1. LOCOMOTIVE WORKSHOP
NORTHEN RAILWAY, CHARBAGH
LUCKNOW
A
SUMMER TRAINING REPORT
ON
DIESEL LOCOMOTIVE TECHNOLOGY
SUBMITTED BY:
HIMANSHU MISHRA
B.Tech (MECHANICAL),2ND
yr
DIT SCHOOL OF ENGINEERING(AMITY
EDUCATION GROUP)
1
2. ACKNOWLEDGEMENT
I take this opportunity my sincere thanks and deep gratitude to
all these people who extended their whole hearted co-operation and
helped me in completing this project successfully.
First of all I would like to thanks all the S.S.E. and J.E. of the
all the sections for creating oppurtunities to undertake me in this
esteemed organization. Special thanks to all the department for all the
help and guidance extended to me by them in every stage during my
training. His inspiring suggestions and timely guidance enabled me to
perceive the various aspects of the project in the new light.
In all I found a congenial work environment in DIESEL
LOCOMOTIVE WORKSHOP, CHARBAGH LUCKNOW and this
completion of the project will mark a new beginning for me in the
coming days.
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3. CONTENTS
INTRODUCTION OF INDIAN RAILWAY…………………………………4
DIESEL LOCOMOTIVE SHED . CHARBAGH……...…………………... 5
DIESEL ELECTRIC LOCOMOTIVE…………….......…………………... 9
FUEL SECTION………………………………...……...…………. ……….11
LUE OIL CONTROL SECTION……......................…………................. 12
TURBOSUPER CHARGER………………………...………….................13
FUEL OIL PUMP……...………………………………….……… ………...17
BOGIE……...…………………………………………………….. …………19
EXPRESSOR/COMPRESSSOR……...……………………....................22
AIR BRAKE……...…………………………………………….…... ……….24
TRACTION MOTER……...………………………………………………... 25
GENERATOR……...………….………………..………………………….. 26
POWER PACK……...………….…………………….….…………………. 27
CROSS HEAD……...………………………………..…………………… 30
FAILURE ANALYSIS……...…………………………………...………….. 32
YEARLY MECHANICAL TESTING……...……………….…………….. . 36
PROJECT STUDY__ TO STUDY ABOUT THE DIESEL BOGIE…
………………………………………….................……………...………… 38
3
4. INTRODUCTION
OF
INDIAN RAILWAY
Indian Railways is the state-owned railway company of India. It
comes under the Ministry of Railways. Indian Railways has one of the largest and
busiest rail networks in the world, transporting over 18 million passengers and
more than 2 million tonnes of freight daily. Its revenue is Rs.107.66 billion. It is
the world's largest commercial employer, with more than 1.4 million employees. It
operates rail transport on 6,909 stations over a total route length of more than
63,327 kilometers(39,350 miles).The fleet of Indian railway includes over 200,000
(freight) wagons, 50,000 coaches and 8,000 locomotives. It also owns locomotive
and coach production facilities. It was founded in 1853 under the East India
Company.
Indian Railways is administered by the Railway Board. Indian
Railways is divided into 16 zones. Each zone railway is made up of a certain
number of divisions. There are a total of sixty-seven divisions.It also operates the
Kolkata metro. There are six manufacturing plants of the Indian Railways. The
4
5. total length of track used by Indian Railways is about 108,805 km (67,608 mi)
while the total route length of the network is 63,465 km (39,435 mi). About 40%
of the total track kilometer is electrified & almost all electrified sections use
25,000 V AC. Indian railways uses four rail track gauges
Indian Railways operates about 9,000 passenger trains and transports
18 million passengers daily .Indian Railways makes 70% of its revenues and most
of its profits from the freight sector, and uses these profits to cross-subsidies the
loss-making passenger sector. The Rajdhani Express and Shatabdi Express are the
fastest trains of India.
DIESEL LOCOMOTIVE SHED
CHARBAGH , LUCKNOW
5
6. L
KO DIESEL SHED (FIG 1)
Diesel locomotive shed is an industrial-technical setup, where repair and
maintenance works of diesel locomotives is carried out, so as to keep the loco
working properly. It contributes to increase the operational life of diesel
locomotives and tries to minimize the line failures. The technical manpower of a
shed also increases the efficiency of the loco and remedies the failures of loco.
The shed consists of the infrastructure to berth, dismantle, repair and test the loco
and subsystems. The shed working is heavily based on the manual methods of
6
7. doing the maintenance job and very less automation processes are used in sheds,
especially in India.
The diesel shed usually has:-
Berths and platforms for loco maintenance.
Pits for under frame maintenance
Heavy lift cranes and lifting jacks
Fuel storage and lube oil storage, water treatment plant and testing
labs etc.
Sub-assembly overhauling and repairing sections
Machine shop and welding facilities.
