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DAV INSTITUTE OF ENGINERING
AND
TECHNOLOGY
TRAINING REPORT OF POST SECOND YEAR TRAINING
ON
DMU CAR SHED JALANDHAR
SUBMITTED IN PARTIAL FULFILLMENT OF REQUIREMENT FOR
THE AWARD OF DEGREE IN
BACHLOR OF TECHNOLOGY
IN
MECHANICAL ENGINEERING DEPARTMENT
SUBMITTED BY:
MANINDER SINGH
1241950
528/12
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ACKNOWLEDGEMENT
I express my sincere gratitude to Mr. Amit Kohli (HOD, ME Deptt.)
for his guidance, proper advice and constant encouragement.
I would also like to thank Mr. HARISH SHARMA Principal of
Training School who granted us the permission of industrial training
in the shed
I do not find enough words which can express my feelings of thanks
to entire faculty and staff of ME department, DAVIET, for their help,
Inspiration and moral support, which went a long in successfully
completion of this report.
They are always present with us for any kind of query and skills to
impart in their students. I heartily thanks them for their
encouragement.
In the end I would like to thank the almighty god and my parents for
their support and trust shown in me and without whom I wouldn’t
have been able to complete my report.
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CONTENTS
1 ACKNOWLEDGEMENT
2 INDIAN RAILWAY HISTORY
3. INTRODUCTION
4 .TURBOSUPER CHARGER
5. FUEL OIL SYSTEM
6 .BOGIE
7. TRACTION MOTOR AND GENERATOR SECTION
8. EXPRESSOR
9. AIR BRAKES
10 .SPEEDOMETER
11 .CYLINDER HEAD
12. DYNAMO
13. PIT WHEEL LATHE
14. FAILURE ANALYSIS
15. POWER PACK SECTION
16. FORKLIFT TRUCK
17INDIRECTLY ASSISTING SECTIONS
18. STEPS TAKEN FOR IMPROVEMENT
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INDIAN RAILWAY HISTORY
INTRODUCTION
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 Indianrailway 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
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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 total length of trackused 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|~|
First railway system in India was proposed
in 1832 in Madras but it never materialized. In the
1840s, other proposals were forwarded to the British
East India Company who governed India at that time.
The Governor-General of India at that time, Lord
Hardinge deliberated on the proposal from the
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commercial, military and political view points. He came
to the conclusion that the East India Company should
assist major companies from England and private
capitalists who sought to setup a rail system in India,regardless of the commercial viability of their project.
On September 22nd,1842,British civil engineer C.B.
Vignoles, FRS, submitted a Report on a Proposed
Railway in India to the East India Company. By 1845,
two companies, the East Indian Railway Company (EIR)operating from Calcutta, and the Great Indian Peninsula
Railway (GIPR) operating from Bombay, were formed.
The first train in India was not a passenger train and was
operational on 1851-12-22, used for the hauling of
construction material in Roorkee. A few years later, on
1853-04-16,the first passenger train between BoriBunder, Bombay and Thana covering a distance of 34
km (21 miles) was inaugurated, formally heralding the
birth of railways in India. Prior to this there was in 1832 a
proposal to build a railroad between Madras and
Bangalore and in 1836 a survey was conducted for this
line.
After the first passenger train run between thane
and bori bander, almost six years later, on March 3,
1859, the first Railway Line in North India was laid
between Allahabad and Kanpur. This was followed, in
1889, by the Delhi-Ambala Kalka line.
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The North eastern Railway was developed rapidly after
that. On October 19, 1875, the train between Hathras
Road and Mathura Cantonment was started running. By
the winter of 1880-81, the Kanpur-Farukhabad linebecame operational and further east, the Dibrugarh-
Dinjan line became operational on August 15, 1882.
Developments were fast and effective in South
India also. The Madras Railway Company opened the
first railway line between Veyasarpaudy and the Walajah
Road on July 1, 1856. This 63-mile line was the first
section, which eventually joined Madras and the west
coast. On March 3, 1859, a length of 119 miles was laid
from Allahabad to Kanpur. Later In 1862, the railway line
between Amritsar and Attari was constructed on the Amritsar-Lahore route.
In 1900, the Great Indian peninsular Railways
became a government owned company. The network
spread to modern day states of Assam, Rajasthan and
Andhra Pradesh and soon various independentkingdoms began to have their own rail systems. In 1901,
an early Railway Board was constituted, but the powers
were formally invested under Lord Curzon. It served
under the Department of Commerce and Industry and
had a government railway official serving as chairman,
and a railway manager from England and an agent ofone of the company railways as the other two members.
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For the first time in its history, the Railways began to
make a profit.
In 1907 almost all the rail companies were taken over by
the government. The following year, the first electric
locomotive made its appearance. With the arrival of
World War I, the railways were used to meet the needs
of the British outside India. With the end of the war, the
state of the railways was in disrepair and collapse.
Indian Railway provided an example of the British
Empire pouring its money and expertise into a very well
built system basically designed for military reasons (after
the Mutiny of 1857), and with the hope that it would
stimulate industry. The system was overbuilt and much
too elaborate and expensive for the small amount offreight traffic it carried. However, it did capture the
imagination of the Indians, who saw their railways as the
symbol of an industrial modernity—but one that was not
realized until a century or so later.
The British built a superb system in India.
However, Christensen (1996) looks at of colonial
purpose, local needs, capital, service, and private-
versus-public interests. He concludes that making the
railways a creature of the state hindered success
because railway expenses had to go through the same
time-consuming and political budgeting process as did
all other state expenses. Railway costs could therefore
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not be tailored to the timely needs of the railways or
their passengers.
By the 1940s, India had the fourth longest railwaynetwork in the world. Yet the country's industrialization
was delayed until after independence in 1947 by British
colonial policy. Until the 1930s, both the Indian
government and the private railway companies hired
only European supervisors, civil engineers, and even
operating personnel, such as locomotive drivers(engineers). The government's "Stores Policy" required
that bids on railway materiel be presented to the India
Office in London, making it almost impossible for
enterprises based in India to compete for orders.
