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Indian railways mechanical vocational training report 2 haxxo24i~iDocument Transcript

1. 2010 INDUSTRIAL TRAINING REPORT

2. ACKNOWLEDGEMENT We take this opportunity to express our sincere gratitude to the peoples whohave been helpful in the successful completion of our industrial training and this project. We would like toshow our greatest appreciation to the highly esteemed and devoted technical staff, supervisors of theDiesel Loco Shed, Tughlakabad. We are highly indebted to them for their tremendous support and helpduring the completion of our training and project. We are grateful to Mr. V.K. MALIK, C.I. (D.T.C.) ofDiesel Loco Shed Tughlakabad and Mr. S.N. BASU Principal of Training School who granted us thepermission of industrial training in the shed. We would like to thanks to all those peoples who directly orindirectly helped and guided us to complete our training and project in the shed, including the followinginstructors and technical officers of Diesel Training Centre and various sections. Mr. V.K. MALIK SEEMechanical (DTC) Date:-12/07/10

3. CONTENTS History Introduction of Diesel Shed TKD Fuel section Control room C.T.Acell Turbo Supercharger Expressor/Compressor Cylinder Head Bogie Fuel Injection Pump(FIP) CTA Cell Fuel Section Control Room Metallurgical Lab. Yearly (Mech.) Pit WheelLathe Running /Mech. /Goods Running /Mech./Mail Air Brake Speedometer Project stud To study about Project Study

4. INDIAN RAILWAY HISTORY INTRODUCTION Indian Railways is the state-owned railwaycompany of India. It comes under the Ministry of Railways. Indian Railways has one of the largest andbusiest rail networks in the world, transporting over 18 million passengers and more than 2 million tonnesof freight daily. Its revenue is Rs.107.66 billion. It is the world's largest commercial employer, with morethan 1.4 million employees. It operates rail transport on 6,909 stations over a total route length of morethan 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 wasfounded 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 manufacturingplants 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

Indian railways mechanical vocational training report 2 haxxo24 i~i

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track kilometer is electrified & almost all electrified sections use 25,000 V AC. Indian railways uses fourrail track gauges|~| 1. The broad gauge (1670 mm) 2. The meter gauge (1000 mm)

5. 3. Narrow gauge (762 mm) 4. Narrow gauge (610 mm). Indian Railways operates about 9,000passenger trains and transports 18 million passengers daily .Indian Railways makes 70% of its revenuesand most of its profits from the freight sector, and uses these profits to cross-subsidies the loss-makingpassenger sector. The Rajdhani Express and Shatabdi Express are the fastest trains of IndiaCLASSIFICATION 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 ofTraction designations:- D = Diesel-electric traction C = DC traction A = AC traction CA=Dualpower 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 5000horsepower 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 3100horsepower.|~|

6. DIESEL SHED TUGHLAKABAD INTRODUCTION Diesel locomotive shed is an industrial-technical setup, where repair and maintenance works of diesel locomotives is carried out, so as to keep theloco working properly. It contributes to increase the operational life of diesel locomotives and tries tominimize the line failures. The technical manpower of a shed also increases the efficiency of the loco andremedies the failures of loco. The shed consists of the infrastructure to berth, dismantle, repair and test theloco and subsystems. The shed working is heavily based on the manual methods of doing the maintenancejob and very less automation processes are used in sheds, especially in India.

7. The diesel shed usually has:- Berths and platforms for loco maintenance. Pits for under framemaintenance Heavy lift cranes and lifting jacks Fuel storage and lube oil storage, water treatmentplant and testing labs etc. Sub-assembly overhauling and repairing sections Machine shop andwelding facilities. ABOUT DIESEL SHED TKD Diesel Shed, Tughlakabad of Northern Railway islocated in NEW DELHI. The shed was established on 22nd April 1970. It was initially planned to home75 locomotives. The shed cater the needs of Northern railway. This shed mainly provides locomotive torun the mail, goods and passenger services. No doubt the reliability, safety through preventive andpredictive maintenance is high priority of the shed. To meet out the quality standard shed has takenvarious steps and obtaining of the ISO-9001-200O& ISO 14001 OHSAS CERTIFICATION is among ofthem. The Diesel Shed is equipped with modern machines and plant required for Maintenance of DieselLocomotives and has an attached store depot. To provide pollution free atmosphere, Diesel Shed hasconstructed Effluent Treatment Plant. The morale of supervisors and staff of the shed is very high andwhole shed works like a well-knit team. AT A GLANCE Inception 22nd April1970 Present Holding 147Locomotives 19 WDM2 37 WDM3A 08 WDM3D

8. 11 WDG3A 46 WDP1 26 WDP3A Accreditation ISO-9001-2000 & ISO 14001 Covered area of shed10858 SQ. MTR Total Area of shed 1, 10,000 SQ. MTR Staff strength sanction 1357 On roll - 1201Berthing capacity 17 locomotives SPECIAL MACHINES & PLANT Pit wheel lathe machine Thismachine is suitable for turn & re-profiles the wheels of locomotives. Effluent Treatment Plant:- In order toprovide pollution free environment, an ETP PLANT is installed. Various effluents emitted from dieselshed are passed through the Plant. The water thus collected is pollution free and is used for non drinkingpurposes such as gardening and washing of the locomotives. TECHNICAL INNOVATIONS Based onday-to-day maintenance problems a large number of innovations/modifications have been conceived andimplemented in Diesel Shed, TKD during 2003-2004 which have improved the reliability and downtimeof locomotives.Some of them are under.

9. Expressor performance test notch wise Simulation of test stand facility on the loco itself with thehelp of only two small fixtures. Testing the performance of expressor in diesel locomotive engines.Cylinder head Stud Removal/ Tightening Arrangement A simple device has been developed to helpreduce the time and effort taken in removal/tightening of cylinder head studs. Diesel Training Centre-DTCIt was setup in the TKD shed premises in 1975 by the Northern Railway with view to train diesel locopilots. It also trains the Diesel Maintenance staff to improve the availability of qualified manpower andimprove the efficiency of and quality of the technicians. It has five classrooms, a hall ,a Model room(withsectional models of TSC, expressor, cylinder head LOP, governor etc.). A well qualified team ofinstructors from the electrical and mechanical fields provides a quality training to the p=loco pilots andother trainees. Courses offered :- (regular) Diesel Assistant to Diesel Loco Driver promotion course Diesel Assistant Refresher coarse Diesel Driver refresher course Other courses:- Up gradation courseof Diesel technicians Electric traction to diesel traction conversion course Course for Drivers,Shunters and Asstt. Drivers 3 years Apprentice technician(Diesel mechanical and electrical) 6months Apprentice Technician(Diesel mechanical and electrical) Vocational industrial training for