DIESEL SHED, CHARBAGH ,LUCKNOW of NORTHERN RAILWAY is
located in LUCKNOW The shed was established on 22nd
April 1857. It was
initially planned to home 75 locomotives. The shed cater the needs of Northern
railway. This shed mainly provides locomotive to run the mail, goods and
passenger services. No doubt the reliability, safety through preventive and
predictive maintenance is high priority of the shed. To meet out the quality
standard shed has taken various steps and obtaining of the ISO-9001-200O& ISO
14001 OHSAS CERTIFICATION is among of them. The Diesel Shed is equipped
with modern machines and plant required for Maintenance of Diesel Locomotives
and has an attached store depot. To provide pollution free atmosphere, Diesel Shed
has constructed Effluent Treatment Plant. The morale of supervisors and staff of
the shed is very high and whole shed works like a well-knit team.
a) OVER VIEW
Inception 22nd
April1857
7
8. Present Holding 147 Locomotives
19 WDM2
37 WDM3A
08 WDM3D
11 WDG3A
46 WDP1
26 WDP3A
Accreditation ISO-9001-2000 & ISO
14001
Covered area of shed 10858 SQ. MTR
Total Area of shed 1, 10,000 SQ. MTR
Staff strength sanction – 1357
On roll - 1201
Berthing capacity 17 locomotives
(b) CLASSIFICATION
8
9. 1. Standard “Gauge” designations and dimensions:-
W = Broad gauge (1.67 m)
Y = Medium gauge ( 1 m)
Z = Narrow gauge ( 0.762 m)
N = Narrow gauge ( 0.610 m)
2. “ Type of Traction” designations:-
D = Diesel-electric traction
C = DC traction
A = AC traction
CA=Dual power AC/DC traction
3. The “ type of load” or “Service” designations:-
M= Mixed service
P = Passenger
G= Goods
S = Shunting
4. “ Horse power ” designations from June 2002 (except WDP-1 & WDM-2
LOCOS)
‘ 3 ’ For 3000 horsepower
‘ 4 ’ For 4000 horsepower
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10. ‘ 5 ’ For 5000 horsepower
‘ A ’ For extra 100 horsepower
‘B’ For extra 200 horsepower and so on
.
Hence ‘WDM-3A’ indicates a broad gauge loco with diesel-electric
traction. It is for mixed services and has 3100 horsepower.
DIESEL ELECTRIC LOCOMOTIVE
10
11. PARTS OF THE LOCOMOTIVE( FIG 2)
SAND BOX
RADIATOR
RADIATOR FAN
TURBO SUPERCHARGER
BOGIE(2 SETS)(3AXLE OR 2 AXLE)
FUEL TANK
AIR RESERVOIERS
POWER PACK
11
12. DYNAMO WITH ALTRNATOR
BATTERIES
DRIVER CABIN
WHEEL ASSEMBLY
DISC
BLOWER
TRACTON MOTER
TRUCK
GEAR AND PENION ASSSEMBLY
CYLINDER HEAD
CROSS HEAD
FUEL INJECTION PUMP
BATTERIES (8 OF 8.68 VOLTS)
FUEL TANK
AFTER COOLING CORE
JUNCTION BOX
12
13. FUEL SECTION
FUEL TANK FOR LOCO (FIG 3)
The section is concern with receiving, storage and
refilling of diesel and lube oil. It has 3 large storage tanks and one
underground tank for diesel storage which have a combined storage capacity
of 10,60, 000 liters. This stock is enough to end for 15-16 days The fuel is
supplied by truck from IOC - PANIPAT REFINERY each truck diesel sample
is treated in diesel lab and after it in unloaded. Sample check is necessary to
avoid water, kerosene mixing diesel. Two fuel filling points are established
near the control room It also handles the Cardiam compound , lube oil. diesel
is only for loco use if the diesel samples are not according to the standard ,
the delivery of the fuel is rejected. Viscosity of lube oil should be 100-1435 CST.
Water mixing reduces the viscosity.
Statement of diesel storage and received is made after every 10 days and the report
is send to the Division headquarter. The record of each truck, wagons etc are
included in it. The record of issued oil is also sending to headquarter. After each 4
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14. months. A survey is conducted by high level team about the storage, records etc.
0.1% of total stored fuel oil is given for handling losses by the HQ. The test reports
of diesel includes the type of diesel ( high speed diesel- Euro-3 with 0.035 % S),
reason for test, inspection lot no, store tank no, batch no. etc.
LUBE OIL CONTROL SYSTEM
It controls and regulates the complete movement, schedules, duty of
each loco of the shed. Division level communications and contacts with each loco
on the line are also handled by the control room. Full record of loco fleet, failures,
duty, overdue and availability of locos are kept by the control room. It applies the
outage target of loco for the shed, as decided by the HQ. It decides the locomotives
mail and goods link that which loco will be deployed on which train. It operates
116 Mail and 11Goods link from the shed locos. For 0-0 outage total 127 loco
should be on line.
The schedule of duty, trains and link is decided by the control room according to
the type of trains. If the loco does not return on scheduled time in the shed then the
loco is termed as ‘ over due’ and control room can use the loco of another shed if
that is available.
The lube oil consumption is also calculated by the control room
for each loco:- Lube Oil Consumption (LOC) = Lube oil consumed in liters/
total kms travelled ×100
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15. TURBO SUPERCHARGER
TURBOSUPERCHARGER(FIG 4)
The diesel engine produces mechanical energy by converting heat energy derived
from burning of fuel inside the cylinder. For efficient burning of fuel, availability
of sufficient air in proper ratio is a prerequisite.
