“Diesel locomotive engines”
mini project report submitted in partial fulfillment of the
requirement for the award of the degree of
BACHELOR OF TECHNOLOGY IN MECHANICAL
ENGINEERING BY
Banoth Vivek
21071A0311
B. Naveen Rathan
21071A0312
Bhavik S. Bhagawati
21071A0313
Under the guidance of
Dr.B. Satyanarayana, HOD Department of
Mechanical Engineering
This Photo by Unknown Author is
VNR VIGNANA JYOTHI INSTITUTE OF ENGINEERING &
TECHNOLOGY (Autonomous) Vignana Jyothi Nagar,
Bachupally, Nizampet (SO), Hyderabad – 500 090
(Approved by AICTE & Govt. of T.S and Affiliated to
JNTU, Hyderabad) DECEMBER 2022
Contents
1.) History
2.) Organization Overview
3.) Overview of internship
4.) Introduction
a.) what is locomotive
b.) working of a locomotive
c.) types of locomotives
 Diesel mechanical
 Diesel electric
5.) Parts of a locomotive
a.) Nose of the engine
b.) Cabin compartment
c.) Alternator
d.) Engine
e.) Air compressor
f.) Radiator
6.) Types of locomotive engine
7.) Maintenance of locomotives
8.) Braking system in locomotives
DEPARTMENT OF MECHANICAL ENGINEERING CERTIFICATE
This is to certify that the project report entitled “Diesel locomotive
engines” has been carried out at VNR VJIET, Hyderabad and
submitted by the following Students.
Name
Roll number
Banoth Vivek
B. Naveen Rathan
Bhavik S. Bhagawati
21071A0311
21071A0312
21071A0313
In partial fulfillment of the requirements for the award of the Bachelor
of Technology in Mechanical Engineering to Jawaharlal Nehru
Technological University Hyderabad at VNR Vignana Jyothi Institute of
Engineering & Technology during the period of 2019- 2023 is a
bonafide of the work carried out by them under the guidance and
supervision of the undersigned. The results embodied in this project
report have not been submitted to any other University or institution for
the award of any Degree.
Dr.B. Satyanarayana
Internship mentor
HOD
Mechanical Engineering
VNRVJIET
of India
PCME-SCR
Sl.No.DSL/MLY/2023!2'
/ CERTIFICATE
This is to certify that Mr./Mrs. BANOTHU VIVEK (Roll No. 21071A0311) student of
VNR VIGNANA JYOTHI INSTITUTE OF ENGINEERING AND TECHNOLOGY
College has undergone Internship Training at Diesel Loco Shed, Moula-ali,
Hyderabad, South Central Railway from 07-06-2023 to 21-06-2023 under the
guidance of Sri. K. NARASIMHAM SSE (LMSM), D. SUSHEEL KUMAR SSE
(CRS),
VIJAY RAM SSE (LUNT), AMJADH ALI HUSSAIN SSE
(LHRM),
MALLESHAM
SSE
Assistant Divisional Mechanical Engineer Diesel Loco
Shed, Moula-ali.
Assistant Divisional
Engineli
DIESEL LOCO
Mechanical
SHED
S C Railway Moula-Ali
SLNo,DSL/MLV/2023
/ CERTIFICATE
This is to certify that Mr./Mrs. BEJAWADA NAVEEN RATHAN (Roll
NO.
21071A0312) student of VNR VIGNANA NOTHI
INSTITUTE OF ENGINEERING
AND TECHNOLOGY College has undergone Internship Training at
Diesel Loco Shed, Moula-ali, Hyderabad, South Central Railway from
07-06-2023 to 21-06 2023 under the guidance of sri. K. NARASIMHAM
SSE (LMSM), D. SUSHEEL KUMAR SSE (CRS), VIJAY RAM SSE
(LUNT), AMJADH ALI RUSSAIN SSE (LHRM), MALLESHA M SSE
(LABORATARY).
Assistant Divisional Mechanical Engineer Diesel
Loco Shed
Assistant Divisional Mechanical Engineer
DIESEL LOCO SHED
SC Railwav Moula-Al'
of India
Sl.No.DSL/MLY/2023
/ CERTIFICATE
This is to certify that Mr./Mrs. BHAVIK S. BHAGAWATI (Roll No. 21071A0313)
student of VNR VIGNANA JYOTHI INSTITUTE OF ENGINEERING AND
TECHNOLOGY College has undergone Internship Training at Diesel Loco Shed,
Moula-ali, Hyderabad, South Central Railway from 07-06-2023 to 21-06-2023
under the guidance of Sri. K. NARASIMHAM SSE (LMSM), D. SUSHEEL KUMAR
SSE (CRS), VIJAY RAM SSE (LUNT), AMJADH ALI HUSSAIN SSE (LHRM),
MALLESHAM SSE
(LABORATARY).
Assistant Divisional Mechanical Engineer Diesel Loco Shed,
Moula-ali.
Assistant Divisional Mechanical
Engim9
DIESEL LOCO
SHED Z. q.
3181.
S C Railwav Moula-All
HISTORY
The first railway on Indian sub-continent ran over a stretch of 21 miles from Bombay to
Thane. The idea of a railway to connect Bombay with Thane, Kalyan and with the Thal
and Bhore Ghats inclines first occurred to Mr. George Clark, the Chief Engineer of the
Bombay Government, during a visit to Bhandup in 1843.
The formal inauguration ceremony was performed on 16th April 1853, when 14 railway
carriages carrying about 400 guests left Bori Bunder at 3.30 pm "amidst the loud applause
of a vast multitude and to the salute of 21 guns." The first passenger train steamed out of
Howrah station destined for Hooghly, a distance of 24 miles, on 15th August, 1854. Thus,
the first section of the East Indian Railway was opened to public traffic, inaugurating the
beginning of railway transport on the Eastern side of the subcontinent.
In south the first line was opened on Ist July, 1856 by the Madras Railway Company. It
ran between Vyasarpadi Jeeva Nilayam (Veyasarpandy) and Walajah Road (Arcot), a
distance of 63 miles. In the North a length of 119 miles of line was laid from Allahabad
to Kanpur on 3rd March 1859. The first section from Hathras Road to Mathura Cantonment
was
opened
to
traffic
on
19th
October,
1875.
These were the small’s beginnings which is due course developed into a network of
railway lines all over the country. By 1880 the Indian Railway system had a route mileage
of about 9000 miles. INDIAN RAILWAYS, the premier transport organization of the country
is the largest rail network in Asia and the world’s second largest under one management.
