)
iii) Introduction of eudiometry as a part
of mandatory medical exam for persons
seeking employment and for persons
engaged in operation where noise level
exceeds 90 dB(A)
iv) Training of work person, front line
supervisors and member of safety
committee.
v) Evaluation of competency of drivers
/ operators of HEMM by a Board of
experts.
vi) Discontinuance of tractor trailer
combination on haul roads.
vii) Relevant training and other job
related briefing to contractor’s works
for safe operation.
viii) Adequate facilities for X-rays and
lung function test at PME centre &
Training of medical officer for use of
ILO classifications of pneumoconiosis.
i) Critical examination and assessment
of danger of inundation before onset of
monsoon.
ii) Embankment to be provided against
river and jore to be designed on civil
engineer parameters.
iii) Filling of surface excavation.
iv)Provision of alternative source of
supply.
v)Establishment of effective communi
cation within the mines and between
the mine as well as between mines and
rescue station, hospitals, DGMS office.
vi) Formation of tripartite committee to
study the feasibility of establishing
rescue room for storing oxygen type
self rescuer for fiery mines.
vii) Preparation of risk management
plan on the basis of risk assessment &
its implementation in the identified
mines.
viii) Computerization of records of
medical & environmental surveillance.
ix) Formulation of guide lines for
referral, re-evaluation, classification of
pneumoconiosis
and
necessary
remedial actions by ODB.
bone dust survey.
By
implementing
these
recommendations,
safety
status in mines has improved
considerably and accident
rate reduced.
For ensuring safety in mines,
DGMS put forward these
recommendations to the
mining industries in the form
of
circulars
for
strict
compliance.
DGMS advised mining
industry to undertake a
formal risk assessment
process for preparation and
implementation of RMP to
reduce the hazards.
Recommendations are being
implemented by mining
companies.
.
Q.No.2. Inundation continues to be a major hazard in below ground
working. As a Manager, what action would you take to identify and
eliminate this hazard from your mine? Draw an action plan for the same.
Ans:- The history of coal mining in India has witnessed several disasters due to
inundation. Inundation has become one of the greatest killers in coal mines of
our country. In spite of elaborate provisions in the statute as well as availability
of guidelines in the form of DGMS Circulars & recommendation of various
committees, court of inquiry & safety conferences, accidents due to inundation
are taking place
Essentials for prevention of dangers due to inundation:i. Maintenance of accurate plans and a meaningful reading of the same.
ii. Identification of the causes of dangers due to inundation both from surface
sources & underground sources.
iii. Formulating the preventive measures and periodical review of the same
for ensuring their sufficiency if there is any changes in the circumstances.
iv. Strict enforcement of the preventive schedules once formulated.
To guard against the hazards due to inundation in belowground mines, the
following methodology shall be adopted systematically:(i) Identification of dangers
(ii) Elimination of dangers/ Protective measures to be taken.
(iii) Regular precautionary measures to be observed.
Conditions assumed :
Mine X is being worked by B/P method of mining. On surface, there are jore,
river, water tanks, rain catchment areas, low lying areas which can
accommodate water, water logged quarries, dams on the up stream side.
These sources in the vicinity of mine openings may pose a problem, specially
during rainy seasons.
In underground, sources of dangers are disused/old abandoned water logged
workings in the same seam, upper or lower seams including goaved out areas
in the same mine or adjacent mine.
As a manager, I shall take the following actions for identification & elimination of
inundation hazards in my mine:1) Action for identification of hazards due to
surface source
i. In the case of mines worked in the
neighborhood of rivers, jores, water courses,
tanks, low-lying areas, water logged quarries, the
following points should get special attention:
 Position of Mine openings w.r.t. HFL of
the Area.
 Presence of subsidence cracks
 Pot holes over the workings or goaf at
shallow depth of cover consisting mainly of
sand, aluminum or soft weathered rock
 Openings formed due to dislodgement of
strata on account of faults.
 Bore holes connected with water
on
surface, study of mine plan & physical
inspection of sources of dangers.
Possible steps /
measures for elimination
of hazards
a) Maintaining all mine
entrances/ opening at a
level at least 1.5m above
HFL of a rising body of
water
b) Properly designed and
constructed embankment
to be provided against
river, nallah etc.
All disused pits, potholes
and subsidence cracks to
be sealed by RCC.
All pits proposed to be
abandoned to be secured
at the collar level.
c) Seeking and obtaining








Blockage of culvert, bridge or higher water
level in the main river on the down stream
side/ obstruction in the course of river.
Bursting of dam on the up stream side on
uncontrolled release of water by the dam
authorities.
Spot levels at the boilers, power substation, electric motors used for winders if
any w.r.t. withdrawal level/ danger mark
fixed and possibility of stoppage of
winders in adverse weather conditions.
Whether or not the HFL line correctly
drawn along entire length of the river, Jore
etc.
Possibility of the HFL changing drastically
due to excessive impoundment of water
against dam and also due to abnormal
release there from.
Open cast workings having connection
with below ground workings either directly
or through subsidence cracks/ fissures.
Possible impending heavy rains.
Effective signaling system between
surface and belowground.

2. Underground working
i. Correctness of mine plans
ii. old water dams – specification not known
iii. Presence of disused / abandoned water
logged workings in the same seam, upper or
lower seams including goaved out area in the
same mine or adjacent mine.
Old working
–a) Accessible
of same mine
b) Inaccessible
shown on plan
not shown on
plan (AMP not
available/AMP
incorrect /not
up to-date.
Water logged workings of adjoining mine
- Inadequate inter mine
barrier
permission from CIM while
making mine workings
beneath and within 15m of
bank of river, stream,
nallah, lake, tank etc.
d) Provisions of captive
generators in working
condition to run the
winders in case of
emergency.
e) Provision of float alarm
at strategic point(s) in
addition to posting river
guard and maintaining
liaison with dam
authorities to get timely
intimation.
f) Reclamation of open
cast working.
g) Linking of mine to the
local meteorological deptt
for timely dissemination of
information.
h) Provision of effective
communication system
capable of functioning
even with failure of power
and in adverse conditions.
Preparation of correct
plans showing correct
extent of workings, spot
levels at ends of galleries
and bringing the plans up
to-date as per statute.
Draining out water from
water
logged
seam
whether developed or
goaved out by putting bore
holes.
For measuring quantity of
increase in seepage or
water, v-notch shall be
installed
in
roadways
leading to faces within
120m of water logged
- Joint survey not done
- Check survey not done
iv) availability of water dams plan
v) Position of geological disturbances w.r.t. water
bodies.
vi) Accumulation of water against stoppings.
working.
No working shall extend
with 60 m of any water
logged working without
written prior permission
from DGMS.
Vertical barriers between
the
mines
shall
be
maintained as per statute
In mines where the
barriers have become
ineffective due to inter
connection or otherwise,
the same may be restored
by constructing suitable
dams / explosion proof
stoppings.
Conducting check survey
of workings at regular
intervals particularly when
the
mine
workings
reached within 120 m of
any adjoining mine which
may contain water.
Maintenance of correct
water danger plan.
All
stoppings
against
which
water
can
accumulate,
shall
be
provided with suitable
drain pipes.
Besides above, risk assessment & risk management / technical audit of mines
before onset of monsoon to identify the sources of danger should be undertaken
and preparatory work should be done as per the details given below:
A) Surface preparation:a) Pre-monsoon- Before on set of monsoon – Pre-monsoon joint inspection by
team consisting of officials from DGMS and agent, manager, safety officer,
surveyor for careful assessment of danger of inundation shall be made . During
course of inspection apprehended dangers shall be pin-pointed, precautions
clearly laid down and implemented. This will involve:
i. Preparatory work on surface like strengthening of existing embankment,
construction of Pucca Wall/ dams around shafts or inclines.
ii. Cutting of drain to divert rain water from near mine openings, subsided areas
or low-lying areas.
iii. Clearing obstructions, widening and re-grading drainage channels before
onset of monsoon, making new drains if needed.
iv. Fixing danger mark and withdrawal level prominently after a thorough study
and after evaluating various features, with a margin of safety.
v. Providing float alarm in addition to river guards and an effective and speedy
communication system capable of functioning independent of power and also in
adverse condition.
vi. Filling of subsidence cracks, low-lying area, plugging of bore holes etc to
avoid rain water to percolate to u/g working.
vii. Providing effective signaling between surface and u/g.
viii. Framing and enforcing standing orders for safe withdrawal of persons in
case of emergency. All persons shall be made familiar with the standing orders.
Mock rehearsals shall also be held at regular intervals.
b) During monsoon:- Constant vigilance shall be exercised during rainy season.
The manager or sr. most official present at the mine shall go round the surface
area of the mine during heavy rains and check vulnerable points and
effectiveness of the safety measures. In case of doubt, persons shall be
withdrawn to safety.
B. Underground Preparations:a. Construction and / or repair of Pucca drain along the traveling and haulage
roadway in order to divert the water to dip side sump of adequate size.
b. Providing safety water pillars or barriers of adequate size to prevent water
accumulations from suddenly breaking into mine openings.
c. Providing adequate sump and pumping capacities at predetermined points
for dealing with in-rush of water even where safety pillars are provided.
Adequacy of the pumping arrangement should be checked, and if needed
strengthening be done.
d. Ensuring vertical inter-mine barrier of adequate thickness between two
mines.
e. Erecting water dams or hydraulic seals to seal abandoned sections of the
mine. The condition of the existing dams shall be checked and if necessary, they
must be strengthened.
f. Cleaning of sumps should be ensured well before the breaking of monsoon.
g. Erecting bulk head doors in mine workings when approaching within 60m of
water logged workings.
h. Providing additional lodgment capacity in worked out area(s) to which sudden
inrushes of water may be directed in an emergency.
i. De-watering of water logged working by in-seam pumping or through long
bore holes.
j. Preparing and maintaining water danger plan showing warning lines based on
known extent of workings and caved areas in upper seams and presence of
inter- connection through drifts, shafts, fault planes etc between the seams.
C. Inventory & Stores: Ensuring adequate inventory of spare parts for pumping arrangement.
 Additional / spare pumps, cables, switchgears, transformer etc should be
kept ready for emergency.
 Sufficient store of cement, rods or other building materials should be kept
ready for emergency work in rainy reasons.
Q.3. Define the following in the context of statutory provisions:
a. Hand-held portable apparatus.
b. Transportable apparatus.
c. Portable apparatus.
d. Voltage.
e. Flame proof apparatus.
f. Owner.
g. Serious bodily injury.
h. General body of air.
i. Ordinarily employed.
J. Person employed in a mine .
Ans:-a) Hand-Held portable apparatus:- means an apparatus which is so
designed as to be capable of being held in the hands and moved while
connected to a supply of electricity.
Ans:-b) Transportable apparatus:- means an apparatus which is operated as
to be capable of being moved readily from one place to another., e.g. A face
conveyor, auxiliary fan etc.
Ans:-c) Portable apparatus:- means an apparatus which is so designed as to
be capable of being moved while in operation. i.e. C.C.M, Drill, SDL, LHD,
Electric shovel etc.
Ans:-d) Voltage: - means the difference of electric potential between any two
conductors or between any part of either conductor and the earth as measured
by suitable voltmeter in volts.
Low voltage
- not exceeding 250V
Medium voltage - not exceeding 650V
High voltage
- not exceeding 33 KV
Extra high voltage - exceeding 33 KV
Ans:-e) Flame proof apparatus:- means an enclosure for electrical machinery
or apparatus that will withstand, when the covers or other access doors are
properly secured, an internal explosion of the inflammable gas or vapour which
may be present in the surrounding atmosphere.
Ans:- f) Owner- means any person who is the immediate proprietor or lessee or
occupier of the mine or part thereof. It includes liquidator or receiver but does not
include a person who merely receives a royalty, rent or fine from the mine or
merely the proprietor of the mine subject to any lease grant or license for the
working of mine or is merely the owner of the soil and not interested in the
minerals of the mine. It also includes any contractor or sub-lease for the working
of the mine but not so as exempt owner from any liability.
Ans:-g) Serious bodily injury- means any injury which involves or in all
probability will involve, the permanent loss of any part or section of a body, or the
use of any part or section of a body, or the permanent physical incapacity or the
fracture of any bone or one or more joints or bones of any phalanges of hand or
foot.
Ans:- h) General body of air:- means the general atmosphere in a seam and
includes the atmosphere in the roof cavities but does not include general
atmosphere in the sealed off area or in any borehole drilled in coal or in the
adjacent strata.
Ans:-i) Ordinary employed- means the average number of persons employed
per day in the mine or part thereof during the preceding calendar year i.e.
Ordinary employed =______________No. of man days worked______________
No.of working days excl. rest days and other non-working days.
Ans:-j) Person employed in a mine- a person who works as the manager or
works under appointment by owner, agent or manager or with knowledge of
manager whether for wages or not
in
a) any mining operation (including the concomitant operations of handling and
transport of minerals upto the point of despatch and of gathering sand and
transport thereof to the mine.
b) Operations/services relating to the development of the mine including
construction of plant but excluding construction of buildings, roads, wells and any
building work not directly connected with any existing/future mining operations.
c) Operating, servicing, maintaining or repairing any part or any machinery in or
about the mine.
d) loading operations for despatch of minerals within mine premises.
f) any office of the mine
g) any welfare, health, sanitary or conservancy services required or watch and
ward within a mine premises excluding residential area or
h) any kind of work incidental to or connected with mining operations.
(clue- m c r l o w a )
Q.4. a) What are the statutory provisions relating to Systematic Supports?
Explain the factors that you will take into account while formulating
Systematic Supports Rules for your mine?
b) What do you understand by the term “RMR”? What is its application in
strata control?
Ans:-a) Systematic Support: - Roof support is one of the most important
components of underground mining activity. Efficient roadway support while
providing a safe working environment should minimize the cost of labour and
material as well as down time.
The objective of providing support is to control deformation of roof by timely
support reactions reducing the long term movement to a minimum and in general
to help the rock mass to support itself.
Systematic support is the term used for erecting supports in such a
manner that the distances between supports are according to a specified
pattern based on rock load estimation as laid down by the Manager and
approval by DGMS.
Purpose of SSR: - Introduction of SSR serves the following important purposes:1. It reposes the responsibility of studying the nature of the roof and designing
the pattern of roof supports on the Manager of the mine and relieves the junior
subordinate officials from exercising their discretion. Thus one important matter
viz. support of roof is left with a person of high technical competence.
2. This gives the Manager of the mine some relief amongst his multifarious work
as he can rest content that with the systematic support rules enforced, work in
the mine will proceed in a safe manner and on every occasion when a particular
patch of bad roof is encountered his attention may not be called to be diverted
from other work at hand.
3. The systematic Support Rules once enforced, the junior subordinate officials
will have to exercise their discretion only in limited areas not covered by the
supports set according to the said rules.
4. Introduction of the Systematic Support Rules provides safety against falls of
roof, an integrated project for production of coal.
5. Provision of Systematic Supports provides for greater safety and thereby has
an effect on minimizing cost of production by avoiding accidents.
Statutory Provisions: - As per reg. 108 of CMR’1957, the following are the
statutory provisions relating to systematic supports:1. Applicability: The following places in belowground workings shall be supported systematically:i) every depillaring district
ii) every long-wall working
iii) every development working within 10m of face (green roof) and every junction
of roadways immediately out-bye of a development face.
iv) every working in a disturbed or crushed ground.
v) any mine or part requiring artificial support as per instruction of DGMS.
2. Framing and Enforcement of SSR: i) The manager of a belowground mine shall frame and enforce systematic
support rules specifying in relation to each working place the type and
specification of supports on roadways, each row of supports, adjacent rows of
supports, last row of supports and the face, hydraulic chocks & powered support
and the pack and face.
ii) The manager shall submit at-least 30days before the commencement of any
mining operation, a copy of SSR to RIM who may require such modification in
this rules as he may specify therein.
iii) The manager shall also hand over copies of SSR together with illustrative
sketches to all concerned supervisory officials including ACM and shall also
paste such copies at all conspicuous places in the mine.
iv) The manager and supervisory officials shall each be responsible for
ensuring effective compliance with the provisions of SSR.
3. Formulation and Implementation of code of standing orders: The Manager shall formulate and implement a code of standing orders
specifyingi) The system and the organisation for procurement and supply of supports
(quantity, quality and strength)
ii) The method of handling and transportation of supports from the surface to
the face and from the face line to their new site.
iii) the system and the organisation for maintenance and checking of supports,
dressing of roof and sides, erecting, examining and re-tightening of supports
and re- erecting dislodged supports.
iv) The panel of substitutes.
v) The manner of making all concerned persons fully conversant with SSR and
code of standing orders related to erection and maintenance of supports
including withdrawal of supports.
Factors taking into account while formulating SSR:Assuming that coal seam (lll seam) is being developed along floor by Board &
Pillar method of mining with SDL’s having thickness of seam 7m, width of gallery
– 4.8m and height of working 3.0 m. The immediate roof consists of 4.0m coal
overlain by sandstone. It is also proposed to adopt roof bolts as a primary
means of support system in my mine. While formulating SSR of the IIl seam
working as mentioned above, the following factors shall be taken into account:i) Physico-mechanical properties of the roof rocks:a. Nature and thickness of layers of different nature in the roof rock and their
compressive strength.
b. Slacking/swelling property, clay, if present will become unstable and provide
poor anchorage to roof bolts.
c. Joints pattern, type of filling material etc.
ii) Local geological conditions: Such as presence of discontinuities like joints,
faults, slips and sedimentary features like cross bedding, sandstone channels
etc.
iii) Rock weather-ability.:
iv) Compressive strength of roof rock:
v) Ground water seepage- presence of water & its pressure in the various
discontinuities, its physical & chemical effect with the infilling materials of various
joints can alter the cohesion; reduce the frictional and shearing resistance.
In addition to above, system of work, level of mechanization and past
experience shall also be taken into account white framing SSR besides gallery
span, profile, virgin stress and induced stresses.
Ans: b) RMR:- Rock mass rating is a rock parameter. It is a geo-mechanic
system of rating of stability characteristics of roof rock in a coal mines.
RMR is a number which is weighted sum total of ratings or marks given to five
parameters of the immediate roof rocks out of a total maximum 100 as follows:
Parameter
Maximum rating
Layer thickness
Structural features
Rock weatherability
Strength of rock
Ground water seepage
RMR = ∑f (
)
30
25
20
15
10
100
=
If there are more than one rock type then the combined RMR is obtained as:
Combined RMR = ∑(RMR of each bed x bed thickness)
∑ thickness of each bed.
RMR so determined is further adjusted for various geo-mining conditions viz.
depth.,lateral stress, influence of adjacent and overlying workings and mode of
drivage. Finally roof is classified on the basis of adjusted / final RMR as given
below:
Sl.No. Range of RMR value
1..
0 -20
2.
20 -40
3.
40 -60
4.
60 -80
5.
80 -100
Class of Roof
V
lV
lll
ll
l
Description of roof.
Very Poor
Poor
Fair
Good
Very Good
Higher the RMR, better is the roof
RMR provides useful information for selection of support system and rock load
values are used for optimum support design.
Applications of RMR is Strata Control:Following are the applications of RMR in Strata Control:1) Classification of Roof – On the basis of final / adjusted RMR value, roof are
classified as mentioned above.
2) Estimation of rock load for support design in development district- For
designing of support of gallery and junction in B/P development working
having maximum span 4.8m, the rock load is calculated by the formula given
below:
For gallery
Rock load, (Pg ) =B x D (1.7 – 0.037 x RMR + 0.0002 x RMR2 ) t/m2
For Junction:
Rock load(Pj ) = 5 x B 0.3 x D ( 1-RMR/100)2 t/m2
Where, B= roadway width/span(m)
D= density of roof rock (t/m2)
RMR=final / adjusted RMR of roof rock.
3) Estimation of support load density in depillaring workingRMR also finds its application in the estimation of support load density for
designing of support system in depillaring working as evident from the following
empirical relationFor slice junction, SLDJn = r.H0.50 . K0.64. W1.17
R0.90
Within Slice,
SLDsL = r.H0.67 . K0.84. W1.74
R1.42
In the split gallery, SLDsp = r.H0.52 . K0.59. W1.12
R1.02
0.54
For goaf edge,
SLDge = r.H . K0.49. W0.89
R0.79
Where, r = weighted average rock density of the immediate roof strata (t/m 3 )
H= depth of cover (m)
K= ratio of horizontal to vertical in-situ stresses
W=Width of split or slice (m)
R= Weighted average RMR of the immediate roof rock.
SLDJn,, SLDsL , SLDsp and SLDge = required suppose density ( in t/m2) at the
slice junction, within slice, in the split gallery and at the goaf edge respectively.
4. Monitoring of Strata/ Support :RMR is also used in calculation of theoretical maximum convergence and
convergence velocity for monitoring of strata/ support. The empirical relations
are:
Cm = 40 x B x D 1/3 (1-RMR/100)3 (mm)
Cv = 0 .55 x B x D1.7 (1-RMR/100)5.6(mm/day)
Symbols have their usual meanings.
Q.5. What are the statutory provision relating to “Emergency Plan”? Briefly
explain the essential elements of a good Emergency Plan and their
rationale. How will you incorporate modern technology advancements into
the emergency plan for a large colliery with belowground workings?
Ans:-Emergency Plan :- An emergency plan is a programme of action to be
followed in emergency. It should clearly indicate the duties and responsibilities
of each mine official and some other key persons like telephone operator,
attendance clerk, cap lamp in-charge etc. This plan should be drawn up taking
into consideration special features of mines, foreseeing every possible
source of dangers and damages. It consists of programmes which provide for
prior arrangements to be kept in readiness before emergency strikes and also
operative part of the emergency plan to deal with the emergency as and when
it strikes.
Statutory Provision: - As per regulation 199A of CMR 1957, the following are
the statutory provisions for framing and enforcement of emergency plan:
1. The manager of every belowground mine shall prepare an emergency plan
outlining the duties and responsibilities of each mine officials and keymen
including the telephone operators who shall be thoroughly instructed in their
duties so as to avoid contradictory orders and confusion at the time when prompt
and efficient action is required.
2. The emergency plan shall also provide for mock rehearsals at regular
intervals.
3. The Manager shall submit a copy of emergency plan within 30 days of
opening of mines to RIM, get it approved and enforce at the mine.
4. When any emergency occurs, manager /principal official shall immediately
put the emergency plan into operation. This Plan should be updated from time to
time.
Essential elements of a good emergency planFollowing are the salient points to be kept in mind while drawing an emergency
plan:
1. The first few hours immediately after any emergency are of vital importance.
2. Each member of the organisation should be given duties with which he is
generally familiar, so that he does not have to learn a new to play.
3. At the time of the actual occurrence, the Manager has to use his discretion in
adopting the plan according to the nature and scale of the emergency.
4. The officials in the pit at the time of the occurrence have to act according to
their own knowledge and initiative
5. Every person involved in the operations must clearly understand, in
advance, his particular role.
6. The possible causes and magnitude of emergency should be envisaged,
The manager has to keep in mind the nature of expected emergency while
drawing up the emergency plan. Various components of the plan would however,
be the same irrespective of the nature of emergency. The various elements
comprising a good emergency plan are:A. Standing Consultative Committee- It should be a permanent committee and
its member should be intimately acquainted with the mine. It should include:o Manager or senior most official present.
o Safety Officer, Ventilation Officer, Surveyor, Medical Officer, Engineer.
o Welfare Officer, Security Officer, Manager of adjoining mines.
o A senior executive of management
o Representatives from DGMS and Rescue Station
o Two representatives from supervisory staff.
o Two representatives from workers unions.
On being informed of an emergency the members will immediately proceed to
the operation Control Room, confer and approve the action Plan. They would
meet from time to time to review the progress of operations.
B. Communication- An efficient communication system is essential for effective
execution of emergency plan. The control telephone exchange should have
telephone connections with all key personnel and key points in the mine and a
list of their telephone numbers should be kept in the control room.
C. Stores and Materials- The following materials should be kept ready at
operation control room:o Emergency operation plans, list of key personnel, Telephone log books.
o List of members of consultative committee, Operation Books, Authorisaion
Card.
o Duty Cards of key personnel, Message forms (with duplicate pages)
o The emergency plan should show all details of rescue plan, water
danger plan, fire fighting equipments belowground.
D. Accommodation- Convenient accommodation shall be provided for –
o Operation control room, Manager’s office, Laboratory, Press, Security
o Rescue apparatus room, Rescue workers rest room.
o Welfare Control and catering.
o Walking casualties, Stretcher Casualties, Mortuary.
The locations shall be predetermined to avoid confusion during emergency: The
existing emergency plans are deficient and some times not effective in dealing
the emergency situation quickly and efficiently. Hence the chances of rescue of
persons belowground may get reduced and an emergency may turn out to be a
disaster. Reactive response through surface management control teams, rescue
teams and emergency duty card systems have limited impact on survival rate of
u/g personnel during the 1st few hours of emergency.
To overcome the inherent drawbacks in the existing emergency plan, adoption of
the doctrine of self escape which offers the best chance of survival to the
underground personnel, when ably supported by an aided rescue strategy,
should be considered. An integrated and well-rehearsed self escape strategy
essentially pro-active in nature offers best chance of survival.
Taking into the above concept and philosophy into consideration, the following
modern technology advancements should be incorporated into the emergency
plan for a large colliery with belowground workings:
1. Risk Assessment: A risk assessment exercise may be carried out and control
measures formulated, specifying responsibilities of individual mine officials with a
protocol of implementation, to obviate the possibilities of dangerous occurrence
in a coal mine.
2. Preparation and prevention: Group discussions may be held with workmen/
officials/managerial personnel to consider various hypothetical scenarios of mine
emergency and to chalk out hazard control measures Scenario planning and
hypothesis testing sessions may be conducted to search for possible solutions /
control of hazards and risks which may not have been identified.
3. Introduction of gas chromatography: Provision of Gas Chromatographs for
speedy and accurate analysis of air samples may be made in modern emergency
plan.
4. Detection and classification:Regular inspection be made as per the
established protocol to identify remedial measures by activating mechanism of
control / elimination.
Present standing orders may be revised to incorporate specific trigger action
points that will activate emergency action plan quickly. Competent persons
should be trained and authorised to recognize emergency and act on those
trigger points.
5. Response and mitigation:- The twin philosophy of “ self rescue” and “
aided rescue” form the foundation of a response and mitigation scheme.
a. Self rescue- All concerned may be trained in the process of self rescue
rather than waiting for aided rescue by taking following steps:i. Mine Officials may be trained in deciding the survival / escape actions with
work persons at the time of emergency, including routes of travel, mode of
travel, order of travel, use of link lines, communication, signaling etc.
ii. All overmen and mining sirdars may be provided with updated mine plans,
showing air circuits and primary and secondary emergency exit routes.
iii. Primary and secondary escape routes may be established and may be fitted
with guide ropes, clearly sign- posted with embossed to make them identifiable in
conditions of poor visibility.
iv. In each district, place may be identified where the workmen can gather in an
emergency. Such places may be equipped with telephone, mine plans, link lines
and blind man walking sticks.
v. Effective telecommunication system may be established so that in an
emergency, district officials can communicate with other districts and the surface.
b. Aided rescue - Aided rescue is essential to provide external assistance to
work persons unable to reach places of safety. Arrangements for getting external
assistance should be pre-decided. Rescue station may be manned by a team of
dedicated and competent personnel.
c. Re-entry and Recovery:- Initiation of a process of hazard analysis and risk
assessment is considered as an essential pre-requisite to the event of re-entry.
Thereafter, barriers to re-entry may be critically examined and evaluated and
recovery be effected as per devised rescue protocols and guidelines.
6. Mock rehearsals- This may be conducted from time to time. Deficiency may
be noted and emergency plan may be corrected and updated as and when
required.
Q.6.(a) What are the causes of Pneumoconiosis? What are its symptoms? What
precautions should be taken to prevent it?
(b) State statutory provisions relating to periodical medical examinations
and discuss its relevance to ILO classification of radiographs for detection
of Pneumoconiosis.
Ans (a) - Dust pollution is a predominant problem associated in mining
operations. Mining activities involving drilling, blasting, crushing, transportation,
dumping of ore etc are closely associated with high levels of air borne coal and
other metal dust including asbestos and exposure to crystalline silica (free silica).
Inhalation and retention in excessive amount of such dust over the length
of time may lead to serious respiratory health problems including
pneumoconiosis.
Pneumoconiosis:- It refers to lung diseases produced by dusts of size range
0.25 – 3.0 microns.
As per ILO “It is defined as the accumulation of dust in the lungs and
tissue reactions to its presence resulting into lungs disease”
Pneumoconiosis is a general term to cover all the dust disease of longs. It is now
well established that all dusts are dangerous. It is only the degree of harmfulness
in which they differ. All dusts, in-haled in large quantity, under suitable conditions,
may give rise to some form of Pneumoconiosis.
Pneumoconiosis is the term given to a group of diseases that result from the
inhalation and deposition of dust in the lungs, characterized by a fibrotic reaction
(microscopic scarring) around the small airways and air sacs of the lung. Usually
these conditions are more accurately described in terms of the dust that actually
causes the problem e.g. coal workers pneumoconiosis (CWP), silicosis,
asbestosis, stannosis (from tin) etc.
A pneumoconiosis may be either ‘simple’ or complicated.
Causes of Pneumoconiosis:- It is caused due to inhalation of dust. It is now
well established that the incidence of pneumoconiosis, silicosis, asbestosis etc
depends upon:
i) The period of exposes to dusty surroundings
ii) Nature and concentration of the dust.
Symptoms of Pneumoconiosis:i) Simple pneumoconiosis is said to exist where the only abnormality found is
the presence of typical small round opacities (shadows) on a chest x-ray, caused
by dust particles being deposited in the air sacs of the lungs. It is generally
considered not to cause any symptoms, like breathlessness and cough, or to
affect the working of the lungs as demonstrated in breathing tests.
ii) Complicated pneumoconiosis is used to describe a situation where a simple
pneumoconiosis is associated with the presence of scarring in the lungs. This
scarring may progress, causing damage to the lungs that may result in disability
or death from respiratory or heart failure. Scarring of this type may be either
diffuse or massive where it appears in one or more discreet patches, as in
complicated CWP.
Chest radiography is the most important tool for the diagnosis of
Pneumoconiosis. There appears clear relationship between total dust exposure
and severity of radiographic changes
Prevention of Pneumoconiosis:- There is need for planning strategy for the
prevention and control of pneumoconiosis. It should consist of two major
components:1. Definition of magnitude of problem
2. Implementation of actual control measures
1. Definition of magnitude of problems- To plan and execute the strategy for
the prevention of Pneumoconiosis, the knowledge of total population at risk and
number of people already affected is very essential. After estimation of
population at risk and identification of major vulnerable groups the industrial and
medical surveys should be carried out for measurement of “total” and respirable
dust at work place and the quantitative analysis of dust samples and chest
radiography of the person respectively
2. Implementation of actual control measures:i) Dust control measures
ii) Medical measures.
i) Dust control measure:a) Engineering control
 use of appropriate technologies
 ventilation & local exhaust
 process enclosure
 wet techniques
b ) Legislative control
 enforcement of laws & regulations
 formation of dust steering committee
 strengthening of OHI
 training for inspectors to enable dust measurement & improve knowledge on
dust control solutions.
c) Administrative control
 use of personal protective equipment
 work practices
 personnel hygiene
 awareness training
 maintaining dust exposure profile record of individual workers.
 computerization of environmental surveillance records.
In addition to above, the following additional measures should also be taken:
 Prevention of production of dust, prevention of dust getting air borne and
dilution and suppression of air borne dust.
 Collecting the dust by suitable dust traps
 Examining the dust concentration at working places at regular intervals by
approved suitable apparatus and taking corrective steps.
Statutory provisions have been for environmental surveillance to be exercised by
the mine management in respect of airborne respirable dust e.g. location,
frequency and manner of sampling. The manager of every mine has to formulate
a scheme specifying locations for collection of dust, nature of sampling
instrument to be used, laboratory facilities for analysis, organisation, reestablishment for dust monitoring and control measures and actions to be taken
including use of respirators where the permissible dust limit is exceeded.
Necessary training should be imparted to the persons engaged in airborne dust
surveys and control measures.
ii) Medical Measures:- As per recommendation of WHO, the medical screening
programme should be integrated and perused with the environmental
surveillance programmes so that the results of both could be related for review of
measures taken to control the environment. It should be confirmed, not as control
method, but to verify the adequacy of dust control measures. It includes preemployment and periodical examinations, incorporating chest X-ray, sputum
examination and spirometery .
Ans:-6(b) Statutory provisions related to PME- Refer to Q.No.5 (i)(1stclass’
2006)
ILO Classification of radiographs for detection of pneumoconiosis –
i) Dust retention and the changes of pneumoconiosis show up on chest x-ray, xray changes are apparent early on in the disease process and provide a method
of detecting the disease in its early stages.. The ILO classification categorises
three things: the size, shape and profusion of opacities on the x-ray of the
lungs and these parameters are converted into a series of codes.
ii) The profusion or amount of opacities is defined by four numbers, categories
0,1,2 and 3 where profusion increases from 0 to 3. Because the four point
profusion scale (0-3) was found to be insufficiently sensitive to assess
progression for some purposes, it is often subdivided and converted to a 12-point
scale. Thus 0/-, 0/0, 0/1, 1/0, 1/1, 1/2, 2/0, 2/2, 2/3, 3/2, 3/3 and 3/+ are
categories often reported.
iii) The shape and size of small (< 10 mm) opacities is indicated by lower case
letters. Codes p, q and r are ‘round’ as they are in CWP, s, t and u are ‘irregular’
or elongated as they are in asbestos; p and s are the smallest; r and u are the
largest. The zones of the lung in which the opacities are seen are also recordedthe right (R) and the left (L) thorax each divided into three zones; upper (U),
middle (M) and lower (L).
iv) The large opacities associated with PME are defined in terms of their
dimensions and given upper case letters; A,B or C. Category A is an opacity
having its greatest diameter exceeding 10mm and up to 50 mm or several
opacities each greater than 10mm, the sum of whose greatest diameters does
not exceed 50mm . Categories B and C, which are more ‘severe’ than category
A, relate the combined area of the opacities to the area of the right upper lobe.
v) It should be noted that the large PME opacities can be associated with any of
the categories of simple pneumoconiosis. Thus category A2 would describe a
case of PME where a category A large opacity is found against a background of
small opacities typical of a category 2 simple pneumoconiosis.
PME vis a vis ILO Classification for detection of pneumoconiosis: Rule 29 F
and 29 L of mines rules’1955 lays down the manner & criteria for conducting
medical examination which are given below:
A full size postero-anterior chest radiograph (large enough to include thoracic
inlet and both costophrenic angles) obtained by an x-ray machine of at least 300
ma (milliampere) strength shall be evaluated in the manner specified by the
Chief Inspector and lung function test (spirometery) to record Forced Vital
Capacity ( FVC ) and Forced Expiratory Volume in one second (FEVI ) shall be
made. There should not be any evidence of active pulmonary tuberculosis, he
may be permitted to work if his sputum is negative on repeated examination and
on production of a certificate that he is taking treatment from a qualified medical
practitioner/hospital.
The pneumoconiosis can be detected at an early on chest x-ray and its effect on
functional capacity can be assessed with the help of lung functions tests.
Q.7. A Large open cast mine is approaching a village hutments that can not be
vacated. What actions would you take to fulfill production targets with due
regard to safety. Draw a detailed plan of action for the same.
Ans:- In a large open cast mine approaching village hutments, the under
mentioned methodology may be adopted in order to fulfill production target with
due regard to safety:i) Using deep hole blasting both in coal & OB
ii)Deploying surface minor in softer strata & coal and practicing deep hole
blasting in harder strata.
In a big open cast mine, use of relatively huge quantity of explosive could not be
ruled out which may lead to various socio-environmental impacts such as:
 Ground vibration
 Noise/air over pressure
 Fly rocks
Hence, in order to fulfill production target with due regard to safety, the
following actions should be taken:
1) Statutory actions:i)Seeking permission for controlled deep hole blasting- Prior permission
should be obtained from DGMS specifying the limiting charge weight per
delay, total charge in a blast hole and total charge in a round of blast alongwith provision of muffling of shot holes with screens and sand bags to limit the
travel of flying fragments to within 10m from the site of blast.
ii) Seeking exemption under regulation 170 (1A & 1B)/ Taking sheltersSince in a big open cast mine, the observance of provisions contained in
regulation 170 of CMR’1957 in respect of removal of people from danger
zone, posting of guards, limit of 2kg charge in all the holes fired at one time
etc are not reasonably practicable and hence exemption has to be obtained
from DGMS.
2) Non-statutory / other actions:- Apart from the statutory actions
mentioned above, the following actions should also be taken:
i)Training:- Blasting operation shall be carried out by a team of qualified and
experienced persons and special training for his purpose shall be given to
them.
ii)Supervision:- Every blasting operation shall be performed under the
supervision of experienced over- man and Asstt. Manager possessing FCC.
iii)Safety flag:- Safety flags shall be pasted at a minimum distance of 50m
from the site of blasting, all along the danger periphery.
iv)Blasting time:- Shots shall be fired only during day light and particularly
between two shifts or during rest interval.
v)Use of explosive:- Charge per delay, charge per hole & charge per round of
blast shall not be more than permissible limit.
vi)Posting of Guards:- Sufficient numbers of trained guards with efficient
communication systems shall be posted near the village.
vii)Blasting shelter:- A substantially constructed blasting shelters shall be
provided near the village hutment and also for the shot firer.
viii)Siren:- Ten minutes before firing, a siren installed for the purpose shall be
blown three times for one minute each at one minute interval and no blasting
shall be done unless the shot-firer has ensured that all persons have taken
proper shelters.
Detailed action plan for fulfilling production targets with due regard to
safety :With the use of controlled blasting method, the socio-environmental impacts
can be minimized to acceptable limits. Before introducing controlled blasting
technique, a scientific study shall be carried out in consultation with blasting
experts from organizations like CIMFR, CMPDIL etc. much before the
hutments fall within the blasting danger zone. For this purpose, the following
action shall be taken:
i) DGMS permission:- When the working has approached the village
hutments, the permission of CIM shall be taken for further working (within
danger zone of 500m)
ii) Taking help of scientific agency- Help of scientific institution such as
CIMFR, CMPDIL, ISMU etc should be sought for designing proper blasting
pattern and taking valuable guidance on control measures for safe working.
Experimental blasting shall be carried out by the scientific agency in presence
of management personnel for the training purpose.
The following scientific studies shall be carried out to formulate safe blasting
practices:a) Study/observations:- Study of ground vibration, air-blast over pressure,
peak particle velocity etc, shall be carried by the scientific agency in the
hutments area, by using modern instruments, and a safe and suitable blasting
pattern shall be designed.
b) Preparation of Plan:- A plan showing structures belonging to the owner
and not belonging to the owner in different prominent shades shall be
prepared. The plan shall incorporate details of construction of the structures in
a tabular form. The plan should also show 50m, 100m, 200m, 300m & 500m
zones from the structures, the place of experimental study and the limit upto
which blasting is proposed to continue.
c) Structural response:- During the study, the response of the structures
assuming different natural frequencies should be calculated and plotted.
d) Monitoring:- In order to ensure effective control over the vibration and
related damages there is a need of regular inhouse monitoring and the
management should train the blasting personnel during the experimental
study and start observations on their own during the regular blasting
operations.
3) Control of ground vibration/fly rock/air-blast over pressurea) Limited /Safe charge per delay, and per round of blast.
b) Use of nonels and electronic detonator.
c) Muffling of shot-holes.
4) Warning & Communication systems:Modern warning & Communication systems approved by CIM should be
used.
5) Shelter:- Substantial shelters shall be constructed near hutment area and
near the public roads lying within the danger zone.
6) Competent Supervision:- The blasting activities shall be performed by the
experienced and trained personnel under competent supervision. The
overall blasting process shall be controlled by an Asstt. Manager having
FCC.
7) Educating villagers about dangers of blasting in open cast mine.
8) Preparation and implementation of Environment Management Plan for
control and reclamation of environmental damages.
9) Providing compensations to villagers for their damages.
10) Rehabilitation of villagers, if necessary.
The above mentioned detailed action plan may be summarized in the
following manner:Action Plan
Pre-blast survey & permission
↓
↓
Experimental/trial
blasting
↓
Record & monitoring with seismograph
↓
Permissible limits
↓
Permission for regular blasting
↓
Code of practices for conducting controlled blasting
↓
Regular in house monitoring
↓
Preparatin & Implementation of EMP
↓
Educating, compensating and rehabilitating villagers
Q.8. (a) In an underground coal mine three persons of shot firing crew including
shot-firer, several hours after returning home, complain of chest pain and
breathing difficulty and have to be hospitalized. One of them dies next day.
What may be the possible causes of this episode? How would you enquire
into it? Discuss possible causes and statutory contraventions.
(b) At the end of a working shift, the assistant manager is informed that one
underground worker is missing. What actions should be taken?
Ans: - Since the effected persons are sort-firing crew and having complaint of
chest pain and breathing difficulty, they might have been exposed to excessive
blasting fumes ( beyond permissible limit ) present in working faces just after
blasting operation.
Under the circumstances, the following may be the possible causes for this
episode:i) Inhalation of ‘Nitrous Fumes’:- Exposure to high concentrations of nitrous
fumes may lead to chest pain or even death from bronchospasm and respiratory
failure.
Nitrous fumes are very poisonous, the maximum tolerable concentration for
Indian Mines is taken as 0.0005%(5 PPM). Men affected by nitrous fumes show
immediate symptoms of cough, nausea, choking, perspiration bronchial
troubles such as bronchitis and bronchopneumonia which may prove fatal within
48 hours.
Nitrous fumes are usually generated when explosives undergo combustion
instead of detonation as may sometimes occur in case of weak detonation.
Hence, when explosives are blasted in confined space in U/G , nitrous fumes are
produced in dangerous concentration after blast. Short firing crew are
encountered with deadly concentration of nitrous fumes, when they return early
at blasting place after blasting. This might be the possible cause for the accident
of short firing crew.
ii) Inhalation of Carbon Monoxide:- CO is also a very poisonous gas, but less
dangerous than nitrous fumes. When explosive is blasted in confined space like
in a drill hole, it produces an appreciable amount of CO which may affect health
of person.
But as in question the short firing crew several hours after returning home
complain of chest pain and breathing difficulty and one of them died the next day
is clear indication of ‘ Nitrous Fumes’ poisoning.
Hence it can be concluded that the possible cause of episode is inhalation of
nitrous fumes in high concentration i.e. in excess of permissible limit.
Enquiry of Accident:- I would make enquiry about the accident in the following
ways:-
i) Background information- ll seam of A mine is being developed by B/P
method with SDLs. The seam thickness, pillar size and galleries width are 2.5m,
25mx25m and 4.8m respectively. The galleries are driven by blasting off-the-solid
using P-5 explosives and CDD.
ii) Event prior to the accident- After drilling and charging of blast holes, blasting
was done by shot firing crew under the supervision of mining Sirdar and
Overman.
iii) Occurrence of the accident:- On ……………. at about 9.30PM ( ll Shift) a
last round of shots were fired at face no. …….. (20m blind level heading) by shot
fires and his two helpers. They rushed at the face immediately after blasting (
without waiting a couple of minutes) to check the condition of the face and to
leave the distt. as early as possible as it was last round of fired shots. As soon as
shot firer and his two helpers reached at blasting fumes face they got 2-3 misfire
of shots. They stopped at the face for a longer period to detect the misfired shots
in blasting fumes environment. They entered at the face repeatedly to check and
fire the misfired shots one by one. Thus they got exposed to high concentration
of blasting fumes environment for a longer period and suffered with their toxic
effect.
iv) Inspection and inquiry:- On next day, I met with the shot firer and his one
living helper and recorded the statement of both of them. Subsequently I also
inspected the place of accident in llnd shift alongwith co-workers of deceased
and asked them to describe the incidents. Thereafter, I also asked mining sirdar,
overman and ACM who were on duty at the time of accident to give their written
statements separately.
During the course of inspection, ventilation measurement, quantity of air was also
measured at the blind end face and also at immediate outbye ventilation
connection from the face.
v) Possible causes of the accident:- Following are causes of accidents:
a) Use of explosives in excess of permissible limit: - One of the cause of
accident may be use of permitted explosives in excess of permissible limit as
permitted by DGMS for given degree of gassiness producing more nitrous fumes.
b) Inspection of face by Shot firer without waiting for clearance of fumes:
The shot firer alongwith his helpers had entered the face without waiting for
clearing of blasting fumes. Even, shot firer did not wait for at least five minutes
after blasting.
c) Ventilation requirement –Quantity of fresh air was not adequate at the face
resulting into high concentration of nitrous fumes in air at face.
d) Coursing of air- Blind heading was not ventilated by coursing of air upto 4.5m
from the face.
In my view, all the above factors collectively were responsible for such type of
accidents.
vi) Contraventions of statutory provisions:- The following provisions of the
statute have been contravened in this case.
a) CMR 176 : After shots have been fired, shot firer or any other person shall not
enter the place until the atmosphere in the area is free from smokes & fumes.
b) CMR 177 : Shot firer and blasting crew entered or re-entered the blasted face
until waiting for 5 minutes ( for clearing of fumes ), thus the shot firer
contravened the regulation 177 of CMR 1957.
c) CMR 130: Quantity of air was not adequate at the faces for clearing the blast
fumes.
d) CMR 136A: Velocity of air shall be at least 30m/ min at immediate outbye
ventilation connection from the face and at 4.5m from the face on the intake side
of the brattice or partition.
e) CMR 146: Air current shall be coursed upto a point within 4.5m of the face by
means of brattices or other materials.
f) DGMS Cir.Tech.30/1973: Adequate arrangement should be made to circulate
such quantity of air upto the site of blasting as to ensure after every round of
blasting, dilution of ‘CO’ and ‘NOx’ in the blasting fumes to less than 50 PPM &
5 PPM respectively within a period of 5 minutes.
Ans: (b) Assumptions of conditions:
Availability of telephonic communication between surface & underground.

Prevailing general practice regarding assembling of all workers including
pump khalasi at rest shelter half an hour before end of shift and then
coming out of mine under supervision of mining sirdar.