In a naturally aspirated engine, during the suction stroke, air is being sucked into
the cylinder from the atmosphere. The volume of air thus drawn into the cylinder
through restricted inlet valve passage, within a limited time would also be limited
15
16. and at a pressure slightly less than the atmosphere. The availability of less quantity
of air of low density inside the cylinder would limit the scope of burning of fuel.
Hence mechanical power produced in the cylinder is also limited.
An improvement in the naturally aspirated engines is the super-charged or pressure
charged engines. During the suction stroke, pressurised stroke of high density is
being charged into the cylinder through the open suction valve. Air of higher
density containing more oxygen will make it possible to inject more fuel into the
same size of cylinders and produce more power, by effectively burning it.
A turbocharger, or turbo, is a gas compresser used for forced-induction of an
internal combustion engine. Like a supercharger, the purpose of a turbocharger is
to increase the density of air entering the engine to create more power. However, a
turbocharger differs in that the compressor is powered by a turbine driven by the
engine's own exhaust gases.
(a)TURBO SUPERCHARGER AND ITS WORKING
PRINCIPLE
The exhaust gas discharge from all the cylinders accumulate in the common
exhaust manifold at the end of which, turbo- supercharger is fitted. The gas under
pressure there after enters the turbo- supercharger through the torpedo shaped bell
mouth connector and then passes through the fixed nozzle ring. Then it is directed
on the turbine blades at increased pressure and at the most suitable angle to achieve
rotary motion of the turbine at maximum efficiency. After rotating the turbine, the
exhaust gas goes out to the atmosphere through the exhaust chimney. The turbine
has a centrifugal blower mounted at the other end of the same shaft and the rotation
of the turbine drives the blower at the same speed. The blower connected to the
atmosphere through a set of oil bath filters, sucks air from atmosphere, and delivers
at higher velocity. The air then passes through the diffuser inside the turbo-
supercharger, where the velocity is diffused to increase the pressure of air before it
is delivered from the turbo- supercharger.
16
17. Pressurising air increases its density, but due to compression heat develops. It
causes expansion and reduces the density. This effects supply of high-density air to
the engine. To take care of this, air is passed through a heat exchanger known as
after cooler. The after cooler is a radiator, where cooling water of lower
temperature is circulated through the tubes and around the tubes air passes. The
heat in the air is thus transferred to the cooling water and air regains its lost
density. From the after cooler air goes to a common inlet manifold connected to
each cylinder head. In the suction stroke as soon as the inlet valve opens the
booster air of higher pressure density rushes into the cylinder completing the
process of super charging.
The engine initially starts as naturally aspirated engine. With the increased quantity
of fuel injection increases the exhaust gas pressure on the turbine. Thus the self-
adjusting system maintains a proper air and fuel ratio under all speed and load
conditions of the engine on its own. The maximum rotational speed of the turbine
is 18000/22000 rpm for the Turbo supercharger and creates max. Of 1.8 kg/cm2
air
pressure in air manifold of diesel engine, known as Booster Air Pressure (BAP).
Low booster pressure causes black smoke due to incomplete combustion of fuel.
High exhaust gas temperature due to after burning of fuel may result in
considerable damage to the turbo supercharger and other component in the engine.
(b)MAIN COMPONENTS OF TURBO-SUPERCHARGER
Turbo- supercharger consists of following main components.
Gas inlet casing.
Turbine casing.
Intermediate casing
Blower casing with diffuser
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18. Rotor assembly with turbine and rotor on the same shaft.
(c)ROTOR ASSEMBLY
The rotor assembly consists of rotor shaft, rotor blades, thrust collar,
impeller, inducer, centre studs, nosepiece, locknut etc. assembled together. The
rotor blades are fitted into fir tree slots, and locked by tab lock washers. This is a
dynamically balanced component, as this has a very high rotational speed.
TYPE POWER COOLING
1.ALCO 2600HP Water cooled
2.ABB TPL61 3100HP Air cooled
3.HISPANO SUIZA HS 5800 NG 3100HP Air cooled
4. GE 7S1716 3100HP Water cooled
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19. 5. NAPIER NA-295 2300,2600&3100HP Water cooled
6. ABB VTC 304 2300,2600&3100HP Water cooled
FUEL OIL PUMP
All locomotive have individual fuel oil system. The fuel oil system is
designed to introduce fuel oil into the engine cylinders at the correct time, at
correct pressure, at correct quantity and correctly atomized . The system injects
into the cylinder correctly metered amount of fuel in highly atomised form. High
pressure of fuel is required to lift the nozzle valve and for better penetration of fuel
into the combustion chamber. High pressure also helps in proper atomisation so
that the small droplets come in better contact with the compressed air in the
combustion chamber, resulting in better combustion. Metering of fuel quantity is
important because the locomotive engine is a variable speed and variable load
engine with variable requirement of fuel. Time of fuel injection is also important
for better combustion.
(a)FUEL OIL SYSTEM
19
20. The fuel oil system consists of two integrated systems. These are-
FUEL INJECTION PUMP (F.I.P).
FUEL INJECTION SYSTEM.