Indian Railways is a multi-gauge, multi-traction system covering the following:
Track Kilometres
Route Kilometres
Broad Gauge
(1676 mm)
86,526
Electrified
16,001
Meter Gauge
Narrow Gauge (762/610 mm)
(1000 mm)
18,529
3,651
Total
63,028
Total
108,706
Other Interesting facts of Indian Railways Indian Railways runs around 11,000 trains every day, of which 7,000 are
passenger trains
7566 - locomotives
300 - Yards
37,840 - Coaching
vehicles
2300 - Good sheds
222,147 - Freight wagons
6853 - Stations
700 - Repair shops
1.54 million - Work force
Territorial Readjustment of Zones and In-House Reforms
In order to bring about greater efficiency in administration, speedy implementation of ongoing projects, better customer care, reduction of workload on General Managers etc.,
Indian Railways have decided to create seven new zones by territorial re-adjustment of
existing zones. The new zones, having limited financial burden on Railways, will have thin
and lean, efficient and modern administrative set up. Two of the new zones have already
started functioning.
National Rail Vikas Yojana
With a view to complete strategically important projects within a stipulated period of time,
a non-budgetary investment initiative for the development of Railways has been
launched.. Under the scheme all the capacity bottlenecks in the critical sections of the
railway network will be removed at an investment of Rs.15,000 crore over the next five
years. These projects would include:
1. Strengthening of the golden Quadrilateral to run more long-distance mail/express and
freight trains at a higher speed of 100 kmph.
2. Strengthening of rail connectivity to ports and development of multi-modal corridors to
hinterland.
3. Construction of four mega bridges - two over River Ganga, one over River Brahmaputra,
and
one
over
River
Kosi.
4. Accelerated completion of those projects nearing completion and other important
projects.
New Steps towards Safety and Security:
Safety of 13 million passengers that Indian Railways serve every day is of paramount
importance to the system. Over the years, apart from the regular safety norms followed,
the network has taken a number of steps through innovative use of technology and
stepped-up training to its manpower to enhance safety standards. Constitution of
Rs.17,000 crore non-lapsable Special Railway Safety Fund (SRSF) to replace the arrears
of aging assets of Railways over the next six years has been a historical move in this
direction. A number of distressed bridges, old tracks, signalling system and other safety
enhancement devices will be replaced during this period. As far as budget allocation for
safety is concerned, Rs.1,400 crore was allocated in the revised estimate for the year
2001-02 and Rs.2,210 crore for the year 2002-2003. Extensive field trials of the AntiCollision Device (ACD), indigenously developed by Konkan Railway, is going on and once
deployed across the Zonal Railways, this innovative technology will help railways reduce
accidents
due
to
collision
between
trains.
Security of railway passengers is at present a shared responsibility of the Railway
Protection Force (RPF) and the Government Reserve Police (GRP). Efforts are on to
amend the Railway Act to give more powers to the RPF in ensuring security of passengers
on trains and within Railway premises. Deployment of women police Force has been made
for security and assistance of women passengers.
Improving Financial Health:
The financial position of Indian Railways has been slowly but steadily improving. Some of
the highlights of the financial performance during 2001-02 include: improved operating
ratio from 98.8 per cent to 96.6 per cent, savings in ordinary working expenses of Rs.1,487
crore, Depreciation Reserve Fund (DRF) balance goes up from Rs. 78.04 crore during
March last year to Rs.632.99 crore during same time this year. Railways have established
a new milestone in incremental freight loading during July this year by carrying 5.70 million
tons of goods. Freight loading for the last financial year crossed the target and attained
492.31 million tons.
New Trends in Passenger Amenities:
To take care of the unreserved segment of the passengers, a new pilot project on
computer based unreserved ticketing has been launched this year. Of the 13 million
passengers served by the network every day, nearly 12 million are unreserved
passengers. To cater to this huge segment, computer-based ticketing systems has been
launched for all stations in Delhi area and in due course throughout the country. With this,
unreserved tickets can be issued even from locations other than the boarding station and
will reduce crowds at booking offices and stations.
Indian Railway Catering and Tourism Corporation
with the assistance of Centre for Railway Information Systems has launched On-line
ticketing facility which can be accessed through website irctc.co.in. Computerized
reservation facilities were added at 245 new locations. At present these facilities are
available at 758 locations in the country covering about 96 per cent of the total workload
of passenger reservation. Computerized Reservation related enquiries about
accommodation availability, passenger status, train schedule, train between pair of
stations
etc.
have
been
made
web
enabled.
A pilot project for issuing monthly and quarterly season tickets through Automated Teller
Machines (ATMs) has been launched in Mumbai this year and has been found very
successful. Another pilot project for purchasing tickets including monthly and quarterly
season t i c k e t s
Smart Card has also been
through
launched.
"National Train Enquiry System" has been started in order to provide upgraded passenger
information and enquiries. This system provides the train running position on a current
basis through various output devices such as terminals in the station enquiries and
Interactive Voice Response System (IVRS) at important railway stations. So far, the
project
has
been
implemented
at
98
stations.
Freight Operations Information System (FOIS) Computerization of freight operations by
Railways has been achieved by implementing Rake Management System (RMS). Such
FOIS
terminals
are
available
at
235
locations
Railways have established their own intra-net ’Rail net’ It provides networking between
Railway Board, Zonal Headquarters, Divisional headquarters, Production Units, Training
Centers
etc.
Sterling Performance by PSUs the public sector undertakings of the Railways, especially
IRCON and RITES, scored commendable achievements during the last three years.
IRCON International has achieved a record turnover of Rs.900 crore during 2001-02 and
the foreign exchange earnings of this prestigious organization has increased sixfold over
the years. At the international level, IRCON is at present executing different projects in
Malaysia, Bangladesh and Indonesia. The PSU has registered a strong presence in the
international
scenario
by
its
sterling
track
record.
RITES, another prestigious PSU under the Ministry has scaled new heights in
performance, profit and dividend to the shareholders during the last three years. Its
turnover increased from Rs.172 crore in 1999 to Rs.283 crore in 2002. RITES for its
sterling performance secured the prestigious ISO-9001 Certification this year. The
company has also entered into export/leasing of locomotives in different countries in Asia
and Africa. RITES is operating all over the world including Columbia, UK, Iran, Malaysia,
Myanmar, Bangladesh, Sri Lanka, Tanzania, Uganda, Ethiopia, Turkmenistan and
Uzbekistan.
Indian Railways Finance Corporation Limited secured excellent rating for fourth year in
succession by the Department of Public enterprises on the basis of the performance
targets. Besides, Standards and Poor’s, the international credit rating agency, also
reaffirmed the sovereign ratings to IRFC. The Corporation has been making profits and
paying dividends.
Indian Railway Catering & Tourism Corporation (IRCTC) Internet based ticket booking has
been launched by IRCTC in Delhi, Chennai, Bangalore, Mumbai and Calcutta this year.
Hygienic and air-conditioned food plazas having consumer-friendly ambience opened at
Pune and Chennai and license for similar plazas awarded for 17 more locations. In all, 50
such plazas will be opened by the end of this financial year across the zonal Railways.
Railneer - packaged drinking water is to be made available from December this year.
More than half a lakh tourist has availed the value-added tour package programme
launched by the Corporation this year.