B.Tech and Diploma student

10. 1.FUEL SECTION 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 storagecapacity of 10,60, 000 liters.This stock is enough to end for 15-16 days The fuel is supplied by truck fromIOC - Panipat refinery each truck diesel sample is treated in diesel lab and after it in unloaded. Samplecheck is necessary to avoid water, kerosene mixing diesel. Two fuel filling points are established near thecontrol room It also handles the Cardiam compound , lube oil. diesel is only for loco use if the dieselsamples are not according to the standard , the delivery of the fuel is rejected. Viscosity of lube oil shouldbe 100-1435 CST. Water mixing reduces the viscosity. Statement of diesel storage and received is madeafter every 10 days and the report is send to the Division headquarter. The record of each truck, wagonsetc are included in it. The record of issued oil is also sending to headquarter. After each 4 months. Asurvey is conducted by high level team about the storage, records etc. 0.1% of total stored fuel oil is givenfor 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.

11. 2.CONTROL ROOM It controls and regulates the complete movement, schedules, duty of each locoof the shed. Division level communications and contacts with each loco on the line are also handled by thecontrol room. Full record of loco fleet, failures, duty, overdue and availability of locos are kept by thecontrol room. It applies the outage target of loco for the shed, as decided by the HQ. It decides thelocomotives mail and goods link that which loco will be deployed on which train. It operates 116 Mail and11Goods 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 onscheduled time in the shed then the loco is termed as over due and control room can use the loco ofanother shed if that is available. The lube oil consumption is also calculated by the control room for eachloco:- Lube Oil Consumption (LOC) = Lube oil consumed in liters/ total kms travelled 100 New andbetter operational loco have less LOC.

12. 3.CTA (Chief Technical Assistance) CELL This cell performs the following functions:- Failureanalysis of diesel locos Finding the causes of sub system failures and material failures Formation ofinquiry panels of Mechanical and Electrical engineers and to help the special inquiry teams Materialfailures complains, warnings and replacement of stock communications with the componentmanufacturers Issues the preventive instructions to the technical workers and engineers Preparationof full detailed failure reports of each loco and sub systems, components after detailed analysis. Thereports are then sent to the Divisional HQ. Correspondence with the headquarters is also done by theCTA Cell. The failures analyzed are:- Category 1 failures:- If the VIP trains loco fails or the train isdelayed by the failure of another trains loco failure. Failure of the single loco may delay a no of trains.Non- reported failures:- the failure or delay of the local passenger trains for 2-3 hours is taken in thiscategory. They are not reported to the higher levels and can be adjusted in the section operations. ForeignRailway-FR failures:- If the loco of one division fails in the other division and affects the traffic seriouslyin that division. The correspondence in this case is done by the cell.

13. Other failures are:- 1. Material failure:- may be due to poor quality, defective material and defects inthe manufacturing of the component. Component is replaced if fails frequently. 2. Maintenance failures:-if lapse is by the maintenance workers. Inquiry is done and punishment is set by CTA Cell on behalf of Sr.DME or instructions are issued for better maintenance. 3. Crew lapse:- proper actions are take orinstructions issued to the crew of locos. After every 4 years IOH of loco is done in the shed. After 8yearsPOH of loco is done at the Charbag loco shed Lucknow. After 18 years rebuilding of loco is done atDMW-Patiala. Total life of a loco is 36 years.

14. 3. TURBO SUPERCHARGER INTRODUCTION The diesel engine produces mechanical energy byconverting 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 thesuction stroke, air is being sucked into the cylinder from the atmosphere. The volume of air thus drawninto the cylinder through restricted inlet valve passage, within a limited time would also be limited and ata pressure slightly less than the atmosphere. The availability of less quantity of air of low density insidethe cylinder would limit the scope of burning of fuel. Hence mechanical power produced in the cylinder isalso limited. An improvement in the naturally aspirated engines is the super-charged or pressure chargedengines. During the suction stroke, pressurised stroke of high density is being charged into the cylinderthrough the open suction valve. Air of higher density containing more oxygen will make it possible toinject more fuel into the same size of cylinders and produce more power, by effectively burning it.

15. A turbocharger, or turbo, is a gas compresser used for forced-induction of an internal combustionengine. Like a supercharger, the purpose of a turbocharger is to increase the density of air entering theengine 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. TURBO SUPERCHARGER AND ITS WORKINGPRINCIPLE The exhaust gas discharge from all the cylinders accumulate in the common exhaustmanifold at the end of which, turbo- supercharger is fitted. The gas under pressure there after enters theturbo- supercharger through the torpedo shaped bell mouth connector and then passes through the fixednozzle ring. Then it is directed on the turbine blades at increased pressure and at the most suitable angle toachieve rotary motion of the turbine at maximum efficiency. After rotating the turbine, the exhaust gasgoes out to the atmosphere through the exhaust chimney. The turbine has a centrifugal blower mounted atthe other end of the same shaft and the rotation of the turbine drives the blower at the same speed. Theblower connected to the atmosphere through a set of oil bath filters, sucks air from atmosphere, anddelivers at higher velocity. The air then passes through the diffuser inside the turbo- supercharger, wherethe 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 andreduces the density. This effects supply of high-density air to the engine. To take care of this, air is passedthrough a heat exchanger known as after cooler. The after cooler is a radiator, where cooling water oflower temperature is circulated through the tubes and around the tubes air passes. The heat in the air isthus transferred to the cooling water and air regains its lost density. From the after cooler air goes to acommon inlet manifold connected to each cylinder head. In the suction stroke as soon as the inlet valveopens the booster air of higher pressure density rushes into the cylinder completing the process of supercharging. The engine initially starts as naturally aspirated engine. With the increased quantity of fuelinjection increases the exhaust gas pressure on the turbine.

16. Thus the self-adjusting system maintains a proper air and fuel ratio under all speed and load conditionsof the engine on its own. The maximum rotational speed of the turbine is 18000/22000 rpm for the Turbosupercharger and creates max. Of 1.8 kg/cm2 air pressure in air manifold of diesel engine, known asBooster Air Pressure (BAP). Low booster pressure causes black smoke due to incomplete combustion offuel. High exhaust gas temperature due to after burning of fuel may result in considerable damage to theturbo supercharger and other component in the engine. 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 androtor on the same shaft. ROTOR ASSEMBLY The rotor assembly consists of rotor shaft, rotor blades,thrust collar, impeller, inducer, centre studs, nosepiece, locknut etc. assembled together. The rotor bladesare fitted into fir tree slots, and locked by tab lock washers. This is a dynamically balanced component, asthis has a very high rotational speed.