(b)FUEL INJECTION PUMP
It is a constant stroke plunger type pump with variable quantity of fuel
delivery to suit the demands of the engine. The fuel cam controls the pumping
stroke of the plunger. The length of the stroke of the plunger and the time of the
stroke is dependent on the cam angle and cam profile, and the plunger spring
controls the return stroke of the plunger. The plunger moves inside the barrel,
which has very close tolerances with the plunger. When the plunger reaches to the
BDC, spill ports in the barrel, which are connected to the fuel feed system, open
up. Oil then fills up the empty space inside the barrel. At the correct time in the
diesel cycle, the fuel cam pushes the plunger forward, and the moving plunger
covers the spill ports. Thus, the oil trapped in the barrel is forced out through the
delivery valve to be injected into the combustion chamber through the injection
nozzle. The plunger has two identical helical grooves or helix cut at the top edge
with the relief slot. At the bottom of the plunger, there is a lug to fit into the slot of
the control sleeve. When the rotation of the engine moves the camshaft, the fuel
cam moves the plunger to make the upward stroke.
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22. BOGIE(FIG 6)
A bogie is a wheeled wagon or trolley. In mechanics terms, a bogie
is a chassis or framework carrying wheels, attached to a vehicle. It can be fixed
in place, as on a cargo truck, mounted on a swivel, as on a railway carriage or
locomotive, or sprung as in the suspension of a caterpillar tracked vehicle.
Bogies serve a number of purposes:-
To support the rail vehicle body
To run stably on both straight and curved track
To ensure ride comfort by absorbing vibration, and minimizing centrifugal
forces when the train runs on curves at high speed.
To minimize generation of track irregularities and rail abrasion.
Usually two bogies are fitted to each carriage, wagon or locomotive, one at each
end.
(a) KEY COMPONENTS OF A BOGIE
The bogie frame itself.
Suspension to absorb shocks between the bogie frame and the rail vehicle
body. Common types are coil springs, or rubber airbags.
At least two wheelset, composed of axle with a bearings and wheel at each
end.
Axle box suspension to absorb shocks between the axle bearings and the bogie
frame. The axle box suspension usually consists of a spring between the bogie
22
23. frame and axle bearings to permit up and down movement, and sliders to
prevent lateral movement. A more modern design uses solid rubber springs.
Brake equipment:-Brake shoes are used that are pressed against the tread of
the wheels.
Traction motors for transmission on each axle.
(b)CLASSIFICATION OF BOGIE
Bogie is classified into the various types described below according to their
configuration in terms of the number of axle, and the design and structure of the
suspension. According to UIC classification two types of bogie in Indian Railway are:-
Bo-Bo
Co-Co
23
24. CO-CO & BO-BO BOGIE(FIG 7)
A Bo-Bo is a locomotive with two independent four-wheeled bogies with all axles
powered by individual traction motors. Bo-Bos are mostly suited to express
passenger or medium-sized locomotives.
Co-Co is a code for a locomotive wheel arrangement with two six-wheeled bogies
with all axles powered, with a separate motor per axle. Co-Cos is most suited to
freight work as the extra wheels give them good adhesion. They are also popular
because the greater number of axles results in a lower axle load to the tracK
24
25. EXPRESSOR / COMPRESSOR
EXPRESSOR(FIG 8)
In Indian Railways, the trains normally work on vacuum brakes and the diesel
locos on air brakes. As such provision has been made on every diesel loco for both
vacuum and compressed air for operation of the system as a combination brake
system for simultaneous application on locomotive and train.
In ALCO locos the exhauster and the compressor are combined into one unit and
it is known as EXPRESSOR. It creates 23" of vacuum in the train pipe and 140
PSI air pressure in the reservoir for operating the brake system and use in the
control system etc.
The expressor is located at the free end of the engine block and driven through
the extension shaft attached to the engine crank shaft. The two are coupled together
by fast coupling (Kopper's coupling). Naturally the expressor crank shaft has eight
speeds like the engine crank shaft. There are two types of expressor are, 6CD,4UC
& 6CD,3UC. In 6CD,4UC expressor there are six cylinder and four exhauster
whereas 6CD,3UC contain six cylinder and three exhauster.
25
26. (a)COMPRESSOR
The compressor is a two stage compressor with one low pressure
cylinder and one high pressure cylinder. During the first stage of compression
it is done in the low pressure cylinder where suction is through a wire mesh
filter. After compression in the LP cylinder air is delivered into the discharge
manifold at a pressure of 30 / 35 PSI. Workings of the inlet and exhaust valves are
similar to that of exhauster which automatically open or close under differential air
pressure. For inter-cooling air is then passed through a radiator known as inter-
cooler. This is an air to air cooler where compressed air passes through the
element tubes and cool atmospheric air is blown on the out side fins by a fan
fitted on the expressor crank shaft. Cooling of air at this stage increases the
volumetric efficiency of air before it enters the high- pressure cylinder. A safety
valve known as inter cooler safety valve set at 60 PSI is provided after the inter
cooler as a protection against high pressure developing in the after cooler due to
defect of valves.
After the first stage of compression and after-cooling the air is again
compressed in a cylinder of smaller diameter to increase the pressure to 135-140
PSI in the same way. This is the second stage of compression in the HP cylinder.
Air again needs cooling before it is finally sent to the air reservoir and this is done
while the air passes through a set of coiled tubes after cooler.