Innovative Technologies by Konkan Railway:
Konkan Railway Corporation (KRC), the technological marvel of Indian Railways, has
invented quite a few new technologies. Anti Collision Device (ACD), state-of-art
indigenous technology of KRC is currently under-going intensive field trials and is capable
of avoiding collision between trains. Sky bus metro is another innovative, economic and
eco-friendly mass rapid transportation solution devised by Konkan Railway. Self Stablising
Track (SST) devised by KRC, which is undergoing trials at present, will help Railways run
the fastest train in the near future and will make tracks much safer and more sustainable.
Private Sector Participation:
The participation of both private and public sectors in developing rail infrastructure has
gone up. A joint venture company was formed with Pipava Port authorities to provide broad
gauge connectivity to Pipava Port. MoUs have been signed between Ministry of Railways
and the State governments of Andhra Pradesh, Karnataka, Maharashtra, West Bengal,
Tamil Nadu and Jharkhand in developing rail infrastructure in these States.
Telecommunication - New Trends:
To give improved telecommunication systems on Railways, Optical Fibre based
communication systems has been adopted and laying OFC has increased to 7,700 route
kilometre this year. Rail Tel Corporation has been created to make a nationwide
broadband multimedia network by laying optical fibre cable along the railway tracks. This
system will provide better operational and passenger amenities and additional revenue to
Railways.
New Technologies:
India became the first developing country and the 5th country in the world to roll out the
first indigenously built "state-of-the-art" high horse power three phase electric locomotive
when the first such loco was flagged off from Chittranjan Locomotive Works (CLW). CLW
has been achieving progressive indigenisation and the cost of locomotives has come down
to
the
level
of
Rs.13.65
crore.
Diesel Locomotives Works, Varanasi has produced state-of-the-art 4000 HP AC/AC diesel
locomotive in April this year. These locos are capable of hauling 4,800 tonne freight trains
at a speed of 100 KMPH and can run continuously up to 90 days in one stretch without
any major maintenance.
Honours and Awards
Indian Railways achieved a number of recognitions and awards in sports, tourism sector
and for excellence in operational matters. In the Common Wealth Games in Manchester,
the Indian teams record performance has been mainly due to Railway team’s excellence
in sports. Except one member the entire women’s Hockey team which bagged the gold
medal belonged to Railways. Mohd Ali Qamar of Indian Railways has bagged gold medal
for boxing and other participants from Railways helped India win medals in many a team
events. A number of sportspersons from Railways were conferred with the coveted Arjuna
Awards and other major sports awards.
Darjeeling Himalayan Railways attained the World Heritage Status from UNESCO.
Fairy Queen, the oldest functioning steam engine in the world, which finds a place in the
Guinness Book of World Records, got Heritage Award at the International Tourist Bureau,
Berlin in March, 2000. On operational front, Delhi Main station entered the Guinness Book
for having the world’s largest route relay interlocking system.
Social obligations and care for weaker sections
Senior citizens, students, disabled persons etc. enjoy concessional benefits from
Railways. New initiatives in this area during the last three years include reduction of age
limits for special concession to senior women citizen from 65 to 60 years, blind and
mentally challenged persons can now travel in AC classes on confessional rates. Free
second-class Monthly Season Tickets (MSTs) for school going children up to tenth
standard for travel between home and school was also introduced.
Tie-Up with Foreign Railways
Indian Railways is in constant touch with Railways across the world to bring in state-of-art
facilities in its system. Towards this, a Memorandum of Understanding was singed during
the Eighth Session of the Indo-Austria Joint Economic Commission held in Vienna. This
seeks to promote and deepen long-term infrastructure-specific cooperation between
Indian and Austrian Railways to their mutual benefit. A three-day International Conference
of Union of Railways was organised by Indian Railways in New Delhi in which hundreds
of delegates from various industries and Railways around the world participated.
Organization Overview
The Ministry of Railways under Government of India controls Indian Railways.
The Ministry is headed by Union Minister who is generally supported by a
Minster of State. The Railway Board consisting of six members and a chairman
report to this top hierarchy. The railway zones are headed by their respective
General Managers who in turn report to the Railway Board. For administrative
convenience Indian Railways is primarily divided into 16 zones:
Overview of internship
DATE
7/6/2023 to 10/6/2023
12/6/2023 to 15/6/2023
16/6/2023 to 17/6/2023
18/6/2023 to 19/6/2023
NAME OF TOPIC
LHRM (Locomotive Heavy Repair Machines)
LUNT (Locomotive Under Truck)
CRS (Component Repair Section)
Laboratory
INTRODUCTION
What is a locomotive:
locomotive engine a self-propelled engine driven by steam, electricity, or
diesel power and used for drawing trains along railway tracks. If a
locomotive is capable of carrying a payload, it is usually rather referred to
as a multiple unit, motor coach, railcar or power car; the use of these selfpropelled vehicles is increasingly common for passenger trains, but rare
for freight.
Traditionally, locomotives pulled trains from the front. However, pushpull operation has become common, where the train may have a
locomotive (or locomotives) at the front, at the rear, or at each end. Most
recently railroads have begun adopting DPU or distributed power. The
front may have one or two locomotives followed by a mid-train locomotive
that is controlled remotely from the lead unit.
Working of Diesel Locomotive Train:
Diesel locomotives are powered by diesel engines. In the early days of
diesel propulsion development, various transmission systems were
employed with varying degrees of success, with electric transmission
proving to be the most popular.
Diesel-mechanical
A diesel–mechanical locomotive uses mechanical transmission to transfer
power to the wheels. This type of transmission is generally limited to lowpowered,
low
speed shunting
(switching) locomotives,
lightweight multiple units and self-propelled railcars. The earliest diesel
locomotives were diesel-mechanical. In 1906, Rudolf Diesel, Adolf
Klose and the steam and diesel engine
manufacturer Gebrüder
Sulzer founded Diesel-Sulzer-Klose GmbH to manufacture dieselpowered locomotives. The Prussian State Railways ordered a diesel
locomotive from the company in 1909. The world's first diesel-powered
locomotive (a diesel-mechanical locomotive) was operated in the summer
of 1912 on the Winterthur–Romanshorn railway in Switzerland, but was
not a commercial success.[21] Small numbers of prototype diesel
locomotives were produced in a number of countries through the mid1920s.
Diesel-electric:
Diesel–electric locomotives are diesel locomotives using electric
transmission. The diesel engine drives either an electrical DC
generator (generally, less than 3,000 horsepower (2,200 kW) net for
traction), or an electrical AC alternator-rectifier (generally 3,000
horsepower (2,200 kW) net or more for traction), the output of which
provides power to the traction motors that drive the locomotive. There is
no mechanical connection between the diesel engine and the wheels. The
vast majority of diesel locomotives today are diesel-electric.
Diesel Locomotives work on the principle of Carnot cycle.