Likewise, the railway companies purchased most of their
material in Britain, rather than in India. Although therailway maintenance workshops in India could have
manufactured and repaired locomotives, the railways
imported a majority of them from Britain, and the others
from Germany, Belgium, and the United States. The
Tata Company built a steel mill in India before World
War I but could not obtain orders for rails until the 1920s
and 1930s.
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DIESEL SHED JALANDHAR
INTRODUCTION
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
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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 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.
SPECIAL MACHINES & PLANT
Pit wheel lathe machine
This machine is suitable for turn & re-profiles the wheelsof locomotives.
EFFULENT TREATMENT PLANT
In order to provide pollution free environment, an ETPPLANT is installed. Various effluents emitted fromdiesel shed are passed through the Plant. The waterthus collected is pollution free and is used for non
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drinking purposes such as gardening and washing of thelocomotives.
TECHNICAL INNOVATIONS
Based on day-to-day maintenance problems a large
number of innovations/modifications have been
conceived and implemented in Diesel Shed
Expressor performance test notch wise
Simulation of test stand facility on the loco itselfwith the help of only two small fixtures.
Testing the performance of expressor in diesellocomotive engines.
Cylinder head Stud Removal/ Tightening
Arrangement
A simple device has been developed to helpreduce the time and effort taken inremoval/tightening of cylinder head studs.
Diesel Training Centre-DTC
It was setup in the JAL shed premises by the
Northern Railway with view to train diesel loco pilots. Italso trains the Diesel Maintenance staff to improve the
availability of qualified manpower and improve the
efficiency of and quality of the technicians. It has five
classrooms, a hall ,a Model room(with sectional models
of TSC, expressor, cylinder head LOP, governor etc.). A
well qualified team of instructors from the electrical and
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mechanical fields provides a quality training to the
p=loco pilots and other trainees.
Courses offered :- (regular) Diesel Assistant to Diesel Loco Driver promotion
course
Diesel Assistant Refresher coarse
Diesel Driver refresher course
Other courses:-
Up gradation course of Diesel technicians
Electric traction to diesel traction conversion course
Course for Drivers, Shunters and Asstt. Drivers
3 years Apprentice technician(Diesel mechanical
and electrical)
6 months Apprentice Technician(Diesel mechanical
and electrical)
Vocational industrial training for B.Tech and
Diploma student
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1. TURBO SUPERCHARGER
INTRODUCTION
The diesel engine produces mechanical energy by
converting heat energy derived from burning of fuel
inside the cylinder. For efficient burning of fuel,
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availability of sufficient air in proper ratio is a
prerequisite.
In a naturally aspirated engine, during the suctionstroke, 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 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 asupercharger, 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.
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TURBO SUPERCHARGER AND ITS
WORKING PRINCIPLEThe 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 isdirected 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.
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
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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 lostdensity. 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 andcreates 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 andother component in the engine.
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MAIN COMPONENTS OF TURBO-
SUPERCHARGER
Turbo- supercharger consists of following main
components.
Gas inlet casing. Turbine casing. Intermediate casing Blower casing with diffuser Rotor assembly with turbine and rotor on the same
shaft.
ROTOR ASSEMBLY
The rotor assembly consists of rotor shaft, rotorblades, thrust collar, impeller, inducer, centre studs,nosepiece, locknut etc. assembled together. The rotorblades are fitted into fir tree slots, and locked by tab lockwashers. This is a dynamically balanced component, asthis has a very high rotational speed.
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LUBRICATING, COOLING AND AIR
CUSHIONING
LUBRICATING SYSTEM
One branch line from the lubricating system of theengine is connected to the turbo- supercharger. Oil fromthe lube oils system circulated through the turbo-supercharger for lubrication of its bearings. After thelubrication is over, the oil returns back to the lube oilsystem through a return pipe. Oil seals are provided onboth the turbine and blower ends of the bearings to
prevent oil leakage to the blower or the turbine housing.
COOLING SYSTEM
The cooling system is integral to the watercooling system of the engine. Circulation of water takesplace through the intermediate casing and the turbinecasing, which are in contact with hot exhaust gases. Thecooling water after being circulated through the turbo-supercharger returns back again to the cooling system
of the locomotive.
AIR CUSHIONING
There is an arrangement for air cushioning between
the rotor disc and the intermediate casing face to reduce
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thrust load on the thrust face of the bearing which alsosolve the following purposes. It prevents hot gases from coming in contact with
the lube oil. It prevents leakage of lube oil through oil seals.
It cools the hot turbine disc.
Pressurised air from the blower casing is taken through
a pipe inserted in the turbo- supercharger to the space
between the rotor disc and the intermediate casing. Itserves the purpose as described above.
AFTER COOLER
It is a simple radiator, which cools the air to increase itsdensity. Scales formation on the tubes, both internally
and externally, or choking of the tubes can reduce heat
transfer capacity. This can also reduce the flow of air
through it. This reduces the efficiency of the diesel
engine. This is evident from black exhaust smoke
emissions and a fall in booster pressure.
Fitments of higher capacity Turbo Supercharger-
following new generation Turbo Superchargers have
been identified by diesel shed TKD for 2600/3100HP
diesel engine and tabulated in table 1.
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TABLE 1
TYPE POWER COOLING1.ALCO 2600HP Water cooled2.ABB TPL61 3100HP Air cooled3.HISPANO SUIZAHS 5800 NG
3100HP Air cooled
4. GE 7S1716 3100HP Water cooled5. NAPIER NA-295 2300,2600&3100HP Water cooled6. ABB VTC 304 2300,2600&3100HP Water cooled
TURBO RUN – DOWN TEST
Turbo run-down test is a very common type of test
done to check the free running time of turbo rotor. It
indicates whether there is any abnormal sound in the
turbo, seizer/ partial seizer of bearing, physical damages
to the turbine, or any other abnormality inside it. The
engine is started and warmed up to normal working
conditions and running at fourth notch speed. Engine is
then shut down through the over speed trip mechanism.