17. LUBRICATING, COOLING AND AIR CUSHIONING LUBRICATING SYSTEM One branch linefrom the lubricating system of the engine is connected to the turbo- supercharger. Oil from the lube oilssystem circulated through the turbo- supercharger for lubrication of its bearings. After the lubrication isover, the oil returns back to the lube oil system through a return pipe. Oil seals are provided on both theturbine 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 water cooling system of the engine. Circulationof water takes place through the intermediate casing and the turbine casing, which are in contact with hotexhaust gases. The cooling water after being circulated through the turbo- supercharger returns back againto the cooling system of the locomotive. AIR CUSHIONING There is an arrangement for air cushioningbetween the rotor disc and the intermediate casing face to reduce thrust load on the thrust face of thebearing which also solve the following purposes. It prevents hot gases from coming in contact with thelube oil. It prevents leakage of lube oil through oil seals. It cools the hot turbine disc. Pressurised air fromthe blower casing is taken through a pipe inserted in the turbo- supercharger to the space between the rotordisc and the intermediate casing. It serves the purpose as described above.

18. AFTER COOLER It is a simple radiator, which cools the air to increase its density. Scales formationon the tubes, both internally and externally, or choking of the tubes can reduce heat transfer capacity. Thiscan also reduce the flow of air through it. This reduces the efficiency of the diesel engine. This is evidentfrom black exhaust smoke emissions and a fall in booster pressure. Fitments of higher capacity TurboSupercharger- following new generation Turbo Superchargers have been identified by diesel shed TKDfor 2600/3100HP diesel engine and tabulated in table 1. TABLE 1 TYPE POWER COOLING 1.ALCO2600HP Water cooled 2.ABB TPL61 3100HP Air cooled 3.HISPANO SUIZA HS 5800 NG 3100HP Aircooled 4. GE 7S1716 3100HP Water cooled 5. NAPIER NA-295 2300,2600&3100HP Water cooled 6.ABB VTC 304 2300,2600&3100HP Water cooled TURBO RUN DOWN TEST Turbo run-down test isa very common type of test done to check the free running time of turbo rotor. It indicates whether there isany abnormal sound in the turbo, seizer/ partial seizer of bearing, physical damages to the turbine, or anyother abnormality inside it. The engine is started and warmed up to normal working conditions andrunning at fourth notch speed. Engine is then

19. shut down through the over speed trip mechanism. When the rotation of the crank shaft stops, the freerunning 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 down time are both considered to be harmfulfor the engine. ROTOR BALANCING MACHINE A balancing machine is a measuring tool used forbalancing rotating machine parts such as rotors of turbo subercharger,electric motors,fans, turbines etc.The machine usually consists of two rigid pedestals, with suspension and bearings on top.The unit undertest is placed on the bearings and is rotated with a belt. As the part is rotated, the vibration in thesuspension is detected with sensors and that information is used to determine the amount of unbalance inthe part. Along with phase information, the machine can determine how much and where to add or removeweights to balance the part. ADVANTAGES OF SUPER CHARGED ENGINES A super charged enginecan produce 50 percent or more power than a naturally aspirated engine. The power to weight ratio in sucha case is much more favorable. Better scavenging in the cylinders. This ensures carbon free cylinders andvalves, and better health for the engine also. Better ignition due to higher temperature developed by highercompression in the cylinder. It increases breathing capacity of engine Better fuel efficiency due tocomplete combustion of fuel . Defect in Turbochargers Low Booster Air Pressure (BAP).

20. Oil throwing from Turbocharger because of seal damage or out of clearance. Surging- Back Pressuredue 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. LubeOil inlet pipe rubber o ring. Turbine end Bearing. Blower end Bearing. Chimney gasket. Rubber o Ring kit. Spring Washers. Lock Washer Rotor Stud.

21. 4.FUEL OIL SYSTEM INTRODUCTION All locomotive have individual fuel oil system. The fuel oilsystem is designed to introduce fuel oil into the engine cylinders at the correct time, at correct pressure, atcorrect quantity and correctly atomised. The system injects into the cylinder correctly metered amount offuel in highly atomised form. High pressure of fuel is required to lift the nozzle valve and for betterpenetration of fuel into the combustion chamber. High pressure also helps in proper atomisation so thatthe small droplets come in better contact with the compressed air in the combustion chamber, resulting inbetter combustion. Metering of fuel quantity is important because the locomotive engine is a variablespeed and variable load engine with variable requirement of fuel. Time of fuel injection is also importantfor better combustion. FUEL OIL SYSTEM The fuel oil system consists of two integrated systems. Theseare- FUEL INJECTION PUMP (F.I.P). FUEL INJECTION SYSTEM.

22. FUEL INJECTION PUMP It is a constant stroke plunger type pump with variable quantity of fueldelivery to suit the demands of the engine. The fuel cam controls the pumping stroke of the plunger. Thelength of the stroke of the plunger and the time of the stroke is dependent on the cam angle and camprofile, and the plunger spring controls the return stroke of the plunger. The plunger moves inside thebarrel, which has very close tolerances with the plunger. When the plunger reaches to the BDC, spill portsin the barrel, which are connected to the fuel feed system, open up. Oil then fills up the empty space insidethe barrel. At the correct time in the diesel cycle, the fuel cam pushes the plunger forward, and the movingplunger covers the spill ports. Thus, the oil trapped in the barrel is forced out through the delivery valve tobe injected into the combustion chamber through the injection nozzle. The plunger has two identicalhelical grooves or helix cut at the top edge with the relief slot. At the bottom of the plunger, there is a lugto fit into the slot of the control sleeve. When the rotation of the engine moves the camshaft, the fuel cammoves the plunger to make the upward stroke.