Contrary to the daily practice, till the end of shirt one pump khalasi has not
reported to the Distt. Mining Sirdar and subsequently information sent to
ACM regarding missing of one pump khalasi.
Under the above assumed conditions, I being an ACM, should take following
actions:-.
i) Checking of attendance & cap lamp issue register- For this purpose, I shall
ask time keeper to check form ‘C’ and cap lamp issuer to check cap lamp
issue-return register to ensure any possibility of his coming outside.
ii) Organising Rescue work- Rescue work shall be undertaken for missing
persons and instruction will be sent that no further person should go in as the
person might have been overcome by noxious gases.
iii) Improving ventilation - Instruction would be sent to improve ventilation by
coursing of air and arranging the materials (brattice, timber) for coursing of air to
the pump site.
iv) I would inform/arrange to inform manager and other senior officials, rescue
station/ rescue room, doctor.
v) I would arrange to send u/g – Flame safety lamps, Brattices, Tube apparatus,
Co-detectors, Self rescuer- O2 type.
vi) I would not rush down the mine without making proper arrangements.
However, after another officer is present on surface, I would go down the mine.
vii) Withdrawal of person from return side would be arranged.
viii) I would improve the ventilation to dilute the noxious gases at pump site by
coursing of air.
xi) If victim is within reach of the tube apparatus, the same would be used to
bring out the victim.
x) Application of artificial respiration to the victim is done till the life is pronounced
by a doctor.
xi) If the place is difficult to ventilate, and also ‘O’2 type self rescuer are not
available, there is no alternative but to wait for the rescue team with breathing
apparatus.
xii) Only after threat from noxious gases is removed, work in the mine will be
resumed.
xiii) Investigation is needed to establish the sources of noxious gases.
Morning Session
THE MINES ACT, 1952
Examination for Mine Manager’s Certificate of Competency under the Coal Mines
Regulation, 1957
SECOND CLASS
MINE MANAGEMENT, LEGISLATION & GENERAL SAFETY
Monday, the 19th December, 2005
Full Marks: 100
Time
: 3 Hours
Answer any SIX Questions
(All questions carry equal marks)
1.
What are the provisions of Mines Act, 1952 for the following:(a) Hours of works belowground.
(b) Extra wages for overtime
(c) Leave with wages.
Ans:-a) Hours of works belowgroundi) No adult shall work belowground in the mine for more than 48 hours in a week
or normally for more than 8 hours in any day , however the daily maximum
hours may be exceeded to facilitate the change of shifts subject to previous
approval of the Chief Inspector.
ii) Work below ground must be carried on by a system of shifts which should be
so arranged that the period of work of each shift is not spread out for more than
the daily maximum of 8 hours.
iii) No person employee in a mine shall be allowed to be present in any part of a
mine belowground except during the period of work shown in respect of him in
form C.
iv) The manager of every mine shall cause to be posed outside the office of the
mine a notice in form ‘A’ not less than 7 days before the commencement of the
work stating the time of commencement and of the end of the work at the mine
and if the mine is to work by a system of relays, the time of commencement and
the end of work for each relay.
Ans:- b) Extra wages for overtime
i) When a person works for more than 9 hours in any day above ground or more
than 8 hours in any day belowground or more than 48 hours in any week above
ground / below ground, he is entitled to overtime wages at twice the ordinary
date of wages.
ii) The period of overtime work shall be calculated on a daily basis or weekly
basis, whichever is more favourable to him. In the case of a person paid on piece
rate basis, the time rate shall be equivalent to the average of his full time
earnings (excluding any overtime) during the preceding week.
iii) Persons holding positions of supervision or management or employed in
confidential capacity are not entitled to overtime wages.
iv) The time spent by any person during examination related to safety &
occupational health survey shall be counted towards his workings time, so
however that any overtime shall be paid at the ordinary rate of wages.
Ans:- c) Leave with wages
Refer to Q.No. 6 (iii) ( 1st class 2006 )
2
An accident had occurred in a depillaring due to fall of roof in slice, in
which one person was killed. Write an enquiry report assuming your own
conditions clearly bringing out contraventions of the statues and persons
responsible.
Ans:From : _____________, Safety Officer,
_____________, Colliery,
Dated, ______________
To
The Manager,
_____________________Colliery,
Sir,
Ref. Your letter No._______ dated ______________
I submitted herewith a report on the roof fall accident that occurred on ________
at about 10 p.m. in the depillaring district in __________________seam at
__________Colliery and resulted in the death of two loaders namely,___________
and ____________________________
Yours faithfully,
(Signed)
Encl. Inquiry Report.
Inquiry Report
i) Description of mine and its workings.
l Seam, which is about 6.0m in thickness and having gradient 1 in 10 and depth
of working 140m has been extensively developed along sand stone roof with 2.2m
height by Bord and Pillar method. Presently depillaring with caving is being done.
ii) Events prior to the accident:
Panel no. 46B was started on 17-07-2005 with conventional depillaring by caving
method. The area of goaf was around 4720 m2 on 16-10-2005. Induced blasting was
regularly done to bring down the hanging goaf as per the existing practice. The first
fall in the goaf had taken place in 3rd shift on 14-10-2005. The extent of fall was 1750
m2. The 2nd fall had taken place in 3rd shift on 15-10-2005 and the area of fall was
1470 m2. The area of exposure left in the goaf was around 1500 m2 at the time of
accident.
iii) Occurrence of the accident:
On 16.10.2005 during lll-shift at 00.50hrs(early hours of 17-10-2005) in panel no.
46B depillaring district in l seam at 1st slice of 55 ½ L.S. / 9 dip, a massive stone
measuring 11m x 7.25m instantaneously caved in. One person succumbed to fatal
injury and two persons sustained serious bodily injuries.
iv)Rescue & Recovery:- Trained manpower were deployed immediately for
removal of
the debris. One dead body & two seriously injured persons were
removed after 2 hours of the accident.
v)Inspection & Enquiry: - On receiving information about the accident, I
immediately inspected the place of accident along with the other supervisory staff
and workmen. I made detailed observations and some measurements at the place of
accident and prepared a sketch of the place of accident giving leading dimensions.
Photographs of the place of accidents were also taken. The sketch and photograph
is attached with the report. I also examined witnesses and recorded their
statements.
vi) Analysis of evidence and findings:
From the inspection of place of accident, careful study of DGMS permission and
analysis of evidence collected, the following were revealed: The total area of exposure of the hanging goaf since 17.07.2005 upto
14.10.2005 was 5480 m2
 On 14.10.05 in 3rd shift 1750 m2 ( 1st fall)
 On 15.10.05 in 3rd shift 1450 m2 (2nd fall)
 The accumulated stresses within the strata were neither released fully nor
settled and it could be concluded that goaf was active.
 Roof strata load was transferred on the supports erected around the working
face.
 In between 2nd shift of 16.10.05 and 3rd shift of 17.10.2005 further bed
separation might have taken place and parted roof might be resting on the
supports as well on the coal rib.
 The hanging stone which partly resting on the coal rib had fallen along with
the supports erected underneath the strata, as the support density was not
adequate to take the load of hanging strata.
 As per the evidence gathered the full was so sudden that the hanging roof
has fallen suddenly without giving any indication of sound due to which no
time left to the workmen to escape for safely.
vii) Cause of the accident:
Speed of extraction is essential in the caving system of depillaring. Induced caving
for bringing down the roof at regular interval in order to relieve the strata pressure is
necessary. A large area remain exposed for considerable period causing dangerous
conditions resulting in the crushing of the think stook and premature collapse of roof
in the working area. Symptoms of the build up of pressure, if any, went unnoticed by
the supervisory staff. These combined factors are responsible for occurrence of such
type of accident.
viii)Contraventions of statutory provisions:- Regulation 108 of CMR 1957 read
with DGMS permission letter for extraction of pillars by caving method were
contravened in respect of the following:a) Support of split galleries & slices - SSR framed by manager were not fully
implemented.
b) Induced caving- Induced caving for bringing down the roof at regular interval in
order to relieve the strata pressure was not done.
c) Installation of convergence recorder- As per condition laid down in statutory
permission letter, sufficient nos of convergence recorders were not installed for
giving symptoms of roof weighting.
ix)Responsibilities:- Enquiry into the accident revealed that if the workings were
supported as per SSR, roof weighting noticed in time & safety precautions taken by
officials as required under statute, the accident could have been averted.
Under the circumstances, the following persons are considered responsible for the
accident:a. Agent- In contravention of provisions of section 18(1) and 18(4) of
Mines Act 1952 read with regulation 190 of CMR 1957, agent of
mine failed to effectively implement that all operations carried on in
connection with the mine are conducted in accordance with the
provision of mines act and regulation made their under.
b. ii)Manager- In contravention of provisions of reg. 108 and 41 of
CMR 1957 read with sec. 18(4) of mines act 1952, the manager
failed to effectively implement the conditions imposed by DGMS for
supporting of splits, goaf edge etc.
b) ACM- In contravention of provisions of reg. 108 and 42 of CMR
1957, the ACM failed to effectively implement the conditions
imposed by DGMS for supporting of splits, goaf edge etc.
c) Overman-In contravention of provisions of reg. 108 and 43 of CMR
1957, the Overman failed to effectively implement the conditions
imposed by DGMS for supporting of splits, goaf edge etc. and also
failed to notice the roof weighting.
x) Recommendations for prevention of similar accidents:
In all depillaring districts where extraction is done with caving, special vigilance is
required. The Overman and Mining Sirdar must be told about the likely dangers and
should be advised to watch carefully for signs of roof weighting. If any indications of
roof movement are observed, they should immediately withdraw the workers. The
Asstt. Manager should inspect such districts more frequently and with greater care.
Q.3. State the provisions on Indian Electricity Rules, 1956 regarding the following:-
(a) Precautions where gas exists.
(b) Flexible cables
(c) Sundry Precautions
(d) Voltage Limits
Ans:- (a) Precautions where gas existsRefer to Q.No.5(d) ( 2nd Class 2007 )
Ans:- (b) Flexible cables
i) It shall be of two core or multi-core and shall be covered with insulating
material efficiently protected from mechanical injury. Even if the mechanical
protection component is used as earth conductor, it must have a separate earth
conducting core.
ii)Where flexible cable is not required to more, it should be effectively
supported and protected against physical damage by roof/side fall, shot firing,
crushing by moving machinery or tubs.
iii) Machine operators and cable men should be trained in safe operation and
handling of trailing cables.
iv) Where flexible cable is joined with the main cable, a switch shall be provided
which is cable of entirely disconnecting supply from the flexible cable.
v) Flexible cable shall be connected to the gate end box and the machine by
suitable and properly constructed connectors. For HV machines, bolted type
connectors shall be used.
vi) Flexible cable shall be examined periodically by the person authorised to
operate the machine. It shall be examined at least once in each shift by the
competent person. Damaged or defective cable shall be replaced by good one
immediately. No flexible cable with a temporary joint shall be used.
vii) Supply of energy shall be disconnected whenever the cable is not in use and
it shall be removed from the face to a safe and secure place.
viii) Arrangements shall be made to prevent energizing of flexible cable by
unauthorized persons.
ix) Joining of flexible cable to the main cable shall be through a circuit breaker
capable of disconnecting supply automatically.
x) If voltage of the circuit exceeds low voltage: flexible cable for transportable apparatus shall be provided with metallic
screening or pliable armoring
 flexible cables for portable apparatus shall have flexible metallic screening
on all the power and pilot cores.
However, this will not apply to flexible cables attached to any transportable
apparatus used in opencast mines if reeling and unreeling of such cable is
necessary as per design features of the equipment.
xi) In case of separately screened flexible cable, conductance of each screen
shall be not less than 25% of that of the power conductor and the combined
conductance of all screens, shall be not less than 0.15 sq. cm. copper
conductor.
xii) Length of flexible cable with any portable or transportable apparatus shall not
exceed 90m. But it may be upto250m when used for long-wall operation, with coal cutting machine or
cutter-loader or armoured face conveyor or with shuttle car or LHD or
cutter loader or all alike equipment for development and depillaring
operations.
350m with electrically operated HEMM in opencast mines, and
1000m with bucket wheel excavator at 11kv.
xiii) Flexible cable shall not be used with apparatus other than portable or
transportable apparatus.
Ans:- (c) Sundry Precautions
i) All apparatus shall be maintained reasonably free from dust, dirt and
moisture, and shall be kept clear of obstruction.
ii) All apparatus other than portable and transportable apparatus shall be housed
in a room, compartment or box so constructed as to protect the contents from
damage by falling material or passing traffic.
iii) Inflammable or explosive material shall not be stored in any such place.
iv) In case of any fault in any circuit, that part of the circuit shall be made dead
without delay and it shall remain dead until the fault is rectified.
v) While lamps are being changed, the supply shall be disconnected.
vi) No lamp holder shall be in metallic contact with the guard or metal part of a
portable hand-lamp.
vii) The following notices in Hindi and local language of the district, so
designed and protected as to be easily seen and read at all times, shall be
exhibited:
 at all places where electrical apparatus is in use, a notice “unauthorized
persons not to operate or interfere”.
 where a telephone or other means of communication is provided, a notice
giving full instructions to persons authorized to effect the
disconnection, at the surface of the mine, of the supply of energy to the
mine.
viii) All apparatus, including portable and transportable apparatus shall be
operated only by persons authorised for the purpose.
ix) When a plug and socket coupling is used with flexible cable, an electrical
interlock or other approved device shall be provided to prevent opening of the
coupling while conductors are live.
Ans:-( d) Voltage Limits
Refer to Q.No.6(a) (2nd class 2004)
Q.4. Write short notes on any three the following:-
(a) Risk assessment as a tool to improve safety.
(b) Haul road gradient in opencast mine
(c) Noise pollution in mines.
(d) Angle of draw and its relevance
Ans:- a) Risk assessment as a tool to improve safety:Refer to Q. No. 6(b) ( 1st Class 2008 )
Ans:-b) Haul road gradient in opencast mine- Good haul roads are a
necessity for successful mining operations. Poorly designed, constructed and
maintained haul roads are major contributors to high cost and pose safety
hazards. Haul roads in O/C mines need to be properly designed, constructed and
maintained for:i) Ensuring operational safety.
ii) Achieving operational efficiency with high dumper speeds and minimum
cycle time.
iii) Reducing breakdowns, maintenance work and consumption of tyres and
spare parts.
iv) Minimizing fuel consumption.
The haul road geometry plays an important part in the safety of operation of
moving vehicles, their productivity as well as cost of construction. Guidelines
provided by DGMS for mechanized OC mines deals with the gradient, width,
visibility at bends and parapet walls of haul roads.
The grade line for a haul road is the profile taken along the centerline of the road
and is a series of straight lines connected by parabolic vertical curves to which
the straight grades are tangent.
All roads for trucks, dumpers or other mobile machinery shall be maintained in
such conditions as to be fit for their use.
No haul road should have gradient steeper than 1 in 14 at any place except for
haul road ramps (going from one bench to another) over a small stretchers where
a gradient upto 1 in 10 may be permitted. Where this condition can not be
fulfilled, prior written permission of CIM should be obtained and the condition
specified must be followed. In case of operational difficulty due to limited property
and adverse topographical consideration, it is necessary to have steeper
gradient/slopes. For this purpose, special permission shall be obtained from
DGMS.
It is advisable from safety and engine life considerations to keep a small stretch
(say 50m length) of lesser gradient after every 500m of steep gradient.
A number of rules of thumb regarding haul road gradients have been provided by
Couzens (1979). These are given below:i) In a pit where there is a considerable vertical component to the haulage
requirement, the grade will have to be fairly steep to reduce the length of the
road and the extra material necessary to provide the road length. The practical
maximum grade is considered to be is 10%. A number of pits operate quite well
at 10% grades both favourable and un-favourable to loads.
ii) An 8% road grade is probably preferred providing that it does not cause too
much extra stripping or unduly complicate the road layout. This grade provides
more latitude in (a) building the road (b) fitting in bench entries without creating
some locally over-steep places, than do steeper grades.
iii) There is normally nothing to be gained by flattening the road below 8% unless
there is a long distance to travel without regarding much lift.
iv) Pit geometry is the prime consideration and roads are designed to fit
particular situation. Thus there often will be number of different grade segments
in haul roads.
Haul road should be maintained smooth, free from fallen rocks and
sprinkled with water to prevent raising of dust and well drained. To ensure this,
road maintenance equipment and personnel should be separately earmarked
depending on size of the mine.
Ans:c) Noise Pollution in mines-A sound without agreeable musical quality is :Noise:- Any unwanted or undesired sound is called noise. Human ear can defect
sound in the frequency range 05 16HZ
It is an abrupt sound of complete chamber with an irregular period and amplitude
originating from a source in a non-periodic motion.
Nose Pollution:- This is a common hazard associated with mining. Almost all
mining operations generate noise. It has got a detrimental effect on the health of
persons working in a mine:
1. Pathological effect Hearing loss
 Reduction of speech intelligibility
 Acoustic traumas
 Auditory fatigue
2. Physiological effect Changes in blood pressure
 Changes in pulse rate
 Constriction of blood vessels
 Dilation of the pupil of eye
 Changes in blood cholesterol contents
3. Psycological effect.
 Feeling of discomforts
 Sleeping interference
 Reduced intellectual performance
 Fatigue
 Vexation
 Irritation distress
 Mental disorder
The degree of injury from exposures to noise depends upon a no. of factors such
as intensity and frequency range, duration of exposures and individual simplicity
Noise level standards:i) Warning level – 85dBA( for eight hours daily exposure)
ii) Danger level – 90dBA (Unprotected for 8hrs daily exposure)
iii)Compulsory wearing of ear protection limit- 115 dBA ( for 8 hrs daily exposure)
iv)Impulse noise of short duration – 130 dBA (Single outburst)
vi) No work limit – 140 dBA.
Measures for noise control and reduction of noise exposure.
a) Engineering Measures (noise control) For new machinery, laying down noise levels in specifications of
machinery to be purchased. Acceptance level could be 85-90-dB (A) in
normal operation of the machine at the operator’s position.
 In case of existing machinery, conducting noise zone survey, reducing
noise at source.
 Interrupting the noise path by putting acoustics noise barriers or
enclosures, isolating men from the source by acoustic cabins & using
remote control equipment.
b) Administrative measures (reducing noise exposure)Noise exposure can be reduced by:
 reduction of exposure time at noisy operation.
 job rotation during a shift or on a day to day basis.
c) Hearing protection:
When all engineering and administrative measures fail to reduce noise to
acceptable levels or as a short term measure, hearing may be protected by
ear protectors.
Regular audiometry as a part of periodic medical examination of workers will
show to what extent the measures have been successful.
Ans:- d) Angle of draw and its relevance:Refer to Q. No.6(a) ( 1st class 2008)
Q.5. What are the causes of damage to buildings and structures due to blasting in
opencast mines. What precaution should be taken to prevent such damages.
Ans:- When commercial explosives are detonated in blast holes, huge amount of
energy is liberated, both useful and waste energy. While useful energy (shock
energy and gas energy) is capable is doing work, the waste energy can not be
used in a constructive way and it creates some environmental problems and
annoyance including damage to buildings and surface structures due to
ground vibrations (seismic energy).
When blasting is done in Open Cast Mines, ground vibrations are generated
outward from the blast areas which cause damage to surrounding surface
structures. The vibrations radiating from the blast holes while passing through
surface structures induce vibration on the structures causing resonance. The
components of ground motion can affect the structures through compression
and tension and also through vertical and horizontal shearing effects.
In a properly designed and executed blast, only 20-30% of energy of commercial
explosives used in the mines is utilized for fragmenting the rock, the rest of
energy is transmitted through the earth in the form of ground vibrations resulting
in damage to the surrounding structures.
As per rough estimation, distribution of energy of commercial explosives in a
surface mine blast is as follows:
Sl.No.
i.
ii.
iii.
iv.
v.
vi.
vii.
viii.
Parameters
% Util. of energy
Fracture in situ
1
Rock Breakage
15
Rock displacement
4
Crushing
in
the
1.5-2
vicinity of hole
Fly rock
1
Deformation of solid
1
rock behind the shot
Ground Vibration
40
Air blast
38-39
Cause of damages to buildings and structures due to open cast blasting:When blasting takes place in an open cast mine, the incoming blast- induced
ground vibrations transmitted through the ground create a dynamic response in
buildings and surface structures. The response depends on various factors, such
as:
 Type and characteristics of the vibration, duration of seismic pulse, frequency
of propagating waves, transmitted energy etc.
 Type of transmitting medium on which the building & surface structure stands,
and

Type of structure and its vibratory character as well as non-structural entity of
the structure.
Damage to any buildings and surface structure due to blast vibration can best be
explained in terms of its response to the passing vibrations. One of the critical
response factors is the amount of differential movement that occurs between
structural members causing strains, which in turn, produce cracking.
Investigation into cause of damage to buildings & surface structure due to O/C
blasting showed that the structural resonance responded to low frequency
ground vibrations, resulting into increased displacement & strain.
Experimentally, it has been verified that if the wave length of the transmitting
wave is long enough compared to the size of the structure (low phase angle) the
entire structure tend to move generally as one.
In India, peak particle velocity (PPV) and frequency of wave has been
considered as the best criterion for evaluating blast vibration in terms of its
potential to cause damage.
Following are the causes of damages to buildings & surface structure due to O/C
blasting:-
i. High magnitude, long duration and low frequency of vibration waves.
ii. Primary or compressional or P-wave produced due to blasting propagating
through the ground materials alternatively producing compressions and dilations,
with particle movement in the direction of wave propagation.
iii.Transverse or shear or S-waves moving the particles in a direction
perpendicular to the wave propagation transmitting through the ground
materials.
iv. Surface waves or ray Leigh or R-waves and Love or L-waves propagating
through the soft rock / soil over hard and competent material.
v. Differential movements of structure due to ground vibration.
vi. Deformation of buildings & structure due to resonance effect i.e. coincidence
of natural frequency of structure with low frequency ground vibration.
v. Compression, tension and shears produced in structure due to ground
movement.
Precautions to be taken to prevent damage to buildings & structures:
i. As far as practicable, buildings & structures should be constructed away
from the blasting zone.
ii. For buildings of historical importance and multistoried structure,
permissible PPV should be lowest to ensure low level of ground vibration.
iii. For ensuring low PPV as well as permissible / safe ground vibration, blasting
operation should be conducted by observing following precautions:a. Charge weight per delay should be less for less intensity of ground vibration
as the later increases with the former.
b. Delay interval between rows should be so arranged that the wave fronts
emanating
from
corresponding
charges
are
separated
avoiding
superimposition.
c. As the bottom initiation generates less vibration as compared to top
initiation, the former system should be adopted.
d. Blast design parameters such as burden, spacing, stemming charge,
bench height, sub-grade drilling, charge length etc. should be optimum in
order to have low level of ground vibration.
e. Charge per delay and charge per round should be restricted for low ground
vibrations.
f. Delay time should be fixed compatible with the type of rocks, the acoustic
properties and period of oscillation of waves.
iv. Practicing controlled blasting techniquesa. Qualified Mining Engineer possessing 1st class certificate holders should be
appointed for conducting control blasting.
b. Sufficient nos. of technical assistance such as blasting over-man, mining
sirdar as well as other person having good knowledge of blasting should also be
appointed for the purposes.
c. Adequate training should be imparted to the persons engaged in control
blasting operation.
d. Controlled blasting technique such as use of nonels, electronic detonators,
muffle blasting, deck charging etc should be practiced to control ground
vibration.
v. Direction of initiation- To have low level of Seismic / ground vibrations,
direction of initiation of blast should be decided after trial and error method.
vi. Charge confinement- Confinement of explosives has significant influence on
generation of vibration. For similar scaled distance, deeper holes generate less
vibration as compared to shorter blast holes.
vii. Duration of blast- It should be less for low level of ground vibration.
In order to ensure effective control over the vibration and related
damages there is a need of regular in house monitoring and the managements
should train the blasting personnel during the experimental study and start
observations on their own during the regular blasting operations.
Q.6. Write short notes on any three of the following:(a) Life of winding rope.
(b) RMR and its application in strata control.
(c) Obligations on manager in case of serious bodily injury.
(d) Illumination in opencast mine.
Ans:- (a) Life of winding rope- Winding rope built to withstand severe
conditions are made of quality steel. Maintenance plays an important role to get
proper life of a rope. Deteriorations such as wear, corrosion, fatigue,
corrosion-fatigue, distortion and plastic deformation badly affects the life of
winding rope.
Reg. 80(4) of CMR’1957 stipulates the max statutory life of winding rope which is
3½ Yrs. Hence, no winding rope, which has been in use for more than 3½yrs
shall be used for winding purposes. However, RIM may allow/permit use of
winding rope for longer period ( i.e. over and above statutory life) if he is
satisfied that due to sparing use any such rope is in good condition.
For seeking permission for extended use of winding rope, mine management
has to submit application accompanied by a copy of certificate containing details
such as breaking load, quality, construction, diameter etc and also by a
certificate as to the strength of the rope. The aforesaid certificate shall relate to
a piece of the rope cut off not more than 3 months prior to the date of
application.
Extension of life of rope may be generally given upto a period of 6 months at a
time if the rope condition is found satisfactory from the test reports, statutory
examination reports and visual examination. In case where there is any
doubt, the winding conditions are adverse, winding duty is heavy and involves
large number by men being wound, the period may be shortened. In case,
where complete test report of the rope sample drawn in accordance with
regulation is not submitted in time with the application, provisional extension
may be given upto a maximum period of 3 months, provided the condition of
rope is found otherwise satisfactory.
RIM may also prohibit the use of winding rope for winding purposes before
expiry of statutory life of 3½ yrs if he is of opinion that the rope has become
unsafe for use in a shaft.
However, in case of kope winder, extension of life of rope is not possible
because of testing of rope samples can not be done due to non provision of
recapping of rope.
Ans-(b) RMR and its application in strata control.
Refer to Q.No.4(b) ( 1st Class -2005)
Ans-(c) Obligations on manager in case of serious bodily injury.
Refer to Q. No.5(b) ( 2nd Class – 2007)
Ans-(d) Illumination in opencast mine.
Refer to Q. No.5(a) (2nd Class – 2007)
Q. 7. Write statutory provisions in respect of the following:(a) Duties and responsibilities of Rescue Superintendent
(b) Rescue Room
(c) Appointment of rescue trained persons in mines their disposition and
accommodation.
(d) Duties of the training officer.
Ans:- a) Duties and responsibilities of Rescue Superintendent- Rule 12 of Mines
Rescue Rules,1985 stipulates the statutory provisions in respect of duties and
responsibilities of Rescue Superintendent as mentioned below :-
i) The rescue superintendent shall be in overall control of rescue station and
rescue rooms served by such rescue station.
ii) He shall ensure that
a) all the rescue equipment & apparatus kept at the rescue station, rescue
room & at the entrance of the below ground mines under his control are
 maintained in perfect order
 inspected by instructors at specified intervals and
 passed fit after tests are conducted and adjustments are made
b) adequate stock of spare parts and supplies are kept for maintaining
rescue equipments and apparatus in perfect order
c) persons selected for initial training and those undergoing refresher training
receive the prescribed course of instructions and practices and are
issued the certificates for the same.
iii) He shall
a) countersign the records maintained by the instructors
b) make periodical inspection of rescue rooms and apparatus and
equipments under his control.
c) perform such rescue and recovery work as may be assigned to him by
the manager/ principal official in the event of an emergency.
d) within 3 days of completion of rescue or recovery work send a report of the
same to RIM or CIM.
e) maintain in a bound paged book a diary and record of results of each of
his inspection and also the action taken by him to the rectify the defects
observed during inspection.
f) submit annual return to CIM & RIM indicating detailed report on the
functioning of rescue station & rescue room under his control with
particular reference to
 type and number of equipment and apparatus provided &
maintained.
 superintendent, instructors, rescue room in-charge and rescue
brigade in position as on 31st December.
 number of rescue trained persons at each mine served by rescue
station and number of such persons given refresher practices and
medically examined with results thereof.
 particulars of emergency attended
 any other relevant matter
It is suggested that a copy of annual return / report submitted by rescue
superintendent is sent to the owner of the mine or the report is routed
through the owner.
Apart from the above statutory provisions, he shall ensure that his rescue
station has an effective rescue cover for all the mines under his station.
Such cover must also ensure that when any station is on a call to one
mine, there must be effective back up arrangements in case of an incident
at any other mine under the same rescue station.
b) Rescue Roomi)
The owner of every below ground mine ordinarily employing more than
100 person belowground and where there is no rescue station within a
radius of 35 km, is required to establish and maintain a rescue room
either exclusively for one mine or for group of mines belonging to the
same owner.
ii)
A rescue room may serve group of mines belonging to the same owner if
the total number of persons ordinarily employed in all such belowground
workings is not more than 5000 and all mines are situated within a radius
of 35 km from rescue room and connected by road with the rescue room.
iii)
CIM may require the owner to establish and maintain a rescue room
irrespective of the number of person ordinarily employed below ground in
case of belowground coal mines having a fiery seam or gassy seam of
second or third degree.
iv)
At each rescue room, there shall be appointed one rescue room incharge and sufficient number of rescue trained persons as per statute.
v)
At-least one rescue trained person shall always be in attendance at
rescue room.
vi)
At every rescue room, there shall be provided and maintained for
immediate use, apparatus and equipment as specified in schedule Il of
Mines Rescue Rule 1985.
vii)
Self contained breathing apparatus provided at rescue room shall be of
the same type and make.
viii)
Every mine shall be connected telephonically with the rescue room
serving the mine. Wherever practicable, wireless or other approved
communication shall also be provided.
Functions of rescue room:1. A rescue room shall provide for the storage, assembly, testing and
adjustments of breathing apparatus and other rescue equipment and apparatus
and for their speedy transport to mines.
2. A rescue room may function as rescue station (if permitted by CIM) for group
of mines having the total number of persons ordinary employed belowground in
excess of 5000, except imparting initial training in rescue work, if such rescue
room is:
a. equipped with requisite additional rescue apparatus including at least 5
extra sets of two hour self-contained breathing apparatus and
b. placed under the charge of an instructor and minimum five no. of rescue
trained persons including one rescue room in-charge are posted.
Ans. (c) Appointment of rescue trained persons in mines their disposition and
accommodation.
Please refer to Q.No. 3(b)(2nd Class 2007)
Ans:- ( d) Duties of training officer-
i) Training Officer shall :a) organize and supervise the training of every person undergoing training
under MVTR 1966.
b) maintain records of the training given to every person and to furnish weekly
reports to the Manager on the progress of persons undergoing training.
c) maintain records of the supervision in respect of practical training on actual
operation specified in schedule l, ll & lll of MVTR,1966.
d) discharge such other duties as may be necessary for the proper compliance
of these rules.
ii) Every training officer shall keep a record of his work and shall, at the end of
every year, forward to the CIM through owner, agent or manager of the mine
a summary of the report of his work during the year.
iii) He has to send regularly the following reports to DGMS and other authorities
as directed from time to time:
 quarterly programme of trainings
 quarterly progress report of trainees.
 monthly performance report of trainees.
iv) He shall plan and prepare schemes for training of workers etc and executed
the same.
v) He shall also ascertain the need of training for each category / class or
trades, prepare with his assistants lesson plans, supervise the training and
finally shall test the trainees and award them certificate if they are found
upto the required standard. He should also follow up the trainees.
Training Officer should not be a reject from production or physically / mentally
handicapped. He must have received training for working as training officer.
Qualities of Training Officers: Good academic record
 Technical knowledge and varied experience
 Aptitude & ability to teach, demonstrate & give good guidance
 Rationality, adaptability, organizing capacity, safety and discipline
mindedness, creativity and motivation to training.
Q. 8.What are the reasons for low productivity in underground coal mines of our
country. Suggest different measures required to improve the productivity.
Ans:- Productivity is conventionally defined as the ratio of output and
input . The term input is not merely confined to manpower alone rather
encompasses a wide domain of resources such as capital, labour, machinery
and materials including raw materials. It is in-fact an index representing the
effective utilization of all the resources used in the process of mineral production.
As per ILO “Productivity is the ratio of output of wealth produced and input
of resources in the process of production.
i) Productivity measurement in u/g :
Different industry uses different indices for measurement of Productivity. In
Coal industry, the index for computing productivity is OMS (output per manshift)
OMS
= Coal Production
Man shift
For calculation of OMS, the manpower deployed in welfare activities, civil
constriction, water supply, health care, recreational facilities, plantation and
security are not considered.
OMS of different mines are not comparable under dissimilar geo-mining
environment and unequal level of mechanization.
ii) Productivity measurement in O/C:In O/C mine, both coal & OB are taken into account white calculating OMS. As
the recommendation of Banerjee Committee, overall OMS in O/C is measures
by the following formula-
OMS =
P+d.x
M(1 + d.S)
Where P = Coal Production (te)
d = density of coal (te/m3)
x = OBR (m 3 )
M= Man-shift (nos.)
S= Striping ratio (m3/te)
However, as per modern concept, productivity of any Organisation is define by
the following formula:Output ( Production)
Productivity =
Input (5M)
5M: Men, Money, Material, Manpower & Management.
Reasons for low productivityThe reasons for low/ poor productivity in Indian u/g mines are listed below:-
i)
Difficult geo-mining condition- presence of geological disturbances,
presence of fire and water, steeply inclined seams, old mines (rate hole and
unscientific mining in past)
ii) Defective/ wrong planning – system deficiencies and mis- match of planning
& mechanization.
iii) Poor technology selection – lack of mechanization, modernization and
standardization.
iv)Irrational manpower- excessive manpower, improper manpower planning,
defective as well as misuse of men/machine, wrong selection of men/machine
for particular job.
v) Lack of planned & preventive maintenance schedule – routine
maintenance, corrective maintenance and preventive maintenance schedules are
not planned & implemented.
vi) Poor availability and utilization of machines – downtime losses with
respect of use of machine arising out of various reasons.
vii) Improper training & retraining:- resulting into loss of efficiency of men &
machine.
viii) Bad work culture – lack of discipline, lack of attitude and motivation.
ix) Non- availability of working faces – insufficient blasted materials.
x) Improper utilization of resources.
xi) Defective communication system.
xii) Socio- economic condition of workmen – Job dissatisfaction/ nonreasonable workload.
xiii) Dis-regard of safety laws- resulting into accident/ incident causing loss of
production, improper detective and incompetent supervision.
xiv) Disparity in wage earnings among of piece rate, time rate and monthly
rated workmen.
Steps for improvements of productivities:For improving productivity in ug mine, the following points should receive
attentions:1) Planning of the mine should be done by fixing the targets for productivity in
different stages of development and depillaring throughout the life of the mine.
During planning itself, the inputs with regards to the selection of technology and
machines should be oriented to the needs of productivity.
2) During planning human elements will be eliminated in circumstances where
the jobs can be performed by machines and as far as practicable emphasis
should be put on automation of different process and operations.
3) To achieve the needs for improved productivity, it is necessary to concentrate
on 3E’s
 Education
 Engineering
 Enforcement
a) Education- Training programmes for Officers, Supervisors and persons
engaged in production activity should include the following:i) Intimate knowledge about the methods of work for assessing the defects and
inefficiencies affecting productivity and taking corrective measures for
overcoming the same.
ii) Knowledge for selection and maintenance of machine as well as selection of
personnel for different jobs.
iii) Science and art of communication of directives for production to the front line
supervisions and other persons involved in the process of productivity.
iv) Training for motivation of workers for developing a sense of belongingness to
the organisation.
v) Training for identifying unsafe conditions and also to avoid unsafe practices
in performance of their duties.
b) Engineering – Engineering plays a vital role in production management. The
areas covered under the heading may include the followingi) Adoption of a sound mining technology which must foresee the impact of the
methods on aspects such as ventilation, fire hazards, risks of explosion &
inundation, strata behavior and strata control techniques, environmental
pollution, system of transport, lighting etc.
ii) While importing technology from foreign countries, correct choice of the
technology keeping in view the geological conditions, physico-mechanical
properties of the strata and the local laws should be made. The technology
should be preferably be imported as a complete package and not in a piece meal
manner.
iii) For purpose of improving productivity, standardization of different machines
should receive attention.
iv) Development of diagnostic and preventive techniques by proper
maintenance of machine shall be encouraged.
c) Enforcement – Enforcement of the formulated measures to secure
productivity is probably the largest area where the officials of the top
management have got to get full involvement for effective management. These
includes:
i) Providing effective organisation for production management
ii) Clean allocation of responsibility within the management structure.
iii) Keeping the work force continued and improving their general and social
condition and job- satisfaction – one important tool for management of
productivity.
In addition to above, the following suggestions would go a long way to help
improve productivity in u/g coal mines.
i) Creation of productivity board/ council for coal industry as a whole and
productivity cell at area / subsidiary level.
ii) Standardization of manpower requirement and material consumption through
work and time study.
iii) Cost reduction through inventory control and materials management.
iv) Modernization of plant and machinery along with improvement in system
and procedure.
v) Creating basic welfare amenities like housing, school, hospital, community
centre be etc should be considered as essential ingredients for an improved
performance.
vi) Innovative maintenance management vis-à-vis equipment utilization.
Afternoon Session
THE MINES ACT, 1952
Examination for Mine Manager’s Certificate of Competency under the Coal Mines
Regulation , 1957
FIRST CLASS
MINE MANAGEMENT, LEGISLATION & GENERAL SAFETY
Sunday, the 17th December, 2006
Full Marks: 100
Time
: 3 Hours
Answer any Six Questions
(All questions carry equal marks)
Q.1.There has been considerable increase in mechanization of underground and
opencast mines. Discuss the adequacy of the provisions of Coal Mines
Regulations, 1957 in respect of qualifications and appointment of Safety
Officers. First Class and Second Class Managers and Engineers in mines.
Assume your own condition.
Ans:- Introduction of large scale mechanization in u/g and o/c mines has become
necessity in recent years because of the following reasons:i. In u/g mines multifarious activities at faces after introduction of face
mechanization are minimized as most of the operations are carried out with the
machines in a sequential manner in order to ensure safety in mines besides
meeting the growing demand of coal.
ii. Availability of huge coal reserve at greater depth, u/g mechanization is a must
for ensuring ever increasing production needs with high safety standards.
iii. The current upsurge in mineral demand has also resulted in massive
mechanization of various mining operation in O/C mines with State of the art
technologies by way of introducing high capacity shovels, dumpers, draglines
etc.
CMR 1957 was framed log back and last amended in 1990.
The statutory provisions in respect of qualification and appointment of safety
officers, 1st class & 2nd class Managers and Engineers contained in Coal Mines
Regulation 1957 are not adequate and needs some amendment. We are
appending below in the table the existing statutory provision vis-à-vis necessary
proposed changes in the present day context of increasing mechanization in
U/G and O/C mines:A. Qualification & appointment of safety officers:Existing Statutory Provisions
i) In all coal mines, having an average
monthly output 5000te, safety officers are
appointed for promoting safe practices in the
mine, on the basis of output, holding the
following qualifications:
Av. Out put( te/month)
a. More than 15,000
b. 10,000 - 15,000
c. 5,000 - 10,000
Mini. Qualification
1st class Mgr’s Certft.
1st & 2nd -do1st or 2nd Class or
deg. or dip.in min.engg.
Adequacy / Proposed changed in
Existing Provision
The existing provisions in respect of
appointment of safety officers is not
adequate. The following additional
provisions should be incorporated in
the statute:i) in case of fiery seam or gassy
seam of 3rd degree, an ACM
possessing 1s class Manager’s
certificate of competency should be
appointed
as
safety
officer
ii) Where special condition – exists, CIM may
permit or require appointment of safety
officer in variation of above provision.
iii) When the CIM is of the opinion that due
to the large size of a mine or other condition
existing at the mine, it is not possible for the
safety officer to attend his duty himself, he
may require the appointment of such number
of persons to assist the safety officer by an
order stating the reasons and qualifications.
B. 1st Class & 2nd Class Managers.
i) Every mine has to be opened, worked or
reopened only under the control, supervision
management & direction of a manager
having been duly appointed by the owner or
the agent having requisite qualification.
ii) In all coal mines, managers are appointed
on the basis of average output, holding the
following qualifications:Av. Out put( te/month)
Mini. Qualification
1st class Mgr’s Certf
1st & 2nd -do1st or 2nd Class or
or Manager’s permit
iii) When special condition exists, CIM may
direct that the manager of a mine in clause
(b) above to be a 1st Class manager’s
certificate holder and the manager of a mine
in clause (c) above to be a 2nd class
manager’s certificate holder.
iv) The scale of appointment of manager as
mentioned at point no.(i) shall remain
unchanged for the succeeding 12 months
even when there is any reduction in the
average output.
v) No person shall act or be appointed as the
manager of more than one mine, except
with prior written permission of CIM. Such a
permission shall be valid for a period not
exceeding 12 months unless renewed.
vi) A person holding an overman’s certificate
may be permitted to work as a manager of
any mine having production less than 600te
a. More than 2500
b. 600-2500
c. less than 600
irrespective of monthly output.
ii) In every mine, the manager shall
be assisted in the work of promoting
safety practices in the mine by a
safety officer who will be senior
most ACM next to the Manager,
possessing
a 1st class Mine
Manger’s certificate. However, in
case of a mine having an average
output in excess of 5,000 te but not
exceeding 10,000 te, the safety
officer shall posses a first class or
2nd class manager’s certificate.
iii) In highly mechanized U/G mines ,
safety officer shall be assisted by
Environment officer possessing 1st
or 2nd class Manager’s certificate for
control of dust, noise and
environment.
The provisions contained in the
statute in respect of appointment of
1st class and 2nd class managers are
inadequate and hence following
additional provisions should be
made:i) In every mine where only pumping
or other preparatory / protective work
is going on belowground and all
other
operations
have
been
suspended, the mine shall be in
charge of a 1st class manager,
particularly in case of fiery mine or
degree lll gassy mine.
ii) A person holding 2nd class
manager’s certificate may not be
allowed to work as manager of more
than one mine if the output of any
mine exceeds 1500 te/ month.
iii) A person holding 1st class
manager’s certificate may be allowed
to work as manager of more than
one mine ifa) the combined output of the mines
does not exceed 7000 te/month.
b) the output of the any one mines
does not exceed 4000 te/ month
and
c) he is assisted by an assistant
manager at the mine other than this
one where he resides, it the output of
that mine exceeds 2500 te/ month.
by CIM for a maximum period of 12 months
unless renewed at an interval of 12 months.
vii) In every mine the average output of
which exceeds 7000te, the under-manager
or assistant manager shall be appointed on
the basis of average output to assist the
manager on the following scale-
iv) In case of highly mechanized
o/c mines, atleast one 2nd class ACM
in each production shift shall be
appointed besides the appointment
of 1st class ACM in general shift for
blasting
operation
and
its
instrumentation.
Av. Output (te/month)
No of ACM’s
v) In case of highly mechanized u/g
a. 7,000 – 10,000
One
mines, such as power support L/W
b. More than 10,000
One additional
working, use of continuous miner etc,
ACM for every
in each shift one 2nd class ACM shall
5,000 te output
be appointed. In addition, one 1st
Or part thereof
class ACM shall be appointed for
in excess of
strata
control
and
ground
10,000 te.
movement monitoring in general
Where the average output exceeds 20,000te shift as overall in-charge.
atleast one of the ACM’s appointed as
above, shall hold a 1st class manager’s
certificate.
CIM may permit or require the appointment
of ACM’s in variation with the above
provisions.
C. Qualification & appointment of Engineers
i. At every mine, where machinery is used, In present context of mining
an engineer, not less than 23 yrs of age, operation both in u/g and o/c mines,
shall be appointed to hold the general charge the aggregate hp of all machinery is
of such machinery and be responsible for its very large due to introduction of high
installation,
maintenance
and
safe mechanization. Under the circums
working. A notice of every such tances, the following statutory
appointment, giving the name and full provision should be incorporated in
particulars of the qualification and experience the statute:of the persons shall be sent to the RIM within i) Scale of appointment of engineers
7 days of the appointment.
in highly mechanized o/c mine shall
ii. In every mine, engineer shall be appointed be as per the following table:
on the basis of hp used in the mine holding a. 10m3 /5m3/3.5m3
For every two
the following qualifications:shovels
shovels- one
Type of Mine
Minimum Qualifications
engineer.
a.O/C mine worked A deg. or equi.
b. Drills
For every four
by HEMM having
qualification in mining
drills- one
aggregate hp of
Engineering from recog
engineer.
all the machinery
nised institution follow
c. 85T/35T dumpers For every 20
exceeding 750 or ed by an orientation
dumps – One
in other case exce course in mining machi
engineer.
eding 500.
nery and not less than
d. Where input cru
A minimum of
1 yrs experience in the
shing and conve
5 engineers
installation and mainte
yor technology is shall be provi
nance of machinery
implemented in
ded.
used in mine.
any project.
Or
ii) Scale of appointment of engineer
A degree or equ. Qualif in highly mechanized u/g mines
ication in electrical and/ shall be as follows:mechanical engineering
from recognised institu
tion and not less than
2 Yrs experience. In
case of diploma holder,
7 yrs experience is
required.
a. L/W face
- One engineer per
face per shift.
- Two engineers/
shift.
b. LHD, CM or
Other mecha
nised operation.
iii) In open cast mines, a person
holding degree in automobile
b) Any other mine A degree on equivalent engineering may be appointed as
in which the
qualification in mining
an engineer.
aggregate hp of
engineering from reco
iv) Persons appointed as an
the all the machin
gnised institution folloengineer should not be permitted to
ery used exceeds
wed by an orientation
perform additional duties of electrical
150
course in mining mach
supervisors except in case of small
inery.
mines for which prior permission of
A degree or equ. Qualif RIM is necessary.
ication in electrical and/ v) Where mine tips, dams or other
or mech. engineering
structures, requiring the services of a
from recognised institu civil engineer, are erected at a mine,
tion and not less than
they should be designed, erected,
6 months experience
and maintained under the
in similar job.
supervision of a qualified Civil
In case of diploma
engineer, who shall be responsible to
holder,2 yrs experience the manager for their safe operation.
is required.
vi) At large mechanized mines, Chief
Engineer should be appointed to coiii. No person shall undertake the duties of an ordinate the activities of the electrical
engineer of more than one mine without prior and mechanical engineering
written permission of RIM.
department. Also a deputy
engineer(maintenance) may be
appointment to
(a) administer and examine the
effectiveness of the managers PPM
scheme.
b) examine the new methods of
routine condition monitoring and
assess their suitability for
implementation in the managers
PPM scheme.
c) Correlate and analyse the
information available and monitor the
failure of equipment, design failure
and subsequent remedial actions to
reduce the machine down – time.
Q.2.(i) What is meant by remote operation of coal face apparatus with pilot core
protection? Discuss the associated voltage and current limits.
(ii) Describe a trans-witch unit used belowground. What area (a) its special
features and (b) the protective devices incorporated in it?
Ans:- i) Remote control circuit with pilot core protectionIn u/g mines at almost every face there are electric motors, coal cutting
machines, ventilating local fans, compressors, pump sets etc. All these coal face
apparatus are switched on and off by means of a remote control circuit known as
pilot circuit. In system of remote control, all switching operations of the power
circuit for starting and stopping the motor are performed not at the motor but at
the circuit breaker which is placed at the safe distance from the face. The
operating switch on the motor operators only low voltage pilot circuit .
The pilot circuit is completed through the trailing cable which supplies
power to the face apparatus. The trailing cables have five cores/conductors,
three power conductors, a pilot circuit conductor and an earth conductor which
serves both to maintain continuity and also to complete the pilot circuit. A
transformer in the gate end box gives supply to the pilot circuit. The typical
values for pilot circuit voltages are 7.5 volts and 12volts.
When the operator operates the pilot switch located in the machine, the
pilot circuit is completed and it energizes the operating coil in the gate end box
placed away from the face at a comparatively safer place well ventilated which
closes the main contactor of the gate end box. Thus the machine operates on
remote control. The pilot circuit is intrinsically safe.
The pilot circuit in the GEB has the following additional features which
ensures protection to pilot core and hence known as pilot core protection.
 An earth leakage trip switch – Preventing power supply to the
apparatus in case of earth leakage.
 An overload trip switch – Cutting off power in case of overload beyond
the designed limit
 A no volt coil – not allowing automatic power supply to the machine
when the power is resumed after interruption.
As per rule 124 of IER 1956, all portable and transportable apparatus used in
underground mines shall operate on remote control from the concerned
switch gear with pilot core protection.
Advantages for use of remote circuit the pilot core protective: Training cable becomes dead when the machine is not running.
 Machine can not self start when the power supply is restored after its failure.
 Machine will not start if earth continuity is interrupted.
 Pilot circuit itself fails if it becomes faulty.
 In case of emergency the pilot switch is near at hand to switch off the circuit
 The circuit is made lead before the live parts are exposed, if the plug attached
to the electrical cable is withdrawn from the socket, the circuit breaker will
automatically trip.
 High voltage arcing during switching on or off the machine at the main
contracts is shifted from the coal face site to the GEB site.
 Machine controller’s function is transferred to the gate end circuit breaker.
 Economy in the machine size.
 Pilot core protection is an additional safe guards in a remote control circuit.
 A pilot circuit is designed as an intrinsically safe circuit.
Associated voltage and curved limits:Voltage limitsi) Pilot Circuits shall operate in the start position at voltage down to 75% of the
declared voltage.
ii) In the run position it shall continue to operate down to 60% of declared
voltage.
iii) With the remote switch in the run position and with a restoration of supply
after failure, the pilot circuit shall not operate at less than 120% of the declared
voltage.
Current limits
The pilot circuit current in the start condition is 125 mA d.c. This is the minimum
current required to energise relay.
Ans:-ii) Trans-switch unit used belowground: With the introduction of coal face mechanization, the number and size of coal
face machines increased tremendously and it became necessary to have large
transformers installed close to the coal face in order to keep the voltage drop
between the transformer and motor to a minimum. Trans switch unit is used for
this purpose.
Virtually all coal face equipment get supply from the FLP transformers used for
supplying intrinsically safe circuits. They are specially constructed with an
earthed screen between the primary and secondary windings to ensure that the
primary voltage can not be connected to the secondary circuit even if there is a
complete failure of insulation.
Trans-switch unit is basically a dry type transformer provided with incoming and
outgoing circuit breakers. It is mobile / portable transformer sub-station mounted
on wheels which moves as the face progress.
It consists of a step down transformer with high and medium tension circuit
breakers attached- all mounted on flanged wheel. An isolator is provided to
permit work on the TSU.
a) Special features of TSU- Following are the special features of TSU used
belowground: Dry type / air cooled
 Certified flame proof
 Built to operate at high temperature using class “C” insulation.
 Capable of withstanding short time overload.
 Fitted with integrated switchgear in the H.V. incoming side and L.V
protection chamber with circuit breakers.
 Robust construction.
b) Protective devices incorporated in TSUFor ensuring safety, the following protective devices are incorporated in TSU:i. Earth leakage and short circuit protection- The LV ends of transformer
houses the earth leakage and short circuit protection devices. On detection
of a fault on the LV circuit, the protective devices automatically trip the HV
Switches.
ii. Overload and earth fault protection- The HV switch also provides
overload and earth fault protection for the transformer.
Q.3. (a) What are bye-laws? How are they framed?
(b) Frame a set of bye-laws for use of continuous miner in a degree-l seam.
Ans:-a) Bye-laws:Bye laws are laws framed by the owner, agent or manager of the mine for a
particular set of conditions, governing the use of any particular machinery or
the adoption of a particular method of working in the mine, when so required
by the Chief Inspector or Inspector, for the prevention of accidents and for the
safety, convenience, and discipline of the persons employed in the mine.
These are complimentary laws which are applicable in a particular situation for a
particular mine to handle the situation by the authority of the mine.
Procedure for framing bye laws:1. The owner, agent or manager of a mine, either on his own initiative or when
asked by the Chief Inspector or an inspector, shall frame draft bye- laws and
submit them to the Chief Inspector.
2. If the drafts bye-laws are not submitted within 2 months of being asked or
having been submitted are considered insufficient, the Chief Inspector or the
inspector may himself propose draft bye-laws or propose such amendments in
the bye-laws submitted as will render them sufficient and send them to the
owner, agent or manager for consideration.
3. If the owner, agent or manager and the Chief Inspector or inspector is unable
to agree as to the terms of the draft bye-laws within two months, the Chief
Inspector or the Inspector shall refer them to the Committee for settlement.
4. When the owner, agent or manager and the Chief Inspector or inspector have
agreed to the draft bye-laws or the differences have been settled by the
Committee, the Chief Inspector or the Inspector shall send a copy of the draft
bye-laws to the Central Government for approval. The Government may make
such modification in the draft bye-laws as it thinks fit.
5. Before approving the draft bye-laws, the Government shall publish them
suitably for informing the persons affected and shall set a time of at least 30
days within which objections may be sent to the Government. The Government
shall consider the objections and approve the bye-laws with or without any
amendments.
6. The bye-laws when so approved shall have effect as if enacted in this Act.
7. The bye- laws so made shall be laid before each House of Parliament while it
is in session for a total period of 30 days (comprising one or more successive
sessions). The parliament can modify or annual the said by laws in the
session(s) in which the 30 days period is completed or in the next following
session. Thereafter the by laws have effect only in such modified form or be of no
effect, as the case may be.
Ans:b) Bye-laws for use of continuous miner in a degree-l seam.A. Machine Operations:1. Continuous Miner shall be operated only by competent person, who has
been properly trained and duly authorised by the manager in writing.
2. A competent person shall examine the Continuous Miner at the beginning of
every shift as per check list provided by the manufacturer for that purpose.
3. Before starting the machine it shall be ensured that no person or any other
obstacles are within the working place of the machine and a pre-start warning
signal shall also be given to warn all the people in the area including operator/
helper.
4. Wherever any inspection is to be made or maintenance are to be done in
job/boom in raised position, a proper support shall be provided under the
job/boom.
5. If power shut off, the supply of every motor shall be shut off immediately.
6. No work shall be done by standing on job/boom.
7. Machine shall be fixed by jacks while cutting operation is going on.
8. Head lights of machine shall be kept on during operation of machine.
9. A log book shall be maintained by the operator and charge shall be given
/taken in writing by the operators.
10. Operator shall keep watch on roof condition also. If any changes noticed, he
shall stop he machine and inform immediately to Mining Sirdar.
B. Precautions against dust:1. Complete set of picks with proper size shall be fitted in cutter head.
2. The speed of cutter head shall be maintained such as to prevent formation of
dust.
3. Water spray system shall be maintained in good working order to prevent
formation and propagation of dust.
4. The spray nozzles shall be kept regularly cleaned.
5. Pyrite band of igneous rock shall be avoided to cut by machine.
6. Cutting of coal shall not be commenced until water spray starts with proper
pressure and quantity.
C. Ventilation:1. At least 284 m3 of air shall be conducted upto 4.5m at every face where
Continuous Miner is being operated.
2. Minimum 0.5m/sec air velocity shall be maintained over the Continuous Miner.
3. Test of inflammable gas shall be made at the face before and during the
operation of Continuous Miner with an approved type of methanometer.
4. Inflammable gas content in the general body of air shall not be 0.5% or more
where Continuous Miner is being operated.
D. Precautions against fire:1. Fire resistant hydraulic oil shall be used as recommended by manufacturer.
2. Sufficient fire fighting arrangement and sufficient number of fire extinguishers
shall be kept near the face.
E. Service and maintenance:
1. Continuous Miner shall be maintained in accordance with the schedule
prescribed by the manufacturer.
2. Before the Continuous Miner is put to work after maintenance, it shall be
thoroughly inspected by the Engineer. A report of every such inspection shall
be recorded in a register kept for the purpose.
F. Electrical:1. Cable shall be connected with motor with suitable connector with interlock
system.
2. Trailing cable shall be handled properly to avoid damage.
3. Continuous Miner operator shall check the trailing cable in beginning of every
shift, if it is found damaged, it shall be replaced by good one.
G. Supervision:1. Every shift shall be run directly under the supervision by an Assistant
Manager.
2. Mechanical foreman shall be posted in each shift for looking after the
Continuous miner.
Q.4.An exploration has occurred in a Degree- lll mine in a depillaring district
with stowing. How will you determine the cause of the explosion and its
point of origin. How would you ascertain whether the explosion has
occurred due to inflammable gas or coal dust or both. Assume your own
conditions.
Ans:Condition assumedSeam being worked – X bottom seam
Depth of working - 100m
Panel being worked – 18 ( depillaring with sand stowing )
Status of stowing – Void more than permissible limit.
Status of gas detector- LMD installed but not functioning.
Status of ventilation – Generally poor
The basic purpose of an investigation after an explosion is to be ascertain the
real causes of such explosion to prevent its recurrence, revealing unexpected
hazards and combating the same. All the explosion evidences shall be carefully
collected. Some of the evidences may be conflicting in nature due to the effect of
backlash.
While determining the cause of explosion and its point of origin, the following
factors shall be taken into account:
 evidence of survivors.
 history of affected district.
 kind of work being done at the time of explosion.
 evidence gathered in inspection after explosion.
I shall follow the following procedure for explosion investigation :
1) It will be ensured that during rescues operations, evidence not to be disturbed
except for actual rescue work.
2) Observations made during rescues operations shall also be kept noted.
Methods of investigation:There are two complimentary methods of approach for making investigation after
an explosion:
a) Intuitive approach – This is based on experience and knowledge of the mine
and the mining operation in progress. This is theoretical approach. For this
purpose, I shall talk to Manager of the mine and gather information from
them.
b) Analytical approach – This is required to be done for a perfect investigation,
practical and scientific, which relies mainly on the observation made for
violence, evidence of burning, fires, coked dust etc. This is based on
dispassionate survey of all the evidence recoverable.
A. Seat of Origin of Explosion:I shall try to locate the area from which explosion violence appears to have
radiated. For this purpose, evidence of violence, evidence of burning, evidence of
coked coal dust, evidence of presence of fire damp, position of equipment and
victims, collection & analysis of air samples & examination of roadway dust shall
be studied and evidences collected.
The following investigation shall be made in underground affected district:
i) Evidence of violence – Violence caused by the explosion and the direction of
travel of the force of the explosion are observed from the movement of the heavy
objects and bending of fixed weak objects.
Violence may appear to radiate from a zone. All evidences of motion and
bending are separately recorded on a plan for analysis in light of other
information Generally, violence is less near the site of origin of explosion and
damage is greatest far away.
ii) Evidence of burning – Evidence of burning is studied and the max. burning
effects will be observed at places where the flames of an explosion have
lingered. As flame passes very rapidly, evidence of burning is not available on
heavy materials. The most sensitive materials are fibrous edges of papers, hairs
on human skin etc. Charring of timbers are found only where the flame had
lingered. This is done with good magnifying glass and under microscope to find
scorching. Doubtful specimen is examined in the laboratory.
iii) Evidence of coked coal dust- Samples of coal dust collected within and
beyond the suspected limits of explosion and examined under microscope to find
signs of exposure to heat confirm direction and passage of flame travel. Some
dust is coked in situ, others carried forward by the blast is impacted on surfaces
facing the origin and coked there, whilst yet other dust, originally raised as a
cloud, is coked and thrown back by the flame so that it is deposited on surface
facing away from the origin.
iv) Evidence of presence of fire damp- Continued issue of CH4 after an
explosion may be due to disturbance of strata by the explosion. They however,
indicate that gas was near at hand and may have been present.
v) Position of equipment and victims - Position of the victims and equipment in
relation to their normal or probable working place might suggest operation being
carried out, such as coal cutting, shot-firing, repair of drill, switch or other
machinery. Posture, nature of injuries and cause of death, whether by burning,
violence or CO poisoning, may give evidence of the course and nature of
explosion. Burning is usually heavy near the origin, violent injuries farther away,
poisoning by CO off the direct path of explosion.
vi) Collection & analysis of air samples – Analysis of samples of atmosphere
taken immediately after explosion is helpful to establish extent and nature of
explosion. Occurrence of firedamp in after damp is not a proof of its presence
prior to explosion, but it is a proof that gas was near at hand. Presence of dead
ends, unventilated headings, goaf edges, disused workings, and examination of
adjacent areas and holes drilled in adjacent strata may reveal source of firedamp
or feeders of gas. This is examined in the light of immediate past history.
vii) Examination of roadway dust- Evidence as to the composition of roadway
dust, the result is compared with those which were analyzed before the
explosion.
All the evidences / data obtained during the investigation are plotted on a large
scale plan. On this plan reduction of evidence is examined.
Such examination gives a general idea about the origin of the explosion but the
exact seat/origin of the explosion will not be known until the cause of ignition is
found.
Source / Cause of ignitionIn the area narrowed down for the origin of the explosion by study of the plan,
searches are made for all possible causes of ignition. While making such
searches, considerations are made regarding the causes which might be
associated with the particular work which was being done in that area at the time
of explosion.
All lamps and electrical equipment are withdrawn for examination/extensive tests
and if it is too heavy, examined on the spot by a scientific agency. All the causes
namely naked light, shot firing, electrical spark including static spark, frictional
spark, defective safety lamp, spontaneous heating, blown-out shot, tampered
FLP apparatus, tampered protective device in electrical switch gear, defective
machinery like drill, opened drill & meggar etc. are considered before making any
final conclusion.
After collection of results of examination, a formal unbiased enquiry are made in
light of full evidence.
It is usually a firedamp explosion or an explosion in which firedamp and coal dust
have taken part. For coal dust explosion, by far the commonest source is a
firedamp explosion and the result is a mixed explosion. Explosion involving only
coal dust is rate- it requires simultaneous formation of coal dust cloud and
striking of ignition source such as blown-out shot, breakdown of electrical
apparatus or cable burst by run-away tubs.
Difference between coal dust and firedamp explosion
i)
Examination of Trickett’s Ratio From analysis of samples of after damp, Trickett’s Ratio are calculated by
the following relation:
TR=
CO2 % +.75 CO % - .25 H2 %
O2 % used
T.R. <
>
0.5 indicates firedamp explosion
0.85 indicates coal dust explosion
0.5 to 0.85 indicates mixed explosion.
2) Extent of affected area:
A gas explosion is localized. It takes place in a district or a gallery, where
blowers or out bursts or other type of gas emission occur. But a coal dust
explosion travels through whole mine, especially through dusty intake
roadway embracing fresh O2.
3) Presence of CO:
In methane explosion, CO2 is found entirely but in coal dust explosion a large
amount of CO is almost always present.
4) A purely gas explosion leaves no traces distinctive of CH4 but a coal dust
explosion leaves coked coal dust.
5) In a gas explosion, worker dies due to burning or due to suffocation on
account of O2 deficiency. But in case of coal dust explosion, workers die due
to CO poisoning and violence. They are bodily thrown out from one place to
another.
Q.5. Write short notes on :
(i) Initial and periodical medical examination
(ii) Workmen’s Inspectors and their duties.
(iii) Medical attention in case of injury.
(iv) Disability allowance and compensation for occupational disease.
Ans:- i) Initial and periodical medical examination1) Type of examination and frequency. Mine management shall arrange for a) IME of every new person seeking employment in the mine unless he has
undergone a similar examination in another mine in previous 5 Yrs.
b) IME of all persons employed in the mine. One-fifth of the persons are to
undergo such examination every year so that all such employees are covered
within 5 Yrs..
c) PME of all persons employed in the mine at intervals of not more than 5 Yrs.
For persons engaged in mining and milling of asbestos Ore, the PME shall be
done at least once in every 12 months.
2)Procedure of Examinationa) Notice : The Manager of the mine shall give at least 20 days notice to the
employee (in Form M). For new recruits the period may be shortened. A copy of
the notice shall be sent to the examining authority (MO of the mine/ MO employed
by the owner/state of central govt. medical officer not below the rank of Asst. Civil
Surgeon). In case of PME, the previous medical certificate shall be sent to such
authority. If the person fails to report for a reasonable cause, the manager shall
give him another chance by serving a notice (in Form N) 10 days in advance.
b) If the person fails to turn up for examination even after second notice, he shall
be issued a show cause notice by the manager. If the explanation is satisfactory,
he will be given a third chance, if explanation is unsatisfactory, his service shall
be terminated.
c) Identity: The candidate shall submit 3 copies of passport size photograph
for identity at the time of examination.
d) Women Candidate: They shall not be examined by a make medical
practitioner without her consent, except in the presence of another woman.
e) Standard: The medical examination shall be as per the standard laid down in
form P and P1 of the Mines Rules.
f) Certificate: The examining authority shall send or deliver two copies of
certificate to the manager/the employee, and retain third copy with him.
g) Retention of certificate: The medical certificate including all medical exam
records with medical history and job details to depict the occupational dust
exposure profile shall be retained by the manager upto 10 years after
employment ceases. If the employee joins another mine, its manager can request
and get the certificate from the manager of previous mine.
h) Persons found unfit shall not be employed after 30 days after the medical
examination unless he has filed an appeal to manager. A person found unfit can
appeal to appellate medical board for re-examination( to be arranged by
manager with 30 days).
i) Re-examination: 2 notices of 15 days time but no 3rd notice shall be given.
Fee shall be paid by appellant if found unfit. After re-examination, if found unfitno employment after 30days.
j) Cost of medical examination, shall be borne by the owner of the mine.
As per recommendation of 10th conference on safety in mines, the following
additional provisions should be made for IME &PME:







IME should be made mandatory for all mining employees whether
permanent, temporary or contractual, before they are engaged in any
mining job.
The frequency of PME should be brought down from existing 5 yrs to 2
yrs for the mining employees above 45 yrs of age.
Each mechanized mine should engage at least one qualified medical
officer for every 500 employees and thereafter, one for every 1000
employees.
One of the medical examinations of every person should be arranged
within one year of his superannuation.
Standards IME & PME shall be suitably modified in order to ensure early
diagnosis of diseases caused due to employment in mines.
Special tests should be included in the PME for employees exposed to
specific health hazard.
Mining companies having mechanized mines are required to computerize
records of the PME.
Ans: ii) Workmen’s Inspectors and their dutiesA workmen’s inspector is a qualified representative of workmen of the mine so
designated by the owner, agent or manager in consultation with the registered
trade union of the mine to carry out inspection of the mine on behalf of the
workmen.
There shall be provision of 3 workmen inspectors ( one each of mining operation,
electrical installations and mechanical installations) in every mine where 500 or
more person are ordinarily employed. When the number of person employed in
the mine exceeds 1500, one additional workmen’s Inspector (mining) shall be
provided for every additional 1000 persons or part thereof. There has to be a
panel of substitutes 3 persons also.
As per recommendation of 9th safety conference, all mechanized mines and
mines using HEMM for exploitation of mineral’s where 100 or more workers are
employed, should appoint workmen’s inspectors.
Qualifications:- (1) Holder of Overman’s certificate in case of mining, an
Electrical Supervisor’s certificate holder for electrical aspect and a person of
equal rank for mechanical installations/equipment. He should have minimum of 5
year’s experience in mines including atleast 2years experience in that particular
mine, and he should have undergone an orientation course as per the syllabus
approved by the DGMS ( 30 lectures of 2 hrs. duration)
Role. (a) To supplement efforts of DGMS
(b) To correct attitude of all.
Duties of Workmen’s Inspector:(1) To inspect all shafts, inclines, roads, work-places and equipment, including
equipment for conveyance and transport of men.
(2) To inform the manager and the Inspector and to suggest remedial measures
in case he notices any urgent and immediate danger.
(3) To accompany the inspector in his complete Inspection of mine, and also
during such other inspections as may be considered necessary by the inspector.
(4) To investigate into accident and dangerous occurrences in or about the
mine/ to be informed forthwith by management in case of such incidence.
(5) To act as a member of the Pit Safety Committee.
(6) To record results of his inspections and furnish the same to the manager.
Manager, agent or owner has to put remarks within 15 days on his inspection
report.
Ans. iii) Medical attention in case of injury: Mining, being the hazardous
industry poses threat to the safety of workmen. Rendering first aid in time to the
persons receiving injury in mining operation is vital in saving life.
First aid is the first assistance or treatment given to a casualty for any
injury or sudden illness before the arrival of an ambulance or qualified
medical expert. It may involve improvising with facilities and materials available
at the time. First aid treatment is given to a casualty:
 To preserve life
 To prevent the worsening of the condition
 To promote recovery
Rule 45 A of mines rules,1955 elaborates the following provisions related to
medical attention in case of injury:
a) Every person receiving an injury in the course of his duty shall, as soon as
possible, report the same to an official. If he is not in a position to report the
same to an official, it shall be the duty of the person who first comes to know of it
to report the same to an official. The official shall make such arrangements for
rending first aid to the injured as may be required. If in the opinion of the official
the injure is of such a nature as to require immediate attention by the medical
practitioner, he shall arrange for the medical practitioner to be called.
b) If an official who is required to carry a first aid outfit receives information
about injury to a work person, he shall himself attend to the injured person.
c) It shall be duty of the person in charge of the nearest first aid station to
render necessary first aid to injured person.
Ans:iv) Disability allowance and compensation for occupational disease - If
during occupational health survey authorized by the Chief Inspector or an
Inspector or an Inspector a workman is found to be medically unfit, he shall be
entitled to medical treatment at the cost of the owner, agent and manager with
full wages. If after treatment also he is declared medically unfit to discharge the
duty which he was discharging in a mine immediately before presenting himself
for such examination and such fitness is directly ascribable to his employment in
the mine, he shall be given an alternative employment. If no such alternative
employment is immediately available, such person shall be paid ‘disability
allowance’ at the rate of 50% of the monthly wages that he was in receipt of
immediately before presenting himself for the medical examination.
Disability Compensation: If a person as above decides to leave his
employment in the mine, he shall be entitled to compensation as may be
admissible under the provisions of the Workmen’s Compensation Act, 1923, as
contracting of such diseases is deemed to be an injury by accident under the Act.
In case the disease is not covered under schedule III of that Act, he shall be paid
by way of disability compensation at the same rates as provided that Act as if it
is an injury.
Q.6. Describe the provisions of the Mines Act 1952 in respect of the following:
(i) Duties & responsibilities of owners, agents and managers.
(ii) Powers of inspectors of mines.
(iii) Annual leave with wages.
Ans: i) Duties & responsibilities of owners, agents and managersa) The owner and agent of every mine shall each be responsible for making
financial and other provisions and for taking such other steps necessary
for compliance of statutory provisions. They shall also be responsible for
proper provision and maintenance of crèche, canteen & pit head bath.
b) The owner, agent and manager shall be responsible to see that all operations
carried on in connection with the mine are conducted in accordance with the
statutory provisions.
c) In the event of any contravention by any person whosoever of any statutory
provision, except those which specifically require any person to do any act /
thing or prohibit any person from doing any act/ thing, besides the person who
contravenes, the owner agent and manager shall be deemed to be guilty of
such contravention unless he proves that he had used due diligence to
secure compliance with the provisions and had taken reasonable means to
prevent such contravention.
The above mentioned persons may not be proceeded against if it appears on
enquiry and investigation that he is not prima facie liable.
d) Every owner, agent and manager shall
 afford the CIM, RIM, IM and every person authorised by inspectorate all
reasonable facilities for making any entry, inspection, survey,
measurement, examination/enquiry under the statute.
 provide / afford all necessary facilities for OHS.
 borne cost of medical treatment with full wages during the period of
such treatment of any person found medically unfit and also provide
alternative employment if declared medically unfit.
Ans:-ii) Powers of Inspectors of Mines- The powers vested with Inspectors of
Mines are given below:a) The Chief Inspector and Inspector of mines may
 make examination and inquiry to ascertain whether the statutory
provisions are observed in the mines.
 enter, inspect and examine any mine at any time by day or night.
 examination into and make inquiry with respect to state and condition of
any mine, the ventilation of the mine, sufficiency of bye-laws and matters
relating to health, safety and welfare of the persons and may take
statements of any person.
 exercise powers as may be prescribed by regulations.
b) They may search any place and take possession of any material or plan,
section, register/record if they believe that offence has been or being committed.
c) They may undertake safety and occupational health survey in a mine at any
time after giving notice in writing to the manager of the mine.
d) Powers of Inspectors under section 22 –
 For any matter for which no express provision is made in statute and it
appears to the CIM or Inspector that such matter, thing or practice is
dangerous to human life or safety or defective so as to threaten the
bodily injury of any person in a mine, he may give notice stating the
particulars of danger and requiring the same to be remedied in a
manner and within the time frame as specified in the notice.
 If mine management fails to comply with the terms of notice, the inspector
may be order in writing prohibit employment of persons except those
whose presence is necessary for securing compliance with the terms of
the notice.
 If depillaring or stopping operations are likely to cause crushing of pillars
or premature collapse of any part of the workings or if adequate
provisions have not been made against fire or flooding, the inspector may
prohibit the extraction or reduction of pillars or blocks of minerals in
any mine.
 If the CIM or inspector authorized by CIM is of opinion that there is urgent
and immediate danger to the life and safety of person, he may, by
order in writing containing a statement of the grounds of his opinion
prohibit employment of person in any mine till the removal of dangers.
(e)
Power to prohibit employment in certain cases under section 22A.
 For any matter relating to safety for which express provision is made in
the statute and mine management fails to comply with such provisions, the
CIM may give notice requiring the same to be complied with within such
time or within such extended time as may be specified.
 If mine management fails to comply with the terms of a notice, the CIM
may order prohibition of employment of persons in the mine.
Ans- (ii) Annual leave with wagesSection 52 to Section 56 of mines act,1952 stipulates detailed provisions in
respect of annual leave with wages popularly known as earned leave which are
appended below:
1) Entitlement and quantum of leavea) Every person employed in a mine who has completed a calendar year’s
service shall be allowed, during the subsequent calendar year, leave with wages,
calculated at the rate of –
 for persons employed belowground, 1 day for every 15 days of work
belowground.
 for other persons, 1 day for every 20 days of work performed by him.
b) A calendar year’s service shall mean in case of a person employed
belowground 190 attendances and in case of other persons a minimum of 240
attendances.
c) A person, whose service commences otherwise that on 1st January shall be
entitled to leave with wages in the subsequent calendar year at the rates
specified above if i) in case of a person employed belowground, he has put in attendance for not
less than half of the total number of days during the remainder of the calendar
year, and
ii) in any other case, he has put in attendances for not less than two-thirds of
the total of days during the remainder of the calendar year.
2) Accumulation of leave- The leave, not taken by any person to which he is
entitled in any calendar year, shall be added to the leave to be allowed to him
during the next calendar year. However, total leave accumulated any time, shall
not exceed 30 days. At the same time, if any person has applied for leave with
wages but has not been given such leave by the granting authority due to
exigencies of the situation, the un-availed leave shall be carried forward without
any limit.
3) Application for leave- Written application for leave with wages earned or
accumulated should be made to the manager at least 15 days before the date
from which leave is required. A person can take earned leave maximum three
times in a calendar year. An application made for leave with wages 15 days in
advance shall not be refused unless the granting authority is of the opinion that
owing to the exigencies of the situation the leave should be refused.
If a person wants to avail himself of the leave with wages, due to him, to cover a
period of illness, he shall be granted such leave even if the application for leave
is not made 15 days in advance.
4) Wages for the leave period- Wages for the earned leave period shall be
paid at a rate equal to the daily average of his total full-time earnings for the
days on which he was employed during the month immediately preceding his
leave, exclusive of any overtime wages and bonus, but inclusive of any
dearness allowance and the compensation in cash, including such
compensation, if any accruing through the free issue of food grains and other
articles, as the employee may be entitled to for the time being. If no such
average earnings are available, then the average shall be computed on the basis
of the daily average of the total full-time earnings of all persons similarly
employed for the same month.
5) Payment of leave wages in advance- Any person who has been allowed
leave for more than 4 days, shall be paid the wages for the period of the leave
allowed before his leave begins.
6) Leave wages at termination of service etci.) If the employment of a person is terminated before he has taken the entire leave to
which he is entitled upto the day of termination of his employments or if such person,
having applied for having not been granted such leave quits his employment, before he
has taken the leave, the owner, agent or manager shall pay him his due leave wages.
ii) The un-availed leave of an employee shall not be taken into account for computing
the period of any notice required to be given before the termination of his employment.
iii)Where a person employed in a mine (a) is discharged or dismissed from service or
(b) quits his employment or (c) is superannuated, or (d) dies while in service, he or his
heirs or nominee, as the case may be shall be entitled to wages in lieu of leave due to
him, if 
in the case of a person employed belowground in a mine, he has put in attendance
for not less than one half of the total number of days from the date of his
employment to the date of his discharge or dismissal or quitting of employment or
superannuation or death and
 in any other case, he has put in attendance for not less than two- third of the total
number of days from the date of his employment to the date of his discharge or
dismissal or quitting of employment or superannuation or death.
Payment of such wages shall be made by the owner, agent or manager of the mine, at
the rate specified above, where the person is discharged/dismissed/quits
employment/superannuated, before the expiry of the second working day after such
discharge/ dismissal quitting of employment / superannuation, as the case may be and
where the person dies while in service, within a period of two months of his death.
7. Register of leave with wages and notice of leave due- A record of leave with
wages shall be maintained in respect of every employment in Forms G and H of the
Mines Rules 1955. On or before 20th February every year, the owner, agent or manager
shall exhibit a notice at the office of the mine ( in Form L of Mines Rules) showing leave
with wages due to each person employed in the mine calculated upto 31st January.
Q.7. What are statutory provisions in respect of :
(i) Precautions after a fire has broken out.
(ii) Danger from underground inundation.
(iii) Splits and airways.
Ans:- (i) Precautions after a fire has broken out.
Reg.119 of CMR,1957 makes detailed provisions regarding precautions to be
taken after a fire has broken out, which are appended below:(1) (a) When there is any indication that fire has broken out, effective steps shall
be taken, without delay, to deal with the fire and all persons shall be withdrawn
from the mine excepts those who are required to deal with the fire.
No person, except those required for dealing with fire, shall be readmitted in the
mine until the fire has been extinguished or effectively sealed off and
examination has been made by Manager or ACM and the mine has been
declared to be safe. Such examination, after the area has been sealed off,
should include the collection and analysis of air samples from behind the sealed
off area. A report of such examination shall be maintained in the register kelp for
the purpose. However, RIM may permit the employment of other persons also.
(b) The above examination shall be made with approved flame safety lamp and
a cage containing suitable birds or approved apparatus. Only approved
safety lamp or torch shall be used.
2) During fire dealing or sealing of fire area :
a) a competent shall be present on the spot throughout.
b) adequate precautions shall be taken to prevent danger to persons from any
noxious, asphyxiating or inflammable gases, flame, steam and ejected or rolling
down hot material, explosion of water gas and falling into crevices or potholes
that may occur in the area on fire.
c) there shall be kept available at or near all places belowground(i) adequate number of self rescuers and atleast two smoke helmets or
other suitable apparatus for use in emergency.
(ii) a cage containing suitable birds or other means of detecting carbon
monoxide gas approved by the Chief Inspector and
(iii) a flame safety lamp or other means of detecting carbon dioxide gas and
oxygen deficiency, approved by the Chief Inspector.
3) The manager of every mine shall prepare and establish a detailed scheme for
the provision and maintenance of suitable fire fighting arrangements for the
prevention, detection, dealing and control of any heating or fire; for the
examination and maintenance of the protective measures taken to control or
isolate a fire or heating and for ensuring safety of persons engaged in the said
operations.
The scheme shall be suitably modified and kept updated as the situation
warrants:
The scheme may contain:
(a) Organisation plan clearly stating the line of command and the
responsibilities of each person in cases of emergency situations,
(b) equipment plan clearly stipulating the equipments make and type,
capacity, location, correct operation and field of operations.
(c ) action plan clearly stipulating alarm & communication system, system of
notifying the authorities, the duties of each person involved, when and how the
equipment shall be used and when how the action shall be carried out.
(d) Plan for training of persons & for drills.
Ans:-(ii) Danger from underground inundationReg.127 of CMR’1957 makes the following statutory provisions to guard against
dangers from underground inundation:1) Proper provisions shall be made in every mine to prevent irruption of water
other liquid matter/wet material likely to flow from the workings of the same mine
or adjoining mine and to prevent accidents while drilling bore holes for probe or
release of water / wet material.
2) A scheme of working shall be prepared and implemented when workings are
to be madea) (i) below an upper seam or section
(ii) at a place which is at a lower level than a body of water in the lower seam
or section.
(iii)advancing towards a fault which passes through an upper seam or section
which contains or may contain an accumulation of water.
b) any water bearing strata.
3) CIM’s permission shall be obtained when a working is to be advanced within
60m (shortest distance) of any other working (excluding that which has been
physically examined and found to be free from accumulation of water etc.).
Workings shall be advanced strictly as per the approved plan, in approved
method and as per the conditions laid down.
For getting the permission, information regarding outline, depth of workings,
proposed method and layout, presence of geological disturbances and other
particulars shall be acquired and submitted to the DGMS with plans and
sections.
4) If at any place in the mine (even outside the restricted area), seepage of
water, not normal to the seam , is noticed or there is suspicion or doubt of such
seepage, work shall be stopped forthwith and intimation sent to the CIM/RIM.
For resumption or work permission of CIM is necessary.
5) Workings done within 60m of accumulation of water or done after noticing
seepage of water, shall have height and width not exceeding 2.4m and there
shall be maintained at least one bore hole near the centre of the working
face and sufficient flank bore holes on each side where necessary, bore
holes above and below the workings at intervals of not more than 5m. All such
bore holes shall be drilled sufficiently close to each other to ensure that the
advancing face will not accidentally hole through into a working containing
water or liquid matter or any material that is likely to flow when wet and shall be
maintained and shall be constantly maintained at sufficient distance in
advance of the working and such distance shall in no case be less than 3m.
These precautions shall be carried out under the direct supervision of an
official, having Manager’s or Overman’s Certificate specially authorised for the
purpose This actual dimension/details of holes shall be recorded and plans
maintained.
Ans:-(iii) Splits and airways- The purpose of adequate ventilation is to clear
away smoke and steam, to dilute gasses, to harmless proportion, to provide air
containing sufficiency of oxygen and to prevent excessive rise of temperature or
humidity likely to be harmful to health of persons. To fulfill this, Reg.135 of
CMR’1957 makes the following provisions:
i)
Every mine shall be divided into such no of districts/splits as to ensure
that separate current of fresh/intake air is made available in every such
district/split. This means that every ventilation district must have
separate intake & separate return airways.
ii)
The intake air shall be so arranged as to travel away from all stagnant
water.
iii)
For fiery seam or gassy seam of 2nd / 3rd degree, there shall be provided
two main intake airways for every ventilating district. One of the two
intake airways shall be used as traveling roadway. However, the RIM
may grant exemption from the provision if situation permits.
iv)
Every connection between a main intake airway and a main return airway
shall be provided with at-least two doors so spaced that whenever one
door is opened, the other door can be kept closed. Steps shall be taken to
ensure that at least one of the doors is always closed. Any such
connection which has ceased to be required shall be effectively sealed.
It has been observed that additional airways result in savings & increased intake
air. In one case when the number of splits at the shaft bottom was increased to
three, the increase in intake air was found 20%.
Q.8. A thick coal seam that was developed in two sections was being extracted
by opencast mining. There was active fire on a coal face and a shovel was
under operation at a distance of 50m on a lower coal bench of the same
seam. Suddenly, water gas explosion occurred and the shovel was covered
by hot ash/dust etc. causing instantaneous death of the shovel operator.
Write an enquiry report of the accident suggesting out contraventions,
responsibilities and suggestions to prevent similar accidents in future.
Assume you own conditions.
Ans:Enquiry Report
Ref.No………………………
Date………...
To,
The Manager,
“ X “ OCP.
Sub:- Enquiry report in respect of fatal accident involving
one shovel operator in X-open cast working due to water
gas explosion.
Dear Sir,
As desired vide your letter no………………… dt…………… I am enclosing
herewith the detailed enquiry report in respect of fatal accident in X-O/C working
due to water gas explosion indicating the cause and circumstances attending to
the accident, contraventions of statutory provisions, responsibilities and
suggestions to prevent similar accident in future as an annex.l . I am also
enclosing the accident plan showing the site of accident along-with photo graphs.
Yours faithfully,
Encl: As above.
( A.C.M. )
“X” OCP
Annexure - l
Detailed Enquiry Report
Assumption of Conditions:________Colliery had two OCPs namely, the pilot OCP(X –OCP) and main
OCP.(Y – OCP). The accident occurred in pilot OCP which was located in the
trough of two strike faults running east-west. The strata dipped at 4º to 5º in
northerly direction. No. 3 seam was 9m thick and occurred at depth of about
12m. No. 2 seam was about 35m thick and occurred 6m below no. 3 seam. The
quarry was worked with shovel and dumpers and was 52m depth .
The coal benches in the south side of the pilot quarry (which was close to a
major fault) almost always had problems of fire since long. At the time of accident
the south side face was on fire in patches over a length of 270m.
I _______________, ACM, X OCP inspected the place, where this
accident occurred and enquired into the cause and circumstances connected
with the same.
i)Introduction & information :- The accident occurred in X OCP of M/s……. on
……… at about 3.00 P.M. in 2nd shift when 14 persons under the supervision of
an overman and two mining sirdars were engaged at the floor of the 2 nd lower
coal bench in various activities at a distance of 50m from the south quarry face of
1st coal bench. I received information about the accident at about 4 P.M. when I
was in my residence.
ii)Background information:The depillaring permission was obtained for
extraction of developed pillars by open cast method with shovel dumper
combination using deep hole blasting. The usual practice at X OCP was to
expose the developed coal pillars by removing OB, extract the pillars and then
cover up the exposed area by dumping the OB material to control heating.
iii)Occurrence of accident:- At about 3.50 PM, one of the worker’s noticed that
large quantity of hot ash and dust ejecting from the coal face of southern side of
the quarry spreading over a wide area including lower coal bench at a distance of
50m from coal face of top bench. All the persons at lower coal bench escaped
safely but shovel operator buried under ejecting hot ash and dust etc.
iv)Rescue & Recovery:- Machines were deployed immediately for removal of
the debris. The dead body of shovel operator could be removed after 5 hours.
v)Inspection & Enquiry: - On receiving information about the accident, I
immediately inspected the place of accident along with the other supervisory
staff and workmen. I made detailed observations and some measurements at
the place of accident and prepared a sketch of the place of accident giving
leading dimensions. Photographs of the place of accidents were also taken.
The sketch and photograph is attached with the report. I also examined
witnesses and recorded their statements.
vi)Analysis of evidence/ Observations: - From the inspection of place of
accident, careful study of DGMS permission and analysis of evidence collected,
the following were revealed:a) Prior to accident there was heavy rainfall for 4 days.
b)There was a slide of material in which huge quantity of material came down
along the south side over a width of about 20m. This slide might have been
caused by fire, heavy rain, presence of fault, plane, water entering through wide
cracks on the surface etc.
c)Active fire was noticed in the exposed u/g galleries as well as in the pillars on
all sides.
d) The entire fire area was not covered / blanketed with 1m thick alluvium as
advised by DGMS in permission letter.
vii)Cause of Accident:- The water gas explosion occurred due to formation of
explosive mixture in the fire affected area.
There was a possibility of generation of superheated steam at high pressure.
The heavy rain on 4 days prior to the accident would have clogged the
cleavage planes and other natural fissures in the coal and associated rocks and
steam superheated to high temperature could be entrapped at high pressures
in interstices of ash and strata. Probably high pressure steam confirmed within
the fire zone played the main role in the ejection of hot ash and dust etc.
The water gas must have formed in the void created by the burning of the coal
seam and air entering the fire area must have rendered the mixture explosive
which was ignited by the burning of coal thus causing water gas explosion.
viii)Contraventions of statutory provisions:- Regulation 119, 120 & 122 of
CMR 1957 read with DGMS permission letter for extraction of pillars by open
cast method were contravened in respect of the following:a) The fire area was not covered / blanketed with 1m thick alluvium and suitably
compacted to prevent breathing of air.
b) Adequate precautions was not taken against explosion of water gas as
required.
c) Sufficient supply of sand of incombustible material was not provided.
d) Adequate precautions was not taken prevent the passage of air from the
surface into the fire area through any broken strata.
ix)Responsibilities:- Enquiry into the accident revealed that if the statutory
provisions for precautions against fire were taken and DGMS conditions were
fully comply, the accident could have been averted.
The following persons are considered responsible for the accident:a)Agent- In contravention of provisions of section 18(1) and 18(4) of Mines Act
1952 read with regulation 190 of CMR 1957, agent of mine failed to effectively
implement that all operations carried on in connection with the mine are
conducted in accordance with the provision of mines act and regulation made
their under.
b)Manager- In contravention of provisions of reg. 119,120, 122 and 41 of CMR
1957 read with sec. 18(4) of mines act 1952, the manager failed to effectively
implement the conditions imposed by DGMS for blanketing of fire area.
c)ACM- In contravention of provisions of reg. 119,120, 122 and 42 of CMR
1957, the ACM failed to effectively implement the conditions imposed by
DGMS for blanketing of fire area..
x) Suggestions to prevent similar accident in future:In my opinion, the following steps should be taken to avoid recurrence of
similar accidents in future:
i) The conditions specified by the DGMS in statutory permission letter should be
strictly followed.
ii) In an open cast mine as soon as a fire is notice, it should be dug out and
quenched. Alternatively, measures should be taken to prevent its spread by
not allowing access of air to the fire i.e blanketing.
Morning Session
THE MINES ACT, 1952
Examination for Mine Manager’s Certificate of Competency under the Coal Mines
Regulation, 1957
SECOND CLASS
MINE MANAGEMENT, LEGISLATION & GENERAL SAFETY
Sunday, the 17th December, 2006
Full Marks: 100
Time
: 3 Hours
Answer any SIX Questions
(All questions carry equal marks)
Q.1. What are the provisions of Mines Act, 1952 for the following:(a) Hours of work belowground
(b) Employment of woman.
(c) Extra wages for overtime.
Ans:- (a) - Hours of work belowground.
Please refer to Q.No. 1(a) ( 2nd Class – 2005)
Ans:- (b) Employment of women.
i) No women can be employed belowground. However, women employed in
health and welfare services and who in course of their duties, occasionally
have to enter the workings belowground for purposes other than manual
work, have exempted from the provision. Every such woman before entering
belowground shall be in possession of a pass granted by the manager
showing the day(s) and hours between which she is permitted to be present
belowground.
ii) No women shall descend/ ascend a shaft/winze, in a cage etc. unless
accompanied by one or more adult males.
iii) Women can be employed aboveground or in opencast workings only
between 6 am and 7pm. However, this does not apply to women employed
in pithead baths, crèches and canteens, and midwives and nurses employed
in hospitals and dispensaries.
The central Govt. may vary these hours but no women shall be employed
between 10 pm and 5 am.
iv) The women employees shall be allowed an interval of rest not less than 11
hours between the terminations of employment on any one day and the
commencement of next period of employment.
v) In any mine workshop coming under the purview of Factories Act. no
women shall be allowed to clean, lubricate or adjust any part of a prime
mover or of any transmission machinery, which is in motion or to clean,
lubricate or adjust any part of any machine if in doing so she would be
exposed to risk of injury from any moving part of either that machine or an
adjacent machine.
Ans:- c) Extra Wages for overtime
Please refer to Q.No. 1(b) ( 2nd Class 2005)
Q.2. What is ‘Occupational Health Survey”? What facilities are to be provided
by
mine management for Occupational Health Survey in accordance
with Mines Act, 1952.
Ans:- Occupational Health Survey
Mining is a hazardous industry. Occupational health hazards in mining are
dust, noise, radiation, heat and humidity, vibration, mine gases etc. To protect
the mine workers from occupational health hazards as well as to know the
safety and health status of a workman, occupational health survey is
necessary.
Occupational Health Survey is defined as the survey which is conducted to
know the status of health of mine workers and associated health problems
due to mining environment. Generally, the following occupational health
survey each conducted both were mine management and DGMS:
i) Medical and Biological Survey(IME & PME)- monitoring of diseases for
detection at an early stage and monitoring to prevent further deterioration in
health of the worker by
 control measures
 rehabilitative methods
ii) Environmental Survey- monitoring of work environment such as dust
survey at specified intervals, noise mapping of work places and personal noise
dosimetry of workmen exposed to noise levels above 85dB(A), vibration
studies, portability test of drinking water etc.
Under Section 25 of Mines Act the mine management is required to report
occurrence of cases of diseases notified by Central Govt. to competent
authority.
Research and academic institutions conduct surveys from time to time to
identify incidence of occupational diseases. DGMS also undertakes surveys
of occupational diseases in priority area or investigate specific complaints
about occurrence of occupational diseases.
Facilities are to be provided by mine management for Occupational
Health Survey:
i) Section 9A of Mines act 1952 empowers DGMS to undertake safety and
occupational health survey in a mine at any time after giving notice in writing
to the manager of the mine. Mine management shall afford all necessary
facilities for this purpose.
ii) Every person chosen for occupational health survey shall present himself
for examination and furnish all information regarding his work and health in
connection with the said survey.
iii) The time spent by any person chosen for examination in such survey shall
be counted towards his working time. So however that any overtime shall be
paid at the ordinary rate of wages.
iv) If such person is found medically unfit on such survey, he shall be
entitled to medical treatment at the cost of the owner, agent or manager with
full wages during the period of such treatment.
v) If after such treatment he is declared unfit to discharge the duty which he
has discharging and such unfitness is directly ascribable to his employment,
he is entitled for an alternative employment in the mine for which he is
medically fit or for payment of disability allowance at the rate of 50% of
monthly wages that he was receiving before such survey.
Provided that where such persons decide to leave his employment in the
mine, he shall be paid a lump sum amount by the way of disability
compensation.
Type of surveys & studies to be undertaken: Epidemiological studies for prevention of occupational diseases.
 Evaluation of chest radiographs for pneumoconiosis opacities.
 Assessment of hearing impairment due to exposes to noise.
 Assessment of physiological stress due to hot and humid working
conditions.
 Assessment of physiological and metabolic capacities of workers.
Facilities available at DGMS
 Electrocardiography(ECG)
 ILO international classification of Chest Radiographs of
Pneumoconiosis
 Audiometer
 Portable laboratory models of lung function tests machine.
 Heart rate monitors
 Necessary equipments for general medical examination.
 Oxycon-5 Metabolic Cart with Bicycle Ergometer.
Q.3. State the provisions of Indian Electricity Rules, 1956 regarding the
following:(a) Isolation and fixing of transformer, switchgear etc.
(b) Flexible cables.
(c) Precautions where gas exists.
Ans:- a) Isolation & fixing of transformer, switchgear etc1. Where necessary, to prevent danger of mechanical damage, transformers
and switchgears shall be placed in a separate room, compartment or
box.
2. No inflammable material shall be used in construction of the room,
compartment or box or fittings therein containing the apparatus, unless the
apparatus is so constructed, protected and worked as to obviate risk of
fire.
3. The room, compartment or box shall be:
o substantially constructed
o kept dry
o well illuminated
o efficiently ventilated for all apparatus installed therein.
4. Adequate working space and means of access, clear of obstructions and
free from danger, shall be provided for all apparatus. Operating handles
shall be conveniently placed.
5. Properly constructed switchgear for disconnecting supply of energy to the
mine shall be provided at the surface at a point approved by the Inspector.
During the time any cable supplying energy from this switchgear is live, a
person authorised to operate the said switchgear shall be available within
easy reach thereof.
6. Every motor shall be controlled by switchgear arranged to disconnect
supply from the motor and all apparatus connected thereto. Such
switchgear shall be so placed as to be easily operated by person
authorised to operate the motor.
7. Whenever required by the Inspector, the switchgear shall be arranged to
disconnect the supply in the even of over current, over voltage and single
phasing.
Ans:-(b) Flexible cables.
Refer to Q. No.3(b) (2nd Class 2005)
Ans:- (c) Precautions where gas exists.
Refer to Q.No.5(d) (2nd Class 2007)
Q.4. Write short notes on any three of the following:-
(a) Noise
(b) Angle of draw and its relevance
(c) Support of freshly exposed roof
(d) Illumination in opencast mine.
Ans:-(a) Noise
Please refer to Q.No.4(c ) (2nd Class-2005)
Ans:- (b) Angle of draw and its relevance.
Please refer to Q.No.6(a)(1st Class 2008)
Ans:-(c) Support of freshly exposed roof.
Please refer to Q.No.7(d)(2nd Class– 2004)
Ans:-(d) Illumination in opencast mine.
Please refer to Q.No.5(a)(2nd Class-2007)
Q.5. An accident had occurred in an opencast mine due to run over by a
dumper being driven in reverse. One worker received fatal injuries.
Write a report of enquiry of the accident bringing the contraventions,
responsibility and also suggestions to prevent similar accidents in
further. Assume your own condition.
Ans:- Refer to Q. No. 3(2nd class 2004)
Q.6. Draw up a suitable scheme of training and facilities to be provided under
Mines Vocational training Rules, 1966 for a large mechanized
underground mine.
Ans:- Refer to Q. No. 8(2nd Class 2004)
Q.7. What is the procedure to frame Traffic Rules for a large opencast mine?
Frame model ‘Traffic Rules for a mine producing about 6 Milton tonnes
of coal per annum with a stripping ration of 1:5.
Ans:- Please refer to Q.No. 1(2nd Class-2007)

Q.8. Write any three of the following:(a) Risk assessment as a tool to improve safety
(b) Applicability, merits and limitations of Long wall mining
(c) Support resistance in a longwall face
(d) Safety in “Contiguous Workings”.
Ans:-(a) Risk assessment as a tool to improve safety.
Please refer to Q.No.6(b)(1st Class-2008)
Ans:-(b) Applicability, merits and limitations of Long wall mining
Applicability of L/W system:The long wall method of mining is applicable to almost any set of geological
conditions, shallow to very deep-seated seams, thin to very thick seams, level
to steeply inclined seams, non gassy to very gassy seam, seams prone to self
heating, outbursts and bumps, hard and massive to fragile roofs, hard and
stable to soft and heaving floors, contiguous seams and mining below the
aquifers, water bodies and important surface features.
However, being the universal method of mining, the long wall mining is best
suited under the following conditions:
 Seam thickness varying from 0.4 to 6m in single slice where thick seam is
to be worked mainly either by multi-slicing system or integral or sub-level
caving system. However, the system is more productive in seam whose
thickness varies from 2m to 3m.
 Flat and moderately inclined seams are best for this method.
 Coal of moderate hardness is suitable for this method. However, very
friable and soft coal or very hard coal are less suitable for this system.
 Uniform seam thickness, free from geological disturbances like faults,
folds, highly fractured are best suitable.
 Immediate roof not too hard or not too weak.
 Strong floor condition.
Merits of L/W system of mining:In L/W method of mining, the extraction front–the long wall face-is 90 –
200m long and continuous. The face is generally straight (but, some time
stepped, notched or even curved). The through air current sweeps the face.
This all leads to the significantly enhanced concentration of production,
supervision, control and safety – resulting in increased production and
productivity. In long wall mining, the following advantages are also claimed:
 Concentration of mine operation.
 Continuity of operation.
 Higher % of extraction.
 Better subsidence control.
 Improved safety & easier ventilation with simple & direct air routs.
 Greater feasibility of winding operation at greater depth.
 Reduction of number of L/W districts.
Better mining method for thin and thick seam and also for multiple seams.
 Means of easier ventilation and environmental control.
 Enhances % of extraction with the help of Pump Packing System.