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27. AIR BRAKE SYSTEM
AIR BRAKE(FIG 9)
An air brake is a conveyance braking system actuated by
compressed air. Modern trains rely upon a fail preventive air brake system that is
based upon a design patented by George Westinghouse on March 5,1872. In the air
brake's simplest form, called the straight air system, compressed air pushes on a
piston in a cylinder. The piston is connected through mechanical linkage to brake
shoes that can rub on the train wheels, using the resulting friction to slow the train.
(a)AIR BRAKE SYSTEM OPERATION
The compressor in the locomotive produces the air supplied to the system. It is
stored in the main reservoir. Regulated pressure of 6 kg/cm2
flows to the feed pipe
through feed valve and 5-kg/cm2
pressure by driver’s brake valve to the brake pipe.
The feed pipe through check valve charges air reservoir via isolating cock and also
by brake pipe through distributor valve. The brake pipe pressure controls the
distributor valves of all the coaches/wagons which in turn control the flow of
compressed air from Air reservoir to break cylinder in application and from brake
cylinder to atmosphere in release.
TRACTION MOTER
27
28. TRACTION MOTER(FIG 10)
Since the diesel-electric locomotive uses electric transmission, traction motors are
provided on the axles to give the final drive. These motors where the traditionally
DC but the development of modern power and control electronics has led to the
introduction of 3-phase AC motors. There are between four & six motors on most
diesel electric locomotives. A modern AC motors with air blowing can provide up
to 1000hp
GENERATOR
28
29. This giant engine is hooked up to an equally impressive generator. It
is about 6 feet (1.8m) in diameter and weights about 17,700 pounds (8029kg). at
peak power this generator makes enough electricity to power a neighborhood of
about 1,000 houses.
So, where does all the power go? It goes into six, massive electric motors located
in the bogies.The engine rotates the crank shaft at up to 1000rpm and this drivesthe
various items need to power the locomotive. As the transmission is electric the
engine is used as the power source for the electricity generator or alternator.
(a)MAIN ALTERNATOR
The diesel engine drives the main alternator which provides the
power to move the train. The alternator generator AC electricity which is used to
provide for traction motors mounts of the axles of the bogies. In older locomotives,
the alternator was a DC machine, called a generator. It produce direct current
which was used to provide power for DC traction motor. Many of these machines
are still in regular use. the next development was the replacement of the generator
by the alternator but still using DC traction motor. The AC output is rectified to
give the DC required for the motors.
(b)AUXILIARY ALTERNATORS
Locomotives used are equipped with an auxiliary alternators. This
provide AC power for lighting, air conditioning, etc. on the train. The output is
transmitted on the train through an auxiliary power line. The output from the main
alternator is AC but it can be used in locomotive with either DC or AC traction
motors. DC motors where the traditional type use for many years but, AC motors
have become standard new locomotives. They are cheaper to build and cost less to
maintain and to convert the AC output from the main alternator to DC, rectifiers
are required. If the motors are DC, the output from the rectifiers is used directly.
Power Pack Section
29
30. FIG OF POWER PACK(FIG 11)
The work of the power pack is to do the fitting work of the head on the loco. They
take out head from the engine and assembled it again on the loco. In the power
pack section the assembly of piston and connecting rod is done. The thorough
checking of piston is done in this section. The piston is send for zyglo test then it is
checked for all the clearances. It is checked whether the piston is seizing or not.
There are two types of piston used modified and unmodified. In modified piston
and piston head is made up of steel, the piston skirt is made up of aluminium.
Unmodified piston is totally made up of steel only. The weight of the assembly is
of 90kg. There are generally 5 rings used in the cylinder, first 3 are compression
ring next 2 are oil rings. The first one is made up of steel and has square face. The
second one is also of steel and has tapered face. The third one is of C.I. and is fuel
efficient taper face. The fourth and fifth are also of C.I. and are called oil scrapper
rings.
(a) PARTS OF THE POWER PACK
30
32. • GEAR CASE
• CYLINDER HEAD
• INLET & EXHAUST VAULVE
• TURBO SUPER CHARGER
• AFTER COOLING CORE
• OVER SPEED TRIP
• HOUSING
• OIL SLEEVE RING
• WATER PUMP
• LUBE OIL PUMP
• OIL SLEEVE
• DRAINE PIPE
• FUEL CONTROOLING SHAFT
CROSS HEAD
32
33. FIG OF CROSS HEAD(FIG 12)
The cylinder head is held on to the cylinder liner by seven hold down
studs or bolts provided on the cylinder block. It is subjected to high shock stress
and combustion temperature at the lower face, which forms a part of combustion
chamber. It is a complicated casting where cooling passages are cored for holding
water for cooling the cylinder head. In addition to this provision is made for
providing passage of inlet air and exhaust gas. Further, space has been provided for
holding fuel injection nozzles, valve guides and valve seat inserts also.
(a)COMPONENTS OF CYLINDER HEAD
In cylinder heads valve seat inserts with lock rings are used as
replaceable wearing part. The inserts are made of stellite or weltite. To provide
interference fit, inserts are frozen in ice and cylinder head is heated to bring about
a temperature differential of 250°F and the insert is pushed into recess in cylinder
head. The valve seat inserts are ground to an angle of 44.5° whereas the valve is
ground to 45° to ensure line contact. (In the latest engines the inlet valves are
ground at 30° and seats are ground at 29.5°). Each cylinder has 2 exhaust and 2
inlet valves of 2.85" in dia. The valves have stem of alloy steel and valve head of
austenitic stainless steel, butt-welded together into a composite unit. The valve
head material being austenitic steel has high level of stretch resistance and is
capable of hardening above Rockwell- 34 to resist deformation due to continuous
pounding action.