23. It may also rotate slightly, if necessary through the engine governor, control shaft, control rack, andcontrol sleeve. This rotary movement of the plunger along with reciprocating stroke changes the positionof the helical relief in respect to the spill port and oil, instead of being delivered through the pump outlet,escapes back to the low pressure feed system. The governor for engine speed control, on sensing therequirement of fuel, controls the rotary motion of the plunger, while it also has reciprocating pumpingstrokes. Thus, the alignment of helix relief with the spill ports will determine the effectiveness of thestroke. If the helix is constantly in alignment with the spill ports, it bypasses the entire amount of oil, andnothing is delivered by the pump. The engine stops because of no fuel injected, and this is known as NO-FUEL position. When alignment of helix relief with spill port is delayed, it results in a partly effectivestroke and engine runs at low speed and power

24. output is not the maximum. When the helix is not in alignment with the spill port through out thestroke, this is known as FULL FUEL POSITION, because the entire stroke is effective. Oil is thenpassed through the delivery valve, which is spring loaded. It opens at the oil pressure developed by thepump plunger. This helps in increasing the delivery pressure of oil. it functions as a non-return valve,retaining oil in the high pressure line. This also helps in snap termination of fuel injection, to arrest thetendency of dribbling during the fuel injection. The specially designed delivery valve opens up due to thepressure built up by the pumping stroke of plunger. When the oil pressure drops inside the barrel, thelanding on the valve moves backward to increase the space available in the high-pressure line. Thus, thepressure inside the high-pressure line collapses, helping in snap termination of fuel injection. This reducesthe chances of dribbling at the beginning or end of fuel injection through the fuel injection nozzles. FUEL

INJECTION NOZZLE The fuel injection nozzle or the fuel injector is fitted in the cylinder head with itstip projected inside the combustion chamber. It remains connected to the respective fuel injection pumpwith a steel tube known as fuel high pressure line. The fuel injection nozzle is of multi-hole needle valvetype operating against spring tension. The needle valve closes the oil holes by blocking the oil holes dueto spring pressure. Proper angle on the valve and the valve seat, and perfect bearing ensures proper closingof the valve. Due to the delivery stroke of the fuel injection pump, pressure of fuel oil in the fuel duct andthe pressure chamber inside the nozzle increases. When the pressure of oil is higher than the valve springpressure, valve moves away from its seat, which uncovers the small holes in the nozzle tip. High-pressureoil is then injected into the combustion chamber through these holes in a highly atomised form. Due toinjection, hydraulic pressure drops, and the valve

25. returns back to its seat terminating the fuel injection, termination of fuel injection may also be due tothe bypassing of fuel injection through the helix in the fuel injection pump causing a sudden drop inpressure. CALIBRATION OF FUEL INJECTION PUMPS Each fuel injection pump is subject to test andcalibration after repair or overhaul to ensure that they deliver the same and stipulated amount of fuel at aparticular rack position. Every pump must deliver regulated and equal quantity of fuel at the same time sothat the engine output is optimum and at the same time running is smooth with minimum vibration. Thecalibration and testing of fuel pumps are done on a specially designed machine. The machine has a 5 HPreversible motor to drive a cam shaft through V belt. The blended test oil of recommended viscosity undercontrolled temperature is circulated through a pump at a specified pressure for feeding the pump undertest. It is very much necessary to follow the laid down standard procedure of testing to obtain standard testresults. The pump under test is fixed on top of the cam box and its rack set at a particular position to findout the quantum of fuel delivery at that position. The machine is then switched on and the cam startsmaking delivery strokes. A revolution counter attached to it is set to trip at 500 RPM or 100 RPM asrequired. With the cam making strokes, if the pump delivers any oil, it returns back to the reservoir innormal state. A manually operated solenoid switch is switched on and the oil is diverted to a measureglass till 300 strokes are completed after operation of the solenoid switch. Thus the oil discharged at 300working strokes of the pump is measured which should normally be within the stipulated limit. Thepurpose of measuring the output in 300 strokes is to take an average to avoid errors. The pump is tested atidling and full fuel positions to make sure that they deliver the correct amount of fuel for maintaining theidling speed and so also deliver full HP at full load. A counter check of the result at idling is done on thereverse position of the motor which simulates slow running of the engine. If the test results are not withinthe stipulated limits as indicated by the makers then adjustment of the fuel rack position may be requiredby moving the rack pointer, by addition or removal of shims behind it. The thickness of

26. shims used should be punched on the pump body. The adjustment of rack is done at the full fuelposition to ensure that the engine would deliver full horse power. Once the adjustment is done at full fuelposition other adjustment should come automatically. In the event of inconsistency in results between fullfuel and idling fuel, it may call for change of plunger and barrel assembly. The calibration value of fuelinjection pump as supplied by the makers is tabulated in table 2 at 300 working strokes, rpm -500,temp.-100 to 120 0 F & pressure 40 PSI: Table 2. Dia.of element(mm) Rack(mm) Required volume offuel(cc) 15 mm 30 mm(full load) 9 mm(Idling) 351 cc +5/-10 34 cc +1/-5 17 mm 28 mm (full load) 9 mm(Idling) 401 cc +4/-11 45 cc +1/-5 Errors are likely to develop on the calibration machine in course oftime and it is necessary to check the machine at times with master pumps supplied by the makers. Thesepumps are perfectly calibrated and meant for use as reference to test the calibration machine itself. Twomaster pumps, one for full fuel and the other for idling fuel are there and they have to be very carefullypreserved only for the said purpose. .FUEL INJECTION NOZZLE TEST The criteria of a good nozzle aregood atomization, correct spray pattern and no leakage or dribbling. Before a nozzle is put to test theassembly must be rinsed in fuel oil, nozzle holes cleaned with wire brush and spray holes cleaned withsteel wire of correct thickness. The fuel injection nozzles are tested on a specially designed test stand,where the following tests are conducted.

27. SPRAY PATTERN Spray of fuel should take place through all the holes uniformly and properlyatomized. While the atomization can be seen through the glass jar, an impression taken on a sheet ofblotting paper at a distance of 1 to 1 1/2 inch also gives a clear impression of the spray pattern. SPRAYPRESSURE The stipulated correct pressure at which the spray should take place 3900- 4050 psi for newand 3700-3800 psi for reconditioned nozzles. If the pressure is down to 3600 psi the nozzle needsreplacement. The spray pressure is indicated in the gauge provided in the test machine. Shims are beingused to increase or decrease the tension of nozzle spring which increases or decreases the spray pressureDRIBBLING There should be no loose drops of fuel coming out of the nozzle before or after theinjections. In fact the nozzle tip of a good nozzle should always remain dry. The process of checkingdribbling during testing is by having injections manually done couple of times quickly and checks thenozzle tip whether leaky. Raising the pressure within 100 psi of set injection pressure and holding it forabout 10 seconds may also give a clear idea of the leakage. The reasons of nozzle dribbling are (1)Improper pressure setting (2) Dirt stuck up between the valve and the valve seat (3) Improper contact

between the valve and valve seat (4) Valve sticking inside the valve body. NOZZLE CHATTER Thechattering sound is a sort of cracking noise created due to free movement of the nozzle valve inside thevalve body. If it is not proper then chances are that the valve is not moving freely inside the nozzle.