Seams liable to spontaneous heating can be satisfactorily worked.
It lends to mechanization with the least capital cost per te of annual
output.
 It provides the most successful methods of working beneath another
workout seam.
 Floor likely to creep may be controlled easily.
Limitations of Long wall mining –
 Generally unsuitable in case of shallow depth mining due to subsidence
problem and hard roof.
 Not suitable for steeply inclined seams.
 Strata control problem.
 Demands high capital investment.
 In case of geological disturbed area the method does not yield good
results.
 In long wall advancing method roadways are to be maintained in worked
out areas and entail substantial recurring maintenance costs. Sometimes
there is convergence of roof in the roadways which are required to stand
for long.
 In the case of long wall advancing with caving a large expanse of goaf left
behind constitutes a vast reservoir of firedamp a potential source of
danger.
 In the case of long wall advancing with strip packing, if roadway packs are
not well maintained against leakage, ventilation current may short circuit
through the goat, which is both wasteful and dangerous ( as it may cause
incipient heating of small coal left in the goat).
(c) Support resistance in a long wall face
Ans:- The first desirable criterion for a support system is its ability to develop
the needed resistance to keep convergence and there fore roof degradation
within acceptable limit (max. convergence should not exceed 60mm/m in
case of sand stone roof and not more than 45mm/m in case of coal and
fragile shale).This resistance can be manipulated within certain limits by
varying support spacing in case of individual supports but such adjustment is
very limited with mechanized support.
The time weighted average resistance developed by the supports per
unit are known as support resistance or load density.
The determination of capacity of powered support involves the determination
of likely load coming on the supports under a particular geo-mining situation.
Once the desired support resistance necessary in particular geo-mining
situation is known, the support capacity may be decided by the following
empirical relationship:
Support capacity ( c) = R.A.K1 . K2 K3
rl
Where R = desired mean support resistance (MLD) in t/m2
A = area supported by a support.
K1 = factor of take care for leakage in hydraulic system and leg circuits.
K 2 = factor to take care of setting load deficiency.
K3 = factor to take care of other imperfections like premature leakage and
deviations from nominal span.
R1= efficiency to take care of inclination of legs vis-à-vis vertical
resistance.
It is now well established that if the immediate roof consists of strong(high
compressive strength) and massive rocks(high RQD), caving of roof would be
more difficult. There will be more overhangs in the goaf leading to more
weighting at the face and this in then would require higher support resistance.
A support system is to be considered adequate if it provides sufficient
resistance to strata movement to keep convergence within limit during the life
of the face including the periods of weightings so that undue deterioration of
roof condition does not take place. There should neither be any roof fall or
undue roof fracturing at the face.
The first line of defense against roof falls during periods of weighting is
adequate supports and higher rate of advance is beneficial.
It is not possible to vary the system of support during day to day
operations of a face advance, the support system would have to be planned
to effectively support the maximum load associated with periodic weights.
With thicker cavable bed immediately above the coal seam, the degree of
filling in the goaf is improved and maximum convergence during weighting is
reduced. One way to increase the thickness of cavable bed is to resort of
blasting the immediate roof in the goaf. But such blasting is not possible in
case of shield support and may be unsafe in gassy seam.
Support resistance for long wall workings deploying power support may be
calculated by the following empirical formula:R={h/(K-1)}.ρ.k1.k2.k3
where, R = support resistance(t/m2)
h = working thickness of seam(m)
k = bulking factor
ρ = specific weight of roof rock(t./m3)
k1 = factor for type of support
k2 = factor for goaf treatment
k3 = factor for delayed caving.
(d) Safety in “Contiguous Workings”.
Ans:- Legal provisions:
 No contiguous seams / sections shall be worked without obtaining
prior permission in writing from CIM.
 For obtaining statutory permission, applications shall be accompanied
by two copies of plan showing the proposed layout of workings,
section of the seam (s), depth (s) , rate & direction of dip, proposed
dimensions of pillars and galleries in each seam / section and
thickness of parting between seam / section.
 Coincidence verticality shall be maintained in seams / sections.
 The minimum parting between any two seams / sections shall be 3m.
Following precautions shall be taken during extraction of pillars by caving
method in two sections of a seam or in two seams which are contiguous to
each other:1. The extraction of pillar i.e. drivage of split gallery and the extraction of
slices in two sections/ seams shall be done simultaneously such that the line
of extraction in both the section/seams are superimposed.
2. The workings in each of the sections/seams shall be under the supervision
of a separate mining Sirdar.
3. The working of both the sections/seams will be placed under the charge of
same overman for better co-ordination of the workings.
4. The overman shall be furnished with an offset plan showing the workings
in both the sections/seams in different colors showing there on the sequence
of extraction of pillars.
5. The overman in each shift shall bring the hand plans upto date by showing
there on the progress of splits and slices in each of the sections/seams.
6. For easy access from one section/seam to the other for supervision, drift or
staple pits with ladders shall be provided at every alternate junction of
galleries.
7. Suitable arrangements for communication between the two sections/
seams shall be provided by provision of signaling devices or telephones.
8. If at any time, any danger is noticed in any of the sections/seams, persons
shall be withdrawn from both the sections/seams.
9. When shot-firing is being done in any of the sections/seams persons
should be withdrawn from other section/seam also if the parting between the
seam is 4.5m or less.
10. Supports should be erected in both the sections/ seams as per SSR and
they shall be as far as practicable vertically one above the another in the two
sections/seams.
11. Withdrawal of supports from both the sections/seams should be done
simultaneously.
Afternoon Session
THE MINES ACT, 1952
Examination for Mine Manager’s Certificate of Competency under the Coal Mines Regulation ,
1957
FIRST CLASS
MINE MANAGEMENT, LEGISLATION & GENERAL SAFETY
Sunday, the 16th December, 2007
Full Marks: 100
Time
: 3 Hours
(Question No.1 is compulsory and carries 20 marks. Answer any five
Questions from the rest and these carry equal marks)
--------------Q.1.
You are the manager of a mine which uses continuous miners and shuttle cars for
extraction of pillars at a depth of about 400 m. The seam dips at 1 in 5 and has a
thickness of 4.0 m. Immediate roof is hand sandstone.
a. List what would you consider the five major risks in such an operation which
are needed to be managed.
b. List and describe control measures for the three highest ranked risks.
c . Who would you involve in the risk assessment process.
Ans:- a) Conditions given
Conditions assumed
Depth of working – 400 m
Method of work – Depillaring with caving
Gradient of seam – 1 in 5
Gassiness - Degree l
Thickness of seam – 4 m
Size of pillars – 35 m x35 m (centre to centre)
Immediate roof – Hard sand stone
Floor - Sand stone/shale/coal
Machinery used- Continuous miner Make of water - Normal seepage
shuttle car combination.
Followings are the five major risks in extraction of pillars with caving method
using continuous miner shuttle car combination under the condition mentioned
above:1) Risk / Danger of air blast
2) Risk / Danger of spontaneous heating or fire
3) Risk / Danger of coal dust. (Health & Explosion Hazard)
4) Risk / Danger of roof / side falls
5) Risk / Danger of subsidence
b. Control measures for the three highest ranked risks1) Control measures against any risk of air blast:i) Depillaring operations shall be conducted in such a way as to leave as small
an area of un-collapsed roof as possible with due regard to danger from an
air blast or weighting on pillars.
ii) Where possible suitable means shall be adopted to bring down any over
hang goaf at regular intervals. In case any overhang goaf not normal to the
strata is observed, extraction shall be stopped.
iii) The manner of extraction such as splitting and slicing of pillars, its width
and height and no. of pillars to be extracted at a time shall be strictly in
accordance with the conditions imposed by DGMS in depillaring permission.
iv) Strata control and ground movement monitoring shall be kept under the
supervision of experienced lst Class Assistant Manager who shall be provided
with adequate number of trained manpower and facilities.
v) Scientific body having expertise and infrastructure shall be engaged for
monitoring of strata behaviour including caving characteristics, convergence,
load on supports and stress developed over the pillars during extraction
and corrective measures shall be taken.
vi) Strata management plan including a detailed scheme of strata monitoring
using suitable instrument such as rotary tell tales, convergence indicator,
strain gauge, stress capsules, bore hole extensometer shall be drawn out
in consultation with RMT and the scientific body.
vii) Monitoring of strata movements and indications thereof shall be carried out
in every shift by experienced officer. Warning and withdrawal limits in terms
of convergence (mm), convergence velocity (mm/day or shift) and./ or strata
dilation(mm) shall be fixed for the safety of work persons. If there is an unusual
or abnormal deformation/ convergence, persons shall be withdrawn to safe
place.
Additionally, following precautionary measures shall also be taken to minimize
dangers from air blast due to sudden collapse of overhanging roof in goaf:A. Construction of Isolation/ Preparatory stopping:i) Initially 1.5 m x 1.5m openings shall be left in sufficient number of isolation
stoppings and covered with approved fire-resistant plastic sheeting to serve as
safety valve in the event of an air blast which shall be subsequently closed
permanently.
ii) Doors meant for closing the preparatory stoppings in emergency shall be
taken off and kept laid flat on the ground in the vicinity.
B. Provision of Shelters:i) Shelters shall be provided at suitable locations away from the probable
path of air blast where workmen way take refuge in emergency.
ii) Shelters and approaches there to shall be kept free of any obstructions by
ensuring support of roof at the shelters using cross- bars / roof bolts.
C. Warning System:- District overman and mining Sirdar shall be provided
with whistles and whenever any danger from air blast is apprehended, they
shall repeatedly blow the whistle to warn persons.
D. Withdrawal of persons:i) Obligation of work persons: On hearing the sound of whistle, all persons shall take refuge in the
shelters.
 If a person is caught in the air blast, he shall immediately lie flat on the
ground, preferably in a gallery not in direct path of air blast.
ii) Obligation of overman and mining Sirdar:He shall, in addition to giving warnings, see that all persons take refuge in
the shelters.
E. MOCK- drills etc.
i) Manager shall ensure that only supervisory officials experienced in
extraction by caving method are deployed in the district.
ii) Regular mock-drills shall be held so that every person remains alert to
perform his duty during an impending air blast.
2. Control measures against risk of Spontaneous heating/fireA. Formation of panel(s)/sub-panel(s) –
i) Formation of panel(s)/sub-panel(s) and size of panels shall be done
keeping in mind the incubation period of the coal seam. Panels should
have independent ventilation in such a manner that it is possible to
isolate one from another easily, if necessary.
ii) No depillaring operation shall be commenced until fire dams or isolation
stoppings/preparatory stopping have been provided around panel(s)/subpanel(s).
B. Sealing of panel(s)/sub-panel(s)
i. Every panel(s)/sub-panel(s) shall be isolated by constructing adequate
nos of stoppoings immediately after it has been goaved out.
ii. Where the extraction of pillars is discontinued which would preclude the
completion of extraction in the panel(s)/sub-panel(s) within the incubation
period of the seam, the goaved out part of the panel(s)/ sub-panel(s) shall
be sealed off.
C. Detection of spontaneous heating:i. In order to detect spontaneous heating at early stage, % of carbon
monoxide shall be tested in the return air way at least once in a shift
with an approved automatic detector.
ii. The air in the return airway shall be completely analyzed once at-least in
every 7 days with a view to determine the ratio of CO formed/ O2
consumed.
iii. In case of detection of heating/fire, suitable arrangements shall be made
for dealing the same.
iv) The quantity of air current at the face shall be measured at least once
in every 7 days and appropriate action shall be taken, if velocity drops
below 30m/min.
D. Inspection of depillaring district and isolation stoppings:i. Every depillaring district shall be inspected on every idle day and all
unsealed and unused workings, shall be inspected once at least in every
7 days by a competent person for any fire risk and record shall be kept
maintained,
ii. The isolation stoppings built up around goaved out areas and unused
workings shall be inspected by a competent persons at similar intervals as
mentioned at point no.(i)
The inspection should also include the isolation stoppings built around the
goaved out areas in the panel(s)/sub-panel(s) still under extraction. The
records of the isolation stoppings shall be maintained stopping wise.
E. Filling of surface cracks:Surface crakes formed as a result of extraction of pillars shall be filled up
expeditiously and the filling material shall be well rammed into the cracks
and kept topped-up as often as necessary thereafter to prevent leakage of
air into the goaf.
3. Control measures against risk of coal dust:In Coal Mines, the two most important hazards arising out of dust are :i) Explosion Hazard and
ii) Health Hazard
To guard against dangers of coal dust, the following pre-cautions shall be
taken:i) The concentration of airborne respirable dust shall not be more than 3
mg /m3 of air, when Si02 <5% & not more than 15
if Si02 > 5%.
%of Si02
ii) Air borne dust survey shall be conducted in prescribed manner at
prescribed interval and record shall be maintained.
iii) If the concentration of dust in mine workings exceeds the permissible
limit, immediate necessary steps shall be taken to minimize the emission
of dust. If needed, the relevant operation(s) causing excessive dust shall
cease.
iv) Mine management shall provide dust respirators in sufficient number
free of cost to concerned work person for use in dusty atmosphere, if
needed.
v) Every working face and the floor, roof and sides of every roadway or
airway within 50m shall be washed down to prevent accumulation of
dust and shall be kept wetted.
vi) Water spraying arrangement shall be made and maintained within 90m
of working faces.
vii) Stone dust barrier of such design & at such place as approved by
DGMS shall be provided and maintained in order to prevent effect of
explosion extending from one part of the mine to the other.
Apart from the above, the following additional precautions shall also be
taken:
i) Complete set of picks with proper size shall be fitted in cutter head.
ii) The speed of cutter head shall be maintained such as to prevent
formation of dust.
iii) Water spray system shall be maintained in good working order to
prevent formation and propagation of dust.
iv) The spray nozzles shall be kept regularly cleaned.
v) Pyrite band of igneous rock shall be avoided to cut by machine.
vi) Cutting of coal shall not be commenced until water spray starts with
proper pressure and quantity.
vii) Cutting of coal at the face by CM shall not be commenced or carried out
unless water spraying arrangement at the cutting picks is provided and
maintained in good working order.
Viii)Suitable mechanism to interlock the operation of water spraying and
cutting shall be provided and maintained at all time in the CM.
ix) Monitoring of air borne dust concentration at the face and 30m out bye
of the face in return airway shall be done at least once in a month.
C. Involvement of persons in risk assessment process:As a manager of mine, I would involve following persons in risk
assessment process including myself
Project Officer/Agent

Manager, Engineer, Safety Officer, Ventilation Officer, Surveyor

Overman, Mining sirdar and short firer, Electrical/Mechanical
foreman

Electrical supervisors, Workmen’s inspector, members of safety
committee

Workmen from different areas of operation

Officials from area and ISO.

Expert from original equipment manufacturer

Retired officials, if needed.
Besides above, assistance may be taken from experts of other
organisation such as CMRI, ISM, CMPDIL etc.
Risk assessment shall be performed on regular basis by the team as
mentioned above. The members of the team shall be varied from session
to session to gain a broad perspective of the hazards across a site. The
goal for each risk assessment session is to identify hazards, determine
risk ratings and controls and to review the implementation of risk controls
from previous risk assessment sessions.
Q.2. A 6.0 m thick coal seam was being extracted by opencast method deploying
HEMMS. The overburden consisted of a 25 m thick cover of soft soil followed by
shale and sandstone. A sudden failure of benches for length of about 400 m. and
part of a dump lying near the edge of the quarry occurred burying two shovels
and four dumpers resulting in death of six operators and an overman. Write an
enquiry report of the accident bringing out contraventions, responsibilities and
suggestions to prevent similar accident in future. Assume your own conditions.
Ans:-
Enquiry Report
Ref.No………………………
Date………...
To,
The Manager,
“ X “ OCP.
Sub:- Enquiry report in respect of fatal accident involving
7 persons in X-open cast working due to sudden
failure of benches & OB Dump.
Dear Sir,
As desired vide your letter no………………… dt…………… I am enclosing
herewith the detailed enquiry report in respect of fatal accident in X-O/C working
due to sudden failure of benches and OB dump indicating the cause and
circumstances attending to the accident, contraventions of statutory provisions,
responsibilities and suggestions to prevent similar accident in future as an
annex.l . I am also enclosing the accident plan showing the site of accident
along-with photo graphs.
Yours faithfully,
Encl: As above.
( A.C.M. )
“X” OCP
Annexure - l
Detailed Enquiry Report
Assumption of Conditions:The present X OCP was earlier part of the Z u/g mine having workings in local
seam about 6m thick and dipping at 1 in 4.5 developed extensively on B/P
system in past through inclines. The property has a major fault with a throw
varying from 10 to 30 m. Two O/C mines were started in the property to extract
the developed local seam with barrier between the two mines being along this
fault plane.
The X OCP is on the dip side of the fault whereas the property lying on the
rise side of the fault has been allocated to Y OCP. The overburden consists of
25m thick soft soil including 10m black cotton soil at the top underlain by 15m to
25m shale and sand stone. Fire was also noticed in the exposed galleries 2
years back and had extended on all sides.
I _______________, ACM, X OCP inspected the place, where this
accident occurred and enquired into the cause and circumstances connected
with the same.
1)Introduction & information :- The accident occurred in X OCP of M/s……. on
……… at about 3.50 P.M. in 2nd shift when 13 persons under the supervision
of an overman and two mining sirdars were engaged at the floor of the coal
bench in various activities including loading of coal by shovels into dumpers. I
received information about the accident at about 4 P.M. when I was in my
residence.
2)Background information:The depillaring permission was obtained for
extraction of developed pillars by open cast method with shovel dumper
combination using deep hole blasting. The usual practice at X OCP was to
expose the developed coal pillars by removing OB, extract the pillars and then
cover up the exposed area by dumping the OB material to control heating.
Some OB material were also being dumped near the edge of the quarry.
3)Occurrence of accident:- At about 3.50 PM, one of the worker’s noticed
loose debris falling from the top of the benches on rise side all along the strike.
By the time, he could raise an alarm, loose debris and boulders started sliding
down rapidly into the quarry. 5 Persons tried to runaway while 7 persons i.e. 6
operators and one overman took shelter behind the HEMM. One person left the
area earlier.
The huge quantity / volume of OB material slid down into the quarry. All the 7
persons, who had taken shelter behind the HEMM were completely buried
under the debris. The 5 persons who had tried to runway were partially trapped
but could escape with minor injuries.
4)Rescue & Recovery:- Machines were deployed immediately for removal of
the debris. All the 7 dead bodies could be removed by 5 AM on next day.
5)Inspection & Enquiry: - On receiving information about the accident, I
immediately inspected the place of accident along with the other supervisory
staff and workmen. I made detailed observations and some measurements at
the place of accident and prepared a sketch of the place of accident giving
leading dimensions. Photographs of the place of accidents were also taken.
The sketch and photograph is attached with the report. I also examined
witnesses and recorded their statements.
6)Analysis of evidence/ Observations: - From the inspection of place of
accident, careful study of DGMS permission and analysis of evidence collected,
the following were revealed:i) Height of benches in black cotton soil was as much as 12m (against permitted
height of 5m) & width of only 4 to 8m . The next two benches in shale/
sandstone were 12m to 15m height (against permitted height of 10m) and had
width of less than 5 m.
ii)The coal bench was 6m high and was almost flush with the sandstone bench
above, the combined height at the place of accident was 40m.
iii)The strata had sets of geological discontinuities, parallel as well as at an
angle to the fault plane.
iv)Active fire was noticed in the exposed u/g galleries as well as in the pillars on
all sides.
7)Cause of Accident:- The benches failed because of their excessive height
and very small width. The following are considered to be the technical reasons
for the accident:i)The main technical reason for the collapse/slide is the gross deviation of the
height & width configuration of benches at the place of accident w.r.t. stipulated
conditions of DGMS.
ii)The Shape of the barrier in relation to the bench height and width was such that
it was near to limiting equilibrium having a factor of safety around one.
iii)A change in the lithology particularly increase in the thickness of top soil
contributed in reduction in the factor of safety near the site of slide.
iv)The existence of fire in the mouth of the galleries near the accident site
probably reduced the cohesive strength of sandstone. A possible collapse of
underground galleries/junction after fire in association with the weakened strata
acted as de-stabilizing factors to initiate the slide.
8)Contraventions of statutory provisions:- Regulation 98 of CMR 1957 read
with DGMS permission letter for extraction of pillars by open cast method
were contravened in respect of the following:i) Formation of benches/ Design of pit slope - The height, width and slope of
benches were not maintained as per statute and conditions imposed by DGMS.
ii)Design of Dump Slope- OB Dump near the edge of quarry were made without
taking into consideration the natural angle of repose of materials. As the height
of the OB dump was more than 30m, its should have been properly benched
with height not exceeding 30m and general slope not exceeding 1 in 1.5.
9)Responsibilities:- Enquiry into the accident revealed that if the workings were
made properly benched and special care taken while working near the fault
plane and coal benches affected by fire as required under statute, the accident
could have been averted.
The following persons are considered responsible for the accident:i)General Manager/ deemed agent and agent- In contravention of provisions
of section 18(1) and 18(4) of Mines Act 1952 read with regulation 190 of CMR
1957, the General Manager/ deemed agent and agent of mine failed to
effectively implement that all operations carried on in connection with the mine
are conducted in accordance with the provision of mines act and regulation
made their under.
ii)Manager- In contravention of provisions of reg. 98 and 41 of CMR 1957 read
with sec. 18(4) of mines act 1952, the manager failed to effectively implement
the conditions imposed by DGMS for formation of benches and design of OB
dump.
iii) ACM- In contravention of provisions of reg. 98 and 42 of CMR 1957, the ACM
failed to effectively implement the conditions imposed by DGMS for formation
of benches and design of OB dump.
iv) Overman-In contravention of provisions of reg. 98 and 43 of CMR 1957, the
Overman failed to effectively implement the conditions imposed by DGMS for
formation of benches and design of OB dump.
10) Suggestions to prevent similar accident in future:In my opinion, the following steps should be taken to avoid recurrence of
similar accidents in future:
i) The conditions specified by the DGMS in relation to width and height of
benches should be strictly followed.
ii) If any change has to be done, it must be supported with scientific analysis
on slope stability and necessary permission should be obtained from the
competent authority.
iii) Slope in the direction of gradient of rocks is more risky, due to gravity
helping the slope failures. Therefore, benches in the in-crop side need extra
precautions.
iv) Existence of fire in the u/g galleries contributes in the weakening of overlying
strata and reduction in factor of safety. Therefore, a higher factor of safety should
be planned in such cases e.g. by increasing the width of bench.
v) Wherever benches are formed near a fault, a detailed examination should be
conducted and it should be ensured that likely sliding mass is removed or is
stabilized properly.
vi) Growth of plants in specific cases may help in stabilizing the soft rocks.
vii) A system should be created in each opencast mine to draw cross sections
of all the sides every month. These cross sections will be signed by Surveyor,
Manager, Agent and countersigned by Chief General Manager of the Area.
viii) Technology using laser profiling system/ computer processed
videography/ high resolution satellite imagery should be used for survey and
section preparation etc.
Q.No.3. In the present day context of heavy mechanization and outsourcing, give your
views on adequacy of the provisions of Mines Vocational Training Rules.
Suggest improvements and steps to be taken make vocational training effective.
Ans:- Mines vocational training Rules, 1966 were framed long back to impart
vocational training to mine workers, which includes:
 Initial/basic training to new entrants followed by further training at the
place of work under close supervision of experienced workmen.
 Refresher training for persons already employed and also for persons
who return to work after absence of 1 year.
 Additional initial training for U/G workers.
 Special training of support gang, shot – firer etc.
Subsequently, MVTR 1966 were revised with a view to make these need-based
and job oriented for improvement of knowledge, skill and correct job
procedures.
However, there has been considerable changes in mining technology in U/G,
Surface and O/C in the form of fast and rapid mechanization and outsourcing
activities. The existing statutory provisions contained in MVTR1966 are not
adequate to fulfill the present day need.
In the present day context of heavy mechanization( in U/G, Surface and O/C)
and increase in outsourcing activities particularly in open cast, the following are
the flaws/ inadequacies in the existing MVTR:1. Duration of training:- The present duration of trainings of 12 days for
surface/opencast/U/G works are not adequate.
2. Course content- The course content designed for the purpose is very old
and inadequate and also does cover all aspects of mining technology:
3. Type of training – In the present rule, there is provision only for theory and
practical training. Training modules are too general in nature and oriented
towards departmental employees.
4. Applicability- MVTR is applicable only for limited categories of workers
debarring officials, supervisors and officers ,office staffs & rescue persons.
5. Training for contractors workers - No provision exists in this regard.
6. Appointment of training officer- Provision in respect of Qualification,
experience, nos. of training officers at training centre is not adequate.
7. Staffing -Provisions in respect of qualified training staff, instructors and their
qualifications are not prescribed adequately in the statute.
8. Training of trainers:- There are no provisions for training of trainers.
9. Training aids & course material:- Existing provisions lacks of modern
amenities like films documentary, video, literature, models etc. at VTC
10. No provision of training on occupational health safety.
11. No provision of special orientation training for female workers.
12. No provision of training for workmen and supervisors in respect of
environmental protection.
13. Training allowance- Allowances paid to trainers and trainees are not
adequate.
Suggestions/ steps to be taken for improvements of MVTR:Suggestions for improvements:MVTR 1966 has become out of date and irrelevant and needs to be repealed
and replaced by a new set of rules incorporating the revised modules for basic
training, modules for refreshing training, provision for different types of VT
centers, building accommodations, furniture, training aids etc.
In view of many changes sweeping the mining industry in the form of new
technologies, changed mining conditions etc, an acute need has been felt to
recast the existing statutory provisions contained in MVTR.1966.
Following are the suggestions/ steps to be taken for improvements in MVTR
1966 in order to make it effective in the present day context of heavy
mechanization and outsourcing in Indian mines:i. Duration of training:- Keeping in mind the increasing mechanization and
outsourcing activities in Indian mines the duration of training should be
increased. The duration should be fixed based on type of organisation, type of
mine and category of workmen. The suggested duration should be as follows:
Sr.No.
1.
2.
3.
4.
Categories of workers
Surface workers
Open cast workers
Underground workers
Additional training for specific categories open cast workers/ supervisors
a. Drillers, blasting crew
b. operators dumper, shovel,dozer
c.Dragline operators,fitters,mechanics
d.Electricians
e.Auto Electricians
f.Electrical supervisors
5.
Duration of training ( days)
Initial
Refresher
training
training
12
06
18
06
48
12
36
54
72
96
72
18
12
12
12
12
12
9
Additional training for specific categories U/G workers/ supervisors
a.Tramm., W.E.drivers, Banksmen,
Onsetter, fan attendants
b. Track layers, ventilation gang,shot
firing gang
c. Support gang
d. Machine drivers/ longwall crew
e. Fitters, electricians, mechanics
f. Electrical supervisors
18
09
24
12
30
48
54
18
12
12
12
09
Refresher training period has been kept 50% of the initial training period but
not exceeding 12 days. In the initial and refresher training, the last 1 – 2 days has
been kept for feedback/test.
2. Course content- For effective training, the syllabus needs to be organisation
specific, mine specific and cadre specific. A standard write-up should be prepared
covering theoretical aspect of syllabus circulated in the form of text book in local
language to all instructors and trainees.
3. Applicability - It should be applicable for all workers, supervisors and officers,
staff and rescue persons.
4. Training of contractors workers- Separate modules should be drawn for
contractors workers as the present modules are too oriented towards departmental
employees.
5. Appointment, duties and responsibilities of training officers – The rule
should provide for appointment of a training officer in each mine employing more
than 500 persons besides instructors. The qualification of the training officer, and
the no and qualification of instructor’s should be prescribed.
All training centers shall be adequately staffed as per following details: 1st class Manager - Overall in-charge
 Adequate nos. of training officer and /or Asstt. Training officers having degree
in Mining/Mechanical/ Electrical Engineering
 Adequate nos of trained instructors at least diploma in Mining /Electrical/
Mechanical Engineering.
 Adequate nos of experienced and safety minded trainers for each specialized
or skilled jobs.
 Adequate sub-ordinate staffs.
6. Training of trainers, instructors & training officers should be given statutory
backing.
7. Training aids:- All training centres should be provided with computers with
required software, overhead projectors, slide projectors & TV + VCP/VCD player etc.
8. Special orientation training for female workings should be included in the
training programme.
9. Considerable damage is occurring to environment due to various mining activities.
Training on Environmental protection to workmen and supervisors should be
made mandatory.
10. Provision of training in respect of occupational health and hygiene should be
made in the statute.
11. In view of the new Information Technology (IT) waves sweeping the globe,
mining industry has to keep pace with it and accordingly the very nature/kind of
vocations done by our workmen change. Such IT application to industry should be
anticipated and accordingly such training should be included in Mines Vocational
Training Rules
Till the existing MVT Rules are thoroughly revised and amended incorporating
the above mentioned suggestions, the following additional steps should be taken:a) Each mining company should draw up model training schedules for different
categories of work persons. Such schedule should be got vetted by the tripartite
review committee.
b) All front line supervisory officials like sirdars, overmen, surveyors, foreman,
electrical/ mechanical supervisors as well as persons supervising other surface
operation should be imparted structured training in safety management for at
least 2 weeks once in every 5 years covering about 20% strength every year.
c) Specialized training courses should be arranged for the development of skilled
operators required for HEMM, L/W face equipment etc including contractor’s
workers.
d) All persons engaged at any work within the mine premises through the
contractors should be imparted relevant training and other job oriented briefings
and the drivers of vehicles belonging to contractors entering the mine premises
should be explained the salient provisions of traffic rules framed by manager of
mine . Each mining company should draw up appropriate training schedules and
modalities in this regard and implement the same.
Q.No..4. Design an emergency plan of a belowground mine with dangers from
spontaneous heating and inflammable gas. How can you make it effective?
Ans:- Emergency Plan :- An emergency plan is a programme of action to be
followed in emergency. It should clearly indicate the duties and responsibilities of
each mine official and some other key persons like telephone operator, attendance
clerk, cap lamp in-charge etc. This plan should be drawn up taking into consideration
special features of mines, foreseeing every possible source of dangers and
damages. It consists of programs which provide for prior arrangements to be kept
in readiness before emergency strikes and also operative part of the emergency
plan to deal with the emergency as and when it strikes.
Necessity of Emergency Plan: - An emergency plan is required to be kept
prepared specially for the following reasons:i)
To avoid chaotic condition which develops after an emergency /
disaster.
ii)
To keep the persons trained before hand with details as to what to do and
what not to do, whenever an emergency arises.
iii)
To save human lives who might get isolated due to emergency.
iv)
To save the mine by taking action to deal with the emergency as early as
possible.
Statutory obligation :- As per regulation 199A of CMR 1957, manager of every
belowground mine has to prepare and submit emergency plan clearly indicating
the duties and responsibilities of key persons within 30 days of opening of mines to
RIM, get it approved and enforce at the mine. When any emergency occurs,
manager/principal official should immediately put the emergency plan into operation.
This Plan should be updated from time to time.
Emergency plan of a belowground mine with dangers from spontaneous
heating and inflammable gas:Components of emergency plan –
A) Prior arrangements
B) Framing and operation of emergency organisation / standing order
C) Operation control room.
D) Enforcement of standing order.
A.






Prior arrangements- A no. of buildings as detailed below shall be kept
earmarked for use during emergency.
Emergency Control Room
Two rooms for rescue organisation.
One room to be used as laboratories
Three room for welfare departments used for control, catering and visitors.
Three rooms for medical appliances – For stretcher casualties, walking
casualties and mortuary.
Rooms for Trade unions, police personnel and media persons.
B. Framing and operation of emergency organisation / standing order.
Standing order for emergency plan should clearly show the duties and
responsibilities of workmen/person noticing danger, mine official and other key
persons besides actions to be taken for withdrawal, re-admittance of persons and
resumption of work as detailed below:
1) System of giving warning/ Action to be taken by any person / official
Action by
i. Any
Person
Action to be taken
i. Any person who notices smoke/fire and detects the presence of
inflammable gas, shall immediately withdraw himself from the place and
fenced off the area. He shall take steps by the fastest means to inform nearest
supervisory officials and also give warning to on-setter, if he is near the pit
bottom.
On receiving information, he shall verify the correctness of information
ii. Mining
Sirdar/
and send information by special messenger/telephone to :Overmen/ i. other part of the mine so that persons may be withdrawn to safe place.
Other
ii. any senior official present in the underground.
mine
iii. manager/principal official present on the surface.
Official
He shall try to with draw all persons safely through escape route with the
help of self rescuer
iii. On
On receiving information, he shall inform the banks-man on surface by
telephone/signaling 10 raps and confirm the same by a special messenger.
setter
iv. Banks- On getting information about the detection of spontaneous heating and
man
inflammable gas, immediately informa) Manager / principal official present on surface
b) Attendance clerk
c) Not allowing anybody to proceed belowground without written permission of
manager / official.
v. Attend- He shall –
ance
a) Inform telephone operator and manager
b) sound emergency siren continuously for one minute and repeat the
Clerk.
same twice at interval of five seconds.
c) Prepare a statement of persons present in different parts of the mine and
send a list to operation control room. The list should be updated time to time.
d) Not allowing anybody to proceed belowground without written permission of
manager/official.
vi. Fire
On being informed, the fire fighting and rescue team shall immediately
fighting &
assemble at operation control room and obey the order of manager/ principal
rescue
official.
personnel
vii. Mana
On getting information about spontaneous heating and inflammable gas, the
gers
manager/principal official shall either himself inform or take suitable action to
inform the Agent and other senior officers of the company, the rescue
station and DGMS. He shall also inform the management of neighboring
mines.
2) Withdrawal of Persons:a) Duty of Mining Sirdar and Overman:i. They shall forthwith withdraw all persons under their control from the mines
except those persons whose presence in the mine is considered necessary
for dealing with the spontaneous heating and inflammable gas.
ii. Persons shall be withdrawn in an orderly manner and without creating any
panic.
iii. Persons shall normally be withdrawn via intake roadways and down cast shaft
or intake incline.
b ) Duty of mine officials:- Mine Officials superior to Mining Sirdar and overman
shall exercise general supervision over the withdrawal of persons for u/g
workers.
3) Admittance of persons
Restriction on employment of persons below ground:i. Only authorized persons shall be allowed to remain in or to enter the mine for
dealing of spontaneous heating and removal of inflammable gas.
ii. Attendance clerk shall record in his register, the entry to and exit from the
mine of every authorised person.
iii. Banksman shall not allow any un-authorised person to go under ground.
4) Conduct of fire fighting operation & removal of inflammable gasi. All work of fire dealing shall be conducted in accordance with
provision and
recommendation of DGMS contained in various
under the supervision of specially trained persons and under rescue
necessary.
ii. During removal of gas, only trained and experienced persons
engaged under competent supervision and in accordance with
provision.
statutory
circulars
cover, if
shall be
statutory
5) Resumption Work- Normal work shall not be resumed u/g except with the prior
permission of the manager and unless all working places have been thoroughly
examined by a competent person and declared safe.
C) Operations Control room
All the persons summoned to the mine under the emergency scheme shall sign a
log
book kept at the control room. At the operation control room the following
actions shall be taken without delay:(a) Making a list of missing persons & casualties.
(b) Making chart of roster duty.
(c) Formation of rescue team.
(d) Recording of events in operation record book in cronical orders.









Items to be kept at operational control roomCopies of emergency action plan
Ventilation plan
Underground working plan
Duty cards of diff. Categories of workmen.
Telephone directory
Authorisation cards for U/G visits
Message form in duplicate
Rescue plans & trainings
Fire fighting plan.
D) Enforcement of standing orderi. A copy of orders shall be posted at the mine office, the attendance room
and every entrance to the mine. It shall be the duty of all mine official and
other concerned persons to make themselves thoroughly familiar with their duties
in case of danger of (i) spontaneous heating & (ii) Inflammable gas.
ii. Mock rehearsals shall be held once at least in every quarter.
Effectiveness of emergency plan:
Even the most carefully prepared plans will developed flaws when put into
practice and only rehearsals can so them up for necessary correction.
.
Following steps shall be taken to make emergency plan effective:1) Mock rehearsals shall be conducted once in every quarter religiously and if
practicable, at shorter intervals so as to check emergency arrangement including
the communication system, alertness and comprehension of allotted duties on
the part of the key personals so as to make sure that the action plan will work
under emergency condition.
2) Simulation exercise shall be done once at-least in every year in order to
check the emergency preparedness and deficiencies, if any.
3) Emergency plan shall be reviewed once in a year by ISO and DGMS and
plan shall be updated as per suggestions.
4) Training & retraining shall be imparted to all key persons to deal with
emergent situations defining their duties and responsibilities during emergency.
5) Emergency escape route and sign board should be marked belowground
right upto face by fluorescent paint.
6) Training & retraining of all rescue trained persons for use of rescue & other
life saving apparatus.
7) Establishment & implementation of occupational health inputs into
emergency plan.
8) To make the emergency plan really effective and meaningful, duties and
responsibilities of some other important key persons and officials such as store
keeper, lamp room in-charge, surveyor, doctor, welfare officer, canteen in-charge
and security staffs should be included in the standing order in order to make
them accountable.
9) The emergency plan including the action plan (s) and the duty cards should
be kept constantly updated.
10)The standing consultative committee as well as the key personnel should
meet at regular intervals to keep themselves abreast with the mine workings
including any changes therein an the action plans and also to review the plan
and preparedness.
11)The emergency duties allotted to individual key personnel should not be very
much different from the work normally done by them.
Q.No.5. Describe different type of man-riding systems available and their limitations.
Discuss safety provisions of each system.
Ans: - In case of large extensive and steeply inclined U/G mines, installation of
man riding system becomes essential in order to avoid arduous traveling,
eliminate chanceas of accidents and to ensure effective utilization of available
shift hours.
Man riding system should be induced in the Indian u/g mines under following
conditions:a) Where seam gradient is more than 1 in 4 and traveling distance is more than
1.5 KM,
b) Where seam gradient is less than 1 in 4 but the traveling distance is more
than 3 KM.
It may be kept in mind that no man riding system shall be used U/G unless it is of
a type
approved by the Chief Inspector of Mines. All equipment used for
man riding system shall be:
(a) of sound construction
(b) inspected at regular intervals and
(c) maintained in good and safe condition.
Different types of man riding system available, their limitations and safety
provisions:- Commonly used man riding system are:1) Haulage .
2) Belt conveyor
3) Locomotives
4) Chairlift
5) Telepher
1) Haulage system: - This system shall be considered where the steep gradient
is required to be negotiated. The maximum operating gradients for direct and
endless rope haulages are 1 to 10 and 1 in 12 respectively. The factor of safety of
haulage rope shall not be less than 10 end the life of rope shall not be more than
1½ Yrs. The system requires a high standard of installation and maintenance of
tracks and safety provision including signaling and automatic braking system in case
of rope breakage or trolley over speeding and used for transport of men in the
beginning and the end of shift, in long-wall and continuous miner mines in India.
Limitation:- This system cannot be used where gradient of roadway is more than 1
in 10 for direct haulage & 1 in 12 for endless rope haulage.
Safety Provisions in man-riding haulage system:
a) Safety devices Over speed tripping device
 Position indicator and rope speed indicator
 Run- over indicator
 Dead man’s handle – to stop the haulage in the event of collapse of or incapacity
of driver
 Service brake – having restraining torque capable of holding 1.5to 2.0 times the
torque resulting from the rope pull.
 Emergency brakes
 Track limit switch – to be provided at in- bye and out - bye end of journey.
b) Clearance :- Below the roof - 0.3 m
On that side of track on which manholes are provided– 0.6 m
On that side of track opposite to the man-holes when there are not more than
two tracks - 0.3 m
In any other case – 0.6 m
c) Effective signaling system – suitable code of signaling to be specified by
manager for strict enforcement.
d) Electrical –
All Electrical equipment & fittings – Flame proof construction in gassy mines,
Voltage - not more than 250 V
All conductors should be properly insulated, protected & maintained to prevent
leakage or sparking.
Proper earthing of metallic parts.
e) Notices:* Rope speed limit notice in the engine room.
* Notice at each stations prohibiting travel beyond specified point.
* Notice specifying max. no of persons to be carried.
f) Operation, Installation, maintenance, inspection and testing- Manager shall
frame and enforce a scheme of operation, installation, maintenance, inspection
and testing of the whole system specifying the manner, interval and
responsibility.
2. Belt Conveyor System:- Top or bottom belt is used in mechanized mines
abroad for man-riding. Using belt conveyor exclusively for transport of men is
economically not viable. The system is provided with several protective features
including stations for getting on or off, pulls wire signaling system and limit
switch. Such a system is not used in any Indian Mines at present.
Limitations of use:(a) The speed of man- riding conveyor shall not be more the 2 m/s and the
gradient not more than 1 in 4.
(b) Where mineral and /or material are being conveyed at the same as men, there
shall be neither mineral nor material on the length of the belt being used for manriding and for not less then 5 m in front of and behind this length.
(c) Where subsidiary conveyors feed on to the man-riding conveyor, neither
mineral nor material shall be placed on the man-riding belt within 5 m of any
person riding on the belt.
(d)No other form of mechanical haulage apparatus shall be in operation in the
same roadway as a man-riding belt conveyor, while persons are being
transported.
Safety Provisions in man-riding belt conveyor system:(a) Safety devices:
Safety gate & Overriding switch

Automatic indicator showing fully engaged safety gate

Belt slipping preventer to prevent danger arising due to belt slip.