Carnot cycle:
A Carnot cycle is defined as an ideal reversible closed thermodynamic
cycle. Four successive operations are involved: isothermal expansion,
adiabatic expansion, isothermal compression, and
adiabatic
compression. During these operations, the expansion and compression of
the substance can be done up to the desired point and back to the initial
state.
Following are the four processes of the Carnot cycle:

In (a), the process is reversible isothermal gas expansion. In this
process, the amount of heat absorbed by the ideal gas is q in from
the heat source at a temperature of Th. The gas expands and does
work on the surroundings.



In (b), the process is reversible adiabatic gas expansion. Here, the
system is thermally insulated, and the gas continues to expand and
work is done on the surroundings. Now the temperature is lower, T l.
In (c), the process is a reversible isothermal gas compression
process. Here, the heat loss qout occurs when the surroundings do
the work at temperature Tl.
In (d), the process is reversible adiabatic gas compression. Again,
the system is thermally insulated. The temperature again rises back
to Th as the surrounding continue to do their work on the gas. 
Steps involved in a Carnot Cycle
For an ideal gas operating inside a Carnot cycle, the following are the
steps involved:
Step 1:
Isothermal expansion: The gas is taken from P1, V1, T1 to P2, V2, T2. Heat Q1 is
absorbed from the reservoir at temperature T1. Since the expansion is
isothermal, the total change in internal energy is
zero,
absorbed by the gas is equal to the work done by the
environment, which is given as:
and
the
gas
on
heat
the
Step 2:
Adiabatic expansion: The gas expands adiabatically from P2, V2, T1 to P3, V3,
T2.
Here, work done by the gas is given by:
Step 3:
Isothermal compression: The gas is compressed isothermally from the
state (P3, V3, T2) to (P4, V4, T2).
Here, the work done on the gas by the environment is given by:
Step 4:
Adiabatic compression: The gas is compressed adiabatically from the
state (P4, V4, T2) to (P1, V1, T1).
Here, the work done on the gas by the environment is given by:
Hence, the total work done by the gas on the environment in one complete cycle
is given by:
Parts in a Diesel Locomotive:
1.)
2.)
3.)
4.)
5.)
6.)
Nose of the engine
Cabin compartment
Alternator
Engine
Air compressor
Radiator
1.) Nose of the engine:
Normally, the short hood is the front of the
locomotive, and may be referred to as the locomotive's "nose". Originally,
this was not the case; railroads preferred to have the long hood leading,
for additional crew protection in a collision, and because it was the familiar
mode of operating steam locomotives. Consists of Air brake valve,
Dynamic brake grids.
2.)Cabin Compartment: The cab, crew compartment
or driver's
compartment of a locomotive, or a self-propelled rail vehicle, is the part
housing the train driver, fireman or second man (if any), and the controls
necessary for the locomotive or self-propelled rail vehicle's operation.
3.) Alternator:
Alternators and generators in locomotives convert
mechanical energy from the prime mover to electrical energy to pull the
train. They are the main device connected to the prime mover .
Advances over the years have improved the type and size of alternators
and generators, enabling locomotive builders and rebuilders to simplify or
eliminate many electrical systems once necessary to achieve maximum
output from a locomotive while under load.
DC generators are in the minority these days with AC alternators found
zalmost everywhere. DC generators were standard until the 1960s,
producing up to 600 volts, but their maintenance and reliability issues
caused the changeover to AC alternators. Alternators would eventually be
able to produce well in excess of 1,200 volts at all speed ranges. AC
alternators can also be produced with one or more sets of windings
allowing for separate outputs to various systems on the locomotive.
The alternator or generator traditionally provides 100% of its output for the
traction motors while a companion or auxiliary alternator is mated to it,
providing power for the rest of a locomotive’s electrical needs. This device
is attached to the end of the alternator and both are bolted directly to the
prime mover. A companion alternator typically has more than one set of
windings to create multiple power outputs dedicated to different
locomotive functions. The companion alternator design and number of
outputs can vary from builder to builder and even from locomotive model
to locomotive model, but will provide electricity for the various cooling
fans, computer systems, battery charging, and alternator excitation,
among other things.
A trend that has been ongoing for many years is for railroads and thirdparty locomotive rebuilders to replace D.C. main generators in older EMD
locomotives when performing major electrical upgrades or complete
locomotive overhauls. EMDs AR10 A.C. alternator fits well in the older D32
D.C. main generator’s footprint inside a locomotives car body, making this
a popular swap. This increases the reliability of the locomotive while
reducing long-term maintenance costs .
4.) Engine:
The engine of a diesel locomotive is a V-type. The fuel
supply for a diesel locomotive is compression ignition. The ignition of the
fuel is caused by the elevated temperature of the air in the cylinder due to
mechanical compression; thus, the diesel engine is called a compressionignition engine. The diesel locomotive engine consists of 16 cylinders.
The components of a diesel locomotive are:





















Camshaft
Connecting rod
Piston a.) Piston head b.) Piston rings
Crank pin
Crank shaft
Gudgeon pin
Cylinder head
Sump
Cylinder line
Fuel Injector
FIP (Fuel injection support)
Turbocharger
After cooler
Water pump
Lube oil pump
Radiator
Radiator fan
Right angle gear box
Compressor
RTTN (Rear truck traction motor) Blower
FTTM Blower (Front truck traction motor) Blower
There are two types of diesel locomotive engines
1.) 4-stroke 16-cylinder V-type, diesel electric locomotive
2.) 2-stroke 16-cylinder V-type turbocharged diesel electric
locomotive
1.) 4-stroke 16-cylinder V-type, diesel electric locomotive:
In a diesel–electric locomotive, the diesel engine drives either
an electrical DC generator (generally, less than 3,000 hp
(2,200 kW) net for traction), or an electrical AC alternatorrectifier (generally 3,000 hp net or more for traction), the output
of which provides power to the traction motors that drive the
locomotive. There is no mechanical connection between the
diesel engine and the wheels.
The important components of diesel–electric propulsion are the
diesel engine (also known as the prime mover), the main
generator/alternator-rectifier, traction motors (usually with four or
six axles), and a control system consisting of the
engine governor and electrical or electronic components,
including switchgear, rectifiers and other components, which
control or modify the electrical supply to the traction motors. In
the most elementary case, the generator may be directly
connected to the motors with only very simple switchgear.
Originally, the traction motors and generator were DC machines.
Following the development of high-capacity silicon rectifiers in the 1960s,
the DC generator was replaced by an alternator using a diode bridge to
convert its output to DC. This advance greatly improved locomotive
reliability and decreased generator maintenance costs by elimination of
the commutator and brushes in the generator. Elimination of the brushes
and commutator, in turn, eliminated the possibility of a particularly
destructive type of event referred to as a flashover (also known as an arc
fault), which could result in immediate generator failure and, in some
cases, start an engine room fire.