28. 5. BOGIE___________________________________________ INTRODUCTION A bogie is awheeled 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 railwaycarriage or locomotive, or sprung as in the suspension of a caterpillar tracked vehicle. Bogies serve anumber 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 runson curves at high speed. To minimize generation of track irregularities and rail abrasion. Usually twobogies are fitted to each carriage, wagon or locomotive, one at each end.

29. Key Components Of a Bogie The bogie frame itself. Suspension to absorb shocks between thebogie frame and the rail vehicle body. Common types are coil springs, or rubber airbags. At least twowheelset, composed of axle with a bearings and wheel at each end. Axle box suspension to absorbshocks between the axle bearings and the bogie frame. The axle box suspension usually consists of aspring between the bogie frame and axle bearings to permit up and down movement, and sliders to preventlateral movement. A more modern design uses solid rubber springs. Brake equipment:-Brake shoes areused that are pressed against the tread of the wheels. Traction motors for transmission on each axle.CLASSIFICATION OF BOGIE Bogie is classified into the various types described below according totheir 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

30. A Bo-Bo is a locomotive with two independent four-wheeled bogies with all axles powered byindividual 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 goodadhesion. They are also popular because the greater number of axles results in a lower axle load to thetrack. 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 the axle and suspension bearing.Lateral clearance is maintained between 60 to 312 thou. Less clearance will burn the oil and will cause theseizure of axle. Condemned parts are replaced. RDP tests are done on the frame parts, welded parts,corners, guide links and rigid structures of bogie and minor cracks can be repaired by welding. Axlesuspension bearings may seizure due to oil leakage, cracks etc. If axle box bearings roller is damagedthen replaced it completely.

31. 6. EXPRESSOR________________________________________ INTRODUCTION In IndianRailways, the trains normally work on vacuum brakes and the diesel locos on air brakes. As suchprovision has been made on every diesel loco for both vacuum and compressed air for operation of thesystem as a combination brake system for simultaneous application on locomotive and train. In ALCOlocos the exhauster and the compressor are combined into one unit and it is known as EXPRESSOR. Itcreates 23" of vacuum in the train pipe and

32. 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 shaftattached 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 ofexpressor are, 6CD,4UC & 6CD,3UC. In 6CD,4UC expressor there are six cylinder and four exhausterwhereas 6CD,3UC contain six cylinder and three exhauster. WORKING OF EXHAUSTER Air fromvacuum train pipe is drawn into the exhauster cylinders through the open inlet valves in the cylinder headsduring its suction stroke. Each of the exhauster cylinders has one or two inlet valves and two dischargevalves in the cylinder head. A study of the inlet and discharge valves as given in a separate diagram wouldindicate that individual components like (1) plate valve outer (2) plate valve inner (3) spring outer (4)spring inner etc. are all interchangeable parts. Only basic difference is that they are arranged in the reversemanner in the valve assemblies which may also have different size and shape. The retainer stud in both theassemblies must project upward to avoid hitting the piston. The pressure differential between the availablepressure in the vacuum train pipe and inside the exhauster cylinder opens the inlet valve and air is drawninto the cylinder from train pipe during suction stroke. In the next stroke of the piston the air iscompressed and forced out through the discharge valve while the inlet valve remains closed. Thedifferential air pressure also automatically open or close the discharge valves, the same way as the inletvalves operate. This process of suction of air from the train pipe continues to create required amount ofvacuum and discharge the same air to atmosphere. The VA-1 control valve helps in maintaining thevacuum to requisite level despite continued working of the exhauster.

33. Compressor The compressor is a two stage compressor with one low pressure cylinder and one highpressure cylinder. During the first stage of compression it is done in the low pressure cylinder wheresuction is through a wire mesh filter. After compression in the LP cylinder air is delivered into thedischarge manifold at a pressure of 30 / 35 PSI. Workings of the inlet and exhaust valves are similar tothat of exhauster which automatically open or close under differential air pressure. For inter-cooling air isthen passed through a radiator known as inter-cooler. This is an air to air cooler where compressed airpasses through the element tubes and cool atmospheric air is blown on the out side fins by a fan fitted onthe expressor crank shaft. Cooling of air at this stage increases the volumetric efficiency of air before itenters the high- pressure cylinder. A safety valve known as inter cooler safety valve set at 60 PSI isprovided after the inter cooler as a protection against high pressure developing in the after cooler due todefect of valves. After the first stage of compression and after-cooling the air is again compressed in acylinder of smaller diameter to increase the pressure to 135- 140 PSI in the same way. This is the secondstage of compression in the HP cylinder. Air again needs cooling before it is finally sent to the airreservoir and this is done while the air passes through a set of coiled tubes after cooler.

34. 7. AIR BRAKES INTRODUCTION An air brake is a conveyance braking system actuated bycompressed air. Modern trains rely upon a fail preventive air brake system that is based upon a designpatented by George Westinghouse on March 5,1872. In the air brake's simplest form, called the straight airsystem, compressed air pushes on a piston in a cylinder. The piston is connected through mechanicallinkage to brake shoes that can rub on the train wheels, using the resulting friction to slow the train. AIRBRAKE SYSTEM OPERATION The compressor in the locomotive produces the air supplied to thesystem. It is stored in the main reservoir. Regulated pressure of 6 kg/cm2 flows to the feed pipe throughfeed valve and 5-kg/cm2 pressure by drivers brake valve to the brake pipe. The feed pipe through checkvalve charges air reservoir via isolating cock and also by brake pipe through distributor valve. The brakepipe pressure controls the distributor valves of all the coaches/wagons which in turn control the flow ofcompressed air from Air reservoir to break cylinder in application and from brake cylinder to atmospherein release. During application, the driver in the loco lowers the BP pressure. This brake pipe pressurereduction causes opening of brake cylinder inlet passage and simultaneously closing of brake cylinderoutlet passage of the distributor valve. In this situation, auxiliary reservoir supplies air to brake cylinder.At application time, pressure in the brake cylinder and other brake characteristics are controlled bydistributor valve.