Belt alignment device to ensure that belts do not move out of line in
excess of 75mm

Belt breakage detection device

Belt tear detection device

Chute blockage detection device

Pull cord system to stop the conveyor from any point along with its length
by any one riding over the belt during emergency.
b) Clearance:- Conveyor road shall be so made and conveyor shall be so located
that the clearance shall be as given below:i) 1.65 m. for top belt and 1.40 m for bottom belt at any boarding platform and
same clearance shall be maintained for a minimum distance of 9 m beyond the
boarding platform in the direction of travel.
ii) 1.65 m. for top belt and 1.40 m for bottom belt at any alighting platform and
for a minimum distance of 3 m beyond each end of alighting platform.
iii) .9 m clearance elsewhere along conveyor for both the system where men
were conveyed and for a minimum distance of 9 m. beyond the safety gate.
c) Other provisions such as signaling, communication, notices, lighting, white
washing etc shall be made.
d) Scheme for operation, installation, maintenance, inspection and testing for belt
conveyor shall be made and enforced by manager.
3)Locomotives system:- This system consists of man-riding cars attached to a
locomotive. The cars are equipped with braking system which can be operated
by passengers. When not required, man-riding cars can be stabled at one end of
journey. These can be used for transport of large manpower, but, only between
limits of loco haulage, in a mine were locomotives are used for coal transport and
the mine is extensive.
Limitation:- No locomotives shall be used where the gradient of the track
exceeds 1 in 15.
Safety Provisions in man-riding locomotive system :i )Service and parking brake and also a dead man control
ii) Ergonomically designed seat for driver
iii) Speedometer, distance indicator, head lights and rear lights
iv) At least two portable fire extinguisher’s of appropriate type and signaling
arrangement.
v) An approved portable lamp for emergency.
vi) Other provisions:
 Pressure and temperature gauge
 Exhaust conditioner
 An exhaust gas cooling box
 Suitable air filter
 Suitable flame arresters/traps
4&5) Chair lift system & Telepher system:Chairlift system:- Chairlift system consists of an endless rope running
near the roof of the roadway. A no. of chair lifts are kept stacked at either end
of journey. Any one who wants to travel takes a chair lift, hangs it on the
traveling rope at specially designed stations & rides on the seat. It is similar to
an aerial ropeway station to put ropeway buckets on or off. Carrying capacity of
the system is high and it can be used both for upward and downward journeys.
It is one of the commonly used systems in India.
Telepher System:- This is a simple system consisting of an endless rope in a
steeply inclined roadway. Each person traveling has a hook attached to his
cap-lamp belt, the other end of which can be put on or off the upward traveling
rope for pulling the person who is traveling. This system is useful for short
distance and helps walking up the inclines only. It is a cheap and simple system
used in some mines in India.
Limitations :1. Gradient of roadways should not be more than 25 degree.
2. This system should not foul with other transport system.
3. No material shall be transported by the telepher system, and while men are
being conveyed by the chairlift system.
4. Rope speed shall not exceed
Chairlift – 1.75 m/s
Telepher – 0.8 m/s
5. Minimum factor of safety of rope – 10
Safety Provisions:For both systems, safety requirements are similar which are given below:(a) Safety devices:i)
Over speed device and device to prevent backward movement of
the system.
ii)
Over travel limit switch at either end of the journey to stop the
system in the event of over riding of persons.
iii)
Over stretch switch to stop the system in the event of the rope
stretch beyond a pre set limit or rope snaps.
iv)
Rope speed indicator
v)
Pull cord to stop the system from any point
(b) Clearance:Chair lift
Telepher
Top of chair seat to floor – 1.0 m
From sides - 0.3m
From sides - 0.8 m
Walking free space
Centre to centre of chairs – 1.2 m
from end of telepher rope rollers1.00m
(c) Efficient & Effective signaling system .
(d) Provision of notices at appropriate places.
(c) Installation operation, maintenance, inspection & testing – scheme to
be prepared and enforced by manager.
Q.6) what are the notified diseases? Which of other diseases you would like to be
included in notified diseases. Discuss the system of “Occupational Health
Surveillance” in your organisation, its short comings and suggest improvement.
Ans:- Notified diseases:-These are those diseases which have been notified
by the central Government in the official Gazette as diseases connected with
mining operations. These includes
 Silicosis
 Coal miner’s pneumoconiosis
 Manganese – poising nervous type
 Asbestosis
 Pneumoconiosis
 Cancer of lung or the stomach or the pleura and peritoneum.
Under factory Act, Noise induced hearing loss has been notified by Central
government as notified disease.
Under section 25 of mines act 1952, it has been specified that where any person
employed in a mine contracts any notified disease, mine management shall
send notice to CIM, DM, RIM, Inspector of Mines (Medical) within three days.
In addition to the existing notified disease, the following additional (other)
occupational diseases should be included in the list of notified diseases:i. Siderosis and Berillyosis.
ii. Noise induced hearing loss
iii. Carbon monoxide poisoning
iv. Contact dermatitis caused by contact with chemicals.
v. Pathological manifestations due to radium or radio active substances.
System of “Occupational Health Surveillance” in our organisation The following comprehensive occupational health services are available in our
organisation:1) Central Hospital- At central hospital, initial medical examination of every
persons to be employed in a mine is done. Besides this, referral cases and
chronic diseases are also taken care of at Central Hospital.
2) Regional Hospital – In addition to central hospital, sufficient nos of regional
hospitals have been set up in the organisation to take care the employees posted
in different parts of the organisation.
3) Empanelled Hospitals- Patients needing specialized treatment and health
care are generally referred to empanelled hospitals across the Country.
4) Periodic medical examination centers with full time medical officer.
5) PME centre equipped with X-ray facilities, facilities for lung function test,
Audiometry and Classification of Chest Radiographs as per ILO
classification.
6) Occupational health physician suitably trained in use of ILO classification
7) Provision of approved type of personal or environmental sampling
instruments for conducting airborne respirable dust surveys with facilities for
determination of free respirable silica.
8) Noise survey instruments are available for conducting Noise surveys.
9) Mechanism for monitoring progress of medical examinations, classification
of chest radiographs, detection of occupational diseases, progress of dust and
noise surveys etc.
Short comings of existing system of occupational health services:
Following are the short comings of occupational health services in Indian mines:-
.
1. Lack of adequate of infrastructure facilities for conducting medical
examinations in PME centres.
2. Failure to conduct initial and periodic medical examinations of all persons
employed in mines as per provision of statute.
3. Failure to evaluate chest radiographs as per ILO classification.
4. Non-reporting of cases of notified diseases.
5. Lack of adequate infrastructure facility for conducting dust and noise
surveys.
6. Failure to conduct dust and noise surveys at prescribed intervals as per
provision of statute.
7. Lack of trained manpower in occupational health and hygiene.
8. Lack of organizational framework on occupational health and hygiene.
9. Poor quality of medical surveillance and use of non uniform subjective
diagnostic criteria.
Suggestion for improvement of system of occupational health services:Suggestions to improve status of occupational health and hygiene in our
organisation are given below:1) Setting up structured occupational health services.
2) Regular short term training programmes on occupational health and hygiene
with special reference to dust and noise monitoring and diagnosis of
occupational diseases and use of ILO classification need to be organized.
3) Identification and assessment of health hazards in workplace.
4) Control of working environment by elimination or minimization of
occupational health hazards
5) Establishment of effective First-Aid machinery.
6) Establishment of necessary arrangement for subsequent Medical
emergency.
7) Proper maintenance of Health records and relevant statistics.
8) Putting in place an effective policy for rehabilitation of sick and injured
person.
9) Development of Health promotional activities including Health education.
10) Noise mapping of various work places in the mine premises based on the
various machines being used in concerned mines along with personal noise
dosimetry of individual workmen exposed to noise level above 85 dbA.
11) Vibration studies of various mining machinery including drills, SDLs, LHDs,
excavators, motor graders, dumpers, etc.
12) Ergonomic assessment of all latest machines, before their introduction into
mining operation. Ergonomical assessment should include:
 Assessment of work process
 Assessment of working aids/tools
 Assessment of working posture
13) Potability test of drinking water supplied to the mine employees, to be made
mandatory once in a year irrespective of its source, the sample of water to be
collected from the points of consumption.
14) IME should be made mandatory for all mining employees whether
permanent, temporary or contractual, before they are engaged in any mining job.
15) The frequency of PME should be brought down from existing 5 yrs to 2 yrs
for the mining employees above 45 yrs of age.
16) Each mechanized mine should engage at least one qualified medical
officer for every 500 employees and thereafter, one for every 1000 employees.
17) One of the medical examinations of every person should be arranged within
one year of his superannuation.
(18) Standards IME & PME shall be suitably modified in order to ensure early
diagnosis of diseases caused due to employment in mines.
(19) Special tests should be included in the PME for employees exposed to
specific health hazard.
Q.7) Discuss the following:
a.
b.
c.
d.
Information Technology in mine safety
Development of communication systems in mines
Use of site mixed slurry explosives with special reference to safety
Electronic detonators.
Ans:- (a) Information Technology in mine safety – Quick and accurate
information is vital to any decision making process in mining operational
environment where numerous technical parameters need to be synthesized and
evaluated. IT specialists design and implement systems to match requirements.
Information technology has become a major resource next only to men,
money and machine to shape and operate an organisation. It can readily affect
the structure of an organisation. Although, industry has recognized the
importance of information technology, its application is still in a stage of infancy.
A corporate information technology network will have to be developed so that it
enables platform for individual and knowledge sharing.
Information Technology is defined as the convergence of
electronics, computing and tele-communication. Large scale use of
computers in combination with modern communication facilities is
generally referred to as IT. It has unleashed a tidal wave of technological
innovation in the collection, storing, processing, transmission and
presentation of information.
In the mineral industry, it will have to play a major role in the areas like
 Planning and design of mines
 Exploration and production of minerals
 Safety
 Accurate mine surveying CGPS,CIS, Total Station.
 Computer aided blast design.
 Spotting of hot spots/fire.
 Inventory control
 Capacity utilization
 Optimization of inputs
The following are the major thrust areas where introduction of information
technology in synchronization with management objectives will yield the tangible
results in terms of production, productivity, safety and utilization.
1.
Remote control and monitoring system for accurate management
information
2.
Management of project implementation through compute- based software
packages.
3.
Introduction of atmospheric monitoring system to improve safety standard
in u / g mines.
4.
Introduction of radio – communication in u / g mines in place of cable –
communication.
5.
Integrated communication network for voice and data transmission right
from work sites to the corporate level.
6.
Computerized maintenance technology like routine condition monitoring of
the health of the equipment for better utilization and taking corrective measures
in time.
7.
Quality forecasting by continuous computerized monitoring of coal
samples for online ash monitoring and also removal of shale / stone from coal.
8.
Introduction of integrated mine management system in large o/c mines
enabling mine management to ensure optimal utilization of system capacity.
Ans-(b). Development of communication systems in mines- In case of
serious bodily injuries, fatal accidents, mine disaster and dangerous occurrence
such as outbreak of fire, collapse of workings, presence of noxious gases etc,
speedy information of such accidents / dangers occurrence will not only help in
rescue and recovery operations but also limit the consequences of danger. This
can be achieved through effective communication system from the wok site in the
mines to all concerned.
As per reg. 87 (4) (b) of CMR’1957, in any mine below ground, if a system of
haulage roadways and conveyors extends to a distance of more than 600 m
from the shaft or the entrance to the mine, efficient telephonic
communication shall be provided and maintained between the end of every
such system and the bottom and the top of the shaft or entrance to the
mine.
Rule 113(2) of IER 1956 also requires that efficient means of
communication shall be provided and maintained between surface switch
room (where switch gear for distribution of power supply is provided) and
shaft bottom or other distributing centers in the mine.
Although statutory provisions have been made in the statute as mentioned above
for communication system in below ground mine and also between surface
switch room and the shaft bottom but these are not sufficient because existing
communication system has its limitation owing to wired transmission and the
need for a person reach the place, where the set for communication is provided
to communicate any message.
Communication system available in O/C mines and at surface of a mine in the
firm of wireless communication through microwave line and mobile phone may
be considered sufficient.
In case of belowground mines, CDS (central dispatcher system) connecting
working place, mine site offices and residence of the mine officials is available, in
addition to point to point telephone connection. With this communication system,
trapped miner could not located precisely and hence they could not be rescued
at right time without wasting the valuable time.
Hence the need for reliable communication between the miners inside the mine
and the outside has been felt.
The following are the communication systems that have been developed and
permitted by DGMS in India.
(i) Mobile Radio Communication System using base station and DECT
(Digital Enhance Cordless Telecommunication hand sets( manufactured by M/s.
HCL Info system Ltd.) :- This system provides communication between working
district to surface and belowground to belowground workings with the system,
voice communication is possible through wireless handsets at a distance of 90
mtr. from the base station. A miner having the handset can communicate his
location if he is alive when trapped under debris. This system do’not have
tracking facility.
(ii) Mine Radio system using leakage feeder cable (manufactured by M/s.
Mine Radio System Canada);- Leaking feeder is the technology used to provide
communication services in u/g mines and tunnels using a special Co-axial /
radiating cable which is partially shielded. This allows radio signals propagating
inside the cable to leak out and radiate into the immediate vicinity. These leaked
radio signals are received by conventional VHF two away radio equipment
(portable radio). This system has been field tried only for voice communication
purpose and the portable radio can cover a radius of 20 mtr. from the nearest
amplifier station.
(iii) Detection system (manufactured by M/s.CMRI, Dhanbad):It is a
wireless transmission system having two different devices working in conjunction
with each other. The two devices are:a)
transmitter unit attached with the mine worker, and
b)
receiver unit carried by rescue team.
The transmitter unit can be incorporated with cap lamp to derive supply for
operation.
The LF radio wave transmitted by the transmitter is capable of
transmitting through rock strata and coal debris. The receiver unit to be carried
by rescue team is designed to catch the said frequency and amplify it several
times before input to the final alarm circuit. As soon as the receiver system finds
a signal, the rescue team, member will turn the antenna associated with the
receiver in order to find the direction where the loudness of alarm is maximum. In
this way the rescue member will be able to reach the trapped miner quickly. If the
trap miner could not switch on his transmitter, than the system will not be able to
locate him.
(iv) Central Electronics Engineering Research Institute, Pilani, India is
developing a system which shall be capable of transmitting data from UG to
Surface where it can be analysed to locate place of roof fall/wall collapse and
shall be cable of detecting the trapped miners and determining whether the miner
is alive under the debris.
To introduce the above mentioned communication system in Indian mines,
the existing rules & regulations under IER,1956 and CMR 1957 regarding
telecommunication system for belowground mines should be suitably
amended.
Ans. ( c ) :-Use of site mixed slurry explosives with special reference to
safety- The following safety precautions shall be taken in using SMS in
opencast mines:i)
Statutory obligation - Mine management shall obtain prior written
permission from DGMS for:
Use of explosives in other than cartridge form.

Use of more than one type of explosives in the same hole.
ii)
Compatibility of booster and the column charge to be ensured by the
management.
iii) All conditions stipulated by the Chief Controller of Explosive granting approval
for SMS regarding manufacturing, storage, transportation and handling shall be
strictly followed.
iv) The operations of mixing of the SMS, loading, charging etc. shall be carried
out under the guidance of the technical service engineer of the explosive
manufacturer and pump truck carrying the explosive constituents shall be
approved by CCE and shall be in safe operating condition and driven by
competent licensed driver.
v) The mine management shall frame a suitable code of practice to be observed
by the blasting crew for handling the SMS in consultation of the explosive
manufacturer. A copy of the same shall be submitted to DGMS.
vi) Loaded pump truck not to be kept at isolated place.
vll) No smoking / open flame to be allowed within a radius of 60m of the pump
truck
vlll) Area within 10m radius of pump truck to be kept free of rubbish, dry grass or
other combustible materials.
ix) (a) Only necessary minimum persons to be allowed during charging and firing
operation.
(b) No spillage of explosive during charging operation.
(c) Ensuring continuity of explosive charge in the hole
(d) Hose pipe used for loading of SMS shall have anti static properties and a
diameter
less than critical diameter of explosives and pump truck shall be
properly earthed with chain link where loading.
(e) Charging and firing of holes only in day light hours.
(f) Preventing un-authorized and inadvertent entry of persons in the area of
loaded holes.
(g) Maintaining proper record of blast geometry as well as post firing data related
to ground vibration, fly rocks, fragmentation etc by authorised competent person.
x) No sleeping of holes without prior written permission of DGMS.
xi) Adequate precautions to be taken in case of misfire.
xii) In case of hot strata, no blasting to be done without obtaining prior permission
from DGMS in writing.
xiii) The entire operation of transportation of explosives to the sites of its use,
charging and blasting shall be placed under the charge of asstt. manager.
xiv) The mine management and manufacturer shall prepare a scheme of training
covering all accepts of operation involving SMS blasting method. The persons
engaged in operation shall be trained as per the scheme at regular intervals.
Ans.(d) Electronic detonators- It is basically a device, which stores electrical
energy for a certain time and then delivers that energy as a sharp pulse at a
precise time to a conventional fuse head. It is based on microchip technology. A
miniature timing circuit replaced the chemical delay element in conventional
electric detonators.
The conventional delay detonators are pyrotechnic based which suffers the
disadvantages of cap scattering. The cap scattering causes inefficient blasting,
poor fragmentation, more ground vibration and other associated problems The
electronic detonator provides the accurate delay of the order of 1 ms, Each
electronic detonator has a unique identification no.(ID No.)
Components of electronic detonators:- Usually the electronic detonator
system consists of three key components:i) Programmable digital detonator.
ii) Logger
iii) Blaster
i)
Digital detonator- The programmable digital detonator contains a micro clip,
energy store capacitor, safety components and conventional explosive
components. The strength is equivalent to detonator No.8. The micro clip
circuitry includes an oscillator for timing, memory for retaining its programmed
delay and communication functions to receive and deliver messages to and
from the central unit. The capacitor can store sufficient energy to run the
micro clip independent of external power for 14 Sec. with enough energy
remaining after the time period has elapsed to fire the fuse head. Protection
against electrostatic discharges, stray current and radio frequencies are
provided through detonator design, chip design and protective component on
the input side of the detonator. Shock protection is provided both internally
and externally. Each detonator has a connector which allows easy connection
to the harnesses wire when hooking up. Each detonator is programmable
between 1 ms to 1500 ms.
ii) Logger – It is used to communicate and assign the desired delay times to the
individual detonators. Operating at an intrinsically safe voltage, it recognizes
and tests each detonator. During the check of the ID No. of the detonator to
be logged, the logger also checks the correct contact between detonator and
twin wire as well as the functioning of the detonator and check the wire of
short circuit or current leakages. One logger can manage maximum of 200
detonators.
iii) Blaster:- It is a unit which controls the programming and triggering of blast. It
is used to fire the blast and only deployed from the firing position once the
operation is clear of persons. It contains the required voltages and codes
capable of firing the detonators.
It communicates to each detonator in turn via the logger. One blaster can
manage upto 8 loggers. Thus the firing system can operate a maximum of
1600 detonators in one go.
Benefits/Advantages:i)
High level of protection against stray currents, static and
electromagnetic radiation.
ii)
Ensuring high diagnostic safety, security and complete system integrity
in the field.
iii)
Very much effective in containing ground vibration level.
iv)
Improved rock fragmentation, increased production and productivity.
v)
Accuracy, programmability and Testability
vi)
Noise free (as DF is completely removed from surface connection.)
vii)
Reduced overall cost.
viii)
Eco-friendly.
Disadvantage:i) Misuse by antisocial elements
ii) High Cost.
The accuracy, simplicity and safety of electronic detonator will lead to total
control of fragmentation, vibration and fly rock in blasting operation. It is expected
that these products would help the mining industry to maintain its sustainable
growth keeping in view the increased human sensitivity and safety
consciousness.
Q.8.Write detailed note on the following as per IER, 1956.
a. Overhead lines in open cast mines
b. Precautions to be taken in use of electricity in degree lll gassy mines.
Ans. a. Overhead lines in open cast mines- Rule 118 of IER 1956 stipulates
that energy shall not be transmitted into a mine ( U/G or O/C) at a voltage
exceeding 11 KV and shall not be used therein at a voltage exceeding 6.6 KV. In
Indian OC mines, energy is generally transmitted at a voltage of 11 KV from
132 KV central substation and small electrical shovels use 3.3 KV but bigger
shovels, draglines and drills use 6.6 KV
In addition to the above, the following statutory precautions shall be taken in
respect of O/H lines in OC Mines:i) Clearance above ground of O/H line in opencast mine- The minimum
clearance of the lowest conductor of the O/H line above ground in the mine
should be 4.6m but if the line is to cross a haul road, the clearance of the lowest
conductor above the raised body of maximum size of dumper plying in the circuit
shall not be less than 3m, but in no case shall the clearance from the ground be
less than 12m.
ii) Precautions to be taken if the O/H line has to cross a road- If the O/H line
has to cross a road (public road), the following precautions will be taken:
a) Clearance above ground: 6.1m
b) Guarding

Cradle guard will be provided below the portion of the O/H line crossing
the road to provide safety against a fallen live conductor.

Cradle guard shall be earthed.

Breaking strength of wires used for making cradle guard shall not be less
than 635 Kg. and the wires shall be made of galvanized iron or steel.

Guard wires used shall be of sufficient current carrying capacity so that in
case a live conductor breaks, there is no risk of fusing of the guard wire
until the line is rendered dead.
iii) Stay wire: Stay wires shall be provided for the poles erected on either side of
the road. These wires shall be earthed.
iv) Anti climbing device and danger notice: If the supports/poles are such as
can be easily climbed upon, anti climbing devices shall be provided on them to
the satisfaction of inspector to prevent an unauthorized persons climbing it.
v) Protective Device- The O/H line shall be protected with a device approved
by the Inspector for rendering the line harmless in case it breaks.
vi) Protection against lightning- O/H line shall be provided with lightning
arrestors – both at the sending and the receiving end.
vii) Blasting operation- No blasting shall be done within 300m of O/H without
consultation of the owner of electric supply lines and in case of mining lease hold
area, without written permission of CIM or Electrical Inspector of mines.
viii) Service Line:- No service line shall be taken off an O/H line except at a
point of support.
ix)Earthing ;Each Support and its metallic fittings of O/H line shall be
permanently and efficiently earthed.
Ans. D. Precautions to be taken in use of electricity in degree lll gassy minesUnder mentioned precautions are required to be taken in use of electricity in
degree lll gassy mines as per rule 126 of IER 1956 in respect of the following:-
1) Cables:- All cables at every place shall be constructed, installed, protected,
operated and maintained ( CIPOM) in such a manner as to prevent risk of open
sparking.
2) Intrinsically safe circuit:- Signaling, telecommunication or remote control
circuits at all places shall be so constructed, installed, protected, operated and
maintained ( CIPOM) as to be intrinsically safe.
3) FLP apparatus and enclosures:i) All apparatus shall be flameproof within 270m from nearest face or goaf or inbye of last ventilation connection or in a return airway.
ii) All electric lamps shall be enclosed in flameproof enclosures at all places.
4) Disconnection & re-connection of supply in general:i) Supply shall be disconnected:
Immediately, if open sparking occurs

During the period of examination or adjustment of the apparatus which
requires exposing of any part liable to open sparking.
iii)
Supply shall not be re-connected until the apparatus has been examined
by the Electrical Supervisor or one of his duly appointed assistants and
until the defect, if any, has been remedied or necessary adjustment made.
5) Provision of flame safety lamp and automatic gas detector :i) A flame safety lamp shall be kept burning near an apparatus ( including
portable or transportable apparatus) which remains energized, and if the safety
lamp indicates presence of inflammable gas, supply to all apparatus in the
vicinity shall be immediately disconnected and the incident reported forthwith to
an official of the mine.
ii) Where apparatus for automatic detection of inflammable gas or vapour is
employed in addition to the flame safety lamps, such apparatus shall be
approved by the Inspector of Mines and maintained in perfect order. The
apparatus shall be interlocked with the controlling switch in such a manner as to
disconnect the power supply automatically if inflammable gas exceeds 1.25% in
that particular district.
6 ) Disconnection & re-connection of supply in case of detection of gas :i) If inflammable gas in the general body of air exceeds 1.25%, power shall be
immediately disconnected from all cables and apparatus in the area. Reconnection shall not be made till the gas remains in excess of 1.25%
Provided that such disconnection shall not apply to intrinsically safe
environmental monitoring scientific instruments.
ii) Such disconnection and re-connection shall be noted in the Daily Log Book
and reported to the Inspector of Mines.
7) i) Only DGMS approved FLP equipment and intrinsically safe equipment shall
be used in u/g mines.
ii) Cables shall be as per BIS specifications.
iii) Only intrinsically safe testers/ meggers shall be used.
Morning Session
THE MINES ACT, 1952
Examination for Mine Manager’s Certificate of Competency under the Coal Mines
Regulation, 1957
SECOND CLASS
MINE MANAGEMENT, LEGISLATION & GENERAL SAFETY
Sunday, the 16th December, 2007
Full Marks: 100
Time
: 3 Hours
Answer any SIX Questions
(All questions carry equal marks)
--------------Q.No.1. What is the procedure to frame Traffic Rules for a large opencast mine? Frame
model Traffic Rules for an opencast mine producing 10 million tonne of coal per
annum with a stripping ration of 1:5.
Ans:- Conditions given:Coal production – 10 mte. OBR – 50 mm3, S.R. – 1:5,
Composite volume- 57 mm3, density of coal – 1.4 te/m3
Condition assumed- HEMM & other machinery to be deployed.
a) Heavy Vehicles:Electric rope shovel (10 m3) – 12 Nos.,Dumpers ( 85te) – 50 Nos
Dozers – 10 Nos.,Drills (250mm) - 10 Nos., Road Graders- 03 Nos.
Explosive Pump trucks- 03 Nos., Buses – 02 Nos., Water Tankers- 04 Nos.,
Pay loaders – 10 Nos.
b) Light Vehicles- Jeeps, land rovers, maruti gypsys etc.
Need of traffic rules:As per recommendation of 7th Safety conference on safety in mines, each
mining company should frame suitable code of traffic rules for regulating the
movement of HEMM commensurate with the capacity, size and type of
machines used in mechanized open cast mines for enforcement in each mine.
Procedure for framing traffic rules:The following rules are designed for the safe operation of vehicles in and around
the mine. Operators of vehicles shall observe these rules and any other special
instructions given by the Mine Manager. The Mine Manager and Officials
appointed by him shall ensure that all persons in the mine comply with these
Rules.
Following are the procedures for framing traffic rules:(a) Only persons authorized by Manager shall drive or operate vehicle in or
about the mine.
(b) A private vehicle shall not be driven within the mine premises unless
authorized by the Mine Manager or the official in charge of the office.
(c) Any driver, not regularly working in or about the mine shall request and
receive permission to enter the mine premises from Mine Manager or an
authorized official, prior to driving a vehicle within the mine premises.
Model Traffic Rules for a large opencast mine:1) Speed Limits:(a) Speed limits fixed by the Mine Manager for class of vehicles shall be strictly
followed.
(b) In case of poor visibility or poor road conditions, speed shall be reduced to
the extent necessary to maintain effective control.
2) Right of way:(a) At inter-sections , all drivers should give way to the vehicle on the right,
except below:(i)
All drivers shall give way to emergency vehicles showing a
flashing red light.
(ii)
Vehicles being used for grading, rolling, watering and repair of
roads have right of way over all vehicles except in emergency
vehicle. These vehicles will show an amber flashing light.
(iii)
Light vehicles shall at all times give way to haul trucks and other
heavy vehicles.
(b) The driver of a vehicle having right of way over another vehicle shall not
endanger himself or other through insistence on that right if this is likely to
cause a collision.
3) Parking and Standing: - Following precautions shall be taken by the drivers
(a) No parking / standing of vehicles in a position endangering other traffic on
the mine premises.
(b) No parking / standing of vehicles opposite another vehicle on a haul road.
(c) No parking/ standing vehicles within 30 m of the working area of mobile
equipment and within the area of swing of the dragline without permission
from the operator.
(d) Ensuring the effective parking of vehicle by applying parking brakes and
lowering implements.
(e) Ensuring that while moving from a parked position his path is free of any
obstruction and /or personnel.
(f) While parking the light vehicles, the following rules to be obeyed:
- Engine to be stopped.
- Leavening vehicle in first / reverse gear:
- Hand brake to be applied.
- No parking in front of or behind a heavy vehicle;
- Chocking the wheels, if parked facing up or down a slope.
4) General:
(a) No driving of vehicle over electric cables, air hoses or water lines.
(b) Wearing of seat belt by the operator’s during operation of vehicles.
(c) No unauthorized riding of vehicles by the passengers.
(d) For break down vehicles, a caution sign or hazard lights are to be
placed at the front and rear.
(e) Cleaning, oiling and checking of water, tyres and fuel of machines
to be ensured by operators.
(f) Ensuring that vehicle is correctly illuminated during hours of
darkness.
(g) Dipping of head lights of vehicle while approaching other traffic or
mobile equipment in working areas.
(h) Sounding one blast on horn for all HEMM before moving off from
parked position.
(i) No permission of smoking or use of naked lights during re-fueling
and checking of batteries.
(j) Loading of trucks in such a manner that spillage is minimized. Loads
should be centralized to maximize stability. Loads which have an
overhang in excess of 1.2 m shall be clearly marked by a red flag
during day and red light at night.
(k) Ensuring that the vehicle has adequate clearance, particularly, when
reversing, parking, passing other vehicles moving / stationary.
5) Overtaking:
(a) During overtaking of vehicles, the following shall be ensured:
(i) The speed limit is not exceeded.
(ii) There is sufficient visibility of the road ahead.
(iii)The vehicles are clear of any road intersection or junction.
(b) The driver of a heavy vehicle may not overtake another vehicle on an
incline unless the overtaken vehicle is traveling at a speed less than 10
km/hour and there is adequate visibility of the road ahead.
(c) No overtaking is permitted in the vicinity of road dividers.
(d) While driving behind a haul truck, the driver shall ensure that he is
visible in the rear view mirror until he pulls out to overtake.
6) Signs:
(a) All signs are to be obeyed.
(b) Temporary signs to be removed after need ceases to exist.
(c) Warning signs are to be noted at all times.
7) Examination of vehicles:(a) Daily examination of heavy vehicles ensuring its safe working and
record of the results of examination to be maintained.
(b) In case of any defect in the vehicle as well as damage to the vehicle
or injury to drivers or passengers, the driver shall report the incident
to supervisor.
8) Implementation –
(a) The manager shall specify the name(s) of the officer(s) who shall be
responsible for enforcing the Traffic Rules.
(b) A copy of the traffic rules shall be handed over to every driver/ operator
and every supervisor.
The above detailed traffic rules governing the movement of all types of
vehicles
including contractors vehicle within mine premises should be
strictly followed in order to ensure safety in open cast mining operation.
Q.No.2.What are the categories of persons employed in mines, who are not covered
under the Mines Vocational Training Rules? What are the provisions regarding
training of these special category of employees?
Ans:- Following are the categories of persons employed in mines, who are not
covered under MVTR’1966 amended time to time:1) Persons employed for saving life or property, dealing with circumstances
arising out of an accident (Rescue persons).
2) Persons employed in a position of supervision or management or in a
confidential capacity as specified i.e. officers, officials, and supervisors.
3) Shotfirer, blasters & Timber mistries.
4) Clerks, accountants and register keepers
5) Persons who have undergone a course of training at an approved institution.
6) Mining apprentices working under personal supervision of a mine official.
7) Apprentice mechanics or apprentice electricians, if they have undergone an
approved course of training at mine mechanization centre.
Provided the persons at (4) to (7) shall undergo refresher training as per rule 8.
Provisions of training of special categories of employees:1)
Training of persons employed for saving life or property dealing with
circumstances arising out of an accident:As per provisions contained in rule 4 of the Mines Rescue Rule,1985, Special
categories of employees engaged for saving life or property, dealing with
circumstances arising out of an accident , should undergo for the following types
of training at mines Rescue Station:(a)
Initial training in rescue and recovery work: - Under this heading both
theoretical and practical training shall be imparted.
Theoretical training includes study on General methods of dealing with fires U/G and recovery of mines after
fires and explosions.
 Construction, use, repair, maintenance and testing of various types of
rescue apparatus.
 Properties and methods of detection of noxious and inflammable
gases.
 Collection of gas samples in irrespirable atmosphere
 Reading of mine plans.
In practical training, not less than 12 practices with breathing apparatus
and not less than 2 practices with smoke helmet shall be carried out under
conditions devised to resemble those likely to be encountered in operations U/G
and requiring the use of rescue apparatus. Each practice shall be of at-least 2
hours.
(b)
Refresher training to rescue trained persons:- Theoretical courses
for refresher training to rescue trained persons shall be same as mentioned in (a)
above. However for practical purposes, at least 8 practices with breathing
apparatus in every calendar year of which at least 4 practices shall take place in
mines and 4 practices in hot and irrespirable atmosphere in the training gallery
at Rescue Station.
However, persons employed in rescue services should be imparted refresher
training time to time and also specialized training for use of modern and
sophisticated rescue apparatus.
(2) Training of persons employed in a position of supervision or
management or in a confidential capacity:-
Under these categories, the persons specified to be deployed in a position of
supervision or management or employed in confidential capacity and provision
for their training are given below:a) Officers – Manager, Asstt. Manager, Ventilation Officer, Safety officer, Mining
/ Electrical / Mechanical Engineer, Medical Officer, Welfare or Personnel Officers.
Training Provisions for officers:(i) Induction/ Orientation training – Such type of training is imparted to newly
recruited officers in order to make them familiar with the organisation and its
structure, service conditions, duties, responsibilities and rights, career growth,
social security, medical facilities etc. The duration of course is generally one
week and the training is generally in-house.
(ii) Medical Officer associated with PME should be imparted proper training in
occupational health and use of ILO classification.
(iii) Supervision & Management Course – One month extensive training is
imparted at Central Staff training College for developing officers through inter
company management development programme as a continuous process.
iv) Special training facilities: - Special training related to introduction of special
mining techniques and methods such as longwall mining, scraper mining,
continuous mining, surface mining etc is imparted to officers engaged in mining
operation. The duration of training is generally one week.
v) External training facilities:- In-house training facilities are not adequate to
meet all the training needs of the industry. Following external training facilities
are given to officers:- Refresher and improved courses in technology at technical institution.
- Management courses at administrative Staff training College.
- Specialized technical skills and advanced management courses outside the
country.
- Seminars and workshops organized by professional bodies like institution of
Engineers, Mine Managers association, educational institution etc.
The course content and time duration for above mentioned courses are different
for different types of training.
(b) Supervisors and officials:- Overman, mining sirdar, mechanical/electrical
foreman, electrical supervisors, Surveyors and assistant surveyors.
Training provision:(i) As per new training modules, Supervisors and mine officials shall be
imparted training as per details given below:Category
Supervisory
Officials
Electrical
Supervisiors
.
Initial training( in no of days)
Theo On
Feed
Total
ry
the job
back
11
06
01
18
11
06
01
18
Refresher training( in no of days)
Theory On the Feed
Total
job
back
05
06
01
12
05
03
01
09
The training shall be imparted strictly as per the syllabus/ modules designed
for the purpose.
(ii)As per recommendation of 8th conference on safety in Mines: All front line supervisory officials like Sirdars, Overman/ foreman,
Surveyors, Electrical/ Mechanical supervisors as well
as persons
supervising surface operations should be imparted structured training in
safety management for at least two week, once in a five years covering
20% strength every year.

Properly designed class room training should be provided to
candidates for Sirdars examination.

Members of safety committee should be given training to prepare
them to discharge their assigned functions effectively and efficiently.
The training programme should be for one week & should comprise
lecture and demonstration sessions as well as field visits as per
approved syllabus.
(iii) Each mine official should be trained in first aid and should see that his
first aid certificate is re-validated whenever necessary and refresher training
to all first aid certificate holders by qualified medical practitioner.
(iv) All workmen’s inspector have to undergo an orientation training
course consisting of not less than 30 lectures and demonstrations of not less
than 2 hours duration each, in accordance with the syllabus specified by and
at a centre approved by CIM.
(v) Necessary training should be organized with the help of experts, both
national and international, for optimal adoptions of the safety management
system.
(vi) Special courses for supervisors and officials should to be imparted to
acquaint them with the special objectives necessary for immediate or future
needs.
(vii) Training in gas testing should be imparted to all mining sirdars,
overman and other supervisors in VTC at least once in every year.
(3). Training for short firers/ blasters and timber mistries:All short firers/ blasters and timber mistries should be imparted training on
development course as per following details:Categories of persons
No of
lectures /
days
i) Short firer/ blasters :-a) All 12 lectures
potential shot firers/ blasters
before appearing for competency
exam as newly appointed shot
firers who have not undergone the
course of training or with a break
of service for more than six
months
b) Training in gas testing for 6 lectures
competency certificate holders &
candidates intending to appear in
gas testing exam within next 3
years
ii) Timber Mistries:- a) To be 6 days
newly
employed
from
the
categories of timber man.
b) To be re-employed after a
break of service exceeding 6
months.
Remarks
Training to be completed
within
one
month
of
employment
/
reemployment.
Instruction course
covered every year
to
be
Training to be completed
before
appointment
as
Timber Mistry.
For clerks, accountants, register keepers, persons undergone training at
approved institutions and apprentice’s mechanics or apprentices electricians
should be imparted refresh training in their field of work from time to time.
Q.No.3.
Enumerate the provisions of Mines Rescue Rules, 1985 regarding –
(a) Establishment and location of rescue stations.
(b) Appointment of rescue trained persons in mines, their disposition
and accommodation.
Ans:- (a) Establishment and location of rescue stationsi) CIM may permit or require the owner of belowground mine or ground of
belowground mines to establish and maintain rescue station(s) with such
design and specifications and at such place(s) as may be considered
necessary in consultation with the owner.
CIM may permit or require two or more owners to jointly establish a common
rescue station
(ii)At every rescue station, there shall be appointed one superintendent, at
least two instructors and also there shall be maintained a rescue brigade of at
least 18 rescue trained persons.
(iii)The owner shall appoint another superintendent in case the period of
absence of superintendent at rescue station exceeds 60 days.
(iv)The owner shall within 7 days from the date of assumption or
relinquishment of charge by the superintendent inform CIM & RIM.
(v) At every rescue station, there shall be provided and maintained for
immediate use apparatus and equipment as specified in schedule –l of
Mines rescue rule 1985
vi) Self – contained breathing apparatus provided at rescue station shall be of
same type and make.
vii) Every mine shall be connected telephonically with the rescue station
serving the mine. Where ever practicable, wireless communication shall
also provided.
Ans.3 (b) Appointment of rescue trained persons in mines, their
disposition and accommodationi) At every belowground mine where more than 100 persons are ordinarily
employed belowground, at least 5 rescue trained persons shall be readily
available at surface at any time.
ii) When more than 500 persons are ordinarily employed belowground,
there shall be appointed one rescue trained person for every 100 persons
or apart thereof.
iii) All rescue trained person shall be provided suitable accommodation
close to their work place by the owner.
iv) There shall be provided at belowground mine effective bell or other
approved arrangement for immediate summoning of rescue trained
persons.
v) A rescue trained person may be suspended or debarred from
undertaking any rescue and recovery work if found in-competent or guilty
of negligence/misconduct in the performance of his duties by owner,
agent, manager or an inspector.
vi) Every rescue trained person shall be re-examined once at least in every
12 months by a qualified medical practitioner and if declared medically
unfit, he shall cease to a rescue trained persons from the date of such
declaration.
vii) Every rescue trained person shall undergo practices and receive
instruction as per the provision of Mines Rescue Rule 1985.
Q.No.4. An accident had occurred in an opencast mine due to fall of dumper from haul
road to lower bench. One worker received fatal injuries. Write a report of
enquiry of the accident bringing out contraventions, responsibility and
suggestions to prevent similar accidents in future. Assume your own
conditions.
Ans:-
Enquiry Report
Ref.No………………………
Date………...
To,
The Manager,
“ A “ OCP
Sub:- Enquiry report in respect of fatal accident involving
1 worker in A-open cast working due to fall of dumper
from haul road to lower bench.
Dear Sir,
As desired vide your letter no………………… dt…………… I am enclosing
herewith the detailed enquiry report in respect of fatal accident in A-O/C working
due to fall of dumper from haul road to lower bench indicating the cause and
circumstances attending to the accident, contraventions of statutory provisions,
responsibilities and suggestions to prevent similar accident in future in Annex.l . I
am also enclosing the accident plan showing the site of accident along-with
photo graphs.
Yours faithfully,
Encl: As above.
( A.C.M. )
“A” OCP
Annexure - l
Detailed Enquiry Report
Assumption of Conditions:A OCP is being worked in V,Vl,Vll,Vlll combined seam 18m thick, dipping
at 1 in 7 with shovel – dumper combination using deep hole blasting after
obtaining statutory permission for extraction of pillars by OC method from DGMS.
The strata above coal seam is hot due to fire. The seam is extensively developed
in 3 sections in past on the pattern of B/P method of mining. The depth of
working from the surface is about 100m. There are 5 benches in OB and 3
benches in Coal.
I _______________, ACM, A OCP inspected the place, where this
accident occurred and enquired into the cause and circumstances connected
with the same.
1) Introduction & information :- The accident occurred in A OCP of M/s……. on
……… at about 5.00 P.M. in 2nd shift when 10 persons under the supervision of
an overman and two mining sirdars were engaged at first OB bench in various
activities including loading of OB by shovels into dumpers. I received information
about the accident at about 5.30 P.M. when I was in my residence.
2) Background information:The depillaring permission was obtained for
extraction of developed pillars by open cast method with shovel dumper
combination using deep hole blasting. The usual practice at A OCP was to
expose the developed coal pillars by removing OB, extract the pillars and then
Coal & OB transported to coal stock and OB dump respectively.
3) Occurrence of accident:- At about 5.00 PM, one of the worker’s noticed the
falling of dumper from haul road to top bench on rise side. By the time, he could
raise on alarm, dumper started sliding down rapidly into the quarry. 9 Persons
tried to runaway while 1 worker could not escaped and buried under the dumper.
4) Rescue & Recovery:- Machines were deployed immediately & the body of
the deceased could be removed by 10.00 PM on same day.
5) Inspection & Enquiry: - On receiving information about the accident, I
immediately inspected the place of accident along with the other supervisory staff
and workmen. I made detained observations and some measurements at the
place of accident and prepared a sketch of the place of accident giving leading
dimensions. Photographs of the place of accidents were also taken. The sketch
and photograph is attached with the report. I also examined witnesses and
recorded their statements.
6) Analysis of evidence/ Observations: - From the inspection of place of
accident, careful study of DGMS permission and analysis of evidence collected,
the following were revealed:i) Dumper operator was operating the dumper carelessly and over speeding.
During investigation, it was also revealed that dumper operator was on overtime.
ii) The gradient of existing haul road was limited to 1 in 10.
iii)The dumper operator was wearing safety belt.
iv) No berms and parapet wall was provided in the haul road.
7) Cause of Accident:- Enquiry into the accident revealed that accident
occurred due to the following reasons:i) Careless driving of dumper by dumper operator who was deployed on
overtime.
ii) Absence of berms and parapet wall in the haul road.
iii)Unsafe haul road – high gradient.
8) Contraventions of statutory provisions:- Regulation 95A of CMR 1957
read with DGMS permission letter for extraction of pillars by open cast method
were contravened in respect of the following:i) Gradient of haul road - Gradient of haul road was not maintained properly.
No haul road shall have a gradient steeper than 1 in 14.
ii) Provision of berms & parapet wall – As per condition stipulated by DGMS,
no berms and parapet wall was provided in the haul road.
iii) Negligence on duty by dumper operator.
9) Responsibilities:- Enquiry into the accident revealed that if the haul road
were made properly and care taken while operating the dumper by operator as
required under statute, the accident could have been averted.
The following persons are considered responsible for the accident:i) Manager- In contravention of provisions of reg. 95A and 41 of CMR 1957 read
with sec. 18(4) of mines act 1952, the manager failed to effectively implement the
conditions imposed by DGMS for design, construction and maintenance of haul
road and arrange adequate no. of dumper operators in all the shifts in order to
avoid deployment of operator on overtime.
ii) ACM- In contravention of provisions of reg. 95A and 42 of CMR 1957, the
ACM failed to effectively implement the conditions imposed by DGMS for design,
construction and maintenance of haul road.
iii) Overman-In contravention of provisions of reg. 95A and 43 of CMR 1957, the
Overman failed to effectively implement the conditions imposed by DGMS for
formation of benches and design of OB dump.
iv) Dumper Operator- He failed to follow the instructions given by senior
officials.
10) Suggestions to prevent similar accident in future:In my opinion, the following suggestions should be implemented in order to
avoid repetition of similar accidents in future:
i) Design, gradient and maintenance of haul roada) No road shall have a gradient steeper than 1 in 16 at any place.. For any
deviation, written permission of CIM should be obtained and the conditions
specified must be followed.
b) Width – The minimum standard road width should be three times the
width of largest vehicle unless definite turnouts and waiting points are
designated. As far as practical, all roads from the open cast workings shall be
arranged to provide one way traffic and separate road for light vehicle.
c) Stopping sight distance/ visibility at corners – All corners and bends in
roads shall be made in such a way that the drivers of vehicles have a clear view
for a distance not less that 30m away the road. Where it is not possible to
ensure a visibility for a distance of 30m, there shall be provided two roads for
up and down traffic.
d) Parapet walls – Where any road exists above the level of the surrounding
area it shall be provided with strong parapet wall or embankments not less than
1 in height to present any vehicle from getting off the road.
e) Design of berms- The size of berm should be at-least half the tyre height
of the largest vehicle plying on the road. The side slopes of a berm should be
graded at 450 to horizontal which stabilizes the side slope and enhances the
impact absorbing quality of the berm.
ii)
Haul road lighting : Haul roads should be adequately lighted during dark
hours. It should have a minimum standard of illuminations 0.5 to 3.0 lux.
iii) Manpower -Adequate nos. of dumper operators should be appointed keeping
in view factors like absenteeism, leave etc. .
iv) Avoidance of overtime duty.- Work on overtime should be avoided..
v) Provision of seat belt - For providing adequate safety to the operators in the
event of overturning; a seat belt should be provided.
vi) Selection of Operators- Operators should be selected from amongst persons
possessing requisite qualifications. The selection process should comprise a
test to check driving / operating skill, aptitude, health and oral examination of the
candidate by a competent selection committee.
viii) Training and re-training- Operators should be imparted proper training and
retraining for their development and strict adherence of safety rules.
Q.No.5. Write short notes on any three of the following:
(State statutory provisions wherever necessary)
a. Illumination in opencast mine.
b. Obligation of manager in case of serious bodily injury.
c. Intrinsically safe circuits and equipment.
d. Provisions of Indian Electricity Rules, 1956 regarding “ Precautions
where gas exists”
Ans:-5(a) Illumination in Open minesAs per regulation 151 of CMR-1957
i) Adequate general lighting arrangements shall be provided during working
hours at every opencast working..
ii) The lighting provided in a mine shall be so arranged to prevent glare or eye
strain.
iii) Where electrical energy is available at the mine, the lighting arrangement shall
be by electrical means.
Standards of illuminations:- The standards of lighting to be provided in
opencast mines during working hours at different places or area where natural
light is insufficient., have been recommended by DGMS as per following details:Sl.No.
1.
2.
3.
4.
5.
6.
7.
Location
Minimum Illumination
(Lux)
Level /plane of illumination
(Horizontal /Vertical)
Operational area
5
Of draglines & shovels,
10
Operational area of drills
20
Operator’s cabin of Shovel, 30
Dragline, drill etc
Dumper haul road
0.5 – 3.0
OB and coal dumps
3
Roadways and footpath
from bench to bench
3
CHP, workshop and
service buildings
As per BlS specification
H
V
V
H
H
H
H
Lighting near the faces and haul road may be arranged by clusters of
high pressure sodium vapour lamps located on the top of an adjustable
telescopic mast, mounted on a platform with rubber tyred wheels or skids and
having a portable DG Set
Ans.b) Obligation of manager in case of serious bodily injuryFollowing are the statutory obligation of manager in case of serious bodily injury
to a person employed in a mine:i. Information & Notice of accident:
Manager shall forthwith inform the RIM about the occurrence by telephone
or express telegram or by special messenger.