Four-stroke diesel locomotives are a type of locomotive that use a fourstroke diesel engine for propulsion. The four-stroke cycle, also known as
the Otto cycle, consists of four strokes: intake, compression, power, and
exhaust.
Here are some key points about four-stroke diesel locomotives:
1. Engine Design: Four-stroke diesel locomotives have a more complex
design compared to two-stroke engines. They feature separate intake and
exhaust valves, which are typically located in the cylinder head. The intake
valve opens to allow air into the cylinder, and the exhaust valve opens to
release the combustion gases after the power stroke.
2. Intake Stroke: During the intake stroke, the intake valve opens, and the
piston moves downward, creating a vacuum in the cylinder. This allows
fresh air to be drawn into the cylinder.
3. Compression Stroke: In the compression stroke, both the intake and
exhaust valves are closed, and the piston moves upward, compressing
the air within the cylinder. This compression raises the temperature and
pressure of the air.
4. Fuel Injection: Once the air is compressed, fuel is injected into the
cylinder through fuel injectors. The fuel mixes with the hot, compressed
air.
5. Power Stroke: The injected fuel ignites due to the high temperature and
pressure in the cylinder. This combustion forces the piston downward,
generating power.
6. Exhaust Stroke: After the power stroke, the exhaust valve opens, and
the piston moves upward, pushing out the combustion gases through the
exhaust valve. This prepares the cylinder for the next intake stroke.
7. Efficiency and Power: Four-stroke diesel locomotives are known for
their fuel efficiency and power output. The four-stroke cycle allows for
better control of the intake, compression, combustion, and exhaust
processes, resulting in improved efficiency compared to two-stroke
engines.
8. Lubrication: Four-stroke diesel locomotives have separate lubrication
systems for the engine's moving parts and the fuel system. Lubricating oil
is supplied to critical engine components, such as the piston rings,
crankshaft bearings, and valve train, to reduce friction and wear.
9. Emissions: Four-stroke diesel locomotives generally have lower
emissions of pollutants compared to two-stroke engines. Advances in
emissions control technologies, such as exhaust after-treatment systems,
have further reduced the environmental impact of diesel locomotives.
Four-stroke diesel locomotives are widely used in the rail industry due to
their reliability, durability, and fuel efficiency. However, there has been an
increasing focus on developing more environmentally friendly
alternatives, such as electric locomotives and hybrid locomotives, to
reduce emissions and dependence on fossil fuels.
Types of 4-stroke 16-cylinder V-type, diesel electric locomotive: -
 WDM3A
 WDG3A
 WDM3D
W-Wide
D-Fuel (Diesel)
G-Goods
M-Mixed (Goods+ Passengers)
P-Passengers
WDM3A: -The Indian locomotive class WDM-3A is a class of diesel–
electric locomotive that was developed in 1993 by Banaras Locomotive
Works (BLW), Varanasi for Indian Railways. The model name stands
for broad gauge (W), Diesel (D), Mixed traffic (M) engine, with 3300
horsepower (3A). The WDM-3A is a later classification of earlier WDM2C. They entered service in 1994. A total of 143+ were built at ALCO
and Banaras Locomotive Works between 1994 and 2003 with rest of the
1246 units being rebuilt from WDM-2 which made them the most
numerous class of mainline diesel locomotive until the WDG-4.
The WDM-3A is one of the most successful locomotives of Indian
Railways serving both passenger and freight trains for over 26 years. A
few WDM-3A units were exported to neighboring countries like Sri
Lanka and Bangladesh. Despite the introduction of more modern types of
locomotives like WDG-4 and electrification, a significant number are still
in use, both in mainline and departmental duties. As of April 2022, 769
locomotives still retain "operational status" on the mainline as WDM-3A,
with further examples having been converted back to WDM-2 or WDM2S. The loco is now widely used across India for long-distance passenger
trains due to its ruggedness and high tractive loads and acceleration.
WDG3A: -The Indian locomotive class WDG-3A is a class of dieselelectric locomotive that was developed in 1994 by Banaras Locomotive
Works (BLW),Varanasi for Indian Railways. The model name stands
for broad-gauge (W), Diesel (D), Goods traffic (G) engine, 3,100 hp (3A)
locomotive. They entered service on 18 July 1995. A total of 1,164 WDG3A units were built between 1994 and 2015 at BLW, Varanasi with a few
units being produced by Diesel Loco Modernisation Works (DLMW) and
Parel Workshop.
It is the dedicated freight version of the very successful WDM-2 and
shares the same engine and horsepower rating with WDM-3A. It is
considered to be a successful locomotive class with high reliability and
few maintenance problems. Despite the introduction of more modern
types of locomotives like WDG-4 and electrification, a significant number
are still in use, both in mainline and departmental duties.
As of April 2022, 1047 locomotives still retain "operational status" on the
mainline as WDG-3A, with a few examples having been converted
to WAGC3 or WAG-10.
WDM3D: - The Indian locomotive class WDM-3D is a class of dieselelectric locomotive that was developed in 2003 by Banaras Locomotive
Works (BLW), Varanasi for Indian Railways. The model name stands
for broad gauge (W), Diesel (D), Mixed traffic (M) engine with 3300
horsepower (3D). The engine is classified WDM-3D though it outputs only
3300 hp and not 3400 hp as the name should suggest. They entered
service in 2003. A total of 590+ WDM-3D were built at Banaras
Locomotive Works (BLW), Varanasi between 2003 and 2016.
The WDM-3D is one of the most successful locomotives of Indian
Railways serving both passenger and freight trains. A few WDM-3D units
were exported
or gifted
to
neighboring
countries like Sri
Lanka and Bangladesh. A significant number of these locomotives are still
in use, both on mainline and departmental duties. As of October 2021,
most of the locomotives still retain "operational status" on the mainline as
WDM-3D, with further examples having been converted from WDM-3B.
2.)2-stroke 16-cylinder V-type turbocharged diesel electric locomotive:2-stroke diesel locomotives are a type of locomotive that utilize a twostroke diesel engine for propulsion. In a two-stroke engine, the power
cycle is completed in two strokes of the piston: the compression stroke
and the power stroke.
Here are some key points about 2-stroke diesel locomotives:
1. Engine Design: Two-stroke diesel locomotives have a simpler design
compared to their four-stroke counterparts. They typically feature uniflow
scavenging, where air enters the cylinder through ports near the bottom
and exits through exhaust valves at the top. This design allows for efficient
air exchange and combustion.
2. Fuel Injection: Two-stroke diesel locomotives use direct fuel injection,
where fuel is injected into the combustion chamber at high pressure. This
ensures efficient fuel atomization and combustion.
3. Power Stroke: In the power stroke, the compressed air-fuel mixture
ignites due to the high temperature and pressure within the cylinder. The
expanding gases push the piston downward, generating power.
