LESSON 10
PREPARATION
FOR STAND-BY
When instructions have been
received that the main engine is to
be prepared for running the
following procedure for any make
of marine diesel engine should be
followed:
1. Check that the fuel, lubricating
oil and cooling water are at
working level and drain any
water or sludge from all
lubricating oil and fuel tanks.
The purified fuel tanks to be
raised to the required
temperature. Switch on the
power to various auxiliaries
and to the control console.
2. Check that all valves in the
various systems are operational
and check the jacket water
and lubricating pumps. Any
leaks to be rectified( 改 正 )
immediately.
3. Start up jacket water pumps
and check pressures. Bring
into operation the heating
system of the cooling water.
The temperature of the
cooling water returns from
the jackets, liners and pistons
should be raised gradually to
60℃(140℉).
The warming through
period should extend
over
a
period
of
approximately four hours.
4.
Check
through
the
crankcase, etc, for any tools,
obstructions(障碍物) or waste
material and remove them and
make sure that everything is
correct(in good order).
5. Start up lubricating oil
pumps and check that at
working pressure, oil flows
uniformly(均匀地) from all the
bearings and then close up the
crankcase.
On engines having oil cooled
pistons the lubricating oil
pre-heater must be put into
operation
and the rate of heating so
arranged
that
the
temperature of the piston
cooling oil returns are 32 to
35℃ over a period of at least
two hours.
6. Start up injector cooling
pumps, check pressure. Bring
into operation the heating system
for the fuel injector cooling water
tank to raise the temperature of
the water to 60℃ over a period of
about two hours.
If the engine is to be started
on high viscosity fuel the
temperature of the water
should be raised to 77 to
82℃.
7. If hoppers or sight glasses are
fitted check that there is an
adequate flow of coolant
through each piston, cylinder
head,
cylinder
jacket,
turbocharger
casing
and
injector.
8. Check that any vents in the
systems are clear to allow the
free flow of air from the
cylinder cooling passages and
turbochargers.
The charge air coolers
should also be vented.
Unvented spaces encourage
the formation of steam,
corrosion, erosion(侵蚀) and
local overheating.
9. Start up fuel priming
pumps, check pressure. The
system should be cleared of
air by means of the various air
vent cocks or valves.
With the fuel oil at about the
working pressure, check for
leakage.
If the engine can be started and
maneuvered on high viscosity
fuel, the temperature of the fuel
reaching the injectors should be
raised to such a point that the
viscosity is less than the required
value, i.e, 27 centistoke(厘沲).
10. Check that the level of oil
in the turbocharger is correct.
11. Ensure that starting and
control air valves are shut off
and engage the turning gear.
12. Start the turning gear, and
with
some
one
handoperating(manual) the cylinder
lubricators at regular intervals,
and with the indicator cocks open,
and with the control gear in the
‘stop’ position, give the engine at
least one complete turn.
Whilst the engine is turning
check to see that no water is
leaking
into
crankcase,
scavenge air belt, or from the
indicator cocks. Having found
all correct, take out the turning
gear.
13. Pump up the starting air
reservoirs to their maximum
pressure and drain the air
reservoirs and air system.
14. The scavenge drain
should be cracked open, the
drains from diaphragm(横隔
板) glands should be slightly
open.
15. All hand oil- and greaselubricated bearing must be
checked to see that their
lubrication is correct, the
control
linkage
is
well
lubricated and easily operated.
16. Check the engine room
telegraph( 车 钟 ) for proper
functioning and at the same
time check the telephones to the
bridge and Chief Engineer’s
office.
17. Check the reversing and
control
gear,
running
direction safety interlocks,
auto-shut-down
devices,
alarm devices for correct
functioning.
18. Open shut-off valve(截止
阀 ) for starting air tank,
close the drain valve on the
starting air manifold.
19. Check and if necessary,
adjust oil, water and fuel
pressure and temperatures.
20. Switch the controls on
the auxiliary blowers to the
automatic position and start
the fuel booster(增压) pump.
21. Inform bridge that engine
room would like to turn
engine over slowly on air. On
engine with bridge control the
control selector must be
turned to the desired position.
22. Start the engine on air
briefly on both direction and
then close all indicator cocks.
23. Finally, before ‘stand-by’
is rung on the engine
telegraph, it is usually to give
the main diesel engine a brief
trial on power ahead and
astern.
READING MATERIAL
A. ARRIVAL IN PORT
If the engine is to be
manoeuvred on diesel oil the
change-over from heavy oil
should be made about one
hour
before
engine
movements are expected.