He shall also give notice in form IVA to District Magistrate CIM, RIM and
Coal Mines Labour welfare Commissioner within 24 hr of serious bodily injury to
any person and shall simultaneously exhibit a copy of notice on special notice
board at the office of mine and shall ensure that the notice is kept on the board in
a legible condition for not less than 14 days from the date of such exhibition.

If any injury already reported as serious bodily injury turns to fatal, a
notice shall be given to above mentioned authorities within 24 hours of being
informed of the death by the Manager.

Manager shall also within 7 days send to CIM, detailed information of
persons injured in form lVB .

He shall also send particulars of injured persons returning to duty within
15 days of return to DGMS in Form IVC.
ii. Inspection and Enquiry: - Manager shall inspect the site of accident as soon
as possible and shall also either himself or through an ACM have an enquiry
made into the cause of and circumstances attending the accident. The result of
every such enquiry and a plan and sections and wherever practicable a
photograph(s) of the site of accident showing details, shall be recorded and a
copy shall be sent to CIM and RIM within 15 days of accident.
iii. Place of accident not be disturbed- The place of accident shall not be
disturbed or altered before arrival or without consent of DGMS, unless such
disturbance or alteration is necessary:
To prevent any further accident.

To remove bodies of the deceased

To rescue any person from danger

To avoid discontinuance of work at the place of accident seriously
impending the working of the mine.
In case of failure by DGMS to inspect the place of accident within 72 hrs of
occurrence of accident, work may be resumed. However, before disturbing or
altering the place of accident, accident plan shall be prepared ( in duplicate) and
duly signed by manager or ACM, Safety Officer, Surveyor and workmen’s
inspector / workmen and a copy of the same shall be sent to DGMS.
Ans.5(c) Intrinsically safe circuits and equipmentIn every gassy seam of ll and lll degree, only flameproof or intrinsically safe
apparatus and equipment can be used belowground. An intrinsically safe
apparatus is an apparatus which is safe in itself.
Intrinsically safe as applied to apparatus or associated circuits shall denote
that any sparking that may occur in normal working is incapable of causing
explosion of inflammable gas or vapor.
In other words – Intrinsically safe apparatus means an apparatus which is so
constructed that when connected and used under the prescribed conditions, any
sparking that may occur in normal working, either in the apparatus or in the
circuit associated therewith, is incapable of causing an explosion of the
prescribed inflammable gas or vapour.
Electrical equipments are to be designed with great care due to sparking caused
by the discharge of energy from the reactive parts of the circuit at the moment
when the circuit is broken. Therefore, in most electric circuits used in mines, the
energy which causes the spark is stored in the magnetic fields created by
electromagnetic apparatus.
Some times a single small spark is capable of igniting air firedamp mixture.
Special type of circuits can be designed so that the discharge of reactive energy
is controlled and does not produce an incendive spark when the circuit is
broken. Hence to control the re-active energy, an electrical circuit is made
intrinsically safe.
Intrinsic safety can be obtained in circuits with a low power consumption i.e. both
the voltage of the system and the current flowing in the circuit must be limited. In
practice, intrinsic safety is confirmed to circuits for signaling, telephone, remote
control and monitoring.
Requirement of intrinsic safety:
The power obtainable from the source of supply must be limited so that
the reactive energy in the circuit does not any time exceed the limit of safety.

There must be a means of absorbing the reactive energy which is
released when the circuit is broken.
Use of Intrinsically safe circuits and equipmenti) In Deg. I gassy mine, at any place in-bye of the last ventilation connection,
Signaling, telecommunication or remote control be intrinsically safe.
ii) In degree ll or degree lll gassy mines, Signaling, telecommunication or remote
control circuits at all places shall be intrinsically safe.
Ans.5(d) Precautions where gas exists –
The following precautions shall be taken in respect of various u/g gassy mines
where gas exists:
A.
In Deg. I gassy mine1) Cables:- All cables at every place shall be constructed, installed, protected,
operated and maintained ( CIPOM) in such a manner as to prevent risk of open
sparking.
2) Intrinsically safe circuit:- At any place in-bye of the last ventilation
connection, Signaling, telecommunication or remote control be intrinsically safe.
3) FLP apparatus and enclosures:i) All electrical apparatus (including portable and transportable apparatus & light
fittings) in- bye of the last ventilation connection shall be flameproof
Provided that electrically operated or battery operated transportable apparatus
such as shuttle car, men and materials transporting equipment of Increased
safety type ‘e’ shall be permitted at any place with suitable monitoring devices
for detection of gasses.
B) In degree ll or degree lll gassy mines :1) Cables:- All cables at every place shall be constructed, installed, protected,
operated and maintained ( CIPOM) in such a manner as to prevent risk of open
sparking.
2) Intrinsically safe circuit:- Signaling, telecommunication or remote control
circuits at all places shall be intrinsically safe.
3) FLP apparatus and enclosures:i) All apparatus shall be flameproof within the range given below :Deg. II – 90m from nearest face or goaf or in bye of last ventilation connection or
in a return airway.
Deg.III - 270m from nearest face or goaf or in-bye of last ventilation connection
or in a return airway.
ii) All electric lamps (anywhere in the mine) shall be enclosed in flameproof
enclosures.
4) Disconnection & re-connection of supply in general:i) Supply shall be disconnected: Immediately, if open sparking occurs
 During the period of examination or adjustment of the apparatus which
requires exposing of any part liable to open sparking.
ii) Supply shall not be re-connected until the apparatus has been examined by
the Electrical Supervisor or one of his duly appointed assistants and until the
defect, if any, has been remedied or necessary adjustment made.
5) Provision of flame safety lamp and automatic gas detector:i) A flame safety lamp shall be kept burning near an apparatus ( including
portable or transportable apparatus) which remains energized, and if the safety
lamp indicates presence of inflammable gas, supply to all apparatus in the
vicinity shall be immediately disconnected and the incident reported forthwith to
an official of the mine.
ii) Where apparatus for automatic detection of inflammable gas or vapour is
employed in addition to the flame safety lamps, such apparatus shall be
approved by the Inspector of Mines and maintained in perfect order. The
apparatus shall be interlocked with the controlling switch in such a manner as to
disconnect the power supply automatically if inflammable gas exceeds 1.25% in
that particular district.
C ) Disconnection & re-connection of supply in case of detection of gas :i) In coal seam of any degree of gassiness, if inflammable gas in the general
body of air exceeds 1.25%, power shall be immediately disconnected from all
cables and apparatus in the area. Re-connection shall not be made till the gas
remains in excess of 1.25% except intrinsically safe environmental monitoring
scientific instruments.
ii) Such disconnection and re-connection shall be noted in the Daily Log
Book and reported to the Inspector of Mines.
(D) (i) Only DGMS approved FLP equipment and intrinsically safe equipment
shall be used in u/g mines.
(ii) Cables shall be as per BIS specifications.
(iii) Only intrinsically safe insulation testers/meggers shall be used.
Q.No.6. What is workers participation in safety management? How can this help to attain
high safety standards? Suggest suitable measures to improve safety
performance of unsafe workers.
Ans:-Workers participation in safety management:Safety in mines is the responsibility of everyone connected with the mine.
Since in almost all the accidents, workers are main victims, it was felt long ago
that workers should also be associated with the management of safety.
Mine safety in general means safety of mine as well as the persons
employed therein. Hence, if the mine is safe, the persons or the workers are
safe. It indicates that while the mine safety depends on planning, equipping
and devising appropriate technology on one hand, it is very much
dependent on the human factor on the other hand.
Those human factors include selection of right person for right job &
proper training.
For prevention of accidents, caused due to human failure, it is necessary
to involve all those persons whose safety is to be ensured in this process of
safety. This process may include:i. Safety promotion
ii. Accident prevention and
iii. Safety audit
This means that workers should be given the right of participating in the
safety management.
“Workers participation in safety management is the forum for
workers through which their trade unions, organizations or their
representatives and workmen himself play an important and active role by
contributing to the implementation of safety instructions, framing and
implementation of codes of practices and in accident investigation”
Workers meaningful participation would mean a conscious effort by them to see
that safe and healthy working conditions are established at the first instance
and there after every effort is made by all concerned to maintain the safety
system and curb the unsafe acts.
Workers participation in safety management forms a small but an essential part
of the total concept of workers participation. Re-cognising the importance and
fruitfulness of workers participation in safety management in shaping safe
behaviour at work, the mining industry and DGMS has taken several measures
to encourage the same. Over the years, this system is functioning and
gradually developing into an effective tool for enhancing safety.
At the national level, workers participation is ensured through participation of
trade unions in various committee and forums.
At various international forums also workers participation is provided in
framing policies where workers are stake holders. ILO, Geneva provides for
participation of workers representatives in formulating various instruments
aimed at providing equality and for workers health, safety, and welfare.
Following are the forums of workers participation in safety & management:a) Statutory forums:1. Safety Committee:- Under Mines Rules, a safety committee shall be
Constituted where 100 or more persons are ordinary employed. In this
committee, workmen, officials and competent persons etc. are nominated. In
large mines, sectional/departmental safety committees under the main
safety committee may be constituted for specific area of operation as per
recommendation of 9th safety conference.
2. Workmen’s Inspectors:- As per Mines rule, workmen’s inspector shall be
appointed in all mines where 500 or more persons are ordinarily employed.
As per recommendation of 9” safety conference, all mechanized mines and
mines using H.E.M.M. for exploitation of minerals, where 100 or more persons
employed, should appoint workmen’s inspectors.
3. Committee:- Under section 12 of Mines Act, a committee shall be
constituted by central govt. in which two persons representing the interest of
workers shall also be appointed by central govt.
4. Works Committee:- The Industrial dispute Act requires the employer of a
mine where 100 or more persons are employed to constitute a works
committee in the prescribed manner consisting of the representative of the
workmen and the employer.
5. Rights of the worker’s representative to inspect the register maintained
under the Mines Rules,1955– The register maintained in Form ‘B’ under the
Mines Rules, 1955 shall be available for inspection to a workers representative
authorised by the person employed in the mine on an application made by him
in this half.
6. Court of enquiry.- Under section 24 of mines act 1952, Central Govt. is
empowered to constitute court of enquiry in which representatives of workmen
may be appointed an assessor(s).
7. Right of work’s inspector or workmen to inspect the site of accident
and to put his signature on sketch plan of site of accident
8. Signatures of WMI on Accident Plan
b) Non- Statutory forms:
1. Tripartite safety committee constituted at company level and consisting of
representatives of DGMS, management and workmen.
2. Safety Board headed by Chief Executive of the Company and having MD’s
, Central trade union representatives, DGMS and a representative of the
ministry as its members
3. Representation of Central Trade Union leaders in standing committee
on safety.
4. Representation of workers organisation in National Conference on
Safety in mines.
5. Formation of Quality Circles.
6. As a members of Emergency organisation.
7. Member in risk assessment and risk management process
Workmen’s participation in safety management can help to attain high safety
standards in mine in following manners:i)
Inspection of mine workings, safety equipment and machinery to
identify hazardous conditions and defects and to check observance of
statutory safeguards. Proper inspection made at frequent intervals
help rectify unsafe conditions well in time and perhaps with lesser
effort.
ii)
Drawing attention of mine officials responsible for taking suitable
remedial measures in case of urgent and immediate dangers.
iii)
Involving themselves in company’s decision-making process
relating to safety and health and then accepting their portion of
responsibility for the results.
iv)
Playing useful role in accident enquiries by helping to bringing out the
real facts or root cause of the accidents for taking corrective actions.
v)
Enabling the higher officers of the management to suitability access
and appreciate the status of implementation of safety polices
dictated from corporate level.
Suitable measures to improve safety performance of unsafe workers:Safety performance of unsafe workers may be improved by taking following
suitable measures:i.
Establishment and enforcement of stringent safety regulation, byelaws and code of practices governing use of new mining machinery and
adoption of new mining technology.
ii. Elimination or control of physical hazards such as designing and
developing machines and systems incorporating automatic safety devices
that could function independent of human behavior.
iii
Imparting training & education to the unsafe workers for their
overall development.
 Imparting initial training- theory, on the job & feedback training
 Refresher training at an interval of 5 years.
 Development training for enhancement of knowledge & skill.
iv) Motivation: - Where as machines and equipment can be controlled, men
must be motivated towards safety to such an extent that they voluntarily
improve this performance and realize the intrinsic value of such effort.
v) Eliminating unsafe conditions, unsafe acts & unsafe practices
prevailing in the mines.
vi) Involving in Risk Management Process & preparation of safety
management plan.
vii) Making a compulsory member of safety committee.
viii) Involving in safety audit of mine, if deemed necessary.
ix) Involving in general inspection by DGMS
ix)
Making a member in emergency plan.
Suggested deterrents for habitual unsafe workers:- In addition to above
suitable measures for unsafe workers, the following deterrents are suggested:
i) Punishment for habitual unsafe workers in terms of issuing warning letter,
issuing charge sheets, suspension from the works and even removal from the
service.
ii) Trial in the court of law as per provisions contained in Mines Act for
contravention of statutory provisions and for deviation from safe practices and
safe acts.
Q.NO.7.Draw a ‘Code of Practice’ for deployment of Side Discharge Loaders in a
depillaring district in which a 5.0m thick seam is being extracted in two lifts in
conjunction with hydraulic sand showing.
Ans:- Conditions given :Thickness of seam – 5.0 mtr.
Method of work – depillaring by sand stowing in two lifts with SDL
Condition assumed
Depth of working – 100 mtr.
Support – Roof bolting as per approved SSR.
Make of water – Normal
Gradient of seam – 1 in 0
Condition of floor – Hard
Degree of gassiness- ll
Since any depillaring operation is risky, a suitable code of practice for safe
operation for SDLs should be framed, got vetted by tripartite safety committee
and implemented. The code of practice shall be as follows:1) Fittings of SDL- The SDL should be provided with safety & other protective
devices are mentioned below :
dump lever with key/push bottom switch

foot brake

temperature switch

oil level switch

adequate front and rear light

audio-visual alarm

Portable fire extinguisher

Dead man’s control where by power will be cut off automatically when the
driver leaves his seat.
2)
Operation:i. SDL shall be operated only by competent person authorized by the
manager. He shall not permit any other person to ride on SDL or interfere with
its operation. However during test and examination, it may be operated by an
authorized competent person other than the driver.
ii. Before putting the machine in operation, the operator shall ensure that the
machine and its accessories have been checked against a checklist and found
in proper working order.
iii. Operator shall give a pre-start warning before starting the machine and give
sufficient time to persons in the vicinity to move away.
iv. Trailing cable shall be protected from external damage during operation.
Helper will use insulated gloves for handling the cable. He shall maintain safe
distance from SDL in motion.
v. During blasting, machine shall be parked at a safe place.
vi. When leaving the working place, the operator shall keep the machine in a
safe position which does not endanger any person, lower the bucket to the
floor, turn and lock levers to neutral position and cut off energy supply from gate
end box. The same procedure will be followed at end of the shift.
vii. No person other than the operator shall be on the SDL when it is in motion
unless permission has been taken from the manager.
viii. No person should be allowed to stand besides the machine while the
machine is running.
ix. Control valve should not be used as a hand hold while climbing on to the
machine.
3. Ventilation:Minimum requirements:Quantity of air- At least 284 m 3/min upto 4.5m from the face,
Velocity- not less than 30m/min;
Inflammable gas in general body of air- not more than 0.5%.
SDL shall not be used out-bye of last ventilation connection.
4. Dust Suppression: - Water spraying upto 90 m from the face of blasting.
5. Other safety precautions:(i) Only approved type of hydraulic fluid shall be used.
(ii) SDL shall not be operated at a gradient more than 1 in 4, Roads shall be
kept clean and free from hindrance. Vertical supports shall be avoided as far as
possible.
(iii) No person shall cross the SDL during its movement.
(iv) It should be ensured that FLP features of SDL electricals/ gate end box are
in proper order, trailing cable is connected with suitable connector and the
machine is controlled by pilot circuit.
(v) For operation of SDLs with coal tubs, seam thickness should be min. 2.4m
(vi)There should be 1 m clear space on either side of the machine where it
works so that vertical support, if any used are not dislodged.
6. Examination and maintenance:- SDL shall be examined in each working
shift by competent person and once in 7 days by the engineer. It shall be
maintained as per recommendations of the manufacturer. Records shall be
maintained.
7. Code of standing order for supports:- Manager of the mine shall frame
SSR and formulate and implement a code of standing orders for supports of
mine workings specifying the method of erection, monitoring and withdrawal of
supports.
Q. No.8.Based on RMR value, design a support plan for support of weak roof for a
Continuous miner to be deployed in a development district.
Ans:- As the roof is weak and the development is to be done with continuous
miner, the width of the gallery is required to be kept minimum. For this purpose,
low height and low capacity continuous miner will be used for development.
Assumption:a) Machine details
C.M. to be deployed – 12CM12B series
Cutting width – 3302 mm
Cutting height- 1270mm to 3683 mm
b) Mining ParametersThickness of seam – 3.0 m
(Working height)
Depth of working – 120 m
Width of gallery, B – 4.2 m
Size of pillars – 30m x 30m (centre to centre)
Nature of roof rock – 1.2m intercalated shale/ sand stone (with two
intermediate thin bands of clay), 0.6m thick coal
overlain by sand stone.
RMR (Intercalated shale/clay/sst),R1 -38
RMR (Coal),R2 -51
Density of parting between two seams, D – 1.6 t/m3
Design of support systemi) Calculation of combined RMR & Categorization of roof:
Combined RMR = (R1 x t1 + R2 x t2 ) =(38x1.2 + 51x0.6)
t1 + t 2
1.2 + 0.6
=42.34 = 42(Say)
Adjustment of RMR: RMR is further adjusted for various geo-mining
conditions i.e. mode of drivage, lateral stress etc.
a) Method of excavation – Continuous miner(10% increase in RMR.
Adjusted for continuous miner (+10%) = 42x1.1 = 46.2
b) Again adjusted for lateral stresses (-20%) RMR =46.2x0.80=36.96
=37 (Say)
:. Adjusted / final RMR = 37, Hence the immediate roof is classified as
category lV, type – poor roof
ii) Estimation of rock load and support distance:
Rock load in gallery and at junction is calculated by the empirical
formula of geo-mechanics classifications developed by CMRI – ISM:
a) For gallery
Rock load, (Pr) =B x D (1.7 – 0.037 x RMR + 0.0002 x RMR2 )
=4.2 x 1.60 ( 1.7 – 0.037 x 37 + 0.0002 x 37 2 )
=6.72 ( 1.7 – 1.369 + 0.2738 )
=6.72 x 0.6048 = 4.06 t/m2 = 4 t/m2
Support Resistance - Considering the anchorage strength/ holding
capacity of 1.5m long bolt (22mm dia) made of M.S. ribbed steel to
be grouted to full length using resin capsules as 12 te after full
setting, support resistance/ bolt density/ bolt spacing will be
calculated as follows:
AS = Pr x a2 x F Where as = Anchorage strength of bolt (12 te )
Pr = rock load ( 4 te/m2 )
a2 = area supported by each bolt in m2
F = factor of safety ( 2- say)
:. a2 =
As = 12 = 1.5
Pr . F 4 x 2
:. a = (1.5) .5 = 1.22 m = 1.2 m ( Say )
b) For Junction:
Rock load = 5 x B 0.3 x D ( 1-RMR/100)2
(Pj)
= 5 x 4.2 0.3 x 1.6 x (1-37/100) 2
= 8.0 x 4.2 0.3 x 1(0.63) 2
= 3.1752 x 4.2 0.3
= 4. 80 t/m2
Similarly, spacing of bolts may be calculated as
a2 =
12
4.80 x 2.25
a2 = As
PjxF
Taking F = 2.25
:. a = 1.02 = 1.0m (say)
iii)Support plan:(a) For galleries: - Galleries shall be supported with 4 resin grouted bolts
of 1.5 m length. Spacing between the bolts in a row will be 1.2m and bolts
will be supplemented by bearing plates and w-straps.
The two side bolts could be inclined at 600 towards the pillars and 0.3m
away from the pillar on either side whereas, the central bolts would be
vertical.
(b) For junctions:- Junction will be supported using four bolts in a row at
1.2m row interval with 1.2m row spacing . Thus 6 rows ( 6 x 4 = 24
bolts ) would be required to support the junctions.
The support plan has been showed in fig.1
iv)Monitoring of support systems:(a) Anchorage testing of installed roof bolts – 9 % bolts should be tested
upto designed capacity and 1% may be subjected to destructive testing
at random under the direct supervision of Asstt. Manager.
(b) Monitoring of Strata behavior- Measurement of roof- floor
convergence and load on support would be done with the help of
convergence recorder & load cells respectively. Theoretically, maximum
convergence and convergence velocity shall be determined with the
help of following empirical formula.
Max convergence, Cm = 40 x B 0.3 x D ( 1-RMR/100)3 (mm)
= 40 x 4.2 0.3 x 1.6 x (1-37/100) 3
= 64.0 x 4.2 0.3 x 0.25
= 24.61 mm
Convergence velocity, Cv = .55 x B 1.7 x D ( 1-RMR/100)5.6(mm/day)
= .55 x 4.2 1.7 x 1.6 x (1-37/100) 5.6
= .88 x 4.2 1.7 x .0752
= 0.76 mm/day
The actual value of max. convergence & convergence velocity should be
compared with the calculated theoretical value & support plan should be
reviewed from time to time, if deemed necessary.
Afternoon Session
THE MINES ACT, 1952
Examination for Mine Manager’s Certificate of Competency under the Coal Mines
Regulation, 1957
FIRST CLASS
MINE MANAGEMENT, LEGISLATION & GENERAL SAFETY
Sunday, the 14th December, 2008
Full Marks: 100
Time
: 3 Hours
Answer any SIX Question
(All questions carry equal marks)
--------------Q.1.In the present day context of large demand of coal, what are the
recommendations of 10th Conference for safety in mines with respect to:
(a) Mechanization with a view to phase-out manual loading & to improve
standards.
(b) Reduction of risk from roof and side falls in coal mine.
Ans:-a) Mechanization with a view to phase-out manual loading & to
improve standards:- Limited potential of opencast reserves coupled with
environmental considerations, land acquisition issues and availability of better
grade coal at depth forced mining industry to extract coal from deeper horizons by
underground methods. At these mining depths, the only course left for ensuring
ever increasing production needs with high safety standards is to introduce
intense mechanization compatible to the geo-mining requirements. Therefore,
for the mining industry to gear up for such daunting situations ahead, it is
imperative that the present and manual mining situation be totally phased out and
a carefully designed mechanization era be introduced.
With the introduction of appropriate face mechanization, accident in mines have
shown positive downward trend due to reduced exposure/concentration of
workmen at active coal faces. The gravity of the problem of continuing with
manual work at bulk production fronts would be too intense for the mining
operators and therefore, calls for an immediate switch over in the production
policy towards face mechanization and reducing conventional crowded work-force
at the production fronts.
Taking into consideration the above facts, 10th National Conference on Safety in
Mines made the following recommendations:i) Identification & Introduction of appropriate technology:-Keeping in view
the objectives of phasing out manual loading, all coal companies should identify
appropriate technology suitable for the prevailing geo-mining conditions and
introduce the same in phased manner to phase out manual loading operations
completely within a period of next five years in coal seams with gradient of 1 in
5 or less and in 7 years in coal seams with gradient steeper than 1 in 5
ii) Compatible back-up facilities: - While formulating the strategies for face
mechanization in underground workings, this is to be ensured that back up
facilities like coal excavation, support system, ventilation arrangements etc, are
compatible with face mechanization.
iii) Scientific investigation for mechanization:- The scheme of face
mechanization should be based on proper scientific investigation. The scheme
should also include arrangements for monitoring strata behavior and
environmental conditions.
iv) Deployment of multi-skilled miners:- Possibility of deployment of multiskilled miners in the face shall be explored to reduce the exposure in
hazardous area without affecting employment.
v) Training:- Suitable training for efficient and safe operation of machinery
shall be imparted to all concerned.
vi) Long term sustainable technology: - While planning for face
mechanization due considerations should be given for long term sustainability of
the technology.
vii) Framing of Policy documents: - A policy document shall be framed by
each coal mining company within 6 months to address implementations issues.
It shall also be ensured that safety features are inbuilt into the system.
Ans:-b) Reduction of risk from roof and side falls in coal mine: - Owing to
continuous efforts by mining companies, research institutions, academicians and
DGMS, the accident caused by fall of roof and fall of sides have shown a down
ward trend. Still fall of roof and fall of sides are the major causes of accident in
u/g coal mines. An in-depth study of roof and side fall accidents in coal mines
during 1997-2006 by DGMS officials revealed the following:


Fall of roof has been responsible for 42% of u.g. accidents and fall of
sides for 16%. There has been a downward trend. These figures falling to
30% and 9% respectively in 2006
In development workings, area of freshly exposed roof upto 10m from the
faces continues to be critical.
In order to ensure safety in mines and also ensure reduction in roof fall and side
fall accidents in coal mines, 10th National Conference on Safety in Mines made
the following recommendations:i) Setting up of strata control cell- In every coal mining company, strata control
cell shall be established at corporate and area levels within 1 year to assist mine
managers in formulation of Systematic Support Rules and for its
implementation. Such cells shall be manned by adequate number of technical
personnel headed by a senior official not below the rank of Chief General
Manager at Corporate level and Dy.Chief Mining Engineer at Area level.
ii) Roof bolting as primary support- Roof bolting shall be used as a primary
means of support for freshly exposed roof in development as well as depillaring
districts. For the roof category “Poor” having value of RMR of 40 or less or
where there is excessive seepage of water from the roof strata, roof bolts
exclusively with resin capsules should be used to ensure adequate and
immediate reinforcement of strata.
iii) Side supports- Due emphasis should also be given to support the sides
while framing systematic support Rules.
iv) No work below unsupported roof- Suitable steps shall be taken by the
mining companies to inculcate the culture of no work at face other than support
work, till the roof is supported by roof bolts right upto 0.6m from the face.
v) Use of suitable roof bolting machine- To ensure proper drilling for roof
bolting in all types of roof strata, suitable, fit for use roof bolting machines
should be introduced in all mines within a period of one year. Such machines
should be capable of being operated from a distance or be provided with suitable
canopy to protect the drillers/roof bolters during drilling or bolting operations.
vi) Risk assessment- Risk assessment shall be carried out for assessing the
risk from hazards of roof and side falls and for identifying control
mechanisms with specific responsibility for implementation. This exercise shall
be reviewed at regular intervals not exceeding one year.
vii) Structured training- Each company shall take steps to impart structured
training to officers, supervisors and support personnel on roof bolting.
Q.2.What are the various problems of safety when a part of the work in an opencast
mine is outsourced? How will you ensure enforcement of Mines Act, Rules and
Regulations by the workers of the hired contractor?
Ans:- There is an increasing trend of contractual work in coal and non-coal
mines in India in recent years. This is due to need of introduction of modern
mining, access to specialized expertise and need to continually improve
efficiency in the face of strong national and international competition, especially
in view of entry of private entrepreneurs and multinational companies.
Mining industry, particularly the coal mining industry has in recent times been
open to the private entrepreneurs and many mines are being opened and
operated by private operators. Multinational Companies are also entering in to
the Indian Mining Industry for extraction of minerals. Out sourcing of certain
operations and equipment is also becoming quite common in the large public
sector or Pvt. Mines. But this is also adding some new dimension to the health
and safety aspects of mining industry.
Various problems of safety when a part of the work in an opencast mine is
outsourced:i) In many cases, the existing mine management structure is not suitable and
effective to control the interfaces with contractors.
ii) Big contractors award parts of the job to petty contractors not having
adequate capacity or concern for safety.
iii) Employees are purely temporary or migratory in nature and not conversant
with mining activities or laws.
iv) Employees are not given required training.
v) Contractors workers have more risk taking attitude as their earnings are
directly connected with output.
vi) Workers are put to extended hours of work and equipment used in many
cases is not fit for the purpose.
vii) There are hardly any medical surveillance and welfare amenities for
workers.
viii) Contractors consider safety as a cost component only ignoring work
conditions.
ix) Deployment of in-experienced, unskilled and ill health persons because of
their cheap availability.
x) Contractors having hiring and firing policy causing influx of unskilled
persons.
xi) ill maintenance of machines.
xii) Over loading of truck & dumpers.
xiii) Unauthorized driving and unauthorized riding
Ensuring enforcement of Mines Act, Rules and Regulations by the workers
of the hired contractor:
For ensuring enforcement of statutory provision by the workers of the hired
contractors, the code of practice for safety of contractor workers and machinery
shall be made by the mine management for the adoption in contractual
operations. The code of practice shall be as follows:
A) Code of Practice for adoption in contractual operations:
Sl.No.
Item
Practice to be followed
1
Training: All
(i) Before commencement of work against work
contractors’
order contractor shall give to the manager a list of
workers engaged his workers /supervisor to be trained as per VTl
on surface & OC
Rules and new VT module.
mines to be
trained.
2
3
Record in “B”
Form
Supervision
4
Issue of Identity
Cards
5
Attendance/
Working hours/
rest day
6
Rest Shelters
7
Safety
Appliances
8
Fitness
Certificate and
road worthless
of vehicle.
(ii) Persons required to be trained, shall be sent for
training by Manager.
(iii) A list of trained workers already available with
the contractors shall be furnished to be Manager.
Manager shall ensure that records of contractors
workers are maintained in Form – ‘B’ as per stature.
Statutory supervision of contractual operation by
departmental competent persons to be ensured by
Manager/Project Officer.
(i)Contractors shall issue identity card to all workers
under him.
(ii) Contractor shall be bound not to employee any
persons whom the Manager/Agent has reason to
believe that the person’s actions are unsafe to the
mining operations or who contravenes the
provisions of Mines Act, Rules and Regulations
framed there under.
Manager to ensure:
(i) Attendance of contractors workers shall be
recorded in the Form-D/E as per Mines Rules.
(ii) Working time on every day shall be limited to 8
hours spread over to a maximum of 12 hours
working shift. Weekly days of rest shall be ensured.
Contractors shall arrange for rest shelter with
drinking water facility to be provided near the place
of work failure which the Manager shall do the
same.
Manager shall ensure that all contractors’ workers
are provided with helmet, shoes & other safety
gadgets. In case of non-provision, the safety guards
shall be provided by him and the amount spent on
the guards deducted from the contractors bill.
Contractors shall ensure the use of helmets and
shoes by his workers.
(i) Before the start of transportation, the contractor
shall submit a list of vehicle/machines to be
deployed at the mine to the Manager/Project
Officer(Agent)
(ii) Fitness of all the vehicle/machines including AVA
shall be checked under the supervision of Colliery
Engineer.
(iii) Fitness Certificate of all vehicles shall be
checked by the Colliery Engineer and proper
records shall be maintained and in case of O/C with
more than 5000 tpd coal transport a separate
engineer with Foreman and mechanic having
automobile engineering back ground to be posted
for checking the vehicle.
(iv) After the checking of the vehicle and fitness
certificates, the Engineer shall recommend for the
issue of valid pass for vehicle/machines to the
9
Unauthorized,
driving / riding
10
Loading areas ,
Face supervisors
: Under Manager /
Overman /
Mining Sirdar.
Manager/Project Officer(Agent)
(v) No’ contractors’ vehicle/ machines shall be
allowed inside mine premises without valid pass
issued by Manager/Project Officer(Agent) of the
Colliery.
(vi) A qualified engineer to have overall
responsibility for daily/weekly checking and
maintenance of contractors’ vehicle. Contractors
shall authorize his engineer /foreman or mechanic
as competent person for daily/ weekly checking and
maintenance of vehicle/machines. Manager/Colliery
engineer shall confirm the competency of such
authorized person and ensure that the daily / weekly
checking of vehicles is as per standards.
(vii)Random
check
shall
be
made
by
Engineer/Safety Officer as regards fitness
certificates, brakes, lights, horns, AVA’S etc.
(viii) If any vehicle is found defective, the same shall
not be allowed inside the mine, unless the defect
has been rectified and vehicle certified to be fit by
the Colliery Engineer in writing.
(ix) The time of incoming and outgoing of
contractors vehicles in the command area should be
recorded in a register at the check post.
(x) Fail Safe Brake should be used in tippler.
(i) Contractors shall submit the list of drivers (whose
antecedents he believes are good) along-with their
valid licenses for verification and record by Engineer
and issue of authorization by Manager/PO(Agent).
No such drivers should be allowed without
verification of license/authorization.
(ii) No helper/ any-unauthorized persons shall be
allowed to travel in tipping trucks.Trained trip
man/helpers shall be provided at the loading and
unloading point and for the miscellaneous jobs at
key positions. Unauthorized ridding in vehicles shall
make both the driver and /or the unauthorized
person traveling liable to punishment.
(iii) Manager shall take all appropriate steps
including his authority of punishment to ensure
prohibition of un-authorized driving as well as
unauthorized riding.
They shall ensure that:(i) Pay loader operation Zones and the parking sites
of trippers for loading and waiting are well defined
and
marked
to
avoid
unnecessary
movement/reversal of vehicles and pay loader at
the face and also for unauthorized parking.
(ii) No unauthorized persons shall be allowed in pay
loaders operation zone and tippers loading/ waiting
zone while loading and transportation are being
carried on at the face.
(iii) Safe distance shall be determined and
maintained.
(a) Between pay loader and tipper stationed for
loading
(b) Between two trippers on movement
(c) From the toe of the benches.
(d) From the edge of the benches.
11
12
13
Roads/Transport (i) A parking area for contractors vehicles/ machines
shall be fixed by Colliery Engineer in consultation
with PO/Agent of the mine.
(ii) The number of vehicles allowed to enter the
mine premises at a time should be fixed by
PO(Agent)/Manager of Mine.
(iii) The rest shelter for drivers/operators should be
made outside the barrier.
(iv) Manager shall ensure that all provisions of the
condition of the use of HEMM issued by DGMS are
complied .
(v) One way traffic should be adopted for movement
of vehicles. However, in extreme case whenever it
is not possible to make one way traffic, alternative
may be used only after approval of Agent of the
Mine.
(vi) Separate roads/lanes of HEMMs and
contractors tripping trucks and for pedestrians shall
be provided.
(vii) Ramps and curved sections of the haul roads
shall have adequate curvature and super elevation
designed in accordance with the speed and height
of vehicle plying on them.
(viii) Escape lane or escape road shall be provided
where there are chances of over speeding or roll
back of vehicles in motion.
(ix) Code of Traffic Rules, dumping practices,
signaling and communication shall be framed and
implemented.
Dumping Place
(i) Sufficient dumping place shall be ensured by the
Manager to avoid over crowding.
(ii) Sufficient level space shall be provided on ramps
close to unloading point for unloading, reversing
and authorized parking.
(iii) Dumping and manual loading shall not be
allowed at the same place.
Parking
i) No vehicle shall be parked on slope/gradient. If it
is unavoidable, hand brakes shall be applied firmly,
engine stopped, vehicle kept in gear and stop
blocks against the wheels used.
ii) The engineer shall ensure that adequate
numbers of stop blocks are always kept in the
vehicle. In addition, he will also ensure that tow start
vehicles are not allowed on the road.
iii) Adequate level parking place should be created
near loading point, CHP/Feeder Breaker/ Weigh
Bridge, dumping place etc for incoming tippers.
14
Surface
i)Jobs shall be done under the supervision of
Electrical Jobs
Engineer/Supervisors.
ii) The Engineer/Supervisors shall ensure that
proper shut down procedures for working on live
lines are followed.
iii) Code of Safe Practices shall be framed by
Colliery Engineer for implementation on such jobs.
B) In addition to above code of practice, the following role and responsibilities
should be played and shouldered by mine owner & contractors for enforcement
of statutory provisions in outsourcing activities as recommended by 10th Safety
Conference:.
a. Managements responsibility i) Inclusion of suitable clauses in the tender document stating how risks arising
from contractual work will be managed
ii) Ensuring that contractors are familiar with relevant statutes, health & safety
management system and are provided with copies of such documents prior to
commencement of work.
iii) Ensuring that contractor’s arrangements for health & safety management are
consistent with those of the principal employer.
iv) Ensuring that contract shall preferably be for longer periods so that there is
an adequate scope for management of safety by contractors.
v) Ensuring that contractor provides fit – for – purpose machinery, operators
and other staffs are provided with written safe work procedures.
vi) Monitoring of all activities of contractors to ensure that they are complying
with all the requirements of the statutes and safety system, in case of non
compliance contractors should be suitably penalized.
b. Contractor’s responsibilitiesi) Preparing written safe operating procedure for the work to be carried out,
including risk assessment and safe method to deal with the risk and providing a
copy of SOP to the person designated by mine owner who shall be supervising
the contractor’s work.
ii) Keeping the SOP up-to-date and providing a copy of changes to the
designated person.
iii) Ensuring that all work is carried out in accordance with the statue and SOP
and deploy adequate qualified and competent persons for the jobs.
iv) Developing and providing site specific code of practice for specified work to
mine owner.
v) All persons deployed by contractors for working in the mines shall undergo
vocational training, IME & PME.
vi) Every person employed by contractors shall wear safety gadgets either
provided by contractor or by mine management
vii) Contractors shall submit quarterly or monthly return indicating details of
contracts, persons engaged, training and medical facilities provided etc to DGMS
for contracts more than one year or less than one year respectively.
Q.3. What is workers participation in safety management? How can this help attain
high safety standards? Suggest some deterrents for habitual unsafe workers.
Ans:- Refer to Q. No. 6(2nd Class-2007)
Q.4.Enumerate various types of instruments (along with the objective, principle and
functioning of each) which are used for monitoring ground movement in a deep
underground mine.
Ans:- Monitoring of the ground movement and stress build up around the
excavation through systematic instrumentation helps to evaluate the stability of
the openings. Instrumentation can help in design verification. With suitable
instrumentation programme, one can work with a safety factor near unity.
Under such conditions, monitoring would provide warning of potential
problems for advance action.
The essential features of instrumentation are:a) Proper layout – location of instruments, type and number are determined in
advance according to the requirement of the Project.
b)Accuracy- a good instrumentation programme should have reliable
instruments with the required accuracy.
c) Recording- frequency and duration of the monitoring scheme should be
strictly followed as decided during layout stage.
Monitoring Ground Movement – Excavation of u/g openings results in
movement of the roof and wall rocks. Ground movement monitoring would
provide useful information to evaluate the stability of these openings.
Various types of instruments used for monitoring ground movement in a
deep u/g mines:
1. Closure meter or convergence recorder:Objective:- To measure the relative ground movements, between two
exposed rock surfaces of an excavation, usually the opposite ones, like roof and
floor, hang wall and footwall etc. If one of the two reference surfaces is free from
any movement, closure measurements give the absolute movement of the other
surface.
Principle:- Working principles of closure meter are as follows :

Mechanical closure meters- Works on mechanical including hydraulic
principles and have the advantages of robust construction and simplicity of
design.

Electrical closure meters- It works on electrical & electronics principles
and have the advantage of versatility and flexibility and are easily adopted
for continuous and automatic monitoring and recording and remote
control.