4. Scavenging: After the power stroke, the exhaust gases are expelled,
and the fresh air for the next cycle is drawn in through the scavenging
ports. The scavenging process is crucial for removing exhaust gases and
providing a fresh charge of air for combustion.
5. Efficiency and Power: Two-stroke diesel locomotives are known for their
high-power output and efficiency. Due to the two-stroke design, they
have a power stroke for every revolution of the crankshaft, resulting in
more power output compared to four-stroke engines of similar size.
6. Lubrication: Two-stroke diesel locomotives require lubrication systems
that provide oil for both the engine's moving parts and the fuel system.
Lubricating oil is typically mixed with the fuel before being injected into the
engine.
7. Emissions: Two-stroke diesel locomotives tend to have higher
emissions of pollutants compared to four-stroke engines. However,
advancements in technology have allowed for the development of
cleaner-burning engines that meet stringent emissions standards.
It's worth noting that in recent years, there has been a shift towards using
more environmentally friendly and efficient locomotives, such as fourstroke diesel engines, electric locomotives, and hybrid locomotives. These
newer technologies offer improved fuel efficiency, reduced emissions, and
lower maintenance requirements.
Railway companies often prefer two-stroke diesel engines in locomotives
because they are more powerful and efficient than four-stroke engines.
Two-stroke engines have a higher power-to-weight ratio, which allows
them to generate more power with less weight. This makes them ideal for
heavy-duty applications such as hauling trains. Additionally, two-stroke
engines have fewer moving parts and require less maintenance, which
helps to keep costs down. Overall, two-stroke diesel engines are a good
choice for railway companies looking for powerful and efficient
locomotives.
Types of 2-stroke diesel locomotives: -
 WDP4
 WDG4
 WDG4D (Dual Cab)
WDP4: The Indian locomotive class WDP-4 (EMD GT46PAC) is a
passenger-hauling diesel-electric locomotive with AC
electric
transmission designed by General Motors Electro-Motive Division and
built by both GM-EMD and under license by Banaras Locomotive
Works (BLW) of Varanasi, India for Indian Railways as the classes WDP4,
WDP4B and WDP4D. The GT46PAC is a passenger version of the
previous Indian Railways EMD GT46MAC freight locomotive. The
locomotive has a 16-cylinder 710G3B diesel engine and is one of the
fastest diesel-electric locomotives in service in Indian Railways.
The WDP-4 was the loco originally designed by GM EMD and 10 of them
were dispatched to India by June 2001. Later on Banaras Locomotive
Works, Varanasi started building them initially using knocked-down kits
and later indigenously. Starting 2003, the locomotives were produced in
large numbers by BLW. The locomotive features self-diagnostics control
using EM2000 onboard microprocessor which was a new technology for
Indian Railways back then.
Unlike the Co-Co wheel arrangement featured on most locomotives,
including its freight hauling variant, WDG-4, this loco has a Bo1-1Bo
wheel arrangement meaning that it has two powered and one unpowered
axle per bogie. This was done to reduce the weight of the loco to make it
suitable for passenger operations and also to reduce maintenance.
Visibility Issue
The use of the locomotive with the long hood forward configuration has
been criticised with respect to the driver's visibility as it is affected due to
the protruding radiator section at the hood-end. This criticism has been
rejected by the Railways. However, in response, the cab profile of some
WDP-4s were widened with a Piggy-face profile, to increase the field of
view from the control cab and the WDP-4B variant was also produced with
the same widened cab profile.
Variants: -
WDP-4B
This was the first attempt of the Railways to improve upon the successful
WDP-4 locomotive. The Bo1-1Bo was found inadequate for hauling 24
coach passenger trains due to the reduced tractive effort. As a result,
DLW, reconfigured the chassis to be Co-Co instead. This led to better
adhesion with the rails to provide better acceleration with heavy trains.
Moreover, the original EMD 710 engine was tweaked to produce an output
of 4,500 HP instead of the original 4,000 HP. this Up-rated engine was
designated as EMD 16N-710G3B-EC, with an RPM of 910 at Notch-8.
This locomotive came to be known as the "GT46PACe". One more
important change added to this loco was the inclusion of Blended Brake
System. This was added to maximise the use of Dynamic brakes by the
loco-pilot and therefore minimise the wear and tear on the fixed brake
rigging of the coaches and the locomotive. The addition of blended brake
is responsible for the subclass to be designated with a 'B'. Some more
features are the widened piggy-face cab profile to aid visibility, change in
the Traction Motor blower by installing a higher power motor and increase
in the axle load to 20.2 tonnes (19.9 long tons; 22.3 short tons). The
locomotive also has a self-load test feature that allows it to test the net
output of the engine. In Siemens and EMD systems, the loco has been
provided with 2 traction inverters (TCC-1 and TCC-2, for the respective
bogies) while in the Medha system, it has 6 traction inverters, one for each
traction motor.
WDP-4D
The final alterations to the GT46PAC came in the form of the WDP-4D.
The locomotive is the most distinctively identifiable of the three thanks to
the addition of a second cab at the long hood end of the locomotive. Due
to the heat generated from the radiator at the second cab end of the
locomotive, DLW had to install air conditioning to protect both the
electrical components and the loco-pilot from the high temperatures.
The existing features from WDP-4B have been carried forward to this
class and it exclusively features the widened cab profile. Since it is a Dual
Cab now, it is called as "JT46PACe". The loco features a completely
different desk control stand, provided by Medha with digital display
screens allowing for remote fault diagnostics.
Many locos also have GSM-R based transmission antennae to transmit
critical loco info for use by maintenance and signalling staff. It features
electro-pneumatic microprocessor-based control adapted from the WDP4B and brake system equipment of KNORR/NYAB CCB type.
This loco again with Dual-Cab, but with More Power and Better Fuel
Consumption and State-of-the-Art features compared to ALCo DL560C,
along with an Air-Conditioned Hood Cab, became a very efficient
replacement of WDP-3A alias "Toaster".
WDG3A: - The Indian locomotive class WDG-3A is a class of dieselelectric locomotive that was developed in 1994 by Banaras Locomotive
Works (BLW),Varanasi for Indian Railways. The model name stands
for broad-gauge (W), Diesel (D), Goods traffic (G) engine, 3,100 hp (3A)
locomotive. They entered service on 18 July 1995. A total of 1,164 WDG3A units were built between 1994 and 2015 at BLW, Varanasi with a few
units being produced by Diesel Loco Modernisation Works (DLMW) and
Parel Workshop.
It is the dedicated freight version of the very successful WDM-2 and
shares the same engine and horsepower rating with WDM-3A. It is
considered to be a successful locomotive class with high reliability and
few maintenance problems. Despite the introduction of more modern
types of locomotives like WDG-4 and electrification, a significant number
are still in use, both in mainline and departmental duties.
As of April 2022, 1047 locomotives still retain "operational status" on the
mainline as WDG-3A, with a few examples having been converted
to WAGC3 or WAG-10.