The valve guides are interference fit to the cylinder head with an interference of
0.0008" to 0.0018". After attention to the cylinder heads the same is hydraulically
tested at 70 psi and 190°F. The fitment of cylinder heads is done in ALCO engines
with a torque value of 550 Ft.lbs. The cylinder head is a metal-to-metal joint on to
cylinder.
33
34. ALCO 251+ cylinder heads are the latest generation cylinder heads, used in
updated engines, with the following feature:
Fire deck thickness reduced for better heat transmission.
Middle deck modified by increasing number of ribs (supports) to increase its
mechanical strength. The flying buttress fashion of middle deck improves the
flow pattern of water eliminating water stagnation at the corners inside cylinder
head.
Water holding capacity increased by increasing number of cores (14 instead of
11)
Use of frost core plugs instead of threaded plugs, arrest tendency of leakage.
Made lighter by 8 kgs (Al spacer is used to make good the gap between rubber
grommet and cylinder head.)
Retaining rings of valve seat inserts eliminated.
BENEFITS
Better heat dissipation
Failure reduced by reducing crack and eliminating sagging effect of fire deck
area.
34
35. FAILURE ANALYSIS
TESTING ACHINE(FIG 13)
A part or assembly is said to have failed under one of the three
conditions:- When it becomes completely inoperable-occurs when the component
breaks into two or more pieces.When it is still inoperable but is no longer able to
perform intended function satisfactorily- due to wearing and minor damages.
When serious deterioration has made it unreliable or unsafe for
continuous use, thus necessitating its complete removal from service for repair or
35
36. replacement-due to presence of cracks such as thermal cracks, fatigue crack,
hydrogen flaking.
In this section we will study about:-
Metallurgical lab.
Ultrasonic test
Zyglo test
RDP test.
(a)METALLURGICAL LAB
Metallurgical lab. concern with the study of material composition
and its properties. Specimens are checked for its desired composition. In this
section various tests are conducted like hardness test, composition test e.g
determination of percentage of carbon, swelling test etc.
Function of some of the metal is tabulated in table below :-
S.No. Compound Function
1. Phosphorous Increase the fluidity property
2. Graphite Increase machinability
3. Cementide Increase hardness
4. Chromium Used for corrosion prevention
5. Nickel Used for heat resistance
6. Nitride rubber Oil resistance in touch of ‘O’ ring
7. Neoprene Air resistance & oil resistance in fast coupling
in rubber block.
36
37. 8. Silicon Heat resistance and wear resistance (upto 600
ºC ) use at top and bottom pore of liner.
(b)ULTRASONIC TESTING
In ultrasonic testing, very short ultrasonic pulse-waves with center
frequencies ranging from 0.1-15 MHz and occasionally up to 50 MHz are launched
into materials to detect internal flaws or to characterize materials.
Ultrasonic testing is often performed on steel and other metals and alloys, though it
can also be used on concrete, wood and composites, albeit with less resolution. It is
a form of non-destructive testing.
(c)ZYGLO TEST
The zyglo test is a nondestructive testing (NTD) method that helps to
locate and idetify surface defects in order to screen out potential failure-producing
defects. It is quick and accqurate process for locating surface flaws such as
shrinkage cracks, porosity, cold shuts, fatigue cracks, grinding cracks etc. The
ZYGLO test works effectively in a variety of porous and non-porous materials:
aluminum, magnesium, brass, copper, titanium, bronze, stainless steel, sintered
carbide, non-magnetic alloys, ceramics, plastic and glass. Various steps of this
test are given below:-
Step 1 – pre-clean parts.
Step 2 – apply penetrant
37
38. Step 3 – remove penetrant
Step 4 – dry parts
Step 5 – apply developer
Step 6 – inspection
(d) RED DYE PENETRATION TEST (RDP)
Dye penetrant inspection (dpi), also called liquid penetrant
inspection (lpi), is a widely applied and low-cost inspection method used to locate
surface-breaking defects in all non-porous materials (metals, plastics, or ceramics).
penetrant may be applied to all non-ferrous materials, but for inspection of ferrous
components magnetic particle inspection is preferred for its subsurface detection
capability. lpi is used to detect casting and forging defects, cracks, and leaks in
new products, and fatigue cracks on in-service components.
YEARY MECHANICAL TESTING
38
39. TESTING OF MECHANICAL SYSTEM(FIG 14)
In this section, major schedules such as M-24, M48 and M-72 are carried out.
Here, complete overhauling of the locomotives is done and all the parts are sent to
the respective section and new parts are installed after which load test is done to
check proper working of the parts. The work done in these sections are as follows:
1). Repeating of all items of trip, quarterly and monthly schedule.
2). Testing of all valves of vacuum/compressed air system. Repair if necessary.
3). Replacement of coalesce element of air dryer.
(4). Reconditioning, calibration and checking of timing of FIP is done. Injector is
overhauled.
39
40. (5). Cleaning of Bull gear and overhauling of gear-case is done.