When the rotation of the crank shaft stops, the free
running time of the turbine is watched through the
chimney and recorded by a stop watch. The time limit for
free running is 90 to 180 seconds. Low or high turbo run
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down time are both considered to be harmful for the
engine.
ROTOR BALANCING MACH INE
A balancing machine is a measuring tool used forbalancing rotating machine parts such as rotors of turbosubercharger,electric motors,fans, turbines etc. Themachine usually consists of two rigid pedestals, with
suspension and bearings on top.The unit under test isplaced on the bearings and is rotated with a belt. As thepart is rotated, the vibration in the suspension isdetected with sensors and that information is used todetermine the amount of unbalance in the part. Alongwith phase information, the machine can determine howmuch and where to add or remove weights to balance
the part.
ADVANTAGES OF SUPER CHARGED
ENGINES
A super charged engine can produce 50 percentor more power than a naturally aspirated engine.The power to weight ratio in such a case is much
more favorable.
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Better scavenging in the cylinders. This ensurescarbon free cylinders and valves, and better healthfor the engine also.
Better ignition due to higher temperaturedeveloped by higher compression in the cylinder.
It increases breathing capacity of engine
Better fuel efficiency due to complete combustionof fuel .
Defect in Turbochargers
Low Booster Air Pressure (BAP).
Oil throwing from Turbocharger because of sealdamage or out of clearance.
Surging- Back Pressure due to uneven gap in
Nozzle Ring or Diffuser Ring.Must change components of Turbocharger.
Intermediate casing gasket. Water outlet pipe flange gasket. Water inlet pipe flange gasket. Lube Oil inlet pipe rubber ‗o‘ ring.
Turbine end Bearing. Blower end Bearing. Chimney gasket. Rubber ‗o‘ Ring kit. Spring Washers. Lock Washer Rotor Stud.
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2.FUEL OIL SYSTEM
INTRODUCTION
All locomotive have individual fuel oil system. Thefuel oil system is designed to introduce fuel oil into theengine cylinders at the correct time, at correct pressure,at correct quantity and correctly atomised. The systeminjects into the cylinder correctly metered amount of fuelin highly atomised form. High pressure of fuel is requiredto lift the nozzle valve and for better penetration of fuelinto the combustion chamber. High pressure also helpsin proper atomisation so that the small droplets come inbetter contact with the compressed air in the combustionchamber, resulting in better combustion. Metering of fuel
quantity is important because the locomotive engine is avariable speed and variable load engine with variablerequirement of fuel. Time of fuel injection is alsoimportant for better combustion.
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FUEL OI L SYSTEM
The fuel oil system consists of two integrated systems.These are-
FUEL INJECTION PUMP (F.I.P). FUEL INJECTION SYSTEM.
FUEL I NJECTION PUMP
It is a constant stroke plunger type pump with
variable quantity of fuel delivery to suit the demands ofthe 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 theplunger. 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
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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.
It may also rotate slightly, if
necessary through the engine governor, control shaft,
control rack, and control sleeve. This rotary movement
of the plunger along with reciprocating stroke changes
the position of the helical relief in respect to the spill port
and oil, instead of being delivered through the pump
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valve moves backward to increase the space available
in the high-pressure line. Thus, the pressure inside the
high-pressure line collapses, helping in snap termination
of fuel injection. This reduces the chances of dribbling atthe beginning or end of fuel injection through the fuel
injection nozzles.
FUEL I NJECTION NOZZLE
The fuel injection nozzle or the fuel injector is fitted in
the cylinder head with its tip projected inside the
combustion chamber. It remains connected to the
respective fuel injection pump with a steel tube knownas fuel high pressure line. The fuel injection nozzle is of
multi-hole needle valve type operating against spring
tension. The needle valve closes the oil holes by
blocking the oil holes due to spring pressure. Proper
angle on the valve and the valve seat, and perfect
bearing ensures proper closing of the valve.
Due to the delivery stroke of the fuel injection pump,
pressure of fuel oil in the fuel duct and the pressure
chamber inside the nozzle increases. When the
pressure of oil is higher than the valve spring pressure,
valve moves away from its seat, which uncovers the
small holes in the nozzle tip. High-pressure oil is then
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injected into the combustion chamber through these
holes in a highly atomised form. Due to injection,
hydraulic pressure drops, and the valve returns back to
its seat terminating the fuel injection, termination of fuelinjection may also be due to the bypassing of fuel
injection through the helix in the fuel injection pump
causing a sudden drop in pressure.
3. BOGIE
INTRODUCTION
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 oncurves at high speed.
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To minimize generation of track irregularities and railabrasion.
Usually two bogies are fitted to each carriage, wagon or
locomotive, one at each end.
Key Components Of a Bogie
The bogie frame itself. Suspension to absorb shocks between the bogie
frame and the rail vehicle body. Common types arecoil springs, or rubber airbags.
At least two wheelset, composed of axle with abearings and wheel at each end.
Axle box suspension to absorb shocks between the
axle bearings and the bogie frame. The axle boxsuspension usually consists of a spring between the
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Co-Co is a code for a locomotive wheel arrangementwith two six-wheeled bogies with all axles powered, witha separate motor per axle. Co-Cos is most suited to
freight work as the extra wheels give them goodadhesion. They are also popular because the greaternumber of axles results in a lower axle load to the track.
Failure and remedies in the bogie section: -
Breakage of coiled springs due to heavy shocks ormore weight or defective material. They are tested
time to time to check the compression limit. Brokensprings are replaced.
14 to 60 thou clearance is maintained between theaxle and suspension bearing. Lateral clearance ismaintained between 60 to 312 thou. Less clearancewill burn the oil and will cause the seizure of axle.Condemned parts are replaced.
RDP tests are done on the frame parts, welded parts,corners, guide links and rigid structures of bogie andminor cracks can be repaired by welding.