35. During release, the BP pressure is raised to 5 kg/cm2 . This brake pipe pressure causes closing ofbrake cylinder inlet passage and simultaneously opening of brake cylinder outlet passage of the distributorvalve. LAYOUT:- PEV ARCR DV DC BC BC DC PEASD PEASD FP BP GEBV Pressure gauge Cut offangle cock Passenger alarm system Guard emergency brake system Core brake system

36. The distributor valve connects brake cylinder to atmosphere. The brake cylinder pressure can be raisedor lowered in steps. In case of application by alarm chain pulling, the passenger emergency alarm signaldevice (PEASD) is operated which in turn actuates passenger valve (PEV) causing exhaust of BP pressurethrough a choke of 4 mm. Opening of guard emergency brake valve also makes emergency brakeapplication. There are two case of braking, when only loco move and when entire train move.Consequently there are two valves in the driver cabin viz SA-9&A-9. Braking operation of above case isshown in chart below. VALVES

37. A-9 Valve The A-9 Automatic Brake Valve is a compact self lapping, pressure maintaining BrakeValve which is capable of graduating the application or release of locomotive and train brakes. A-9Automatic Brake Valve has five positions: Release, minimum Reduction, Full Service, Over Reductionand Emergency. SA-9 Valve SA-9 Independent Brake Valve is a compact self lapping, pressuremaintaining Brake Valve which is capable of graduating the application or release of Locomotive AirBrakes independent of Automatic Brake. The SA-9 Independent Brake Valve is also capable of releasingan automatic brake application on the Locomotive without affecting the train brake application. The SA-9Brake Valve has three positions : quick release, release and application. MU 2B VALVE The MU-2BValve is a manually operated, two positions and multiple operated valve arranged with a pipe bracket andis normally used for locomotive brake equipment for multiple unit service between locomotives equippedwith similar system in conjunction with F-1 Selector Valve.

38. D-1 Emergency Brake Valve The D-1 Emergency Brake Valve is a manually operated device Whichprovides a means of initiating an emergency brake application.

39. 8. SPEEDOMETER INTRODUCTION The electronic speedometer is intended to measure travelingspeed and to record the status of selected locomotive engine parameters every second. It comprises acentral processing unit that performs the basic functions, two monitors that are used for displaying themeasured speed values and entering locomotive drivers identification data and drive parameters and aspeed transducer. The speedometer can be fitted into any of railway traction vehicles. The monitor is

mounted on every drivers place in a locomotive. It is connected to the CPU by a serial link. Monitortransmits a driver, locomotive and train identifications data to the CPU and receives data on travel speed,partial distance traveled, real time and speedometer 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 are monitored on analog and digital displays, whereasalphanumeric displays, LEDs and a buzzer signal provide information on speedometer and vehicle status.WORKING MECHANISM Speedometer is a closed loop system in which opto-electronic pulse generatoris used to convert the speed of locomotive wheel into the corresponding pulses. Pulses thus generated arethen converted into the corresponding steps for stepper motor. These steps then decide the movement ofstepper motor which rotates the pointer up to the desired position. A feed back potentiometer is also usedwith pointer that provides a signal corresponding to actual position of the pointer, which then comparedwith the step of stepper motor by measuring and control section. If any error is observed, it corrected bymoving the pointer to corresponding position. Presently a new version of speed-time-distance recordercum indicator unit

40. TELPRO is used in the most of the locomotive. Features and other technical specification of thisspeedometer are given below. Salient features Light weight and compact in size Adequate journeydata recording capacity Both analog and digital displays for speed Both internal and externalmemories for data storage Memory freeze facility Stepless wheel wear compensation Dual sensoropto 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 reportsgeneration for easy analysing of recorded data Cumulative, Trip-wise, Train-wise, Driver-wise andDate-wise report generation Master-Slave configuration Applications Speed indication for driver.

41. Administrative control of traction vehicle for traffic scheduling. Vehicle trend analysis in case ofderailment/accident. Analysis of drivers operational performance to provide training, if required.Technical Specifications The system requires a wide operating voltage of 50 V DC to 140 V DC. A.Operating conditions Conditions Values Temperature -5C to +70C Relative humidity 95% (max)Accuracy of Master & Slave 1.0% of full scale deflection B. Analogue indication Factors Values Scalespread over 240

42. Illumination 12 equally spaced LEDs on dial circumference Brightness control 0-100% in 10 stepsDial size 120 mm Dial colour White with black pointer & numerals Max speed range 0-150, 0-160 & 0-180 Kmph (can be made as per customers request) C. Digital indication Features Values LCD display16x2 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) Odometer 7 digit with 1km resolution Input speed sensing 2 inputs for opto-electronic pulse generator 200 or 100 pulses/rev (configurable)

43. 9. CYLINDER HEAD INTRODUCTION The cylinder head is held on to the cylinder liner by sevenhold down studs or bolts provided on the cylinder block. It is subjected to high shock stress andcombustion temperature at the lower face, which forms a part of combustion chamber. It is a complicatedcasting where cooling passages are cored for holding water for cooling the cylinder head. In addition tothis provision is made for providing passage of inlet air and exhaust gas. Further, space has been providedfor holding fuel injection nozzles, valve guides and valve seat inserts also. Components of cylinder headIn cylinder heads valve seat inserts with lock rings are used as replaceable wearing part. The inserts aremade of stellite or weltite. To provide interference fit, inserts are frozen in ice and cylinder head is heatedto bring about a temperature differential of 250 F and the insert is pushed into recess in cylinder head. Thevalve 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 2exhaust and 2 inlet valves of 2.85" in dia. The valves have stem of alloy steel and valve head of austeniticstainless steel, butt-welded together into a composite unit. The valve head material being austenitic steelhas high level of stretch resistance and is capable of hardening above Rockwell- 34 to resist deformationdue to continuous pounding action. The valve guides are interference fit to the cylinder head with aninterference of 0.0008" to 0.0018". After attention to the cylinder heads the same is hydraulically tested at70 psi and 190 F. The fitment of cylinder heads is done

44. in ALCO engines with a torque value of 550 Ft.lbs. The cylinder head is a metal- to-metal joint on tocylinder. 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 deckmodified by increasing number of ribs (supports) to increase its mechanical strength. The flying buttressfashion of middle deck improves the flow pattern of water eliminating water stagnation at the cornersinside 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 crackand eliminating sagging effect of fire deck area. Maintenance and Inspection Cleaning: By dipping in atank containing caustic solution or ORION-355 solution with water (1:5) supported by air agitation andheating. Crack Inspection: Check face cracks and inserts cracks by dye penetration test. Hydraulic Test:Conduct hyd. test (at 70 psi, 200F for 30 min.) for checking water leakage at nozzle sleeve, ferrule, coreplugs and combustion face. Dimensional check : Face seat thickness: within 0.005" to 0.020" Straightnessof valve stem: Run out should not exceed 0.0005"