(6). RDP testing of radiator fan, greasing of bearing, checking of shaft and keyway.
Examination of coupling and backlash checking of gear unit is done.
(7). Checking of push rod and rocker arm assembly. Replacement is done if bent or
broken. Checking of clearance of inlet and exhaust valve.
(8). Examination of piston for cracks, renew bearing shell of connecting rod
fitment. Checking of connecting rod elongation.
(9). Checking of crankshaft thrust and deflection. Shims are added if deflection is
more then the tolerance limit.
(10). Main bearing is discarded if it has embedded dust, gives evidence of fatigue
failure or is weared.
(11). Checking of cracks in water header and elbow. Install new gaskets in the air
intake manifold. Overhauling of exhaust manifold is done.
(12). Checking of cracks in crankcase, lube oil header, jumper and tube leakage in
lube oil cooler. Replace or dummy of tubes is done.
(13). Lube oil system- Overhauling of pressure regulating valves, by pass valve,
lube oil filters and strainers is done.
(14). Fuel oil system- Overhauling of pressure regulating valve, pressure relief
valve, primary and secondary filters.
(15). Checking of rack setting, governor to rack linkage, fuel oil high-pressure line
is done.
(16). Cooling water system- draining of the cooling water from system and
cleaning with new water carrying 4 kg tri-phosphate is done. All water system
gaskets are replaced. Water drain cock is sealed. Copper vent pipes are changed
and water hoses are renewed.
(17). Complete overhauling of water pump is done. Checking of impeller shaft for
wear and lubrication of ball bearing. Water and oil seal renewal.
40
41. (18). Complete overhauling of expressor/compressor, pistons rings and oil seal
renewed. Expressor orifice test is carried out.
(19). Complete overhauling of Turbo supercharger is done. Dynamic balancing and
Zyglo test of the turbine/impeller is done. Also, hydraulic test of complete Turbo
supercharger is done.
(20). Overhauling of after-cooler is done. Telltale hole is checked for water leak.
(21). Inspection of the crankcase cover gasket and diaphragm is done. It is renewed
if necessary.
(22). Rear T/Motor blower bearing are checked and changed. Greasing of bearing
is done.
(23). Cyclonic filter rubber bellows and rubber hoses are changed. Air intake filter
and vacuum oil bath filter are cleaned and oiled.
(24). Radiators are reconditioned, fins are straightened hydraulic test to detect
leakage and cleaning by approved chemical.
(25). Bogie- Checking of frame links, spring, equalizing beam locating roller pins
for free movement, buffer height, equalizer beam for cracks, rail guard distance is
done. Refilling of center plate and loading pads is done. Journal bearings are
reconditioned.
(26). Axle box- cleaning of axle box housing is done.
(27). Wheels- inspection for fracture or flat spot. Wheel are turned and gauged.
(28). Checking of wear on horn cheek liners and T/M snubber wear plates.
(29). Checking of brake parts for wear, lubrication of slack adjusters is done.
Inspection for fatigue, crack and distortion of center buffers couplers, side buffers
are done.
Diesel Locomotive
41
42. A diesel locomotive is a type of railway locomotive in which the prime
mover is a diesel engine. Several types of diesel locomotive have been
developed, differing mainly in the means by which mechanical power is
conveyed to the driving wheels (drivers).
Diesel-Electric Locomotive
Twin Power-Pack 700HP Diesel Engine
42
44. Parts of a Diesel Locomotive
• Diesel Engine
• Main Alternator
• Auxiliary Alternator
• Rectifier
• Motor Blower
• Air Reservoirs
• Turbo charger
• Battery
• Air Compressor
• Radiator & Radiator fan
• Hydraulic Transmission
• Traction Motor
• Pinion/Gear
• Fuel Tank
• Drive Shaft
• Gear Box
• Sand Box
44
45. Diesel Engine:-
This is the main power source for the locomotive. It comprises a large cylinder
block, with the cylinders arranged in a straight line or in a V .The engine rotates
the drive shaft at up to 1,000 rpm and this drives the various items needed to
power the locomotive. As the transmission is electric, the engine is used as the
power source for the electricity generator or alternator, as it is called nowadays.
A diesel engine (also known as a compression-ignition engine) is an internal
combustion engine that uses the heat of compression to initiate ignition to burn
the fuel that has been injected into the combustion chamber.
45
46. Main Alternator :-
The diesel engine drives the main alternator which provides the power to move the
train. The alternator generates AC electricity which is used to provide power for the
traction motors mounted on the trucks (bogies). In older locomotives, the alternator was
a DC machine, called a generator. It produced direct current which was used to provide
power for DC traction motors. Many of these machines are still in regular use. The next
development was the replacement of the generator by the alternator but still using DC
traction motors. The AC output is rectified to give the DC required for the motors.
Auxiliary Alternator :-
Locomotives used to operate passenger trains are equipped with an auxiliary alternator.
This provides AC power for lighting, heating, air conditioning, dining facilities etc. on the
train. The output is transmitted along the train through an auxiliary power line.
46
47. Rectifier :-
The output from the main alternator is AC but it can be used in a locomotive with either
DC or AC traction motors. DC motors were the traditional type used for many years but,
in the last 10 years, AC motors have become standard for new locomotives. They are
cheaper to build and cost less to maintain and, with electronic management can be very
finely controlled.