Axle suspension bearings may seizure due to oilleakage, cracks etc. If axle box bearing‘s roller isdamaged then replaced it completely.
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4. TRACTION MOTOR AND
GENERATOR SECTION
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.
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Main alternator
The diesel engine drives the main alternator which
provides the power to move the train. The alternatorgenerator 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 nextdevelopment 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.
Auxiliary Alternators
Locomotives used are equipped with an auxiliaryalternators. 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 yearsbut, 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. If the motors are AC
the DC output from the rectifier is converted to 3-phase
AC for the traction motors.
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5.EXPRESSOR_____________________
___________________
INTRODUCTION
In Indian Railways, the trains normally work onvacuum brakes and the diesel locos on air brakes. Assuch provision has been made on every diesel loco forboth vacuum and compressed air for operation of thesystem as a combination brake system for simultaneous
application on locomotive and train.
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In ALCO locos the exhauster and the compressor arecombined 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 systemand use in the control system etc.
The expressor is located at the free end of the engineblock and driven through the extension shaft attached tothe engine crank shaft. The two are coupled together byfast coupling (Kopper's coupling). Naturally theexpressor 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 aresix cylinder and four exhauster whereas 6CD,3UCcontain six cylinder and three exhauster.
WORKING OF EXHAUSTER Air from vacuum train pipe is drawn into the exhauster
cylinders through the open inlet valves in the cylinderheads during its suction stroke. Each of the exhaustercylinders has one or two inlet valves and two dischargevalves in the cylinder head. A study of the inlet anddischarge valves as given in a separate diagram wouldindicate that individual components like (1) plate valveouter (2) plate valve inner (3) spring outer (4) springinner etc. are all interchangeable parts. Only basicdifference is that they are arranged in the reversemanner in the valve assemblies which may also havedifferent size and shape. The retainer stud in both theassemblies must project upward to avoid hitting the
piston.
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The pressure differential between the availablepressure in the vacuum train pipe and inside theexhauster cylinder opens the inlet valve and air is drawn
into the cylinder from train pipe during suction stroke. Inthe next stroke of the piston the air is compressed andforced out through the discharge valve while the inletvalve remains closed. The differential air pressure alsoautomatically open or close the discharge valves, thesame way as the inlet valves operate. This process ofsuction of air from the train pipe continues to create
required amount of vacuum and discharge the same airto atmosphere. The VA-1 control valve helps inmaintaining the vacuum to requisite level despitecontinued working of the exhauster.
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 inthe low pressure cylinder where suction is through awire mesh filter. After compression in the LP cylinderair is delivered into the discharge manifold at a pressureof 30 / 35 PSI. Workings of the inlet and exhaust valvesare similar to that of exhauster which automatically open
or close under differential air pressure. For inter-coolingair is then passed through a radiator known as inter-cooler. This is an air to air cooler where compressed airpasses through the element tubes and coolatmospheric air is blown on the out side fins by a fanfitted on the expressor crank shaft. Cooling of air at thisstage increases the volumetric efficiency of air before it
enters the high- pressure cylinder. A safety valve knownas inter cooler safety valve set at 60 PSI is provided
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after the inter cooler as a protection against highpressure developing in the after cooler due to defect ofvalves.
After the first stage of compression and after-coolingthe air is again compressed in a cylinder of smallerdiameter to increase the pressure to 135-140 PSI in thesame way. This is the second stage of compression inthe HP cylinder. Air again needs cooling before it isfinally sent to the air reservoir and this is done while theair passes through a set of coiled tubes after cooler.
6. AIR BRAKES
INTRODUCTION
An air brake is a conveyance braking systemactuated by compressed air. Modern trains rely upon afail preventive air brake system that is based upon adesign patented by George Westinghouse on March
5,1872. In the air brake's simplest form, called the
http://en.wikipedia.org/wiki/File:Westinghouse_Air_Brake_control_handle_and_valve.jpg
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straight air system, compressed air pushes on a pistonin a cylinder. The piston is connected throughmechanical linkage to brake shoes that can rub on the
train wheels, using the resulting friction to slow the train.
AI R BRAKE SYSTEM OPERATION
The compressor in the locomotive produces the airsupplied to the system. It is stored in the main reservoir.Regulated pressure of 6 kg/cm2 flows to the feed pipethrough feed valve and 5-kg/cm2 pressure by driver‘s
brake valve to the brake pipe. The feed pipe throughcheck valve charges air reservoir via isolating cock andalso by brake pipe through distributor valve. The brakepipe pressure controls the distributor valves of all thecoaches/wagons which in turn control the flow ofcompressed air from Air reservoir to break cylinder inapplication and from brake cylinder to atmosphere in
release.
During application, the driver in the loco lowers the BPpressure. This brake pipe pressure reduction causesopening of brake cylinder inlet passage andsimultaneously closing of brake cylinder outlet passageof the distributor valve. In this situation, auxiliaryreservoir supplies air to brake cylinder. At applicationtime, pressure in the brake cylinder and other brakecharacteristics are controlled by distributor valve.
During release, the BP pressure is raised to 5 kg/cm2 .This brake pipe pressure causes closing of brakecylinder inlet passage and simultaneously opening ofbrake cylinder outlet passage of the distributor valve.
The distributor valve connects brake cylinder to
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atmosphere. The brake cylinder pressure can be raisedor lowered in steps.
In case of application by alarm chain pulling, thepassenger emergency alarm signal device (PEASD) isoperated which in turn actuates passenger valve (PEV)causing exhaust of BP pressure through a choke of 4mm. Opening of guard emergency brake valve alsomakes emergency brake application. There are twocase of braking, when only loco move and when entiretrain move. Consequently there are two valves in the
driver cabin viz SA-9&A-9. Braking operation of abovecase is shown in chart below.