45. Free & Compressed height (at 118 lbs.) of springs: 3 13/16" & 4 13/16" Checks during overhauling:Ground the valve seat insert to 44.5/29.5, maintain run out of insert within 0.002" with respect to valveguide while grinding. Grind the valves to 45/30 and ensure continuous hair line contact with valve guideby checking colour match. Ensure no crack has developed to inserts after grinding, checked by dyepenetration test. Make pairing of springs and check proper draw on valve locks and proper condition ofgroove and locks while assembling of valves. Lap the face joint to ensure leak proof joint with liner. Blowby test: On bench blow by test is conducted to ensure the sealing effect of cylinder head. Blow by test isalso conducted to check the sealing efficiency of the combustion chamber on a running engine, as per thefollowing procedure: Run the engine to attain normal operating temperature (65C) Stop runningafter attaining normal operating temperature. Bring the piston of the corresponding cylinder at TDC incompression stroke. Fit blow-by gadget (Consists of compressed air line with the provision of apressure gauge and stopcock) removing decompression plug. Charge the combustion chamber withcompressed air. Cut off air supply at 70 psi. Through stop cock and record the time when it comesdown to zero.7 to 10 secs is OK.

46. 10. PIT WHEEL LATHE INTRODUCTION Various type of wear may occur on wheal tread andflange due to wheel skidding and emergency breaking. Four type of wear may occur as follows:- Treadwear Root wear Skid wear and Flange wear For maintaining the required profile pit wheel latheare used. This lathe is installed in the pit so that wheel turning is without disassembling the axle and liftingthe loco and hence the name pit wheel lathe Wheel turning Wheel turning on this lathe is done byrotating the wheels, both wheels of an axle are placed on the four rollers, two for each wheel. Rollersrotate the wheel and a fixed turning tool is used for turning the wheel. Different gages are used in thissection tocheck the tread profile. Name of these gages are:- Star gage

47. 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 brakecylinder pressure (more than 2.5 kg/cm). Using dynamic braking at higher speeds. When at the timeof application of dynamic braking, the brakes of loco would have already been applied. (in case of failureof D-1 Pilot valve). Continue working , when C-3-W Distributor valve P/G handle is in wrong position. Due to shunting of coaches with loco without connecting their B.P./vacuum pipe. Shunting at higherspeeds. Continue working when any of the brake cylinder of loco has gotten jammed. The time ofapplication/release of brakes of any of the brake cylinder being larger than the others. When any of theaxle gets locked during on the line.

48. 11. FAILURE ANALYSIS INTRODUCTION A part or assembly is said to have failed under one ofthe three conditions:- When it becomes completely inoperable-occurs when the component breaks intotwo or more pieces.When it is still inoperable but is no longer able to perform its intended functionsatisfactorily- due to wearing and minor damages. When serious deterioration has made it unreliable orunsafe 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 willstudy about:- Metallurgical lab. Ultrasonic test Zyglo test and RDP test. Metallurgical lab.

49. Metallurgical lab. concern with the study of material composition and its properties. Specimens arechecked 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 themetal is tabulated in table below :- S.No. Compound Function 1. Phosphorous Increase the fluidityproperty 2. Graphite Increase machinability 3. Cementide Increase hardness 4. Chromium Used forcorrosion prevention 5. Nickel Used for heat resistance 6. Nitride rubber Oil resistance in touch of Oring 7. Neoprene Air resistance & oil resistance in fast coupling in rubber block. 8. Silicon Heat resistanceand wear resistance (upto 600 C ) use at top and bottom pore of liner. Swelling test Swelling test isperformed for rubber in this test percentage increase in weight of the rubber after immersing in solution ismeasured and increase in weight should not be more than 20%. Two type of swelling test viz low swellingand high swelling are performed in the lab. Three type of oil solution are used for this purpose listedbelow:- ASTM 1 ASTM 2 ASTM 3 Procedure 1. Select specimen for swelling test 1. Note theweight of the specimen 2. Put in the vessel containing ASTM 1 or ASTM 3 3. Put the oven at 100 C 4.Put the vessel in the oven for 72 hrs.

50. 5. After 72 hrs. Weigh the specimen. Rubber Broadly there are two types of rubber: 1). Naturalrubber- this has very limited applications. It is used in windows and has a life of 1 year. 2). Syntheticrubber- this is further subdivided into five types. 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 inoily or watery area, neoprene is used in areas surrounded by oil and air while betel and silicone are used inareas subjected to high temperatures 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, whichare subjected to the vapors of the rubber under test and then the color change in solution is used fordetermination of the type of rubber. The various color changes are as follows: Violet- natural rubber Pink- nit rile Green-SBR When no color change is observed the vapours are passed through solution 2.The colour change in solution 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, veryshort ultrasonic pulse-waves with center frequencies ranging from 0.1-15 MHz and occasionally up to 50MHz are launched into materials to detect internal flaws or to characterize materials.

51. Ultrasonic testing is often performed on steel and other metals and alloys, though it can also be usedon concrete, wood and composites, albeit with less resolution. It is a form of non-destructive testing.ZYGLO TEST The zyglo test is a nondestructive testing (NTD) method that helps to locate and idetifysurface defects in order to screen out potential failure-producing defects. It is quick and accqurate processfor locating surface flaws such as shrinkage cracks, porosity, cold shuts, fatigue cracks, grinding cracksetc. 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. Step2 apply penetrant Step 3 remove penetrant Step 4 dry parts Step 5 apply developer Step6 inspection RED DYE PENETRATION TEST (RDP) Dye penetrant inspection (DPI), also calledliquid penetrant inspection (LPI), is a widely applied and low-cost inspection method used to locatesurface- breaking defects in all non-porous materials (metals, plastics, or ceramics). Penetrant may beapplied to all non-ferrous materials, but for inspection of ferrous components magnetic particle inspectionis preferred for its subsurface detection capability. LPI is used to detect casting and forging defects,cracks, and leaks in new products, and fatigue cracks on in-service components. Principles DPI is basedupon capillary action, where low surface tension fluid penetrates into clean and dry surface-breakingdiscontinuities. Penetrant may be applied to the test component by dipping, spraying, or brushing. Afteradequate penetration time has been allowed, the excess penetrant is removed, a developer is applied. Thedeveloper helps to draw penetrant out of the flaw where a visible indication becomes visible to theinspector.