An additional generator engine
should be started to provide a
spinning( 自 转 , 绕 转 , 空 转 )
power reserve during the
arrival period, and the starting
air system should be drained.
If permissible, a test reversal
of the engine should be
carried out prior to arrival
in restricted waterway(狭窄
水域).
After ‘finish with engine’ is
given,
ensure
that
the
telegraph is at stop, the fuel
control or speed adjusting
lever is at zero and the
starting air lever is in the
neutral position.
Shut the starting air valve
and starting air tanks, close
the automatic starting air
valve, if fitted, isolate control
air to engine.
Open drain cocks on
starting air manifold
ensure that there is
pressure anywhere in
starting air line.
the
and
no
the
The fuel booster pump and
steam to fuel heater, together
with fuel pipe heater tracer
lines should be shut off as soon
as the ‘finished with engines’
order is acknowledged.
Engage the turning gear and
lock the lever, open the
indicator cocks. By-pass the
jacket water and lubricating
oil coolers and continue
circulating the coolant.
The
cooling
water
temperature
should
be
gradually reduced over a
period of 8 hours to allow the
engine to cool down to an even
temperature equal to the inlet
temperature of the cooling
water.
This should also be the
procedure when lubricating
oil is used for piston cooling.
Crankcase lubricating oil
pumps should be kept
running for about half an
hour and oil then pumped
up to the gravity tank(重力
油柜) for treatment.
The main engine should be
turned through three or four
complete turns at first and
through one turn at intervals
during cooling.
The cylinder lubricators
should be operated by hand
during the turning.
Open all drain cocks of the
scavenge
air
receiver,
diaphragm glands, scavenge
spaces and exhaust gas
systems.
Shut down the lubricating oil
pump and open up the
crankcase for running gear
inspection, but it should not be
opened until 15 minutes after
the engine is shut down,
the staff should also be
engaged
in
thoroughly
cleaning
the
engine
externally which of course is
easier to do when the engine
is still warm.
If in port for only a few days,
keep
the
cooling
water
circulating at near normal
temperature by using either a
heating system or the heat of
the cooling system from the
auxiliary engines.
At regular intervals the
engine should be turned over
by turning gear with the
indicator cocks open
and the lubricating oil
pumps in operation, and the
cylinder lubricators worked
by hand to minimize
corrosive action on the liners.
In high humidity climates
the engine should be turned
over twice a day.
All fastenings (nuts, bolts, etc.)
to be tested for tightness, notes
taken of all leaking glands, and
excessive lubricating oil leakage
from bearings and connections,
and any damage to be corrected
before the engine is next used.
Any adjustments needed to
improve efficiency noted
during the previous voyage to
be carried out.
Spare parts and the stores to be
checked, including consumption
of all lubricating and fuel oils
and
other
consumable.
Replacements are, if necessary,
to be requisitioned.
If the engine is to remain idle
for several weeks it must be
given an extra cleaning and
all bright parts suitably
protected against corrosion.
The cylinder liners and pistons
should be thoroughly oiled.
This could be achieved by
turning the engine with the
turning gear and operating the
cylinder lubricators by hand.
Should the auxiliary engines
and boilers be put out of
action and there is a danger
of frost then the water
cooling system should be
thoroughly drained.
Chemically clean charge air
coolers
if
necessary.
Turbocharger air filter to be
inspected and if necessary
washed in a bath of paraffin(煤油)
and then thoroughly dried before
reassembly.
B.MAINTENANCE AND
OVERHAULING(大修,彻底检修)
Satisfactory
and
operation of the
depends not only on
manoeuvring but also
well it is kept in order.
proper
engine
correct
on how
Regular maintenance of the
engine helps a lot in preventing
early wear of parts and in
ensuring a long service as well
as the working efficiency of the
engine.
With various types of engines,
of course, the maintenance
and overhaul, is different.
Instruction books are to be
referred
to
whenever
necessary.
The individual parts of the
engine should be inspected
and thoroughly cleaned at
regular intervals.
The periods for such overhaul
work depend largely on the
quality of the lubricating oil and
fuel used, on the load of the
engine and on the efficiency of
the operator in locating troubles
and remedying them in time.
During overhaul the safety
rules have to be observed as
required in order to prevent
the danger of accidents.
Special
precaution
is
necessary when the engine is
running with the lagging
removed.
During overhauls, with the
engine shut down, safety
measures should be taken to
avoid undesirable turning of
the crankshaft.
All pipes should be pressure
relieved before the repair work
is started. Read the pressure
gauges and/or check the pipe by
carefully loosening the screw
plugs( 插 头 ， 插 销 ) or
connections.