LAYOUT
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VALVES USED I N BRAKING SYSTE
PEV
ARCR DV
DC
BC BC
DC
PEASD PEASD
FP
BP
GEBV
Pressure
gauge
Cut off
angle cock
Passenger alarm
system
Guard
emergency
brakesystem
Corebrake
system
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7. SPEEDOMETER
INTRODUCTION
The electronic speedometer is intended to measuretraveling speed and to record the status of selectedlocomotive engine parameters every second. Itcomprises a central processing unit that performs thebasic functions, two monitors that are used fordisplaying the measured speed values and entering
locomotive driver‘s identification data and driveparameters and a speed transducer. The speedometercan be fitted into any of railway traction vehicles. Themonitor is mounted on every driver‘s place in alocomotive. It is connected to the CPU by a serial link.Monitor transmits a driver, locomotive and trainidentifications data to the CPU and receives data on
travel speed, partial distance traveled, real time andspeedometer status from the CPU A locomotive drivercommunicates with the speedometer using the monitor:a keyboard and alphanumeric displays are used forauthorization purposes, travel speed values aremonitored on analog and digital displays, whereasalphanumeric displays, LEDs and a buzzer signal
provide information on speedometer and vehicle status.
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WORKING MECHANISM
Speedometer is a closed loop system in which opto-
electronic pulse generator is used to convert the speedof locomotive wheel into the corresponding pulses.Pulses thus generated are then converted into thecorresponding steps for stepper motor. These stepsthen decide the movement of stepper motor whichrotates the pointer up to the desired position. A feedback potentiometer is also used with pointer that
provides a signal corresponding to actual position of thepointer, which then compared with the step of steppermotor by measuring and control section. If any error isobserved, it corrected by moving the pointer tocorresponding position.Presently a new version of speed-time-distance recordercum indicator unit TELPRO is used in the most of thelocomotive. Features and other technical specification ofthis speedometer are given below.
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Salient features
Light weight and compact in size Adequate journey data recording capacity Both analog and digital displays for speed
Both internal and external memories for data storage Memory freeze facility
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Stepless wheel wear compensation Dual sensor opto electronic pulse generator for speed
sensing
Over speed audio visual alarm 7-digit odometer User friendly Windows-based data extraction and
analysis software Graphical and tabular reports generation for easy
analysing of recorded data Cumulative, Trip-wise, Train-wise, Driver-wise and
Date-wise report generation Master-Slave configuration
Applications
Speed indication for driver. Administrative control of traction vehicle for traffic
scheduling.
Vehicle trend analysis in case of derailment/accident. Analysis of drivers operational performance to provide
training, if required.
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Technical Specif ications The system requires a wide operating voltage of 50 V DC to 140 VDC.
A. Operating conditions
Conditions Values
Temperature -5°C to +70°C
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Relative humidity 95% (max)
Accuracy of Master &Slave
±1.0% of full scale deflection
B. Analogue ind icat ion
Factors Values
Scale spread over 240°
Illumination 12 equally spaced LEDs on dial
circumferenceBrightness control 0-100% in 10 steps
Dial size 120 mm
Dial colour White with black pointer & numerals
Max speed range 0-150, 0-160 & 0-180 Kmph (can bemade as per customer‘s request)
C. Digital indication
Features Values
LCD display 16x2 character alphanumeric LCD with
backlit control
Time display HH:MM:SS on 24-hour scale
D. General
Factors Values
Size 145x215x160 mm (typical)
Weight: Master & Slave(approx)
3.5 kg (Master); 3.15 kg (Slave)
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Odometer 7 digit with 1km resolution
Input speed sensing 2 inputs for opto-electronic pulsegenerator 200 or 100 pulses/rev
(configurable)
8. CYLINDER HEAD
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INTRODUCTION
The cylinder head is held on to the cylinder liner by
seven hold down studs or bolts provided on the cylinderblock. It is subjected to high shock stress andcombustion temperature at the lower face, which formsa part of combustion chamber. It is a complicatedcasting where cooling passages are cored for holdingwater for cooling the cylinder head. In addition to thisprovision is made for providing passage of inlet air and
exhaust gas. Further, space has been provided forholding fuel injection nozzles, valve guides and valveseat inserts also.
Components of cylinder head
In cylinder heads valve seat inserts with lock ringsare 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 tobring about a temperature differential of 250F and theinsert is pushed into recess in cylinder head. The valveseat inserts are ground to an angle of 44.5 whereas thevalve is ground to 45 to ensure line contact. (In thelatest engines the inlet valves are ground at 30° and
seats are ground at 29.5°). Each cylinder has 2 exhaustand 2 inlet valves of 2.85" in dia. The valves have stemof alloy steel and valve head of austenitic stainless steel,butt-welded together into a composite unit. The valvehead material being austenitic steel has high level ofstretch resistance and is capable of hardening aboveRockwell- 34 to resist deformation due to continuous
pounding action.
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The valve guides are interference fit to the cylinderhead with an interference of 0.0008" to 0.0018". Afterattention to the cylinder heads the same is hydraulically
tested at 70 psi and 190F. The fitment of cylinderheads is done in ALCO engines with a torque value of550 Ft.lbs. The cylinder head is a metal-to-metal joint onto cylinder.
ALCO 251+ cylinder heads are the latest generationcylinder heads, used in updated engines, with thefollowing feature:
Fire deck thickness reduced for better heattransmission.
Middle deck modified by increasing number of ribs(supports) to increase its mechanical strength. Theflying buttress fashion of middle deck improves theflow 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.
Maintenance and Inspect ion
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Lap the face joint to ensure leak proof joint with liner.
Blow by test :
On bench blow by test is conducted to ensure thesealing effect of cylinder head.
Blow by test is also conducted to check the sealingefficiency of the combustion chamber on a runningengine, as per the following procedure:
Run the engine to attain normal operating temperature(65°C)
Stop running after attaining normal operatingtemperature.
Bring the piston of the corresponding cylinder at TDCin compression stroke.