Seismic closure meters- Works on the principle of seismology and are
very sensitive and accurate and helps in certain measurements which are
otherwise impossible.
Functioning:- Telescopic closure meter or convergence indicator is a very
simple instruments consisting of a graduated rod ( with a least-count of 0.5 – 1
mm) fitted in a pipe for telescopic movement over a length of 2 to 4 m. The
measuring points are metal rods grouted in the rock at the desired locations.
Measurements are taken by simply stretching the telescopic rod between the
reference points and reading the graduations on the rod.
To measure closure at inaccessible locations, electrical closure meter can be
used. In this instrument, a rheostat is fixed to the telescopic portion of the rod
and a pointer is attached to the pipe in which the telescopic rod moves over a
high tension spring. The instrument is permanently fixed between the reference
points and measurements can be taken from a distance.
2. Borehole extensometers: - Extensometers are one of the principal
instruments used to measure rock deformation.
Objective: - To directly measure/monitor relative or absolute movements in
un-exposed rock mass as well as bed separation.
a. Tape extensometer- To measure changes in distance between two
reference points in any direction.
b. Multipoint borehole extensometer- To measure relative displacement of
bore hole anchors which are fixed to rock mass units along the axis of the drill
hole.
c. Sonic multiple point extensometer- To monitor horizontal pillar expansion
and the growth of the yield zone in a chain pillars.
d. Wire extensometer- To measure axial displacement between a numbers of
reference points on the same measurement axis.
Principle:- Depending on the type of instruments, extensometer works on
mechanical, magnetic and electromagnetic system, seismic and micro seismic
principles as explained earlier.
Functioning:Tape extensometer can be used to measure closure between points upto 30m
apart with accuracy of 0.05-2m. It is made of precision invar steel measuring
tape with punched holes. For taking the readings, the free end of the steel tape is
hooked to the remote reference point and the instrument is hooked to the nearest
point. The steel tape is pulled taut and tension applied to the tape. The dial
gauge reading after tensioning indicates the reading for the site.
For measuring the extent of movement inside the wall rocks (or in the
pillars), at grater depth, multipoint extensometer are used. It consists of a
transducer head, usually installed at the collar of a drill hole and a number of inhole anchors, each of which is fixed in place at a known depth in the drill hole. As
the rock adjacent to the drill hole is deformed, the distances between adjacent in
hole anchors change, as do the distances between the individual in-hole anchors
and the transducer head. These changes are measured, and the resulting data
are used to compute the distribution, magnitude, rate and acceleration of
deformation in the rock intersected by the extensometer drill hole.
In the wire type multi point extensometer, expansion shells are used as
anchors. A stainless steel wire of 1-2 mm diameter is attached to the anchor.
The free end of the steel wire hangs through a collar station, to which a portable
readout unit can be easily attached. The readout consists of a micrometer head
and a dial gauge that serve both as tensioning and measuring devices.
Sonic multiple point extensometers consists of a 7.6m long probe which is
inserted inside a guide tube located along the borehole axis passing through all
20 or so snap-ring borehole anchors. A magnet is located within each anchor.
The position of each magnet relative to either the head of the extensometer or to
a neighboring anchor is measured and displayed directly on the readout unit.
Tell Tale systems are simple wire extensometers which give a visual wearing of
rock deformation through movement of an indicator, anchored in a small
diameter borehole. It is now possible to integrate about 400 telltales into a mine
wide monitoring system with the use of computer plus software development.
The standard display provides information on the current reading and recent
history of all the connected telltales. Individual warning and action levels can be
set for each telltale, both as absolute levels and rates of change.
3. Stress meters, Earth pressure cells and Micro seismic geophones:Stress meters in use at present are electrical ones, either vibrating wise based or
resistance strain gauge based. Generally, vibrating wire type instruments are
more reliable for long term monitoring than strain gauge based instrument.
Objective:- To measure/monitor changes in in-situ stresses in rock as the
excavation continues and to predict the stability of the openings.
Principle:- The basic principle of the vibrating wire stress meter is that the
change in natural frequency of a stretched wire is proportional to the change of
tension in the wire.
FunctioningThe vibrating wire stress meter can be installed with the help of installation tool in
a bore hole; with its ring-wedge tightened across the diameter. A vibrating wire is
put under tension across the diameter. Changes in rock stress distort the ringwedge, thus changing the resonant frequency of vibration of tensioned wire. The
square of the vibration frequency is directly proportional to the change in the
diameter of the gauge and is calibrated, to the change in the stress of the rock. In
other variation, the coil / magnet are used to vibrate the wire at its natural
frequency in the pre-loaded condition. Stress changes in the surrounding rock
cause small change in the diameter of the hollow cylinder.
Pneumatic Earth pressure Cells can be installed in slots at shallow depth
(maximum 2m) from the excavation surface. The pneumatic cell may be grouted
in boreholes at much greater depth, the reach of grouting system, the capacity of
drilling facility available and the length of cable being the limiting factors.
Micro seismic geophones record the level of emission of micro seismic waves
from the rock mass under stress. Re-distribution of in-situ stresses at or in the
vicinity of the site of monitoring is clearly indicated by the anomaly in frequency
and magnitude of emission of these waves. These may be used to predict rock
burst/ coal bumps and roof falls in coal mines.
4. Strain gauged roof bolt:Objective- To measure the strains developed in the bolt at up to mine locations
along the length of the bolt.
Principle: It works on the principle of wheat stone bridge. The gauges are photo
etched resistive elements which, when affixed to a material to which a stress is
applied, changes their resistance in proportion to the strain in the material. If the
gauge is in one arm of a wheat stone bridge circuit, the resistance change will
be seen as bridge unbalance which creates a voltage differential between
opposing corners of the bridge and it is this voltage which is amplified and
measured by the strain Bridge Monitor.
Functioning:- This is a strain- gauged mild steel 1.5 m / 1.8 m long bolt with 9
pairs of gauges bonded into two long slots along the bolt. The strain values
measured for each of the gauges are processed by a computer programme to
calculate the axial force, the bending moments, the axial strains and the bending
strains generated in the bolt.
Instrumental bolts are connected via a cable to read out locations, 10-15 m away
from the installation site. This enables the instruments to be monitored safety
during mining operations and without causing delays to production.
(5) Australian New Zealand Inflatable(ANZI)Cell:Objective:- To measure in-situ stresses and stress changes in rock strata.
Principle:- It works on electrical principles.
Functioning:The ANZI cells are essentially an inflatable membrane type of low modulus
polyurethane material with strain gauges on its outer surface. It has a pressure
meter design that enables 18 electrical résistance strain gauges to be
pressure bonded directly to the rock of a bore hole wall. To install the ANZI Cell,
the surface of the membrane and the strain gauge are coated with low slump
epoxy cement. The instrument is inserted into a bore hole and pneumatically
inflated at the location where the measurement is to be made. Once the cement
has cured, a pressure test is conducted using ANZI Cell as a bore hole
dilatometer or pressure meter. The configuration of strain gauges carried on the
instrument can be varied to suit rock conditions.
6) Load Cells/ DynamometersObjective- To measure the load on active supports, evaluate effectiveness
of support system and monitor the support performance.
Principle- It works on mechanical & hydraulic as well as electrical and photoelastic principle.
Functioning- While mechanical and photo-elastic devices measure the support
load directly, in electrical devices, load is estimated indirectly from the resultant
strain occurring in them due to loading.
Loads cells are mechanical, hydraulic or electrical. Of these, electrical load cells
give precise readings. This could be strain gauge or vibrating wire type. In strain
gauge load cells, electrical resistance strain gauges are bonded to the periphery
of a spool of heat treated steel or aluminum cell. The gauges are mounted in a
full bridge configuration that compensates for unevenly distributed loads. They
can be remotely read.
In case of hydraulic load cells, a cell is first placed in a proper bore hole and
then pressurized hydraulically with the use of hand pump suitably connected to
the flexible tubing. Uni-axial stress change can be monitored at that localized
position where the cell is placed in the bore hole. The flat jack is connected to a
hydraulic diaphragm transducer that in turn is connected by flexible tubing to a
dial gauge showing the stress change.
Rock bolt load cells are used to measure the variation in bolt load. In case of
full column bolts, strain gauges are fixed on the bolt at different intervals so that
the stress transfer from the ground to the bolt at different horizons could be
monitored.
Q.5.Enumerate the provisions of Mines Rescue Rules, 1985 regarding any two
of the following:
(a) Establishment and location of rescue stations.
(b)Appointment of rescue trained persons in mines, their disposition and
accommodation.
(c)Apparatus and equipment to be provided in a belowground mine where
no rescue room is located.
Ans:- 5(a) Establishment and location of rescue stationsRefer to Q. No. 3(a) (2nd Class-2007)
Ans.5 (b) Appointment of rescue trained persons in mines, their disposition
and accommodationRefer to Q. No. 3(b) (2nd Class-2007)
Ans.5 (c)Apparatus and equipment to be provided in a belowground mine
where no rescue room is located.
As required under rule 11(3) of the Mines Rescue Mines 1985, at a
belowground mine, where no rescue room is located, the following minimum
apparatus and equipment shall be kept available in perfect working order at the
surface of mine:Type of apparatus & equipment
 Pressure type tube apparatus with bellows
 Flame safety lamp with maintenance tool kit
 (i) CO detector
(ii) CO tube
 Whirling hygrometer
 Safety belt
 Resuscitating apparatus
 First aid box
 Blankets
 Folding stretcher
 Self rescuers
Min.Nos. Requid.
Remarks
1
1
DGMS approved
1
DGMS approved
10
10
1
1
1
1
2
1
DGMS approved.
However in case of belowground coal mines having a fiery seam or gassy seams
of second or third degree, the Rescue room shall be established and maintained
and the rescue apparatus & equipment as specified in schedule II of Mines
Rescue Rule’1985 shall be kept available in perfect working order if required by
CIM by written specific order stating the reason for the same.
Q..6.Write short notes on any four of the following:(a) Angle of draw and its relevance in longwall mining.
(b) Risk assessment as a tool to improve safety.
(c)Vocational training as an effective tool in improving safety &
productivity.
(d) Role of Internal safety organisation in reducing accidents.
(e) Direct & indirect costs of accidents.
(f) Use of diesel locomotives.
Ans:- a) Angle of draw and its relevance:- Subsidence is the downward
settlement of ground due to an u/g excavation. It occurs as a symmetrical
trough which is always larger than the excavation. Vertical movement less than
5 mm are neglected, so that the limit of subsidence is defined by all points which
subsides by 5 mm.
It is a manifestation of the action of gravity on strata which have been
rendered unstable by the withdrawal of their natural support over a sufficiently
large area. All the strata from the coal seam to the surface sink slowly at different
rates, until in the course of time with the development of opposing forces,
equilibrium is restored at the lower level. Apart from vertical subsidence, lateral
movement and change in slope occur at the surface.
Angles of draw – It indicates the limit upto which subsidence takes place. It is
used to determine the extent of subsidence trough over the surface in reference
to the extraction perimeter underground. The angle of draw is the angle
subtended by the line joining the limit of subsidence and the edge of
excavation with the vertical.” It is also called the limit angle. Nowadays it is
also defined as the angle between the horizontal and the edge of the
subsidence through from the edge of u/g working
Angle of draw depends upon the following factors:(i) Nature of overlying strata- In soft strata, the draw is greater while it is less in
brittle hard rock. Harder is the strata, smaller is the angle of draw and viceversa.Higher proportion of shale in strata increases the draw. Indian strata have
0-36% shale and a lower draw than UK, where shale is higher. European coal
fields have higher draw (250-430) because of softer strata where as Indian coal
fields have lower draw (40-210 ).
ii) Existence of faults and their location- The faults tend to arrest and also
extends the subsidence trough depending upon the direction of the working face
in relation to the strike of the fault.
iii) Cleavage / Natural joints of rocks - If the line of advance is parallel to the
natural joints, it will tend to reduce the angle of draw but at right angle, the effect
will be minimum.
iv) Dept. of seam: - The angle of draw depends upon angle of dip. The influence
of the dip of the seam is to reduce the angle of draw on rise side of the working
and to increase it on the dip side of the working.
Mathematically,
βr = βh – K.Sin 2 α
βd = βh + K.Sin 2 α
where, βr = angle of draw in rise side
βd = angle of draw in dip side
α = angle of dip
βh = angle of draw in horizontal workings.
K = a constant.
v)Thickness of seam – Thick seams when worked by slicing in descending
order with caving may result in more subsidence and also in increased angle of
draw.
Significance of angle of draw in longwall as well as in B/P workingsFor assessment of boundary conditions in order to predict subsidence, slope
and strain profiles in depillaring operations, the knowledge of angle of draw is
essential. The angle of draw gives a true picture about the extent and magnitude
of surface subsidence in different strata conditions. Hence it is very much
relevant in managing and controlling the effect of subsidence. Ground
subsidence causes damage to surface structures. The maximum damage
occurs where the curvature is maximum and not necessarily where the maximum
subsidence occurs. The ground straining occurs as a result of differential
movement which may be in tension or in compression and causes damage to
surface structures. It may also cause damage to upper level workings and also
to roads and shaft linings if they are crossed by the limit plane. The gradient of
the floor of the top seam workings may change and roadway pillars may develop
fractures.
The ground surface within the subsidence through is subjected to displacement
( horizontal and vertical), tilt, sag ( change in gradient per unit length) and
strain, which must be kept within the permissible limits for the safety of this
surface structures (building, plants, rail tracks etc) and sometimes the mine
workings themselves:Angle of draw & angle of slide are the main factors used to determine the
extent of subsidence as mentioned below:
i) Ground displacement can be estimated from this value of angle of draw by
the following formulav= k.h.(tan β)i
where, v = ground displacement
h = depth for working
β = angle of draw
K = a contant.
i = ground slope.
ii) Radium of shaft pillar:
R = K1 + h1 tan 45º + h2 Tan β
(m)
Where K1 = a constant
h1 = thickness of soft cover
h2 = thickness of hard cover
β = angle draw
β = 25º for flat seams of gradient less then 15º
40º on the rise side of the shaft for steep seam (up-to 35º)
20º on the dip side of the shaft for steep seam (up-to 35º)
In B/P method of working, partial extraction system of workings is adopted to
extract as much of the coal as possible while providing permanent support with
an acceptable factor of safety to prevent subsidence. The concept of angle of
draw is used for determination of size and distribution of coal pillars to provide
permanent support of the surface structure and is given by
SA = 2[(tan β.h) + Sz] + L + (SL.h)
Where SA = length of the side of the support area
β = angle of draw
h = depth of cover
Sz = safety zone/ additional protection zone
L = length of structure
SL =slope of the ground surface away from the protected structure.
Ans:- b) Risk assessment as a tool to improve safety:- Risk assessment is a
process whereby risk management priorities are evaluated. The objectives of risk
assessment are: Identification of risks which need to be reduced and options for risk reduction.
 Identification of risks which need careful ongoing management and the nature
of ongoing controls.
 Identification of risks which can be tolerated.
Considering the accident scenario in Indian Mining Industry, it has now
become essential that risk assessment be undertaken of all hazardous
operations, equipment and machinery taking account of the procedures used,
maintenance, supervision and management. The process involves the entire staff
in the realization of safety improvement programme with responsibility and
accountability sharing proportionate to the decision making authority.
It is now widely accepted world over that the various techniques of risk
assessment and risk management contribute greatly toward improvement in the
safety of mining operation. It aims to improve the understanding of the potential
for accidents, their possible consequences and the adequacy (or inadequacy) of
the various safeguards.
Risk assessment plays a vital role in hazard identification in mines. It proves a
potent tool in improving safety standards because of the following reasons:i) It helps management in preparation of mine specific action plan to mitigate
the risks.
ii) It helps in preparation of safety management plan for its implementation in
potential mines.
iii) A well laid emergency preparedness plan / pre-monsoon action plan can be
prepared for every mine every year to take care of any emergency situation.
iv) It helps in preparation of documents related to:
 Code of traffic rules for regulation of movement of machine.
 Code of practice for safe operation of mining machinery.
 Formation of safe work practices.
v) It helps in elimination of unsafe condition, unsafe acts & unsafe practices.
vi) It helps in obtaining certification for mines in respect of:
 Quality management system ISO 9001 : 2000
 Environment management system ISO 14001 : 2004
 Occupation health & safety – OSHAS 18001 : 1999
Ans:-6(c) Vocational training as an effective tool in improving safety &
productivity- The vocational training and the safety as well as productivity are
inter-related. Training helps in improved quality of work and high morale.
Systematic training efforts are reflected in higher productivity and committed
work force. An effective training to the work personnel of mining industry will
reduce the overall accident and the cost involved in it. Mine workers are imparted
training suitable to their respective vocations with a view to achieve improved
knowledge, skill and correct job procedure which in turn improves
productivity and safety standards in the mining industry. It is an apt to effect
considerable changes in attitudes, behavior and thought process of human
being. It can bring forth:



Consciousness and awareness of the problems and situations.
Change of behavior in the positive direction.
Improvement in skills in operation and maintenance and better
understanding of individual action, new conditions and changed
environment.
 General improvement in living conditions which can reduce mental stress.
 Change of attitude to achieve a unified and unidirectional approach of the
groups to achieve the desired goal.
An effective, scientific and modern vocational training programme provides the
following outputs:i. improves knowledge on operation, maintenance, management, safety and
others.
ii. improves skill of the worker.
iii . improves safety standard of the mine and hence reduces mine accidents.
iv. gives guidelines on correct job procedure.
v. improves efficiency of the workers.
vi. imparts knowledge on handling of machine, tools and method of workings.
vii. enhances the team spirit, fellow feeling and makes the workers more social.
viii. enhances high morality, job satisfaction, strong national feelings, etc.
ix. enhances efficient use of material.
x. reduces much of supervision, wastage of time and also reduce the production
cost.
xi. enhances motivation, grows self realization and responsibilities.
xii. improves the quality and makes ease of management by the mine official
since workers are also trained on the policy of mine management.
xiii. assists better development and growth of the mine organisations and
companies as a whole.
All the above mentioned outcomes cause an outstanding performance by human
and ultimately improve the production, productivity and safety of the mine.
Ans:-6(d)- Role of Internal safety organisation in reducing accidentsAs per recommendation of Gugnani Committee, in each mining company ISO
was set up. ISO is a channel for transmitting the guide lines on the safety
policy of the company including short term and long term objectives into
action programmes and for feed back on the state of its implementation. It
is a basic ingredient of self regulation which is based on the sound premise that
internal safety promotion can be more effective than external enforcement.
The major functions of the ISO are contained within the following four basic
areas:i) Identification and appraisal of accident producing conditions and practices
and evaluation of the severity of the accident problem.
ii) Development of accident prevention methods, procedures and programme.
iii) Communication of accident control information to those directly involved.
iv) Measurement and evaluation of the effectiveness of the accident control
system and the modifications needed to achieve optimum results.
ISO plays active roles in reduction of accidents by taking following
measures/actions:
Risk assessment & risk management exercise for various mines within
the organisation to ensure safety of mines and reduction in accidents.

Inspection by senior officials of ISO in back shift to improve the
supervision level.

Arranging for safety audit of mine of the organisation.

Regular monitoring of safety status in mines.

Ensuring supply of safety materials, safety appliances & apparatus.

Conducting mock rehearsal for checking of emergency preparedness.

Conducting safety drives in mines time to time involving key officials in
inspection team.

Organising workshop for various safety aspects of mining.

Organizing orientation training for mine managers & other statutory
officials.

Co-ordination meeting & brain storming session on safety at different
levels of company for critical analysis of accidents and incidents.

Vetting of plans and applications for seeking permission, relaxation and
exemption from statute to statutory authority.

Issuance of safety clearance for opening a new mine / district.

Enforcing the statutory provisions in mines by regular inspection.

Enquiring into all fatal accidents and studying the cause of accidents and
making necessary recommendation for improving safety.

Helping company in formulating safety policy.

Monitoring the implementation of recommendation of various safety
conferences, recommendation of court of enquiry and committee on
safety in mines.

Ensuring implementation of directives issued by corporate safety Board
in the Mines.

Keeping liaison with DGMS and other organization for implementation of
safety provisions.

Channelising the research in safety matters in close collaboration with
research and scientific institution.

Formation and functioning of the safety research and standardization
wings in the organisation.

Scrutiny of Abandoned Mine Plans before submission to statutory
authority.

Reviewing functioning of safety committee and workmens inspector
and giving suggestions for improvement.
Ans:-6(e)- Direct & indirect costs of accidents- Accident in no way causes
gain or benefit to an individual, firm or company but always remains a damager,
painful and loss maker. Accident does not happen but it is caused. There will be
no interruption of production and productivity if the firm or company is free from
accident. There will be neither loss of man-shift nor psychological upsetting in
co-workers and friends.
Mine executives are responsible for running their business profitably. Reliable
and detailed cost information is essential for determining the efficiency and
profitability of the business. Hence it is logical to compute the cost of accident
and cost of expenditure on programme listed for accident prevention so as to
estimate the savings made through expenditure for accident prevention. It is
considered useful to prepare monthly reports showing the cost of accident per
tonne of coal raised. The reduction in such costs by good accident records will
work as a motivating factor for the mine executive concerned with overall cost
and profitability for attention towards safe work procedures.
The employer, the state as well as the community at large have all
considerable financial interest in preventing accident in mines.
Elements of cost of accidents:i) Cost to Employer.
ii) Cost to Employee.
iii) Cost to State.
iv) Cost to community at large.
Direct Cost
Indirect Cost
i)Cost to Employera. Medical treatment and ex-gratia payment. a. Loss of Employee’s scheme.
b. Compensation paid under WCA.
b. Loss of uniform and / or estim
c. Pension paid
ated production.
d. Employee pro-rata plant increased
c. Investigation of accident an
e. First aid
preparation of accident reports.
f. Loss of production due to temporary
d. Increase in labour tension.
stoppage of work
e. Lessened goodwill in public &
g. Plant damage / loss and cost for repairs /
employees relation.
replacement.
f. Breaking in new men.
h. Cost due to loss of time of co-workers.
g. Damage to the tools
i. Extra cost due to OT work.
&equipment
h. Loss of time for the period, the
damaged equipment was out of
order.
i. Spoiled jobs.
j. Failure to fill orders.
k. Loss of revenue for loosing
contracts and even markets due to
fall in production.
l. Overhead cost while wok was
interrupted.
ii) Cost to Employee
a. Decrease income.
a. Personal Pain & Mental concern
b. Financial Loss attributable to decrease
income.
c. Loss or decrease in future earning power.
iii) Cost to State
a. Ex-gratia payment if any made under
welfare scheme.
b. Cost of medical arrangement including
rehabilitation and retraining provided by
Govt. organisation.
c. Loss of tax due to decreased profitability of
the mine undertaken consequent upon the
accident.
d. Loss of state owned insurance Company
with whom the victim of accident was
insured.
iv) Cost to community at large.
a. Cost incurred by benevolent funds etc.
b. Cost on the injured persons himself for
making arrangements for looking after him.
c. Loss of earning capacity of the partially
disabled workers.
b. Inability to enjoy normal
relations.
c. Increased difficulties in matters
of family life.
d. Deterioration in morale.
e. Economic Loss to the family of
injured.
f. Loss of time of the fellow
workmen.
a. Cost of Establishment
maintained for making payment.
b. Cost of public services for
making investigation into the
accident and maintaining law &
order in certain cases.
a) Cost of investigation into
accident.
b) Cost of procedure entailed the
claiming damages/ compensation.
c) Loss of services and other
material gain provided by the
victims of accident.
An objective analysis of elements of cost of accident will indicate that the needs
of safety are not in conflict with needs of production. On the contrary, it may be
seen that economizing on safety is counter productive.
Statistics reveal that the indirect cost due to accident may be as low as 1: 1 and
as high as 20: 1 as compared to direct cost. An average figure may be taken as
4: 1
Realisation of the enormous cost of accidents, both injury and non injury type,
has led to the development of a new approach to safety i.e.:
 Damage control
 Total accident control
 Total Loss control
The philosophy behind the approach is that the emphasis has to be on “accident
prevention” rather than injury prevention. As a matter of fact, majority of
accidents/ incidents are precisely those which do not involve physical injury.
Ans: 6(f) Use of diesel locomotives1) Statutory Provision- As per Reg. 95 of CMR, 1957, following are the
statutory provisions in respect of use of diesel locomotives:
i. No locomotives shall be used belowground without prior written permission
of CIM.
ii. No locomotives shall be used where the gradient of the track exceeds 1 in 15
iii. No person other than the driver shall ride on any locomotive unless
authorised in writing to do so by the manager.
iv. Except during shunting operations, the locomotive shall lead the tubs or set of
train of tubs.
2. Construction of locomotivesi. Locomotives and its accessories shall be of non-inflammable material.
ii. No engine other than that worked by liquid fuel of flash point not less than 68ºC
shall be used. The engine will be of compression – ignition type.
3. Locomotives tracks, roads and roadwaysi. Track shall be ballasted and where necessary drained and rail joints secured
by suitable fish plates.
ii. Weight of rail per meter shall not be less than that permissible limit.
iii. Distance between the centers of adjacent slippers shall not exceed 1m.
iv. Ventilation Velocity of air current not less than 30 m / min.
 Inflammable gas in the general body of air not more than 0.5 % at any
point in the roadway.
 Carbon monoxide in general body of air not more than 0.01%
 Oxides of nitrogen in general body of air not more than 0.001%
Where more than one locomotives are used in any road or roadway in common
ventilation circuit, such additional quantity of air shall be supplied in the road or
roadway as will be necessary to satisfy the above requirements.
v. Clearance from roof and sidesLocomotive shall not be used in any road or roadway where there is not after
allowing for the swing of the locomotives and the tubs and trolleys, clear space
not less than the following:
a. below the roof of its supports:
i. if the locomotive is fitted with covered cab-0.3 m from the top of the cover;
ii. in any other case – 1.8 m from the floor of the driver’s cab;
b. on that side of the track on which manholes are provided – 0.6m
c. on the side of the track opposite to the manholes:i. where there are not more than two tracks – 0.3m
ii. in any other case -0.6m
d. between any two adjacent tracks so much as to afford a clearance of at least
0.3m between any locomotive or tub or trolley on track and any locomotive, tub
or trolley on the other.
vi. Electricals Equipment and fittings on the locomotives shall be of flameproof
construction.
 Voltage not more than 250volt.
 All conductors properly insulated, protected and maintained so as to
prevent leakage or sparking.
vii. Precautions against coal dust- The locomotive shall not be used on any
roadway / part thereof unless the % of incombustible matter(including moisture) in
dust samples which shall be taken from that roadway or part once at least in every
seven days, is less than 85% or the working are naturally wet. A record of every
such analysis of sample shall be recorded in a bound paged book kept for the
purpose.
4. Safety Provisions in locomotive system :i ) Service and parking brake and also a dead man control
ii) Ergonomically designed seat for driver
iii) Speedometer, distance indicator, head lights and rear lights
iv) At least two portable fire extinguisher’s of appropriate type and signaling
arrangement.
v) An approved portable lamp for emergency.
vi) Other provisions:
 Pressure and temperature gauge
 Exhaust conditioner
 An exhaust gas cooling box
 Suitable air filter
 Suitable flame arresters/traps
5. Examination of locomotives - The following examinations shall by made by a
competent person appointed in writing by the manager and the results of the
examination shall be maintained in a bound paged book kept for the purpose.
a) daily examination
b) weekly examination
c) monthly examination
In case, defect is noticed either during examination or while in use, the
locomotive shall be stopped and shall not be put into use before the defect is
rectified.
Q.7.What are the provisions of Electricity Rules with respect to:
(a) Portable & transportable apparatus.
(b) Switch gears.
(c) Appointment and duties of electrical supervisors.
Ans:- 7(a) Portable & transportable apparatusi) Definition :Portable apparatus means apparatus capable of being moved while in
operation, e.g. coal cutting machine, electric shovel, continuous miner etc.
Transportable apparatus means apparatus which is operated in a fixed
position but is capable of being moved readily from one place to another, i.e.
pumps, conveyors, auxiliary fans etc.
ii) Operation:-All portable and transportable apparatus shall be operated only by
authorised persons.
iii) Disconnection of supply:- The person authorised to operate an electrically
driven coal cutter, or other portable or transportable machine, shall not leave the
machine while it is in operation and before leaving the area in which such
machine is operating shall ensure that the supply is disconnected from the cable.
When any such machine is in operation, the operator shall ensure that the
flexible cable is not dragged along by the machine.
iv) Safety devices:-All portable and transportable machines used in
underground shall operate on remote control from the concerned switchgear with
Pilot Core Protection.
v) Length of flexible cable, with any portable or transportable apparatus shall
not exceed 90m, but it may be upto250m when used with coal cutting machine or cutter or loader or armoured face
conveyor for long-wall operation, or with shuttle car or load haul dumper or cutter
loader or alike equipment for development and depillaring operations.
300m with electrically operated heavy earth moving machinery in opencast
mines and
1000m with bucket wheel excavator at 11 KV.
vi) Permissible Voltage LimitsHand held portable apparatus- 125V
vii)Flame proofing -All portable and transportable apparatus shall be flameproof
as detailed below:


Deg l - At any place in bye of LVC.
Deg ll – 90m from nearest face or goaf
or in-bye of LVC or in a return airway.
Deg lll – 270m from nearest face or goaf
or in-bye of LVC or in a return airway.
(Provided that electrically operated or battery operated transportable apparatus
such as shuttle car, men and material transporting equipment of increased
safety type e shall be permitted at any place with suitable monitoring devices for
detection of gasses)
viii) Detection of gas -A flame safety lamp shall be kept burning near portable
and transportable apparatus which remains energized, and if the safety lamp
indicates presence of inflammable gas, supply to all apparatus in the vicinity
shall be immediately disconnected and the incident reported forthwith to an
official of the mine. Where apparatus for automatic detection of inflammable gas
or vapour is employed in addition to the flame safety lamps, such apparatus shall
be approved by the Inspector of Mines and maintained in perfect order. The
apparatus shall be interlocked with the controlling switch in such a manner as to
disconnect the power supply automatically if inflammable gas exceeds 1.25% in
that particular district.
ix) All portable and transportable apparatus shall be maintained reasonably free
from dust, dirt and moisture and shall be kept clear of obstruction.
x) If the voltage of the circuit exceeds low voltage, all flexible cables attached to
any transportable apparatus shall be provided with metallic screening or pliable
armouring.
Ans :- (b) Switch Gears:i) Definition - Switchgear denotes switches, circuit breakers, cut outs and other
apparatus used for operation, regulation and control of circuits
ii) Construction- Every switchgear shall be so constructed as to be capable of
opening the circuit it controls, and dealing with any short- circuit without danger.
iii) Disconnection of supply:a) Properly constructed switchgear for disconnecting supply of energy to the
mine shall be provided at the surface at a point approved by the Inspector.
During the time any cable supplying energy from this switchgear is live, a person
authorised to operate the said switchgear shall be available within easy reach
thereof.
b) Every motor shall be controlled by switchgear arranged to disconnect supply
from the motor and all apparatus connected thereto. Such switchgear shall be so
placed as to be easily operated by person authorised to operate the motor.
c) Whenever required by the Inspector, the switchgear shall be arranged to
disconnect the supply in the event of over current, over voltage and single
phasing.
iv) Protectiona) Where necessary to prevent danger of mechanical damage, switchgears shall
be placed in a separate room, compartment or box.
b) No inflammable material shall be used in construction of the room,
compartment or box or fittings therein containing the apparatus, unless the
apparatus is so constructed, protected and worked as to obviate risk of fire.
c) The room, compartment or box shall be: substantially constructed
 kept dry
 well illuminated
 efficiently ventilated for all apparatus installed therein.
d) Adequate working space and means of access, clear of obstruction and free
from danger, shall be provided. Operating handles shall be conveniently placed.
If the voltage of the circuit is low voltage, all flexible cables attached to any
transportable apparatus shall be provided with metallic screening or pliable
armouring ( except in opencast equipment fitted with cable reel as its design
feature)
v) No switch gear shall be located within 60m of an U/G magazine or reserve
station.
vi) The switchgear should be so designed that it cannot be accidentally closed by
gravity, impact, or any other cause.
vii) Where the switchgear can be electrically charged from a duplicate source of
supply, means should be provided to isolate the switchgear from both sources.
Ans :- (C) Appointment and duties of electrical supervisor:Appointment of electrical supervisor1. Under IER, an electrician holding the electrical supervisors certificate, covering
mining installations, issued or re-cognised by the state govt. shall be appointed
by the mine management.
2. The notice of the appointment containing the name of the electrical
supervisor and the full particulars of the certificate held by him, shall be forthwith
sent by the mine management to the electrical inspector of mines.
3. The notice shall be duly countersigned by the person authorised.
4. An engineer shall not be permitted to perform the duties of electrical
supervisors, in addition to his own duties, except in case of small mines and with
the prior approval of the concerned regional inspector.
5. If necessary, for the proper fulfillment of the duties under the IER, one or
more assistants to the electrical supervisor shall be appointed by the mine
management.
6. In the absence of the authorised electrical supervisor, no electrical installation
work will be carried out within the premises of the mine. If the period of absence
extends, or is likely to extent more than 7 days, immediate notice to this effect
shall be sent to the electrical inspector of mines.
7.Adequate number of authorised electrical supervisors shall be on duty in every
mine while energy is being used therein.
Duties of Electrical Supervisor:1. Supervisiona) The authorised electrical supervisor shall not undertake the duties of
supervision of electrical installations at more than one mine without prior written
permission from the electrical inspector of mines.
b) He shall supervise – (a) new installations, and (b) additions and alternation to
existing installation.
2. Sending of notices - He shall :a. apply/ arrange to apply for approval for the installation of HT apparatus and
shall not energise it until approval is obtained.
b. carry out necessary insulation and continuity tests before energizing.
c. give / arrange to give notices of all electrical installation.
d. ensure correct maintenance of flexible cables and flameproof and intrinsically
safe characteristics of such equipment.
e. ensure proper earthing of all electrical equipments and apparatus and efficacy
of earth fault relays.
3.Testing- He shall carry out the following tests:a. tests of earth fault relays.
b. tests of earth electrode resistance at-least once a year and
c. tests of oil of the oil immersed apparatus for di-electric strength and acidity.
4. Maintenance of plans and records-He shall maintain the following plans and
records:i. log books
ii. record of testing of earth fault relays
iii.record of earth fault resistance.
iv. record of testing of di-electric strength and acidity of the oil immersed
apparatus.
v. register of maintenance of the flameproof and intrinsically safe apparatus and
of flexible cables.
vi. schematic diagram of the electrical installation of the mine.
vii.electrical plan of mine.
5. Maintenance of fire extinguishers:- He shall ensure proper maintenance of
the fire extinguishers and keep records of their testing.
Q.8.Spontaneous heating in advanced stage has been detected in a caving
district.
i. How could you deal with the situation, and
ii.What are the statutory obligations that should be fulfilled.
Ans:- i) Dealing with spontaneous heating detected in advanced stage in a
caving district :
It may be appreciated that the course of action of mine officials below ground at
the time of occurrence of fire/spontaneous heating in advanced stage can not be
laid down in any details. They would have to act largely according to their
initiative and knowledge of the mine and situation. However, in instant
situation, the following actions should be taken to deal with the spontaneous
heating detected in advance stage in caving district:a) Prompt action to control the situation ( e.g. to combat the fire) by those on
the spot may prevent a minor emergency from becoming major disaster. This
should include testing of noxious and inflammable gasses, cutting off
electricity, control of ventilation, care for fire fighting men and mobilising
all available resources (fire fighting equipment and material) to the site.
b) Immediate steps must be taken to withdraw men in close proximity to, and
those on the return side of the seat of the fire/ sp. heating and to send all
unwanted men of the pit as soon as possible.
c) Notification of the incident must be telephoned to the surface (i.e. direct the
Manager’s office, if possible) without delay, stating what action the official has
taken or intends to take and if possible what kind of assistance is required.
d) A reliable man should be stationed at the telephone to maintain
communication with the pit bottom and surface.
Taking into consideration the above facts, as an official of mine, I shall take the
following action immediately:a) Sending information in-bye so that all persons assembled at one particular
place.
b) When the persons have assembled, situations should be explained to them
and thereafter steps should be taken depending upon the circumstance
prevailing –
i) if the IA not affected, leave the persons out bye the lA. It must however be
ensured that the team is controlled by cool headed person.
ii) If there is difficulty in traveling by IA in the district concerned, try to get into
another unaffected district and travel safety along the intake airway of that
district.
The main principle in case (a) as well as (b) above is to avoid places affected by
the fire. The persons should use self rescuers and while traveling outbye, test
for presence of O2 deficiency should frequently be made.
Ans:- ii)- Statutory obligations to be
spontaneous heating/fire-
fulfilled in case of detection of
The following statutory obligations / precautions are required to be fulfilled /
taken while dealing with fire1) (a) Reg. 119 of CMR’1957 stipulates that on appearance of smoke or
indication of spontaneous heating, all persons shall be withdrawn from a mine
except those required for dealing with the fire. Normal work shall not be resumed
till fire or heating has been extinguished or sealed off effectively and on
examination made by the managerial staff, the place has been declared safe.
b) When there occurs in or about a mine, spontaneous heating or out break of
fire or appearance of smoke or other indication of heating, the mine management
shall forthwith inform RIM and send a notice in form IVA within 24 hours to
prescribed authority.
c) While dealing with a firei) a competent person shall be present on the spot throughout
ii) adequate precautions shall be taken to prevent danger to persons from any
noxious or inflammable gas, flame, steam and ejected or rolling down hot
materials, explosion of water gas and falling into crevices or potholes they may
occur in the area on fire.
iii) there shall be kept available at or near all places belowground:
 Adequate number of self rescuers and at-least two smoke helmets or
other suitable apparatus.
 A cage containing suitable birds or approved CO detector
 A flame safety lamp or other approved means of detecting CO2 gas and
O2 deficiency.
d) The manager shall prepare and establish a detailed scheme for the provision
and maintenance of suitable fire fighting arrangements for prevention, detection,
dealing and control of fire, for examination and maintenance of protective
measures taken to control and isolate the fire and for ensuring the safety of
persons engaged in said operations i.e. emergency organization for fire fighting.
The scheme shall be suitably modified and kept updated as the situation
warrants.
2) Rule 24 of Mines Rescue Rule 1985 requires that :a) On receiving information of spontaneous heating, the manager shall
immediately.
 Inform the rescue room or Rescue Station Serving the mine for
necessary assistance.
 Summon rescue trained persons employed in the mine.
 Inform the management of nearby mines to make available the services
of rescue trained persons employed therein.
 Summon medical assistance and
 Send information of the occurrence to RIM.
b) All rescue & recovery work shall be conducted under the control, supervision
& direction of the manager or principal official.
Morning Session
THE MINES ACT, 1952
Examination for Mine Manager’s Certificate of Competency under the Coal Mines
Regulation, 1957
SECOND CLASS
MINE MANAGEMENT, LEGISLATION & GENERAL SAFETY
Sunday, the 14th December, 2008
Full Marks: 100
Time
: 3 Hours
Answer any SIX Questions
(All questions carry equal marks)
Q.No.1.What is typical composition of “Mine Air”? What are the physiological
effects on human body of breathing air containing more than normal
percentage of CO2? What is “oxidation of coal”?
Ans:- Typical composition of “Mine Air”:- Mine air varies from atmospheric air
in its composition because atmospheric air entering the mine undergoes changes
and gets contaminated with noxious gases given off by the strata and from other
sources i.e. blasting, fire, burning of lights, bacterial action etc.
The chief harmful gasses met within the mines are, carbon dioxide, methane,
carbon monoxide and sulphuretted hydrogen.
Typical composition of mine air (return air) is given below:Sl.No.
1
2
3
4
5
Gas
Oxygen
Nitrogen
Argon
Carbon
dioxide
Methane
Chemical Notation
O2
N2
Ar
CO2
CH4
Total-
% by volume
20.28
78.90
0.36
0.46
100.00
Physiological effects on human body of breathing air containing more than
normal percentage of CO2:CO2 causes irritation of the mucous membranes of the eyes, mouth and nose
and produces a sensation of burning (more than 5 -10%). It increases the rate
and depth of breathing resulting in the labouring of the lung.
At higher concentration of CO2 with corresponding reduction of the 02% causes
the following physiological effects on human organism:
1%
2%
3%
Noticeably deep breathing.
50% increased amount of air breathed at rest.
Breathing doubled even at rest, fatigue( flame
5%
6%
10%
20-25%
safety lamp extinguishes)
Breathing tripled, extremely heavy breathing.
Suffocation and desire to sit down.
Violent panting and exhaustion.
Loss of sense, can not be endured for more than
a few minutes, headache, dizziness, sweating
Fatal, cause death after some hours.
Oxidation of coal: - When coal is exposed to air, oxygen is absorbed on its
exposed surfaces and certain fractions of the coal substance oxidize with
production of some gases (mainly C0 & C02) and water vapor, with evolution of
heat. This is known as oxidation of coal.
3 C + 2 02 → 2 C0 + CO2 + Q
This is an exothermic reaction in which heat is liberated.
This oxidation takes place even at normal temperature and humidity but it is a
slow process and the heat evolved is carried away by the air, unless, of course if
the air is stagnant. However, if the rate of dissipation of heat does not keep pace
with the rate of generation of heat, the temperature of the coal rises. At this
raised temperature, some other fractions of coal become susceptible to
oxidation. Thus, this process accelerates until the coal reaches the stage of
active combustion. This process of self heating of coal resulting eventually in its
ignition without the application of heat is termed as spontaneous combustion
or spontaneous heating or self heating or auto oxidation.
It is essentially a process of oxidation of coal under conditions in which this heat
generated is cumulative.
Various stage of spontaneous heating of coal are : Incubation period
 Indication period
 Open fire.
Q.No.2.There had been a number of roof and side fall accidents in the recent past
while dressing the roof or sides in underground coal mines. What could be
the possible reasons of such accidents? How recurrence of such accidents
can be prevented?
Ans:- An analysis of roof and side fall accidents in U/G Coal Mines during the
period 1997 to 2006 revealed that a good number of accidents and fatalities due
to fall of roof and sides are taking place during dressing of roof and sides-- an
operation being carried out to secure the roof and sides to ensure safe working.
The analysis further revealed that 10% of total roof fall accidents occurred
during dressing operation in which 7% dressers were involved. Similarly 12%
of total side fall accidents occurred during dressing operation in which 8%
dressers were involved.
Possible reasons of roof & side falls accidents while dressing the roof or sides
in U/G coal mines:i. Non-provision of suitable tools for dressing and non-use of the dressing tools
ii. Carrying out dressing operations by a coal miner’s pick at high roof.
iii.Using drum for reaching high roof for dressing instead of suitable bunton or
crowbar.
iv. Dressing of roof or sides by dressers from unsafe position i.e. from beneath
the unsafe roof or from the in-bye dip side of the roof.
v. Dressing operations carried out by untrained dressers in the absence of
suitable class-room and on-job-training.
vi. Skilled dressing operations by unskilled mazdoors due to non-availability of
regular dresser.
Suitable measures / steps to avoid recurrence of roof and side fall
accidents during dressing operations:- The following measures/ steps should
be take to prevent recurrence of roof & side fall accidents during dressing
operations:i. Proper training of existing dressers- Available dressers in the belowground
mine should be imparted class room and on-job training for adopting a sound,
safe and standard dressing procedure. If, even after training, found unfit for
job, they should not be engaged in dressing operations.
ii. Selection of persons for dressing operation – Persons to be newly selected
for dressing / recess cutting job shall have a strong physique and good health.
iii. Proper training of persons selected for dressing operationsSelected dressers shall
 undergo initial / basic training as per VT rules and specific training
modules.
 be appraised of different geological disturbances likely to be encountered.
 be trained to note the grumbling sound to detect the bad roof with
stick/crowbar/bunton.
 be told about taking personal protection by way of standing at safe place and
guarding the shinbone with basket while testing and dressing the roof and
sides and also about the importance of Deflector rings on crowbar/bunton.
 be trained for the use of proper tools w.r.t. situation of workings i.e. Pick for
low height, crowbar for big and strong overhangs and buntons for high roofs.




be explained about cleats and how they can take advantage of weak planes
so as to get more result exerting less and also about importance of geological
disturbance including slip planes.
be apprised about the seals with particular attention to the dimensions of the
recess for isolation/sectionalisation/ ventilation stoppings.
be made aware of the manhole size.
he told about the hazard mechanisms of roof & side falls.
iv. Panel of substitutes- Panel of sufficient number of persons shall be made &
they shall be trained properly to take care of the absenteeism on account of
leave/sick/other reason of the regular dresser.
v. Procedure of Testing and dressing of roof & sides: Dresser shall test the roof and sides of every face at the beginning of the shift
in the place of mining Sirdar.
 After blasting, all places within the zone of influence of blasting shall be tested
by dresser.
 He shall also test other places of the mine as instructed by supervising staff.
 During dressing operation, he shall stand at a place where the roof and sides
are safe and secure and then dress the roof & sides with proper tools.
Dressing should proceed from out-bye to in-bye side.
 He shall leave the face only when the Mining Sirdar declares that the face has
been dressed properly.
vi. Supply of equipment/ tools: Dressers shall be provided with coal miners pick, crowbar and buntons.
 They shall also be given personal protective equipment such as helmet,
mining shoes and shin guard.
 Sufficient stock of equipment & tools shall be maintained in stores.
vii. Responsibilities: Presser shall be made responsible for dressing the roof and sides of working
places assigned to him in such a way that there is no loose coal/ stone in the
roof, no overhangs and the sides are not loose.
 He shall make recesses of the prescribed dimensions when engaged in
recess or manhole cutting job.
 He shall be responsible for his own safety while dressing the roof and sides or
engaged in recess cutting job.
viii. Additional measures He should made compulsory member of safety committee.
 He should also be involved in risk assessment and risk management
exercise.
Q.No,3.What are the provisions contained in the Mines Act, 1952 in respect to the
following?
a) Managers
b) Functions of the Committee.
Ans:-a) Managers- Section 17 of Mines Act, 1952 stipulates statutory provisions
for managers as mentioned below:i) Every mine shall be under a sole manager having prescribed qualifications
ii) Owner or Agent of every mine shall appoint a person having prescribed
qualifications to be the manager.
iii) Owner or Agent having prescribed qualifications may appoint himself as
manager.
iv) Subject to any instructions given to him by or on behalf of the owner or agent
of the mine, the manager shall be responsible for the overall management,
control, supervision and direction of the mine and all such instructions when
given by the owner and agent shall be confirmed in writing forthwith.
v) Except in case of an emergency, the owner or agent of a mine or anyone on
his behalf shall not give, otherwise than through the manager, instructions
affecting the fulfillment of his statutory duties, to a person employed in a mine,
who is responsible to the manager.
vi) It shall be the responsibility of the manager to see that the officials and
competent persons so appointed are competent to perform the duties assigned
to them. No person shall be so appointed unless he is paid by the owner or agent
and is answerable to the manager.
vii) Every manager on taking over charge of a mine shall satisfy himself that all
officials & competent persons already appointed are competent to perform the
duties assigned to them and if he finds them competent, he shall either,
countersign their authorizations or issue fresh ones.
Ans. b) Functions of Committee under Section 12 of the Mines ActFunctions of Committee:
i) To consider proposals for making rules and regulations (not bye laws) and to
make appropriate recommendations to the central Govt.
ii) To enquire into such accidents or other matter as may be referred to it by the
Central Govt.from time to time and make reports thereon and
iii) To hear and decide such appeals or objections against notices or orders
issued under the statute.
Q.No.4.What is “Safe Work Procedure? Why it is necessary? Write a “Safe Work
Procedure” for manual loading of trucks in an opencast mine.
Ans:- In recent past, the rate of accidents has increased in Indian Mines,
particularly in outsourcing patches in which mining operations are carried out by
engaging contractors men & machines. Thus management of safety issues
becomes an essentiality for mine operators. Improvement in contractor worker’s
safety performance will play a significant role in the industries overall
performance. Mine Operators must ensure that work is carried out in compliance
with the existing statute. Any system of work established by the contractor must
be consistent with the mine operators, and it is the responsibility of mine
operator to determine the safety standards. For this purpose, safe work
procedure or safe operating procedure as recommended by 10th National
Conference on Safety in Mines is required to be prepared by the mine operator
and also by contractors for strict enforcement in the mines.
Safe Work Procedure- It is a working document which outlines all the actions to
be carried out to ensure safety and health at the work place in order to comply
with all requirements of statute and the system related to safety. It is a document
that would be available to all workers on site and should enable them to be
aware of not only this framework within which they have to do their work but also
what is expected from them to ensure a safe and healthy work environment.
Basic ingredients of Safe Work ProcedureAn effective safe of procedure should contain the following:
 Relevant Acts, Regulations and Circulars
 Emergency procedures
 Standing orders
 Individual job procedures
 Process for introducing new methods, equipment or materials etc.
 Training requirements
 Hazard identification and Risk Management process
 Safety management forms ( accident investigation, hazard analysis, reporting
etc)
 Medical examinations
 Entitlements for employees injured or suffering health impacts at the mine.
It needs to be made to suit the site specific conditions of the mine. It should
be simple and clear whilst meeting the requirements of legislation, regulation,
standing orders etc.
Thrust Areas for safe work procedure:
Typically, safe work procedures would be required for the following areas: Work associated with each step of the mine production and maintenance.
 Roof support methods & rules.
 Explosives transport, storage, handling and usage.
 Mineral handling, storage and transport.
 Traffic rules and safety in haul roads
 Rules for operating equipment
 Usage of personal protective equipment and critical spots in the mine for dust,
noise, heat, vibration, illumination etc.
 Inspections, Supervisions and daily reporting requirements.
 Emergencies
 House keeping rules.
Necessity of safe work procedure: To ensure safety
 To reduce overall costs of operation
 To reduce occupational health hazards
 To ensure optimum utilization of available resources thereby cutting costs and
reducing wastages.
 To enforce strict compliance of safety legislation in mines.
 To ensure use of fit-for-purpose men/machine
 Suitable works
 To avoid unsafe conditions & unsafe acts.

