LOCOMOTIVE WORKSHOPNORTHEN RAILWAY, CHARBAGH

LUCKNOW

A

SUMMER TRAINING REPORT

ON

DIESEL LOCOMOTIVE TECHNOLOGYSUBMITTED BY:

HIMANSHU MISHRA

B.Tech (MECHANICAL),2ND yr

DIT SCHOOL OF ENGINEERING(AMITY EDUCATION GROUP)

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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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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

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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 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.

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DIESEL LOCOMOTIVE SHED

CHARBAGH , LUCKNOW

LKO 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.

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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.

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.

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a) OVER VIEW

Inception 22nd April1857

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

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(b) CLASSIFICATION

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 ‘ 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.

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DIESEL ELECTRIC LOCOMOTIVE

PARTS OF THE LOCOMOTIVE( FIG 2)

SAND BOXRADIATORRADIATOR FAN TURBO SUPERCHARGERBOGIE(2 SETS)(3AXLE OR 2 AXLE)

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FUEL TANK AIR RESERVOIERSPOWER PACK

DYNAMO WITH ALTRNATORBATTERIESDRIVER CABIN WHEEL ASSEMBLYDISC BLOWER TRACTON MOTERTRUCKGEAR AND PENION ASSSEMBLYCYLINDER HEADCROSS HEAD FUEL INJECTION PUMPBATTERIES (8 OF 8.68 VOLTS)FUEL TANK AFTER COOLING CORE JUNCTION BOX

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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 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.

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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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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 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.

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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.

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.

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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 Rotor assembly with turbine and rotor on the same shaft.

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(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 COOLING1.ALCO 2600HP Water cooled2.ABB TPL61 3100HP Air cooled3.HISPANO SUIZA HS 5800 NG 3100HP Air cooled4. GE 7S1716 3100HP Water cooled5. NAPIER NA-295 2300,2600&3100HP Water cooled6. ABB VTC 304 2300,2600&3100HP Water cooled

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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

The fuel oil system consists of two integrated systems. These are-

FUEL INJECTION PUMP (F.I.P). FUEL INJECTION SYSTEM.

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(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.

FUEL INJECTION PUMP(FIG 5)

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BOGIE

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.

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(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 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.

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(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

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

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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.

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(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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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 MOTER24

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

GENERATOR25

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 Section26

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

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EXHAUST MANIFOLD WATER CHANNEL PGEV GOVERNOR CRANK CASE MOTER CYLINDER (MAX. 16 CYLINDER) PISTON FUEL OIL INJECTOR ROCKER ARM YOKE LUBE OIL HEADER PIPE L PIPE F PIPE S PIPE CAM SHAFT CRANK SHAFT CROSS HEAD FUEL INJECTION PUMP CROSS PIPE FIP COVER FUEL OIL BENZO LUBE OIL SUMP 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

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OIL SLEEVE DRAINE PIPE FUEL CONTROOLING SHAFT

CROSS HEAD

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

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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 250F 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 190F. 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.

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

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Better heat dissipation Failure reduced by reducing crack and eliminating sagging effect of fire deck

area.

FAILURE ANALYSIS

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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 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.

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(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.

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.

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(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

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

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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

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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.

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(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.

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(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

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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

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Twin Power-Pack 700HP Diesel Engine

Single Power-Pack 2400HP Diesel Engine

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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

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Drive Shaft Gear Box Sand Box

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.

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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.

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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.

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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.

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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 :-

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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.

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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.

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(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.

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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 :-

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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.

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.

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Locomotive Data

General Data Of Locomotive:-

Model No. : WDM2

Specification : 16 cylinder V-type 4 strokeDiesel Engine

Type : Co-Co

Power : 700hp, 1400hp, 2400hp

Maximum Speed : 120 kph

Gear Ratio : 68/18

Compression Ratio : 16:1

Cylinder Bore : 230mm

Cylinder Stroke : 279mm

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Wheel Base

Wheel Dia : 1092mmWheel Base : 12834mmTraction Motor : Bhel 165Track Gauge : 1676mmBrake Equipment : Vaccun/Air

Maximum Overall Dimension

Height : 4185mmWidth : 3010mmLength : 17120mm

Capacity

Fuel : 5000 lt Cooling Water : 1210 lt Lube Oil : 910 lt Water Expansion : 155 lt Sand : 0.4 m3

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Auxiliary Horse Power Requirement

Auxiliary Generator Maximum : 17HP

Exciter Maximum : 12HP

Traction Motor : 400HP

Blower at full speed : 62HP

Radiator Fan : 80HP

Expresser Unloaded at 1000 rpm : 13 HP

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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 WWW.RAILWAY TECHNICAL.CO.IN WWW.HOWSTUFFWORKS.IN WWW.IRFCA.CO.IN

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