Fit blow-by gadget (Consists of compressed air linewith the provision of a pressure gauge and stopcock)
removing decompression plug. Charge the combustion chamber with compressed air. Cut off air supply at 70 psi. Through stop cock and
record the time when it comes down to zero.7 to 10secs is OK.
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9.DYNAMO
A dynamo is an electrical generator that produces direct
current with the use of a commutator . Dynamos were
the first electrical generators capable of delivering power
for industry, and the foundation upon which many other
later electric-power conversion devices were based,including the electric motor , the alternating-current
alternator , and the rotary converter . Today, the simpler
alternator dominates large scale power generation, for
efficiency, reliability and cost reasons. A dynamo has
the disadvantages of a mechanical commutator. Also,
converting alternating to direct current using power
http://en.wikipedia.org/wiki/Electrical_generatorhttp://en.wikipedia.org/wiki/Electrical_generatorhttp://en.wikipedia.org/wiki/Electrical_generatorhttp://en.wikipedia.org/wiki/Direct_currenthttp://en.wikipedia.org/wiki/Direct_currenthttp://en.wikipedia.org/wiki/Direct_currenthttp://en.wikipedia.org/wiki/Direct_currenthttp://en.wikipedia.org/wiki/Commutator_%28electric%29http://en.wikipedia.org/wiki/Commutator_%28electric%29http://en.wikipedia.org/wiki/Commutator_%28electric%29http://en.wikipedia.org/wiki/Electric_motorhttp://en.wikipedia.org/wiki/Electric_motorhttp://en.wikipedia.org/wiki/Electric_motorhttp://en.wikipedia.org/wiki/Alternatorhttp://en.wikipedia.org/wiki/Alternatorhttp://en.wikipedia.org/wiki/Rotary_converterhttp://en.wikipedia.org/wiki/Rotary_converterhttp://en.wikipedia.org/wiki/Rotary_converterhttp://en.wikipedia.org/wiki/Rotary_converterhttp://en.wikipedia.org/wiki/Alternatorhttp://en.wikipedia.org/wiki/Electric_motorhttp://en.wikipedia.org/wiki/Commutator_%28electric%29http://en.wikipedia.org/wiki/Direct_currenthttp://en.wikipedia.org/wiki/Direct_currenthttp://en.wikipedia.org/wiki/Direct_currenthttp://en.wikipedia.org/wiki/Electrical_generator
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rectification devices (vacuum tube or more recently solid
state) is effective and usually economic.
10. PIT WHEEL
LATHE
INTRODUCTION
Various type of wear may occur on wheal tread and
flange due to wheel skidding and emergency breaking.Four type of wear may occur as follows:-
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Tread wear Root wear Skid wear and
Flange wear
For maintaining the required profile pit wheel lathe areused. This lathe is installed in the pit so that wheelturning is without disassembling the axle and lifting theloco and hence the name ―pit wheel lathe ‖
Wheel turn ing
Wheel turning on this lathe is done by rotating thewheels, both wheels of an axle are placed on the fourrollers, two for each wheel. Rollers rotate the wheel anda fixed turning tool is used for turning the wheel.
Different gages are used in this section tocheck thetread profile. Name of these gages are:-
Star gage Root wear gage Flange wear gage J gage
j-gage is used to calculate the app. Dia of wheel.
Dia. Of wheel = 962 +2×(j-gage reading) mm
CAUSES OF WHEEL SKIDDING -
On excessive brake cylinder pressure (more than 2.5kg/cm²).
Using dynamic braking at higher speeds.
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When at the time of application of dynamic braking,the brakes of loco would have already been applied.(in case of failure of D-1 Pilot valve).
Continue working , when C-3-W Distributor valve P/Ghandle is in wrong position. Due to shunting of coaches with loco without
connecting their B.P./vacuum pipe. Shunting at higher speeds. Continue working when any of the brake cylinder of
loco has gotten jammed.
The time of application/release of brakes of any of thebrake cylinder being larger than the others. When any of the axle gets locked during on the line.
11. FAILURE ANALYSIS
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INTRODUCTION A part or assembly is said to have failed under one
of the three conditions:-When it becomes completely inoperable-occurs whenthe component breaks into two or more pieces.When itis still inoperable but is no longer able to perform itsintended function satisfactorily- due to wearing andminor damages.
When serious deterioration has made it unreliable orunsafe for continuous use, thus necessitating itscomplete removal from service for repair orreplacement-due to presence of cracks such as thermalcracks, fatigue crack, hydrogen flaking.
In this section we will study about:-
Metallurgical lab. Ultrasonic test Zyglo test and RDP test.
Metallurgical lab.
Metallurgical lab. concern with the study of materialcomposition and its properties. Specimens are checkedfor its desired composition. In this section various testsare conducted like hardness test, composition test e.gdetermination of percentage of carbon, swelling test etc.
Function of some of the metal is tabulated in table below:-
S.No. Compound Function
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1. Phosphorous Increase the fluidity property2. Graphite Increase machinability3. Cementide Increase hardness
4. Chromium Used for corrosion prevention5. Nickel Used for heat resistance6. Nitride
rubberOil resistance in touch of ‗O‘ ring
7. Neoprene Air resistance & oil resistance infast coupling in rubber block.
8. Silicon Heat resistance and wear
resistance (upto 600 ºC ) use attop and bottom pore of liner.
Swell ing test
Swelling test is performed for rubber in this test
percentage increase in weight of the rubber afterimmersing in solution is measured and increase inweight should not be more than 20%. Two type ofswelling test viz low swelling and high swelling areperformed in the lab. Three type of oil solution are usedfor this purpose listed below:-
ASTM 1
ASTM 2 ASTM 3
Procedure
1. Select specimen for swelling test
1. Note the weight of the specimen
2. Put in the vessel containing ASTM 1 or ASTM 3
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3. Put the oven at 100 ºC4. Put the vessel in the oven for 72 hrs.5. After 72 hrs. Weigh the specimen.
Rubber
Broadly there are two types of rubber:
1). Natural rubber- this has very limited applications. It isused in windows and has a life of 1 year.