Sub Classes
WDG-3B
They were an experimental technical variant of the WDG3A with an
upgraded ALCO engine to output 3,200 hp. But the experiment was
unsuccessful and all units were reverted to normal WDG-3A. One of the
locomotives of this class was numbered #14796.
WDG-3C
Another experimental class, but this time rated at 3300 hp. Only one unit
(#14962) was produced and was painted in a unique "Dark
Rose/Cheetah" livery. This loco was derated to 2,600 hp, but is still with
the Katni diesel locomotive shed. This class was unsuccessful as well.
WDG-3D
Freight version of the WDM-3D. Only one (#13301) unit was marked with
this marking. It may possibly be rated at 3400 hp. Now it has been derated
to 2600 hp with WDG-3A class markings and homed at the Vatva Loco
Shed.
WDG-3A Converted into Electric Locomotive WAGC-3
In 2018, Chittaranjan Locomotive Works, Banaras
Works and Research Design and Standards Organisation
WDG-3A into a purely electric, twin-section 10,000 hp
locomotive, classified as the WAGC3. This locomotive was
Locomotive
converted a
(7,457 kW)
the result of
the initiative taken up by the Railway Board in November 2017, asking
RDSO to work out details of conversion of diesel locos to electric locos.
RDSO had suggested that such conversion would be possible with
retaining the Motorized Truck assembly (which includes traction motors
and drive side traction converters), computer-controlled brakes (CCBs)
and other relevant parts, suitably redesigning the under-frame and
superstructure and adding the conversion kit. It was completed in only 69
days. Both units will together be considered as one asset and one
locomotive by Indian Railways. Only a single unit has been produced so
far and it is in service. It has been given to Bondamumda Shed of SER.
WDG4D (Dual Cab): The WDG4D has been developed in conjunction with
RDSO and is equivalent to the existing single cab WDG4 (EMD GT46MAC)
design. A WDG4D costs Rs147m compared to Rs143·8m for the single cab
version, and is 2 m longer at 21·7m. The air-conditioned cabs have TFT screens
displaying operating and fault diagnostic information, and an ergonomicallydesigned control stand and seat with tilting back and lumbar support based on
designs used on excavators.
The 4 500 hp locomotive is powered by a 710 G3B engine, IGBT
controlled three-phase traction motors and computerised braking controls.
Top speed is 105 km/h, with a maximum of 100 km/h envisaged in
revenue service. The WDG4D could also be used to haul passenger trains
in emergencies.
The WDG4D shares components with twin-cab passenger locomotives
built by DLW, which is expected to simplify the start of series production
after successful trials with the prototype.
5.) Air compressor:
In trains of all lengths, compressed air is
used to power the suspension system, which is responsible for the
running smoothness of rolling stock along the tracks. When air
compressors fail to deliver as needed, rides become turbulent,
uncomfortable, and possibly dangerous. The air compressor consists of 3
heads a.) 2 heads at low pressure
b.) One head at high pressure
c.) 3 cylinders
d.) 2 air coolers
The processes happening in air compressor are
Suction->Inter cooling->High pressure head
Compressors in conventional locomotives are fitted with oil bath air
filters while in three phase locomotives they are fitted with dry type
air filters. These are connected to the suction side of the LP cylinder
heads. A fan with a fan guard is provided to direct cool air on to the
compressor unit in conventional loco.




6.)
The compressor room in locomotive has a
High pressure head
Low pressure head
Turbo supercharger system
Lube oil pressure gauge
Radiator:
Radiators are heat
exchangers used
to
transfer thermal energy from one medium to another for the
purpose of cooling and heating. A radiator is always a source of
heat to its environment, although this may be for either the
purpose of heating this environment, or for cooling the fluid
or coolant supplied to
it,
as
for
automotive engine
cooling and HVAC dry cooling towers. Despite the name, most
radiators transfer the bulk of their heat via convection instead
of thermal radiation.
The radiator room in a locomotive consists of a
 ECC (Eddy current clutch)
 Drum
 Spider
 Radiator fan
 Oil cooler
 RTTM (Rear truck traction motor blower)
 Lube oil filter pump
Radiator fan
Eddy current clutch: Eddy current clutches are available
in various
sizes and can produce power thousands of kilowatts in both
vertical and horizontal configurations. ECC’s are adjustable speed drives
and have soft starting capability. They are actually a slip control device.
ECC operates at 100% slip which provides good acceleration. When the
speed is decreased the slip decreases to the desired rate, providing
disengagement
of clutch
An eddy current clutch and an induction machine are identical in working
principle. Fig shows an eddy current clutch. The input shaft directly
coupled to the motor and variable speed output shaft is connected to load.A
metallic drum is connected to driving shaft and field coil system is mounted
on the output shaft. The slip rings used to excite the field system.
The load is initially at rest when the motor reaches the full speed; DC
current is passed through the electromagnets. The resultant magnetic field
produced an eddy current in the metallic drum. The magnetic flux produces
a torque that brings the load to desired speed.
Supercharger: The Turbo-supercharger is generally provided at the
free end of the locomotive, above the After-cooler. Generally TSC is
having four casings- 1) Gas Inlet Casing, 2)Turbine Casing, 3)
Intermediate Casing, 4) Blower Casing. Gas inlet casing is connected with
extended exhaust manifold. In exhaust manifold, gas comes from 14
exhaust elbows and remaining R1 & L1 exhaust elbows are connected
directly to gas inlet casing (in case of 16 cylinder locomotives). One dome
and nozzle ring is provided in this casing. Rotor assembly comprises of
common shaft, turbine disc with blade and impeller. It is mounted over the
intermediate casing. One side of the blower casing is connected with air
filter and other side is connected with expansion joints to after-cooler.
After-cooler is connected with “V” gallery or air channel. The inlet passage
of every cylinder is connected to this air channel to suck fresh air as per
the pre-set cycle.
OIL COOLER:
An oil cooler is a help to maintain the oil supply at a
consistent, optimal temperature. Its purpose is to cool the oil passing
through the coils, thus improving the engine and the transmission's
lifetime. They are situated in front of an engine's cooling system.
Maintenance of locomotives:
Schedule for light repair medium:
Trip 1
Trip 2
Monthly schedule:
Quarterly
6 months
18 months
Heavy repair:
36 months
Diesel Loco shed laboratory:
It’s a vital role in diesel loco shed to conduct various types of testing.
Ex: Lube oil testing, Fuel oil testing, Grease testing, Coolant water
testing, (Non-destructive testing).
1.) Lube oil testing: For checking the lube oil
a.) Water coolant testing: it’s done for checking the water content
in the lube. It’s also called crackling test
b.) Viscosity testing: It’s done for checking the viscosity of the
lubricant. The viscosity of the lubricant should be in between
12.8-20.2 centistokes.
c.) Flash point: The flash point of the lube should be at a minimum
of 200 degree Celsius.
d.) Spectro rapid analysis: In Spectro rapid analysis we find out
wear and tear of the elements in the serviced lube oil.