47
48. To convert the AC output from the main
alternator to DC, rectifiers are required. If the motors are DC, the output from the
rectifiers is used directly. If the motors are AC, the DC output from the rectifiers is
converted to 3-phase AC for the traction motors.
Motor Blower :-
The diesel engine also drives a motor blower. As its name suggests, the motor blower
provides air which is blown over the traction motors to keep them cool during periods of
heavy work. The blower is mounted inside the locomotive body but the motors are on
the trucks, so the blower output is connected to each of the motors through flexible
ducting. The blower output also cools the alternators. Some designs have separate
blowers for the group of motors on each truck and others for the alternators.
Air Reservoirs :-
Air reservoirs containing compressed air at high pressure are required for the train
braking and some other systems on the locomotive. These are often mounted next to
the fuel tank under the floor of the locomotive.
48
49. Turbo charging :-
The amount of power obtained from a cylinder in a diesel engine depends on how much
fuel can be burnt in it. The amount of fuel which can be burnt depends on the amount of
air available in the cylinder. So, if you can get more air into the cylinder, more fuel will
be burnt and you will get more power out of your ignition. Turbo charging is used to
increase the amount of air pushed into each cylinder. The turbocharger is driven by
exhaust gas from the engine. This gas drives a fan which, in turn, drives a small
compressor which pushes the additional air into the cylinder. Turbocharging gives a
50% increase in engine power.
The main advantage of the turbocharger is that
it gives more power with no increase in fuel costs because it uses exhaust gas as drive
power. It does need additional maintenance, however, so there are some type of lower
power locomotives which are built without it.
Battery :-
49
50. Just like an automobile, the diesel engine needs a battery to start it and to provide
electrical power for lights and controls when the engine is switched off and the
alternator is not running.
Air Compressor :-
The air compressor is required to provide a constant supply of compressed air for the
locomotive and train brakes.
50
51. Radiator & Radiator fan :-
The radiator works the same way as in an automobile. Water is distributed around the
engine block to keep the temperature within the most efficient range for the engine. The
water is cooled by passing it through a radiator blown by a fan driven by the diesel
engine.
(Radiator fan) (Radiator)
Hydraulic Transmission :-
Hydraulic transmission works on the same principal as the fluid coupling but it allows a
wider range of "slip" between the engine and wheels. It is known as a "torque
converter". When the train speed has increased sufficiently to match the engine speed,
the fluid is drained out of the torque converter so that the engine is virtually coupled
directly to the locomotive wheels. It is virtually direct because the coupling is usually a
fluid coupling, to give some "slip". Higher speed locomotives use two or three torque
converters in a sequence similar to gear changing in a mechanical transmission and
some have used a combination of torque converters and gears.
51
52. (Hydrolic tank)
Traction Motor :-
Since the diesel-electric locomotive uses electric transmission, traction motors are
provided on the axles to give the final drive. These motors were traditionally DC but the
development of modern power and control electronics has led to the introduction of 3-
phase AC motors.
52
53. Pinion/Gear :-
The traction motor drives the axle through a reduction gear of a range between 3 to 1
(freight) and 4 to 1 (passenger).
Fuel Tank :-
A diesel locomotive has to carry its own fuel around with it. The fuel tank is normally
under the loco frame and This huge tank in the underbelly of the locomotive
holds 2,200 gallons (8,328 L) of diesel fuel.
Drive Shaft :-
The main output from the diesel engine is transmitted by the drive shaft to the
alternators at one end and the radiator fans and compressor at the other end.
Gear Box :-
The radiator and its cooling fan is often located in the roof of the locomotive.
Drive to the fan is therefore through a gearbox to change the direction of the
drive upwards.
53
54. Sand Box :-
Locomotives always carry sand to assist adhesion in bad rail conditions. Sand is not
often provided on multiple unit trains because the adhesion requirements are lower and
there are normally more driven axles.
Locomotive Data
General Data Of Locomotive:-
Model No. : WDM2
Specification : 16 cylinder V-type 4
strokeDiesel Engine
Type : Co-Co
54
55. Power : 700hp, 1400hp,
2400hp
Maximum Speed : 120 kph
Gear Ratio : 68/18
Compression Ratio : 16:1
Cylinder Bore : 230mm
Cylinder Stroke : 279mm
Wheel Base
Wheel Dia : 1092mm
Wheel Base : 12834mm
Traction Motor : Bhel 165
Track Gauge : 1676mm
Brake Equipment : Vaccun/Air
55
56. Maximum Overall Dimension
Height : 4185mm
Width : 3010mm
Length : 17120mm
Capacity
Fuel : 5000 lt
Cooling Water : 1210 lt
Lube Oil : 910 lt
Water Expansion : 155 lt
Sand : 0.4 m3
Auxiliary Horse Power Requirement
Auxiliary Generator Maximum : 17HP
56
57. Exciter Maximum : 12HP
Traction Motor : 400HP
Blower at full speed : 62HP
Radiator Fan : 80HP
Expresser Unloaded at 1000 rpm : 13 HP
REFRENCES
• Workshop technology by Hazara & Chaudhary
• Production technology by P.C. SHARMA
• Study material provided by TECHNICAL TRAINING CENTRE
• Workshop technology by S. K. GARG
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