2). Synthetic rubber- this is further subdivided into fivetypes.
VUNA-N (2 year life) Polychloroprene or Neoprene (2 year life) SBR (3 year life) Betel (3 year life) Silicone (3 year life).
VUNA-N rubber is used in oily or watery area, neopreneis used in areas surrounded by oil and air while beteland silicone are used in areas subjected to hightemperatures such as in pistons.
When the fresh supply of rubber comes from thesuppliers it is tested to know its type.The test consists of
two solutions, solution 1 and solution 2, which aresubjected to the vapors of the rubber under test andthen the color change in solution is used fordetermination of the type of rubber. The various colorchanges are as follows:
Violet- natural rubber Pink- nit rile Green-SBR
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When no color change is observed the vapours arepassed through solution 2. The colour change insolution 2 is: Pink- neoprene.
Silicone produces white powder on burning. If there isno result on burning then the rubber is surely betel.
ULTRASONIC TESTING
In ultrasonic testing, very short ultrasonic pulse-waveswith center frequencies ranging from 0.1-15 MHz and
occasionally up to 50 MHz are launched into materials todetect internal flaws or to characterize materials.
Ultrasonic testing is often performed on steel and othermetals and alloys, though it can also be used onconcrete, wood and composites, albeit with lessresolution. It is a form of non-destructive testing.
ZYGLO TEST
The zyglo test is a nondestructive testing (NTD) methodthat helps to locate and idetify surface defects in order toscreen out potential failure-producing defects. It is quickand accqurate process for locating surface flaws suchas shrinkage cracks, porosity, cold shuts, fatigue cracks,
grinding cracks etc. The ZYGLO test works effectively ina 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 testare given below:-
Step 1 – pre-clean parts. Step 2 – apply penetrant
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Step 3 – remove penetrant Step 4 – dry parts Step 5 – apply developer
Step 6 – inspection
RED DYE PENETRATI ON TEST (RDP)
Dye penetrant inspection (DPI), also called liquidpenetrant inspection (LPI), is a widely applied and low-cost inspection method used to locate surface-breakingdefects in all non-porous materials (metals, plastics, or
ceramics). Penetrant may be applied to all non-ferrousmaterials, but for inspection of ferrous componentsmagnetic particle inspection is preferred for itssubsurface detection capability. LPI is used to detectcasting and forging defects, cracks, and leaks in newproducts, and fatigue cracks on in-service components.
Principles DPI is based upon capillary action, where low surfacetension fluid penetrates into clean and dry surface-breaking discontinuities. Penetrant may be applied tothe test component by dipping, spraying, or brushing.
After adequate penetration time has been allowed, theexcess penetrant is removed, a developer is applied.The developer helps to draw penetrant out of the flawwhere a visible indication becomes visible to theinspector.
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12. POWER PACK SECTION
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
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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 oilscrapper rings.
13.FORKLIFT TRUCK
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A forklift truck (also called a lift truck, a fork truck, or
a forklift) is a powered industrial truck used to lift and
move materials short distances. The forklift was
developed in the early 20th century by variouscompanies including the transmission manufacturing
company Clark and the hoist company Yale & Towne
Manufacturing.[1][2][3] Following World War II the use and
development of the forklift truck has greatly expanded
worldwide. Forklifts have become an indispensable
piece of equipment in manufacturing and warehousingoperations.[4] In 2013 alone the top 20 manufacturers
worldwide posted sales of $30.4 billion with 944,405
machines sold.;[5] and the U.S. forklift market was nearly
$33 billion.
Indirectly assisting sections
Those sections which indirectly assist in the
maintenance work are called indirectly assisting
sections. The labs generally come under this sections.
The various indirectly assisting section are as follows:-
1. Metallurgical lab2. Machine shop
3. C.T.A. cell
4. Control room
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The brief introductions of these section are given below.
1.Metallurgical lab
In this section the properties of the lube oil & fuel oil are
tested and if they are up to the mark then they are only
used.
When the loco comes for a schedule, the lube oil of the
loco checked thoroughly. When the metals slides over
each other
Sometimes they cause wear, but there is continuous
flow of lube oil between them which takes those
particles with them. This increases the quality ofdifferent metals in them. So, in this lab the different
percentage of elements are taken out by electronics
method.
In this test, a very thin film is created between two
graphite electrodes having high potential difference
between them. This causes a spark between themwhich carries a high temperature (25000 C). this
process is done in UV-Rays. So the valence electrons of
different element in outer shell get excited and jump to
the excited level. They remain there for 10-2 sec. when
they come down to normal state they release energy in
the form of light rays. Different elements releasedifferent intensity waves which are focused on a
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different grating, which splits the light into a spectrum.
These spectrum lights are focused on the potential
tubes based on photo electric effect. This generates
electric signals that are read & compared by thecomputer to the standard data. The data is as follows:-
Elements Min. Limit (inppm)
Max. limit (inppm)
Cu 10 20Pb 5 10
Sn 5 10Fe 20 50Cr 5 10Na 30 50
Al 5 10Si 15 20B 10 20
So according to these limits we can easily detect which
metal is wearing more, and according to that which part
has to be checked and changed.
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The standard properties of the fluids are as
follows:-
Fuel Oil Properties
Acidity nil
Pour point
3oC(winter)15oC(summer)
Distillation record(370oC) 95% min.
Flash point 35oC min.
Kinematic viscosity (40oC) 2 – 5 cst.
Density (15oC) 820-860
kg/m3
Sulphur max% by weight 0.25
Water max% by volume 0.05
Carbon residue % wise by weight 0.30
Lube oil properties
Appearance clean &
bright
Kinematic viscosity (100oC) 15.5 – 16.3
cst
Viscosity index 110min.
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Pour point 21max
Flash point 200oC
Sulphur 1.39-1.63%
Different tests are conducted on the oil and their properties are
tested out. If the readings are different then the action is taken
by the administration.