Limit of the element: Aluminium: 5-10 ppm
Chromium: 5 -10 ppm
Copper:10 -20 ppm
Iron:30-50 ppm
Sodium:20
Lead:5-10 ppm
Silicon:10-20 ppm
Boron:10-20 ppm
Braking system in locomotives:
Air brakes are used in
diesel locomotives. Compressed air is used as operating medium. The
air is provided from the air compressor.
Types of braking system in diesel locomotive: 1.) A9
2.) SA9
A9:
The A-9 Automatic Brake Valve is a compact, self-lapping, pressure
maintaining brake valve, which is capable of graduating the application or
release of locomotive and train brakes. The A-9 Automatic Brake Valve
has five positions: Release, Minimum Reduction, Full Service, Overreduction, and Emergency. The full-service application position is
preceded by a zone in which brake pipe air is supplied or exhausted in
proportion to brake valve handle movement through this zone, thus
providing the graduation of an automatic application or release of the
locomotive and train brakes.
The A9 Automatic Brake Valve maintains 5kg/cm2-air pressure in Brake
Pipe System against normal leakage at its release position. It also
maintains air pressure drop in the system according to its handle position.
The A-9 Automatic Brake valve consists of a self-lapping regulating
portion, which supplies or exhausts the brake pipe pressure, and a vent
valve which is actuated only when the brake valve handle is placed in
Emergency position for the purpose of venting brake pipe pressure at an
emergency rate. The self-lapping portion is actuated by regulating cam
dog 3 on the brake valve handle shaft 32 which controls the supply or
exhaust of brake pipe pressure. The vent valve 19 is actuated by special
cam dog 23 attached to the brake valve handle which is operative only in
Emergency position of the brake valve handle. The A-9 Automatic Brake
Valve is provided an adjusting handle or set screw 15 which serves to
permit the proper adjustment of the automatic brake valve to supply brake
pipe air to the required operating pressure. There is an inlet valve
assembly along with double ball check valve, which moves up and down,
when handle moves.
A9 braking system is used when the locomotive formation is applied.
Operation Charging the A9 automatic brake valve handle is kept at
release position normally. The regulating cam dog 3 holds the inlet and
exhaust unit at farthest down ward position. While the regulating valve
spring 12 will cause the double ball check assembly 5 to be seated at the
exhaust valve and unseated at the inlet valve (see diagrammatic). Main
reservoir air is supplied at port No. 30 in the pipe bracket and passes
through a strainer to the open inlet valve in to port No.5. This air in port 5
is also ported through a choke passage to the face of regulating valve
diaphragm 9. When the pressure on the face of the regulating valve
diaphragm 9 overcomes regulating valve spring 12 tension, the 11
regulating valve diaphragm assembly moves down ward and allow the
inlet valve spring to seat the double ball check assembly at the inlet valve
seat. The A-9 Automatic Valve resumes a lap position. Application When
the brake valve handle is moved into the minimum reduction, service
application zone or full-service position, the regulating cam dog 3 on the
brake valve handle shaft 32 will permit the inlet valve assembly to move
away from the exhaust port by the exhaust valve spring 7. The inlet valve
assembly will carry the double ball check assembly with it. This movement
will unseat the double ball check valve at exhaust valve seat, thus allowing
brake pipe air to flow to exhaust. With the reduction of pressure on
regulating valve diaphragm 9, the regulating valve spring 12 will cause a
movement of the diaphragm assembly toward the inlet valve and the
double ball check valve assembly will be seated at the exhaust valve seat
again. The brake valve to assume a lap position. Pressure drop in
Minimum reduction—.5/.7kg/cm2 Full service ---------- --1.7/2kg/cm2 Overreduction--------2.5kg/cm2 Release after application Movement of the
brake valve handle toward release position will cause regulating cam 3 to
move the inlet valve assembly toward the regulating valve diaphragm
assembly. This movement will cause the double ball check valve 5 to be
unseated at the inlet valve. Main reservoir air will then flow through the
inlet valve to port No. 5. The supply of main reservoir air to the face of
regulating valve diaphragm 9 will increase and move down word, resulting
in the compression of the regulating valve spring 12. When the force has
equalized across the regulating valve diaphragm 9, the double ball check
assembly 5 will again seat at the inlet valve due to the force of the inlet
valve spring and the brake valve will assume a lap position. Thus, it can
be seen that the brakes can be graduated off in proportion to the brake
valve handle movement from an application position toward release
position. Emergency position When the brake valve handle is moved to
emergency position, the brake valve will perform all the service
operations. In the emergency position, the emergency cam dog 23 is
actuated through special cam dog 23 to open vent valve 19 and allow
brake pipe air to be vented at an emergency rate. Release after an
emergency is the same as previously described under release after
service.
SA9:
Its applied only for the locomotive. The SA9 independent Brake
Valve is a compact, self– lapping pressure maintaining independent brake
valve, which performs the function of graduating the application or release
of the locomotive air brakes independently of the automatic brake valve.
The SA9 Independent Brake Valve is also capable of releasing an
automatic brake application on the locomotive without affecting the
application on the train brakes. The independent brake valve has three
positions: Quick Release, Release, and Application. The quick release
position is the farthest right-hand position of the brake valve and serves
to release an automatic brake application on the locomotive. The
application position consists of a zone in which regulated air pressure is
supplied or exhausted in proportion to brake valve handle movement
through this zone, thus piloting the graduating of brake cylinder pressure
during an independent application or release.
The SA9 Independent Brake Valve maintains 3.5kg/cm2-air pressure in
the independent brake system against normal leakage through C2-Relay
valve. It is supposed to maintain graduated application and release
according to its handle position. 3. Construction The SA9 Independent
Brake Valve consists of a self–lapping regulating portion, which supplies
or exhausts air pressure for piloting the graduated application or release
of brake cylinder pressure on the locomotive. This brake valve also
includes a quick release valve. Both the self-lapping regulating portion and
quick release valves of the SA9 Independent Brake valve is actuated by
cams attached to the brake valve handle stem. It has regulating valve
spring 12, which regulates supply pressure. Exhaust valve spring 7
regulates the movement of exhaust valve. Inlet valve spring keeps inlet
ball valve at seat. Quick release valve 17 keeps port no.1&7 separate
through its rubber ` o’ rings. 4. Operation Charging. In the release position
of the brake valve handle, the inlet valve, due to the spring tension of
exhaust valve Sparing 7, is positioned at its farthest travel from the
regulating valve diaphragm assembly. Which will unseat the double ball
check valve at the exhaust valve while being seated at the inlet valve by
the inlet valve spring. With the exhaust valve open, there is no air pressure
in the independent application port no. 20. Main reservoir air is supplied
through port 30 in the pipe bracket and a strainer to the spring chamber
of the inlet valve where it is blanked.