If some parts of the running
gear are dismantled, before
using the turning gear, make
sure that no loose parts are
jammed( 上 紧 ， 卡 住 ) in the
crankcase where it is easy for
them to cause damage.
During dismantling work,
lubrication
lines
and
orifices( 孔 , 口 ) must be
sealed off.
The main bearings and the
connecting-rod
bearings
should be checked at regular
intervals.
In some cases the bearing
clearance may increase to
approximately
twice
its
original size.
Defective bearing shells
should be turned out of the
housings and renewed.
The piston, as a rule(通常),
should be lifted out after a
period of operation and
cleaned with the piston rings
renewed if necessary.
If the piston rod stuffing box
is carefully handled and
thoroughly
greased,
it
requires overhaul only when
the piston is removed.
In such a case, the gap
clearance(天地间隙) of the
sealing rings and fire
rings(顶环) must be reset to
original value and the wornout parts replaced.
The withdrawing of the
cylinder liners, in general(as a
rule), depends on their wear.
This
may
amount
to
approximately 1/120 of the
diameter in some engines.
When carrying out overhaul,
thoroughly check to see that all
bolts are properly re-tightened.
The bolts for the piston rods,
connecting rods and all other
important bolts must be given a
proper pre-stress.
After overhaul, the inner
spaces have to be checked to
see whether all impurities,
tools, etc. have been removed.
Any parts which have been
filed(锉，刮) or, scraped(刮，
磨 ) must be thoroughly
cleaned. Make sure that all
safety devices have been refitted.
Check renewed and /or refitted parts for exact setting
and clearance.
Before starting the engine
after overhaul work the
crankshaft should be turned
by means of a turning gear to
see that all parts move freely.
C. CYLINDER
EXAMINATION THROUGH
SCAVENGE PORTS
In port the scavenging air boxes
should be cleaned of sludge after
every 2,000 running hours(500 to
1,000 hours for a new engine), liner
ports cleaned, and components
inspected.
Jacket and piston coolants
should be circulated at this time
so that possible leakage may be
discovered. Similar action may
also be necessary to see if piston
ring leakage or scavenge fires are
experienced.
With the piston on bottom dead
centre a power lamp may be
introduced through the scavenge
ports to sight the liner wall
surface, which should be clean
and mirror surface bright with a
well-oiled appearance.
Inadequate lubrication may be
indicated by deterioration of
the liner surface and piston
ring faces,
with a striped(有斑的，有条纹的)
appearance
due
to
microseizure(微咬) of liner/piston ring
mating surfaces and by a sharp
burr(毛刺) on the edges of piston
rings.
Dark areas or black dry zones
on the upper part of the wall
may indicate combustion gas
blow-by between wall and
piston rings.
The surface of the rings may be examined
by turning the engine to bring the rings in
line with(与…成直线) the scavenge ports.
*The outer surface of the rings, the
underside and the mating floor of the piston
grooves should be worn bright; the rings
must move freely in the grooves, should
show oil at the edges(excepting the top
ring), be intact(完好的，完整的), and not
unduly(过度的，不适当的) worn.
The surface of the rings may be
examined by turning the engine
to bring the rings in line with
the scavenge ports.
The outer surface of the
rings, the underside and the
mating floor of the piston
grooves should be worn
bright;
the rings must move freely in
the grooves, should show oil
at the edges(excepting the
top ring), be intact(完整的),
and not unduly( 过 度 的 )
worn.
Micro-seizure will almost
always be due to oil starvation.
It will cause excessive local
wear and may be spread
over the whole liner contact
surface due to ring rotation
in the grooves.
Free movement of rings may
be checked by pressing them
into the grooves by means of
wooden
stick;
Partial
sticking increases the risk of
ring breakages;
Broken rings, which are
always due to ring collapse(内
陷), appear blackish(带黑色的)
and without tension when
pressed into the grooves;
‘clover-leafing( 苜蓿草 )’, i.e.
increased wear between
cylinder lubricating points
giving a pattern of such
shape,
may also cause collapse of
rings due to admitting gas
pressure to their outside;
Blow-by of combustion gas is
due to collapsed or sticking rings
and in later stages when it
becomes persistent, is usually
due to broken rings caused by
the collapse and loss of tension.
Piston deposits will occur on
the sides of the piston crown
and in the upper ring zone,
especially
opposite
the
lubrication holes in the
cylinder liner.
When abnormally thick the
deposit surface will be
smooth
from
rubbing
against the cylinder wall.
Such
contact
may,
by
removing the oil film locally,
result
in
micro-seizure
causing increased wear of
liners and rings.
Colored ash-like deposits
usually
originate
from
alkaline additives in the
cylinder lubricant.