To ensure improvements in levels of safety, health and welfare of persons
employed in mine.
Safe work procedure for manual loading of trucks:1. General Safety:i. Loading of trucks by mannual means should be done during day light
hours or the area of operations shall be properly illuminated.
ii. A loading platform / stage or scaffold of adequate width with proper
fencing shall be provided.
iii. A danger board indicating “MEN ENGAGED IN LOADING OF TRUCKS”
shall be suitably placed.
iv. Cane basket and safety shoes should be provided for loading of coal into
trucks.
2. Design & construction of trucks:Trucks shall be provided with:
 Canopy of an approved design.
 Efficient Head light
 Audio-visual alarms to transmit signals during reversal.
 Service brake, parking brake & emergency brake to be maintained in safe
working order.
3. Selection & training of manual loaders: Persons engaged in loading jobs shall be trained in safety matters as
per provisions of statute before hand.
 Before commencement of work, Manager shall arrange training of loaders
including briefing of traffic rules.
4. Issue of identity cards- All workers shall be issued identity cards.
5. Entry in Form B Register- Manager shall ensure maintenance of record of
workers in Form “B” register as per provisions contained in Mines Rule,
1955.
6. Attendance – Attendance shall be marked in statutory attendance register.
Working hours shall be limited to 8 and spread over to 12 hrs (max.)
Weekly days of rest shall be ensured.
7. Provision of rest shelter- Rest shelter with drinking water facility near the
place of work shall be provided and maintained.
8. Fitness certificate & road worthiness of trucks: Fitness certificate including functioning of AVA and other safety devices
should be checked by colliery engineer and records of the same should
be maintained.
 Colliery Engineer and safety officer shall make random checks of fitness
certificates, brakes, lights, horns, AVA’s etc. Defective truck shall not be
permitted for loading purposes.
 Time in and out shall be recorded in a register at the check post.
9. Unauthorised driving / riding: Drivers license shall be verified by the colliery engineer.
 No helper or unauthorized persons shall drive/ ride/ travel trucks.
 Trained trip men and helpers be provided at loading points during the
loading operation.
 No negligent / careless driving.
10. Supervision:- Mine management shall deploy competent persons for
statutory supervisions.
11. Traffic : As far as practical one way traffic shall be adopted.
 Sufficient space shall be provided to avoid over crowding.
 Manual loading and dumping shall not be allowed at the same place.
 Standard traffic rules shall be adopted and followed during movement of
trucks.
12. Parking: During loading of trucks, vehicles shall be parked on level ground.
 Adequate width shall be ensured for parking of trucks.
 Maintenance of minimum safe distance between two tracks.
13. Roads- Roads should be well maintained and kept free from spillage and
slipping matters. Proper arrangements should be made for dust
suppression for good visibility.
14. Operation Loaded trucks shall not be reversed on gradient.
 While trucks being loaded on gradient, the same shall be secured
stationery by parking brake & other means.
 Driver shall keep the cab window clean so as to ensure clear vision at all
times.
 He shall handle the trucks carefully and keep it under control at all times.
 He shall see that the truck is not overloaded and material is not loaded in
a truck so as to project horizontally beyond the sides of its body.
Q.No.5.What dangers may be anticipated while sealing off a fire in the goaf of a
degree lll gassy mine? What procedure would you follow to seal off such a
fire? What precautions should be taken against the anticipated dangers?
Ans:- An underground fire is sealed off, by creating stoppings when all other
direct methods of combating proves unsuccessful or are considered not possible.
It is a sure method of cutting of oxygen feed to the fire though it requires a long
time for extinguishing the fire.
An area under fire in a mine may have to be sealed off in the following cases:i. When the fire has attained so large proportions that it cannot be extinguished
by methods of direct attack.
ii. When the fire is inaccessible, as in the case of a spontaneous heating or fire
in a goaf or in a crushed zone or near fault plane - where methods of direct
attack fail.
iii. When there is a possibility of occurrence of an explosion.
Sealing off consists of building stoppings in all the galleries to
prevent access of air to the fire. The fire soon dies out through lack of oxygen,
provided the stoppings are not leaking.
Dangers while sealing off fire area:
Dangers anticipated while sealing off a fire in the goaf of a degree III gassy mine
are enumerated below:i) Risk of dust or gas explosion (from air borne coal dust or methane or other
combustible gasses) threatening heavy casualty of men & material.
ii) Risk of toxic and asphyxiating fumes, particularly from CO – moving through
the workings downwind the fire and endangering workmen, even in remote
areas from the location of fires.
iii) Chances of flash over of fire
iv) Chances of back lush of smoke.
v) Affecting the U/G ventilation – due to constriction effect and buoyancy effect.
vi)Chances of roof falls.
Sealing off fire in the goaf of a degree III gassy mine:Once it is decided to seal off a fire area, no time should be lost. The materials of
construction of stoppings should be speedily transported to the site and
arrangements should be made for adequate labour force to form relays of
builders.
The main problems posed in sealing off a fire are the leakages of air within (even
after sealing) and the threat from explosion during the sealing off operation,
immediately after it and during recovery operation of the fire area. The different
phases of sealing off operation are carried out keeping the above problems in
view. These operational phases for underground sealing are:i. Site selection for erecting stoppings- While selecting the site, distance from
fire, minimum number of stoppings, good ground conditions, space for
reinforcement, transport facilities, ease of ventilation, accessibility for inspection,
facility of balancing air pressures etc. should be taken into consideration.
ii Sequence of seal making.
iii.Modus oparandi of building up the stoppings
iv.Inspection and subsequent control of the fire.
v.Recovery of the fire area.
Essential requirements for sealing off fire area The first requirement of stoppings constructed to seal off a fire area in a
degree lll degree mine is the construction of explosion proof stoppings to
withstand the force of possible explosion.
 The second requirement is that the ventilation is to be maintained as near to
normal as possible and stoppings at the intake and return end are to be
sealed simultaneously.
 Sudden reduction of ventilation is to be avoided to prevent the fire gases
on downwind side of fire being blown back to the fire causing an explosion.
Procedure to be followed for sealing of a fire in the goaf of a Degree lll gassy
mine
1. Organisation of the work of sealing off:
a. The work of sealing should be done by workers trained in the use of rescue
apparatus and a rescue team with SCBA should be kept in reserve.
b. A control room should be set up at the surface of the mine. Duty roster of
officers and supervisory staff should be drawn up. The requirement of
workman shiftwise should be assessed and arrangement should be made
accordingly. An officer should be incharge of manpower and allotment of
duties.
c. For supply and issue of essential stores such as building materials,
appliances, tools and safety devices and for their speedy transport to the
selected site, a separate officers should be made responsible.
d. Haulage track and telephones should be extended as near to the site of
stoppings as possible.
e. At the operation control room, a mine plan and large scale tracings of the
affected area should be kept available. Progress of all operations should
be recorded in the operation register kept in the control room.
2. Operating procedure:During the construction, the affected area is heavily stone dusted. Sufficiently
large area near the fire is enclosed by the stoppings so that a large volume of
air is trapped behind them to ensure that there is enough air near the fire to
prevent formation of explosive gas – air mixture and the normal quantity of
ventilating air should be allowed to reach the district by keeping the fan at the
usual speed.
First of all, sand bag stoppings about 1.5m thick followed by 0.5m thick brick
in cement stoppings on their out bye sides are built. One stopping in the
intake airway and other in the return airway are provided with a tapered
passage, about 1m square at the in bye end and about 0.75m square at the
out bye end for maintaining the ventilation in the area to be sealed off. The
floor & sides of this passage are made of sand bags while the roof is of
corrugated sheets to take up the load of sandbags above. An observer is
stationed at the return stopping to check the % of CH4 in the return air at
short intervals and to take samples of air periodically. If the % of CH4 rises,
the air passage must be enlarged. The air passages in the two stoppings are
then quickly closed simultaneously by sand bags. Every stopping is provided
with a sampling pipe. After initial closure in this airway, men are withdrawn
to surface and after waiting for 48 hrs. , the stoppings are inspected by a
rescue team for any signs of disruption or leakage. The team also collects
samples of air. When these stoppings show that the atmosphere inside the
sealed off area is non-explosive and there is no CO or CH4 in the mine
roadways upto the stoppings, ordinary workmen are employed to repair the
stoppings. The stoppings are then strengthened by adding a brick work 0.5 m
thick and 1 m brick work so formed is plastered outbye. The seals are then
made permanent and explosion proof by building a 1 m thick brick stopping
4.5 m out bye of it and filling the intervening space with sand or other inert
packing material.
Precautions against anticipated dangers during sealing off operations:i. Stoppings should be sited as far as possible from seat of fire.
ii. Under no circumstances the ventilation be interrupted when building
stopping.
iii. In order to prevent propagation of explosion of fire damp or fire gases and
coal dust during sealing operation, the roadways between seat of fire and
stoppings shall be thoroughly stone dusted.
iv. During sealing operation with ordinary men, rescue teams should be kept
stand-bye.
v. Detection of inflammable gas from return of fire area shall be made at
shorter intervals and persons shall be withdrawn from mine if the methane
content approaches explosive limit.
vi. Ventilation shall be maintained to the fire area to prevent building up of
inflammable gases to a dangerous level. The last intake and return seals shall
be closed simultaneously preferably by closing small steel doors provided in
the stoppings.
vii. The affected area should be isolated quickly by erecting temporary
stoppings which will require minimum time for construction with reasonable air
tightness such as sand bags, stone dust bags, sheet & brattice, and brick
stoppings etc.
viii. Permanent stopping out bye of temporary stopping shall be built later to
withstand rock pressure and to have complete air tightness of the sealed off
area.
ix. Permanent stopping should be built after a lapse of at-least 48 hours being
the critical period during which methane content may reach explosive limit
before O2 is reduced to 12% or less.
(iii) Before construction of a stopping is begun, an adequate SDB should, if
practicable, be erected in the part of the roadways between the seat of the
fire and that of the stopping proposed to be sealed.
Q.No.6.Write short notes on any three of the following:a) Standards of medical examination
b) Controlled blasting
c) Natural ventilation
d) Abandonment Mine Plan.
Ans:- (a) Standards of medical examination- The Rule 29B of Mines Rule
1955 provides for :a) Initial Medical Examination of every person to be employed in the Mine.
b) Periodical Medical Examination of all persons already employed in the mines
once in five years.
c) In case of asbestos mines, PME to be done once in a every 12 months and
every such examination shall include all the tests except the x-ray examination,
which shall be carried out once in every three years.
The medical examinations provide valuable information about the health of the
individual workers and epidemiological information on prevalence of
occupational diseases in mines.
IME provides baseline data on the health parameters of the workers, enables
identification of workers sensitive to a particular hazard, identification of workers
whose handicap can be safety risk and suitable placement of worker depending
on his physiological and mental capacity.
PME are helpful in early detection of occupational diseases and other nonoccupational diseases so that they can be treated at an early stage and the
worker can be suitably rehabilitated by providing job placement if required.
Rule 29F of Mines Rules’1955 requires that IME & PME of persons should be
conducted in accordance with the standards laid down in Form P and Form
P1 respectively as mentioned in the table given below:Parameter
Sl.
1
General
Standard
2
Locomotor
system
3
Skin
Standard of IME (Form- P1)
Standard of PME( Form-P)
The person should be in good
mental and bodily health and free
from any physical defect likely to
interfere
with
his
efficient
employment in a mine.
Due allowance in the standard
should be made for the age of
candidate.
The limbs should be well formed
and developed and the function of
all the limbs should be within
normal limits. Any deformity
should be recorded. There should
be no deformity or paralysis which
may interfere with his efficient
employment in a mine.
The person should be in good
mental and bodily health and
free from any physical defect
likely to interfere with his
efficient employment in a
mine.
The limbs should be well
formed and developed and
the function of all the limbs
should be within normal limits.
Any deformity should be
recorded. There should be no
deformity or paralysis which
may interfere with his efficient
employment in a mine.
There should be no evidence of There should be no evidence
extensive and chronic skin of extensive and chronic skin
disease or ulceration.
disease or ulceration.
In case of infective type of
4
Vision
a) Distant vision of eye with or
without glasses should be not
less than following standard;
Surface U/G
Better eye – 6/12
6/6
Worse eye – 6/18
6/9
b) Night blindness should be
tested in special cases only of
underground workers where the
examining authority considers it
necessary.
c) Unioculor person should not be
employed
belowground.
For
employment on surface, the vision
of such a person in the other eye
should be 6/12 with or without
glasses.
d) Colour blindness will be tested
only in special caees. Where the
job
requires
good
colour
discrimination.
(e) There should not be any
organic disease of the eyes which
is likely to affect the distant vision
within a period of five years.
Hearing should be good and
person be able to hear voice from
a distance of 3m. Any progressive
disease affecting hearing should
be recorded.
Speech must be without serious
impediments.
5
Hearing
6
Speech
7
Respiratory a) It should be sound and free
system
from any chronic bronchial or
laryngeal disease.
b) After chest radiograph and lung
function test, there should not be
any evidence of active pulmonary
disease.
8
Circulatory
There should be no evidence of
skin disease; the candidate
could be made fit after
medical treatment.
a) Eye vision should be not
less than the following
standard:
Better eye – 6/12
Worse eye – 6/18
b) There should be no night
blindness
for
persons
employed below ground and
for persons employed in open
cast workings in shifts other
than in morning shifts.
c) Unioculor person should
not be employed belowgro
und. For employment on
surface, the vision of such a
person in the other eye
should be 6/18 with or without
glasses.
Hearing should be good. Any
progressive disease affecting
hearing / or occupational
deafness should be recorded.
Speech must be without
serious impediment. Unless
this is also accompanied by
generalized partial paralysis,
this should not be reason for
declaring unfit.
a) It should be sound and free
from any chronic bronchial or
laryngeal disease.
b) After chest radiograph and
lung function test, there
should not be any evidence of
active pulmonary disease. If,
there are evidences of active
pulmonary tuberculosis, he
may be permitted to work if
his sputum is negative on
repeated examination on
production of a certificate that
he is taking treatment from a
qualified medical practitioner/
Hospital.
There should be no evidence
system
9
10
any cardiac or vascular disease of any heart or vascular
which may interfere with his disease which may interfere
efficient employment in a mine
with his efficient employment
in a mine.
Disease of There should not be any evidence
abdominal
of disease of abdominal organs
organs.
which is likely to affect his efficient
discharge of duty in a mine.
Hernia
In case the candidate has hernia,
he may be declared fit after he
has been successfully operated
for the same.
11
Hydrocele
It should not be large enough to
impede the normal activities of the
candidate. In such a case he may
be declared fit after being
successfully operated.
12
Nervous
system
13
General
Examination
It should be sound. Persons with
history for epilepsy or any other
type of organic or historical fit,
should not be declared fit for
employment.
The medical examination should
include examination of urine. Mere
presence of albumen and sugar in
the urine without any gross
organic disease producing signs
and symptoms should not be
considered as a disability.
14
Skiagram
In case the candidate has
hernia, he may be declared fit
after
he
has
been
successfully operated for the
same.
It should not be large enough
to
impede
the
normal
activities of the candidate. In
such a case he may be
declared fit after being
successfully operated.
The medical examination
should include examination of
urine and other system for
evidence of disease. Mere
presence of albumen and
sugar in the urine without any
gross
organic
disease
producing
signs
and
symptoms should not be
considered as a disability.
Skiagram of the chest should also
be obtained by directing the
candidate to undergo special test
or / and to obtain opinion of a
specialist
from
recognized
institutions / hospitals.
The Standard of medical examination should be in conformity with the ILO
classification.
Ans:- (b) Controlled Blasting- Controlled blasting is a method of rock blasting
where the risk for damage to surrounding structures and installations are
eliminated by planned drilling and charging procedures to enable vibration
control and by taking all measures such as covering for protection against fly
rock.
Purpose of Controlled Blasting – Controlled blasting is done to :
i) Reduce over-break.
ii) Minimise fracturing of rock at the bottom of an excavation and
iii) Control fly rocks
In controlled blasting, blast dimension is achieved by trial and error method.
Techniques of controlled blasting
1. Blast design- Optimum blast design should be adopted based on blast
parameters such as depth and diameter of blast hole, burden, spacing, charge
factor, stemming etc in order to have desired peak particle velocity (PPV),
frequency and amplitude within permissible limit. Use of computerized blasting
model, constant monitoring and review of blasting practice is recommended.
2.Deck charging- Dividing the explosive charge in more than one deck by
incorporating inert material between different segments when strata are
alternately hard and soft. This provides better energy distribution and different
decks can be blasted with different delay timings to reduce the charge per delay.
3.Air decking- In this method, during deck charging, instead of inert material,
gas bags or wooden spacers are used between decks. Air column lowers the
initial pressure of explosion products and increases time of interaction of
detonation front with surrounding strata.
4.Use of Electronic detonators- Normal pyro-technique delay detonators have
a scatter in the delay timings. Electronic detonators provide accurate delay (upto
1ms) and cut down chances of overlapping of different delays.
5. Use of Non-electric detonators (Nonels)- These shock tube based initiating
devices provide a low order shock wave for initiation of the explosives. They
have an advantage over detonating cord in that they do not de-sensitize the
explosives and do not disturb the stemming column thus avoiding fly-rock.
Nonels also help in firing deck charges with separate delays.
6.Line drilling- It involves in a single row of closely spaced uncharged holes
between the blasting site and the area to be protected. It provides a plane of
weakness to which the primary blast can break and effectively arrest ground
vibrations. It is tedious and more suited for protection of construction sites.
7. Pre-splitting- It consists of a row of holes on 3 sides of the blasting block at a
closer spacing (8- 12 diameters) charged with lesser explosive (only 10-15% per
hole of the main blast). It isolates the blasted zone from remaining rock mass by
creating a fracture line.
8. Cushion blasting Drilling of row of 50- 100 mm dia bore holes along final line of extraction.
 Loading with light well distributed charge
 Burden = spacing
 Loading similar to pre-splitting
 Maximum depth – 30m
9. Muffle blasting- It aims to limit the blasted material within 10m of the hole.
Generally, rejected tyres are kept over the holes and mats or meshes( 40mm x
40mm) made of locally available rope strands (5-6mm) loaded with sand bags of
40-50kg placed over it are used. Loading should be adequate otherwise, mat
would be thrown away causing damage and allowing fly-rock. Mats should
overlap and a portion also kept hanging over the free face.
Ans :- (C) Natural Ventilation:- Flow of air through the mine workings by purely
natural means is called natural ventilation. Such flow takes place when there is
a natural difference in densities between the up cast and downcast shafts.
Small and shallow mines are some times ventilated by natural means only
though the ventilation in such cases is usually poor, fluctuated to a large extent
and is even subject to reversal of direction.
Causes of Natural Ventilationi. Temperature
ii. Moisture content of air
iii. Barometric pressure
iv. Addition of gases
v. Leakages
vi. Circulation of refrigerated air.
All the above factors are responsible for the difference in densities of air between
up cast and down cast shafts.
Mechanism of Natural Ventilation:- The heavier air sinks down and the lighter
air moves up setting an air current. The difference in densities may be due to
difference in temperature, moisture, gas content etc.
Consider two shafts AB and CD whose mouths are situated at two
different levels as shown in above fig. In winter the cold and consequently heavy
outside air in the column EA together with AB will force out of the mine the lighter
warm column of air CD. The shaft AB will be working as downcast shaft and CD
the up-cast shaft. If one of these shafts is replaced by an incline, the same
principle will hold good, that is, if there is difference in densities of two vertical or
inclined columns of air contained between two horizontal planes, natural
ventilation pressure will be created.
In the above illustration, in summer season when the temperature of outside air
is higher than mine air temperature, CD will act as the downcast shaft and AB as
the up-cast shaft. In a season when the temperature of outside air and
underground air are the same, there would be no natural ventilating pressure.
Thus both the direction and the amount of n. v. p. vary with weather. Also in an
emergency like fire in the mine, mechanical ventilation can be controlled which is
not possible with natural ventilation. As such natural ventilation cannot be relied
upon, and installation of mechanical ventilators for mine is a statutory
requirement.
However, even in mechanically ventilated mines, natural ventilation has a role to
play. In case the two shaft collars are at the same level, in winter the fan would
draw cold air into the mine. As a result the natural ventilation draught in winter is
in the same direction as the fan draught but in summer it usually opposes the fan
draught or its assistance reduces.
Calculation of N.V.P. from air density- Natural ventilation pressure in a mine
is the difference in pressures of air columns in the downcast and up-cast shafts.
i.e. N.V.P.
= P 1 – P2
= D. Pd . g – D. Pu . g (pascal)
= D.g (Pd – Pu)
Where
D
g
Pd
Pu
= depth of D.C. shaft (in m )
= acceleration due to gravity in ms-2
= mean density of air in D.C.shaft in kg.m-3
= mean density of air in U.C.shaft in kg.m-3
Density of air is affected mainly by temperature (effect of moisture is minor and
neglected in usual calculations). If the mean temperature ( in K) in the downcast
and up-cast shafts are Td and Tu respectively.
Density of air in D.C.shaft Pd
= Bd x 103 kg.m-3
287 Td
And density of air in U.C. shaft Pu
= Bu x 103
kg.m-3
287 Td
Where Bd and Bu are mean barometric pressures in Kpa in the
downcast and up-cast shafts respectively.
For mine shafts in general barometric pressure Bd = Bu say B
:. N.V.P.
= D. g (B/287 Td – B/287 Tu) x 103
= g.D.B ( Td - Tu ) x103
287
pascal
Pascal
Tu.Td
Note:- In the above formula, barometric pressure is in kPa.
Motive Column: - It is defined as the height of air column in the down cast shaft
which causes the natural ventilating pressure. In other words, motive column is
the N.V.P. expressed in terms of the height of a column of air with a density
equal to that of air in the down cast shaft.
The hight of motive column is expressed as:
H= N.V.P
Pd. g
Where H = height of motive column
NVP
= natural ventilating pressure
Pd
= density of downcast air
g
= acceleration due to gravity.
Ans:- d) Abandonment Mine PlanThis is the true copy of up-to-date plan and section of the u/g workings of the
mine or part and seam having average inclination more than 30º from the
horizontal. It shall show the bearing and distance of at least one of the shafts or
openings of the mine from a tri-junction pillar or revenue pillar or from any other
prominent and permanent surface feature, the position of water dams built u/g
(with its dimension and other particulars of construction) and also the spot levels
at the end of the workings.
Statutory obligationi)
When any mine or seam or section thereof is abandoned or the
working thereof has been discontinued over a period exceeding 60
days, the owner of the mine shall submit within 30 days of
abandonment or 90 days of discontinuance, to the DGMS, two copies
of Abandoned Mined Plan and sections.
ii)
The original or certified true copy of the AMP shall be kept in the office
of the mine.
iii) DGMS may supply copies of AMP to:
a) any person having a bona-fide interest in the mine, seam or section or
b) the owner, agent or manager of an adjacent mine.
Utility of AMP-
a) When an adjacent mine is worked at a later date, the AMP is utilized to leave
adequate barriers to avoid danger of inrush of water/liquid matter or gas or
ingress of fire.
b) It helps in assessing danger to surface structures also.
Requirement of AMP- The AMP should be submitted on tracing cloth or
polyester tracing film with index number of the original plan from which it is
traced. It should be certified to be a true copy of the original plan by the
surveyor and countersigned by the manager. The AMP shall show the
detailed information as required under statute as follows:
i) Name of owner, mine, plan, true north or magnetic meridian with date of the
latter, a scale at least 25cm long and suitably divided; conventions as per the
second schedule.
ii) Distance and bearing of at least one shaft or opening of the mine in relation
to tri-junction or revenue pillar or any other permanent surface feature.
iii) Up-to-date position of workings belowground, ends of workings to be marked
with dotted lines and last date of survey.
iv) General direction and rate of dip of strata. Section of the seams(s).
v) Position of every fault, dyke and other geological disturbances with amount of
throw and direction.
vi) Vertical mine sections (if inclination exceeds 30º)
vii) Multi-section workings lying within 9m to be shown in different colours on a
combined plan separately.
viii) Every important surface feature with the boundaries such as railway, road,
river, stream, water course, tank / reservoir, opencast working, village (with
name) and building which is within 200m of any part of the working measured
horizontally. HFL of river/stream.
ix) Surface contour lines at vertical interval not exceeding 5m. Bench mark on the
surface in relation to mean sea level (MSL)
x) Spot levels along all important drivages and at the ends of the heading; also at
the end of all workings.
xi) Mine boundary.
xii) Up-to-date workings of all the mines situated within 60m from the boundary
any connection with adjacent mines.
xiii) Position of water dams and embankments (with dimensions and particulars
of construction).
xiv) An abstract of all statutory restrictions in respect of the workings (with
DGMS letter number)
xv) If the plan has not been updated up to the time of abandonment, this fact
should be recorded on the plan. If barriers with adjacent mines are not adequate,
this fact should be recorded on the plan and , where necessary management of
the adjacent mines should be warned. If any workings lie beneath railway, public
road and building not belonging to the owner, and are inaccessible, the fact
should be recorded on the plan.
xvi) Position of all pumps and lodgments underground together with information
concerning the quantity of water being pumped out before abandonment. Also
position and extent of known water logging.
xvii) A certificate of correctness of the plan (as printed in the original plan.)
xviii) In case of coal mines only
 degree of gassiness of the seam
 particular section of the seam being worked
 abstract of precautions taken against heating or fire or explosion, if
any.
Q.No.7.How the brakes of a dumper are tested in an opencast mine? What are the
different types of brakes provided in typical dumpers? What steps can be
taken to reduce accidents caused by dumpers in opencast coal mines?
Ans:- Testing of brakes of a dumper in an open cast mine:- Brake system is
vital element for controlling accidents caused by wheeled trackless
transportation machinery like dumpers, trucks and tippers.
Following international standards provide requirement of brake system and
procedure of brake testing:i. ISO V3450-1985(E):- Earth Moving Machinery- Wheeled machines –
Performance requirement and test procedures for braking system.
ii. SAE J1152 April 1980 - Braking performance – Rubber Tyred Construction
Machine.
As per circular No. 3 of 1981, brakes of a dumper shall be tested as per the
following details :i) Periodicity - Brakes of dumpers are required to be checked /tested at least
once in every two weeks.
ii) Test Procedurea) Service Brake Test – The brake shall be tested on a specified gradient and
speed when the vehicle is fully loaded. The vehicle should stop within a
specified distance when the brake is applied.
As per manufacturers instructions, service brake should be checked by
application of brake when a fully loaded dumper is running at a speed of 32 km/
hr. The dumper should stop dead within 21m from the application of brake. This
is for dumpers having capacity more than 32 Te.
b) Parking Brake Test- The parking brake should be capable to hold the vehicle
when it is fully loaded and placed at the maximum gradient of roadway which
is permitted for a period of a least 10 minutes.
Parking brake should be capable to hold a fully loaded dumper at a roadway
gradient of 15 0 and an empty dumper at a gradient of 18 0.
c) Emergency Brake Test- Functioning of emergency brake should be checked
at specified intervals.
A record of above tests shall be maintained in a bound pages book and shall be
signed by the persons carrying out the test. These records should be
countersigned by the engineer and manager.
Surprise inspection shall also be carried out by the engineer / superior official at
an interval not exceeding 15 days to ensure that the examination schedule of
dumpers are carried out.
Different types of brakes provided in typical dumpers- As per standard, all
dumpers shall be equipped with:a) A service brake system- the primary system used for stopping and holding
the dumpers.
b) An emergency / secondary brake system:- the system used for stopping
the vehicles in the event of any single failure in the service brake system.
c) A parking brake system:- a system used to hold the stopped dumpers in a
stationery position.
d) A retarder brake system.
e) A dump brake system.
Brake system may have common components. However, in the event of failure of
any single components, the brake system shall have the capability of bringing
vehicle to a halt. Such arrangement will not allow rolling down of vehicles in case
of busting of hose pipes etc.
Parking brake system shall be so designed that it shall not depend on
exhaustible energy source like air in reservoir. In most of the dumpers working in
our country parking brakes are working on air. This leads to rolling down of
vehicles when air pressure becomes low.
Steps to be taken to reduce accidents caused by dumpers in opencast coal
mines:i) Arresting negligent and un-authorized driving –
a) Dumper drivers must be selected very carefully and given a through initial
training.
b) Periodical refresher training and examinations should be organized to test
their skills and attitude.
c) Only authorized and properly trained operators should operate the vehicle.
d) Adequate number of operators should be appointed to avoid deployment on
OT.
e) No dumper should be driven in fog or mist unless special fog lights are
provided.
f) Competency of operators should be evaluated by a Board.
g) To prevent un-authorized driving, a system should be evolved whereby the
ignition key and / or cabin key always remains with the operator or with
specifically designated competent persons.
ii) Arresting un-authorized traveling on dumpersa) Adequate transport arrangement should be made for the equipment
maintenance staff, operators, cable man, dump man etc. so that they are not
tempted to steal a ride on dumpers.
b) Any unauthorized person including driver caught a riding on a dumper should
be given exemplary punishment to deter others from doing so.
iii) Planning and designing of haul roads:a) Haul roads should be planned, designed, constructed and maintained on
sound scientific principles. Particular attention should be paid to the drainage of
surface water.
b) All bends in haul roads should be designed with a large radius so that the
driver has a clear view for a distance of not less than 30 m along the road.
iv) Safe Practices:a) Selection of dumpers: Only well designed vehicles conforming to international safety standards
should be used.
 Vehicles should be provided with service, emergency and parking brakes.
 All dumpers must be equipped with audio-visual alarms to facilitate safe
reversal. Where reversal is required as a routine, a “stopper” should be
appointed to guide the driver.
 A seat belt for the safety of operator should be provided in operators cabin.
b) Maintenance of dumpers: A scheme of maintenance, examination and testing should be drawn up and
strictly followed. Such a scheme must specify the nature and frequency of
examinations and the way in which the information is to be reported and
stored.
 Testing of brakes should be carried out as per laid down schedule.
 Lights and horn of each dumper must be checked at the start of each shift.




Test run of the dumper should be done only by a mechanic holding driving
license.
Starting – key of dumper should remain with the supervisor as long as works
are being done below or beneath it.
Dumper should be parked on a hard and level ground and tapered wooden
blocks should be placed in front of and behind the tyres to avoid rolling of
dumper on either side.
For lifting purpose, only tested and certified slings should be used.
c) Traffic rules:- Traffic rules specifying speed limits, right of way, overtaking,
parking and other general precautions should be framed and strictly enforced.
d) Code of practice for safe tipping and dumping  Code of practice should be framed for prevention of injuries to persons
engaged in tipping on stock piles and dumping of OB at dump-yard.
 All unloading points should be adequately manned for traffic control and safe
unloading.
 Dumping edge should be provided with properly designed portable wheel
stops to prevent the dumpers from running into unstable ground, loosing their
balance and falling down the slope.
e) Precautions against fire - Every dumper must be provided with at least one
fire extinguisher in the driver’s cabin so that as soon as a fire is noticed, it can
be extinguished.
Q.No.8.What do you understand by the following terms?
a) Vertical coincidence
b) Safety Management System
c) Wide stall method of working.
Ans:-a) Vertical coincidenceIf the distance between the consecutive seams is small, the workings of one
seam may affect the workings of the other seam. If the workings of a seam are
above the one being worked, the workings in the top seam will certainly be
affected.
In India, seams lying within 9 m of each other, are termed as contiguous seams
and their workings must confirm the certain statutory requirement as laid down in
reg.104 of CMR 1957 , which are re-produced below:
No work in a higher seam or section shall be done over an area in a lower
seam a section which may collapse.

Where two or more such seams or sections are worked in a mine, the
pillars in one seam or section shall, as far as possible, be vertically above
or below the pillars in the other seam or section unless the strata are
inclined at an angle more than 30º from the horizontal.

The parting left between the two such seam/sections shall not be less than
3 m in thickness at any place.
A thick seam may be worked in two sections, one along the floor and another
along the roof and parting between any two such sections
of a thick seam
or between two contiguous seams should not less than 3m thick . If two sections
of a thick seam or two seams of contiguous seams, have to be work at a time or
one after and another, prior approval of DGMS is essential.
When two seams lying within 9m of each other or when two or more sections of a
thick seam are worked in such a manner that pillars and galleries of one seam or
one section lies vertically above or below the pillars and galleries of another
seam or section, then this is known as vertical coincidence of pillars and
galleries
Seam-II
Seam-I
3m
4m
3m
Roof
floor
θ<30º
(i) Vertical coincidence in contiguous seams
Coal Seam
θ<30º
(ii) Vertical coincidence in thick seams
Possible alternatives for the extraction of contiguous seams / thick seam:
i. Extraction in the upper seam / section followed by extraction in the lower
seam/section.
ii. Extraction in lower seam / section followed by extraction in upper seam/ seam.
iii. Simultaneous extraction in both the seams / sections.
All the above alternatives have their applications in different conditions. None of
them can be of universal application. But by and large; the extraction in
descending order is preferred, especially if extraction is done with caving. In
designing the extraction system in contiguous seams or thick seam, the prime
consideration is the stability of workings.
General precautions during extraction of pillars in contiguous seams / thick
seams:1. The extraction of pillars i.e. drivage of split gallery and the extraction of slices
in two sections/ seams shall be done simultaneously such that the line of
extraction in both the section / seams are superimposed.
2. The workings in each of the sections / seams shall be under the supervision
of a separate mining Sirdar.
3. The working of both the sections/ seams will be placed under the charge of
same overman for better co-ordination of the workings.
4. The overman shall be furnished with an offset plan showing the workings in
both the sections / seams in different colours showing there on the sequence of
extraction of pillars.
5. For easy access from one section/seam to the other for supervision, drift or
staple pits with ladders shall be provided at every alternate junction of
galleries.
6. If at any time, any danger is noticed in any of the sections/seams, persons
shall be withdrawn from both the sections/seams.
Ans:-8(b)-Safety Management System- It is essential to offer a working
condition free from hazards to the extent of highest magnitude by the
application of safety management.
Safety management may be defined in very simple terms as the control or
elimination of the origins of the causes for the harm. This helps to realize that
the hazards are not simply the agents most closely identified with the injuries.
Therefore, it is necessary first to employ means of controlling the causes
responsible for the presence of injuries agents.
Aim of Safety Managements:Safety managements must aim for the identification of hazards, determination
of their significance, evaluation of the available correctives and selection of
the optimum remedies. Unwanted events can be controlled to an irreducible
minimum. Therefore the hazard that causes the unwanted harmful events is to be
eliminated to have an accident free environment. Hence the focus of safety
efforts should be on hazard control rather than on accidents.
The basic purpose of health and safety management is to create a mechanism
involving all concerned at every level by which dangerous events and accidents
may be prevented.
Health and safety management system include well documented modules of
safety management method in the form of action procedures at all levels of
management and decision making. It may be defined as an auditable
documented system that forms part of the overall management that
includes organizational structure, planning activities, responsibilities,
practices, procedures, processes and resources for developing,
implementing, achieving, reviewing and maintaining a safety and health
policy of a company.
Safety Management is as a structured process composed of well defined system
that emphasizes continuous improvement in work quality, health, welfare and
productivity of workforce engaged in mineral industry through setting up of
improved safety standards and their effective implementation and administration.
Because the statutory provisions can never be fully comprehensive, appropriate
and site specific and the process of legislation making is often slow, these often
trail behind the technological innovations. Trend, world over is, therefore, to
make the statutory provisions “Flexible” by switching over from the regime of
‘Prescriptive Regulations’ to Self Regulatory or Goal Setting Legislation’.
The Safety Management System established by a mine must ensure all risks are
identified and critical risks are controlled to ensure long-term health and safety.
A safety Management System should set the culture, framework and actions
necessary to ensure that mining operations are carried out safely.
Elements of SMS: Health & Safety Policy of the company and the mine.
 Roles and Responsibilities at all levels in the organisation
 Specified competencies of staff
 Safety Committee, its formation and role
 Method to identify and control high risk
 Forward program to ensure actions to control hazards are carried out
 Emergency Preparedness to cope with a hazard if it should occur.
 Monitoring process for all identified hazards with or without residual risks.
 Identification of trigger points and resultant actions if these are reached.
 Safety clearance for new equipment, work methods and materials used.
 Accident statistics collection, analysis & actions.
 Reporting and record keeping requirements.
 Auditing and review processes.
Structure of Safety Management System:Structure of safety management system may be broadly classified into following
categories containing different elements:
1. Strategic levela. Health & Safety Policy- This is a statement by the organisation of its
occupational health and safety philosophy and intentions. It provides a
framework for action to achieve safety objectives and targets.
b. Roles & Responsibility- Ensuring the safety of a mining operation is a
complex task requiring the continued commitment of all personnel
associated with the mine, as well as compliance with all safety legislation,
guidelines and circulars.
c. Health & Safety Committee- The Safety committee can have a significant
role in effective Mine Safety Management. It contains representatives from
all aspects of the mine, with a focus on ensuring and improving health and
safety in the workplace.
2. Management Level:a. Hazard Identification & Risk Management- The management of the
mine should conduct a risk assessment process to identify any hazard that
could influence the safety and health of workers of the mine. It should not
be considered to be a once off occurrence but should be done at regular
intervals to ensure that the plans to cope with the identified hazards are
pertinent and up to date.
b. Preparation of safety management plan- The Safety Management Plan
is a working document, which outlines all of the actions to be carried out to
ensure the safety and health at the work place.
3. Operational level- Operational process and safe operating procedures need
to be made to suit the site-specific conditions of the mine. These need to
be simple and clear whilst meeting the requirements of legislation,
regulations, mine standing orders and recognize hazards associated with
the work.
The safety management system should at all time be such that it promotes
a process of continuous improvement.
Because of their status and immediacy to the job, Managers and
Supervisors have a key safety role in the mine to ensure: The work environment is safe for workers.
 Planned work methods are safe & followed.
 All accidents and near misses are investigated.
 Workers are competent & know their duties.
 Adequate reporting on shift change-over occur.
Benefits of safety management system:i) Improved work culture and supervision of hazardous jobs.
ii) Casts specific responsibilities on the management.
iii) Gainful utilization of resources on prioritized risks. More acceptable because
of involvement of grass root level and management.
iv) Selection of best possible means to achieve better work environment and
reduced risk.
v) Introduction of new technology with proven safety records expedited.
vi) More reliance on team work.
vii) Better concentration on use of systems, standards and safe practices.
viii) Consistency and control for continuous improvement.
ix) Reduction of incidents, accidents and their severity.
x) Making the mines more efficient along with improvement of health and
safety status.
Strategies for implementation:i. Every mine should employ a sound risk analysis process and develop a
Safety Management Plan.
ii. Management should commit itself for proper formulation and implementation
of SMP.
iii. Management should allocate resources necessary for control measures.
iv. All employees should be trained with the help of national and international
experts for optimal adoption of the safety management system.
Ans:- (C )Wide stall method of working- Huge amount of coal in thick seams
is locked up in the form of standing pillars, due to presence of important
surface features, townships, rivers, rails etc. The level of coal recovery from
thick seams underneath delicate structures has been 7-12% only. In general,
even the final recovery from such seams by conventional method of spliting and
stooking never exceeds 30-35%, after which the safety factor drops below
one.
To increase the recovery of locked up coal without endangering the surface
feature with factor of safety more than 1 , wide stall method of mining is found
suitable which is nothing but widening of galleries leaving pillars core
undisturbed. In view of the pillar stability vis-à-vis strain, deformation in and
around and long term stability, wide stall method of mining is preferred as
compared to narrow panel mining, splitting and stooking.
It is well known that strength of a pillar depends on its height. If stowing is done,
the effective height of a pillar can be reduced and a pillar can, thus, be made
stronger. Thus % age of coal extraction can be increased in a partial extraction
scheme which first makes the pillar smaller (thus weaker) and then increases
its strength by stowing to the desired level to ensure that surface features or
upper seams are not distributed.
If, for same F.O.S. of pillars, the choice is between widening and heightening of
gallery, the later should be preferred as strength of pillars reduces more sharply
with reduction in area than with increase in height.
Wide stall methods are suitable for shallow depths only as, at deeper depths, %
age of extraction becomes low since wider pillars are to be kept for protection
of surface features.
The wide stall method involving formation of 15m pillar core and 6m wide stall
has been found to be quite safe giving 49% recovery of in-situ coal without any
damage to surface feature during mining of Xl/Xll seam of selected Jharia
Section as shown in the fig.(i) below:
Fig.(i) Wide stall mining – forming 6m wide stall and 15m pillar core.
The success of wide stall method of mining depends upon the stability of
immediate roof and pillars under abutment loading and prevention of resultant
pot holding and surface subsidence. Spliting of pillars with heightening of the
galleries reduced the pillar stability and even the central portion of the stooks
developed appreciable pressure and strain as shown in the fig. (ii) below:
fig-(ii)
This method has been field trialed in Xl/Xll seam at East Bhagatdih Colliery of
BCCL under the following boundary conditions:i. Seam thickness
16.5 – 16.8m
ii. Cover
90-120m
iii.Pillar & gallery size
30m(Centre) & 3.6m wide gallery.
iv.Development
in 2 sections of 3m bottom and 2.4m top
v. Coal parting between the 2 Sections- 6.4m
vi. Parting between x and Vll/Vlll seam – 43m
vii.Surface constraint
- Private dwelling & Colliery Structure.
viii.RQD of immediate roof rock - 80%
Manner of extraction in wide stall method of mining- As per condition
imposed by DGMS, the manner of extraction shall be as follows:i. (a)The pillars shall not be split. They may, however, be reduced by widening
the galleries around the pillars. The width and height of such gallery shall
not be more than 6.0m and 4.5m respectively and the residual pillars after
widening of galleries shall not be less than 17m square in size from corner
to corner.
(b)No heightening or widening shall be done where the pillars size from
corner to corner is 17m or less.
ii. Widened galleries may be heightened upto a maximum height of 4.5m in
stages in conjunction with stowing in such a manner that the height of gallery
over the stowed sand shall not be more than 3.0m at any time.
iii. Heightened and widened galleries shall be fully stowed with sand.
iv. (a) Not more than 40m of heightened and widened gallery shall remain
unstowed in the panel at any time.
(b) Not more than 75 m2 of roof shall be exposed at any place at a time.
v) Widening or heightening of any gallery shall not be undertaken unless all
adjacent / in bye voids are fully stowed with sand.
vi) Extraction shall commence from dip most side and advance towards rise
maintaining a diagonal line of extraction and formation of “V “in the line of
extraction shall be avoided.
Sequence of extractions:- The fig(iii) below shows the sequence of extraction
by wide stall method at East Bhuggatdih Colliery of BCCL under the boundary
conditions mentioned above.
The stall formation involves widening of 3.6m wide development gallery to 9m by
operating a 5.4m wide winge face on one side of the gallery.
The total workable section of 13.8m (excluding 3m parting) is worked in 2 lifts,
each of 3.2m thickness in ascending order in bottom section and 2 lifts each of
3.6m in the top section also in ascending order. The pillars are attacked from dip
to rise keeping diagonal line of extraction. During the widening, the pillars are not
to reduced below 21m size and coincidence of verticality of pillars are maintained
during workings.
The stepwise operation includes widening of the existing gallery, in bottom
section, upto 9m width followed by hydraulic sand stowing. Above the stowed
gallery (1st list of 3.2m), further development for 2nd lift of 3.2m is done and then
the galleries are widened to 9m. After stowing the 2 nd lift gallery, a solid coal
parting of 3m are left over the stowed bottom section and then the top section are
also taken. Similarly in 2 lifts of 3.6m thickness by developing, widening and fully
stowing the 9m wide galleries. Coal parting offers lateral support to the pillars
and reduces slenderness ratio, which are punctured at regular intervals for sand
flushing to ensure its stability.
.Fig(iii)- Plan and section showing the sequence of extraction by wide stall
method at East Bhuggatdih Colliery.
In this method of mining, following study should be conducted from safety view
points during actual mining operation:
i. Observation within the stalls(a) Convergence (b) Load on support
ii. Observation around the stalls(a). Bed separation (b) Stress variation (c) Strain variation (d) convergence
measurement (e) Pillar dilation and (f) subsidence study.
Support System:- The widened stall is supported by 2 rows of wooden or
triangular steel chocks flanked by 3 rows of wooden props as shown in fig-(iv)
Fig (iv) – Support system practiced in wide stall method of mining.
Optimization of coal recovery by spluttering & stocking of pillars causes
considerable drop in strength of the natural support, which restricts % age of
recovery during extraction of thick coal seam below important surface structure.
The effective bearing capacity of pillar is comparatively more than a no of stooks
of the equivalent area. Wide stall formation accommodates existing galleries of a
developed Coal Seam as well as improves recovery and safety of the ultimate
mining structure in comparison to the convectional method.
:
THE MINES ACT, 1952
Afternoon Session
Examination for Mine Manager’s Certificate of Competency under the Coal Mines
Regulation, 1957
FIRST CLASS
MINE MANAGEMENT, LEGISLATION & GENERAL SAFETY
Monday, the 13th December, 2009
Full Marks: 100
Time
: 3 Hours
Answer any Six Questions
(Question no. 1 carries 20 marks and all other carry 16 marks each)
………………………..
Q1.
Write short notes on any four of the following:
i) Site mixed slurry as compared to other explosives.
ii) Flameproof apparatus.
iii) Corporate social responsibility.
iv) Risk management as a tool to reduce accidents.
v) Methods to make Pit Safety Committee, more effective.
Ans. i) Site mixed slurry as compared to other explosives- The merits of bulk
explosives are summarized below:Parameter
1. Safety
Cartridge Explosives
Explosive
is
handled,
Stored and transported.
Thus potential hazard is
always there.
Bulk Explosives
Explosive, handling, store &
transportation
totally
eliminated, the ingredients
become
explosives
on
being charged into holes.
2. Explosive Maga Large
size,
storage Small magazine needed
zine size
magazine is needed and only for cast booster and
hence cost of magazine is detonating fuse.
more.
2A. Safety Zone.
Large safety zone is A very small safety zone is
required which would be required.
difficult to get.
3. Explosive Van.
More numbers of explosive A small explosive van
vans and more manpower mounted on a jeep chasis
is needed.
would be sufficient.
4. Blasting crew
Blasting crew comprising of Blasting crew comprising of
large number of persons.
few no. of persons.
5. Charging hole
Charging / stemming is time Quick charging / stemming
taking.
due to fully mechanized
operations.
6. Explosive energy Explosives of fixed energy
A wide range of explosive
energy.
7.Explosive density. Density of product cannot Density of product can be
be varied.
varied
to
suit
the
requirement over a wide
range.
8. Bore hole
The coupling is not full.
9. Cost.
The cost is fixed
10. Pilferage
There
is
hazard
explosive pilferage.
The coupling is full resulting
in maximum tramper of
energy from explosive to
rock.
The cost is lower as off take
increase.
of Pilferage is not possible.
The above compansion has been made for some quantity of explosives to be
used either in the form of cartridge or in form of bulk, for a big O/C mine.
Q2.
An explosion has been reported in a mechanized development district with five
persons missing. Draw a list of action, in order of priority that you would take to
deal with the emergency and rescue/recover operations.
Q3.
In the present day context of heavy mechanization and outsourcing, draw up a
scheme of training and retraining to ensure effective safety awareness amongst
the workers at the mine.
Q4.
What are the statutory provisions relating to emergency plan? Briefly describe
the essential elements of an effective emergency plan and their rationale. How
would you incorporate modern technology advancement into an emergency
plan?
Q5.
Enumerate various sources of conflict in a mining project. As manager of a mine
how would you organize to deal with a conflict arising out of a complaint of
neighboring villagers regarding ground vibrations being generated by the blasting
being conducted at your mine.
Q6.
What do you understand by pay back period of a project? Describe in details any
one cost analysis and cost control methods used to operate a mine.
Q7.
A 8 MT per annum opencast mine is being planned in a virgin area. Draw up a
scheme for selection training and development of human resources for the
project. Also state the statutory notices to be sent and the permission/relaxation
to be obtained.
Q8.
(a) What are the causes of Pneumoconiosis? What are its symptoms?
Enumerate the precautions to be taken to prevent it.
(b) State statutory provisions relating to periodical medical examinations and
discuss its relevance to ILO classification of radiographs for detection of
pneumoconiosis.
Morning Session
THE MINES ACT, 1952
Examination for Mine Manager’s Certificate of Competency under the Coal Mines
Regulation, 1957
SECOND CLASS
MINE MANAGEMENT, LEGISLATION & GENERAL SAFETY
Sunday, the 13th December, 2009
Full Marks: 100
Time
: 3 Hours
Q1.
Answer any SIX Questions
(Question no. 1 carries 20 marks and all other carry 16 marks each)
………………………..
Write statutory provisions in respect to the following:
a) Nominated owner
b) Working near mine boundary
c) Voltage limits
d) Notice of accident.
Q2.
While a group of drillers was drilling holes in a rise gallery in a development
districts, adjoining dip gallery which was within a distance of 3 m from the rise
face was fired, resulting death of the drillers. Write an enquiry report bringing out
the contraventions, responsibility and recommendations to prevent similar
accident in future. Assume your own conditions.
Q3.
While driving a level gallery along floor of a 8 m. thick scant, unusual seepage of
water was observed from the face. What steps are required to be taken by a shift
assistant manager? What information and documents are required to be
submitted along with an application for permission to extend the gallery?
Q4.
Enumerate the precautions required to be taken while firing shorts in vicinity of
hot strata in open cast mines.
Q5.
What are the objectives of Environment Management Plan (EMP)? Discuss its
important features.
Q6.
Write statutory provisions on any three of the following:
(a) Duties of manager in emergency.
(b) Rescue tracing
(c) First and station
(d) Initial and periodical medical examination.
Q7.
What are the major causes of accidents in Indian Coal Mines?
Describe in brief safety management system, which will be useful to identify and
control existing and probable hazards in mine.
Q8.
How workers participation in safety management can help in improving safety
standards of a mine. Enumerate the existing statutory provisions in this regard.