1. Machine shop
In this section machining of different parts is done. The
machine shop has different lathe, grinding machine,
power hacksaw, drill machine & shaper machine. But
the machining of very few components like expresser
shaft, generator armature is done and most of the parts
are replaced because there is no comprise for the
efficiency.
2. C.T.A Cell
The information for any movement is necessary to be
given to the head office. So there should be a body
which can form a like between administration and the
shed. This is done by C.T.A cell.
The few main works are as:-
1. Interaction between H.O and shed.
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2. To keep check of the technical view
on the working in the shed.
3. To check the work quality according
to the standards.4. To solves the problem s of the
shed‘s different departments.
5. To contact the concerned private
agencies if there is some problems
in their services.
6. To maintain the standard criteria ofI.S.O as they need the six monthly
contracts.
So, in this way C.T.A cell plays an important role of
interaction between shed and administration.
3.CONTROL ROOM
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 arekept 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.
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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 ter med as ‗ over due‘ and control room can usethe loco of another shed if that is available.
The lube oil consumption is also calculated by the
control room for each loco.
STEPS MAY BE TAKEN FOR
IMPROVEMENTS
1. Assembly wise Trend analysis of failures
- Identification of critical assemblies
– Internal Audit of the sections in the
order of criticality
– Identification of nonconformities
– Implementation of revised
maintenance instructions.
– Follow up
2. Responsibility wise analysis of
failures
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– Counselling and check sheets
3. Strictly ensuring that booked repairs areattended along with the Scheduled repairs
4. Trouble shooting guide covering all types of
locos
5. Sensitising the staff to actual performance
- Display Boards for performance, Failure
meetings
6. Training
- Emphasis on refreshers- Animated electrical circuits
7. Emphasis on staff welfare
- Regular grievance meeting with ‘P’Branch officials
8. Enhancing the safety features of thelocomotive
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- Auto flasher lights have been provided on
all locomotives
- Dynamic braking have been madefunctional on all WDM class locos
- Provision of Twin Beam head lights has been made on 43 locomotives
- Focusing of head lights is being ensuredon all locomotives
- Check lists have been issued for
inspection of safety items on locos.- Comprehensive attention to bogie is
ensured when bogie run out for any work
DIESEL TRACTION IS THE LATEST
First steam locomotive ‗Puffing Devil‘ was built byRichard Trivethick, a Conish Engineer in 1801-
Thus, beginning of steam traction.
Electricity first used for traction purpose in 1881
by German engineer Werner Van Siemens usingboth rails to carry the current- Thus, beginning of
Electric traction.
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First diesel loco came into existence in 1912 after
invention of diesel engine in 1893- Thus,
beginning of Most Modern Diesel Traction.
DIESEL TRACTION IS MOST ENERGY
EFFICIENT
Diesel Traction is most energy efficient mode of
traction.
Thermal efficiency of a diesel engine is 40% and
transmission losses reduce it to about 32%.
The efficiency of Electric traction when electricity
is generated from coal is only about 29% with
63% losses in Power Station, 4% in Transmission
lines & 4% in locomotives.
DIESEL LOCOS CAN HAUL HEAVIERLOADS
Modern Diesel Locomotives have higher load
hauling capability.
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Load hauling capability of locomotive depends on
the ability of the locomotive to start a load, which
in turn depends on the following factors.1. Axle Load- A function of track geometry and is
independent of the mode of traction.
2. Adhesion- Ability of loco to hold onto rail and
move forward. Max adhesion of 43% achieved
in state of the art 4000 HP GM Loco against
37% achieved in 6000 HP ABB loco.
Starting tractive effort of 4000 HP loco is 53
tonnes as compared to 47 tonnes in case of 6000
HP ABB loco.
The world over, Diesel locomotives haul trains up
to 23,000 tonnes while there is no evidence of
such capability in case of electric traction.
DIESEL TRACTION IS CLOSEST TO
NATURE
Diesel traction is most environment friendly mode
of traction.
In diesel traction both the production and use of
power takes place on the locomotive itself
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whereas in case of electric traction, electricity is
produced in the power plant and then used on the
electric locomotive. A comparison made on the basis of pollution
created on account of generation of one KW of
power in power plant shows that seen that electric
traction results in 65% more pollution than diesel
traction.
WDM3A A long distance express train
http://en.wikipedia.org/wiki/Image:Irchnkanngc.jpghttp://en.wikipedia.org/wiki/Image:Irchnkanngc.jpghttp://en.wikipedia.org/wiki/Image:Wdm4A.jpg
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WDG-4 numbered 12049 WDP-4 diesel locomotive
DIESEL TRACTION IS MOST
ECONOMICAL
Diesel traction is more economical as compared
to Electric traction.
A comparative cost study reveals the following.
CAPITAL COST
S.
No
Description Diesel
Traction
Electric
Traction
1. Locomotive cost 2.69 crore 3.11 Crore
2. Electrification
cost (One electric
NIL 3.25 crore
http://en.wikipedia.org/wiki/Image:WDG4-12049.jpghttp://en.wikipedia.org/wiki/Image:WDP_4-20012.jpghttp://en.wikipedia.org/wiki/Image:Wdm4A.jpg
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loco every 5 km).
Total Rs. 2.69
crore
Rs. 6.36 crore
RUNNING COST (Rs./1000 GTKM)
S.
No
Description Diesel
Traction
Electric
Traction
1. Passenger
service
Rs. 72.25 Rs. 98.62
2. Freight services Rs. 50.07 Rs. 51.03
DIESEL TRACTION IS IDEAL FOR INDIAN
CONDITIONS
Diesel Traction is least prone to sabotage. With on
board power generation, it can move anywhere any
time. In Electric traction OHE are the one‘s which
are very much prone to sabotage activities.
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In case entire traffic is diverted on electric traction,
it will cause more power shortage for domestic &
household use, as people will be forced to useinefficient ―Gensets‖. Thus more loss in terms of
foreign exchange will be incurred.