52. 12. SCHEDULE EXAMINATION INTRODUCTION The railway traffic requires safety andreliability of service of all railway vehicles. Suitable technical systems and working methods adapted to it,which meet the requirements on safety and good order of traffic should be maintained. For detection ofdefects, non-destructive testing methods - which should be quick, reliable and cost-effective - are mostoften used. Inspection of characteristic parts is carried out periodically in accordance with internalstandards or regulations; inspections may be both regular and extraordinary; the latter should be carriedout after collisions, derailment or grazing of railway vehicles. Maintenance of railway vehicles isscheduled in accordance with periodic inspections and regular repairs. Inspections and repairs areprescribed according to the criteria of operational life, limited by the time of operation of a locomotive intraffic or according to the criteria of operational life including the path traveled. For the properfunctioning of diesel shed and to reduce the number of failures of diesel locos, there is a fixed plan forevery loco, at the end of which the loco is checked and repaired. This process is called scheduling. Thereare two types of schedules which are as follows:- Major schedules Minor schedule

53. MINOR SCHEDULES Schedule is done by the technicians when the loco enters the shed. After15 days there is a minor schedule. The following steps are done every minor schedule & known asSUPER CHECKING. The lube oil level & pressure in the sump is checked. The coolant water level& pressure in the reservoir is checked. The joints of pipes & fittings are checked for leakage. Thecheck super charger, compressor &its working. The engine is checked thoroughly for the abnormalsounds if there is any. F.I.P. is checked properly by adjusting different rack movements. This processshould be done nearly four hour only. After this the engine is sent in the mail/goods running repairs forrepairs. There are following types of minor schedules:- T-1 SHEDULE AFTER 15 DAYS T-2SHEDULE AFTER 30 DAYS T-1 SHEDULE AFTER 45 DAYS M-2 SHEDULE AFTER 60DAYS T-1 SHEDULE AFTER 75 DAYS T-2 SHEDULE AFTER 90 DAYS T-1 SHEDULEAFTER 105 DAYS TRIP-1 Fuel oil & lube check. Expressor discharge valve. Flexible couplingsbubbles. Turbo run down test. Record condition of wheels by star gauge. Record oil level in theaxle caps for suspension bearing. TRIP-2 All the valves of the expressor are checked. Primary andsecondary fuel oil filters are checked. Turbo super charger is checked. Under frame are checked.

54. Lube oil of under frame checked. MONTHLY-2 SEHEDULE All the works done in T-2schedule. All cylinder head valve loch check. Sump examination. Main bearing temperaturechecked. Expressor valve checked. Wick pad changed. Lube oil filter changed. Strainer cleaned. Expressor oil changed. MAJOR SCHEDULES These schedules include M-4, M-8 M-12 and M-24. TheM-4 schedule is carried out for 4 months and repeated after 20 months. The M-8 schedule is carried outfor 8 months and repeated after 16 months. The M-12 is an annual schedule whereas the M-24 is twoyears. Besides all of these schedules for the works that are not handled by the schedules there is an out ofcourse section, which performs woks that are found in inspection and are necessary. As any Locomotivearrives in the running section first of all the driver diary is checked which contains information about thelocomotive parameters and problem faced during operation. The parameters are Booster air pressure(BAP), Fuel oil pressure (FOP), Lubricating oil pressure (LOP) and Lubricating oil consumption (LOC).After getting an idea of the initial problems from the drivers diary the T-1 schedule is made for inspectionand minor repairs.

55. M-4 Schedule (1). Run engine; check operation of air system safety valves and expressor crankcaselube oil pressure. (2). Stop engine; carry out dry run operational test, check FIP timing and uniformity ofrack setting and correct if necessary. (3). Engine cylinder head:-Tighten all air and exhaust elbow bolts,check valve clearance, exhaust manifold elbow etc. (4). Engine crankcase cover:-Remove crankcase coverand check for any foreign material. Renew gaskets. (5). Clean Strainer and filters, replace paper elements.(6). Compressed air and vacuum system:-Check, clean and recondition rings, piston, Intake strainers, andinlet and exhaust valve, lube oil relief valve, unloading valve. Drain, clean and refill crankcase. (7).Radiator fan- tightens bolts and top up oil if necessary. (8). Roller bearing axle boxes.Check for loosebolts, loss of grease, sign of overheating. Remove covers, clean and examine roller races and cages fordefects. Carry out ultrasonic test of axles. (9). Clean cyclonic filters, bag filters and check the condition ofrubber bellows of air intake system. (10). Renew airflow indicator valve. (11). Carry out blow bye test andgauge wheel wears.

56. 13.YEARLY/MECHANICAL In this section, major schedules such as M-24, M48 and M-72 arecarried out. Here, complete overhauling of the locomotives is done and all the parts are sent to therespective section and new parts are installed after which load test is done to check proper working of theparts. The work done in these sections are as follows: 1). Repeating of all items of trip, quarterly andmonthly schedule. 2). Testing of all valves of vacuum/compressed air system. Repair if necessary.

57. 3). Replacement of coalesce element of air dryer. (4). Reconditioning, calibration and checking oftiming of FIP is done. Injector is overhauled. (5). Cleaning of Bull gear and overhauling of gear-case isdone. (6). RDP testing of radiator fan, greasing of bearing, checking of shaft and keyway. Examination ofcoupling 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). Examinationof piston for cracks, renew bearing shell of connecting rod fitment. Checking of connecting rodelongation. (9). Checking of crankshaft thrust and deflection. Shims are added if deflection is more thenthe tolerance limit. (10). Main bearing is discarded if it has embedded dust, gives evidence of fatiguefailure or is weared. (11). Checking of cracks in water header and elbow. Install new gaskets in the airintake manifold. Overhauling of exhaust manifold is done. (12). Checking of cracks in crankcase, lube oilheader, jumper and tube leakage in lube oil cooler. Replace or dummy of tubes is done. (13). Lube oilsystem- 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 andsecondary filters. (15). Checking of rack setting, governor to rack linkage, fuel oil high-pressure line isdone. (16). Cooling water system- draining of the cooling water from system and cleaning with new watercarrying 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.

58. (17). Complete overhauling of water pump is done. Checking of impeller shaft for wear andlubrication of ball bearing. Water and oil seal renewal. (18). Complete overhauling ofexpressor/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 theturbine/impeller is done. Also, hydraulic test of complete Turbo supercharger is done. (20). Overhaulingof after-cooler is done. Telltale hole is checked for water leak. (21). Inspection of the crankcase covergasket and diaphragm is done. It is renewed if necessary. (22). Rear T/Motor blower bearing are checkedand changed. Greasing of bearing is done. (23). Cyclonic filter rubber bellows and rubber hoses arechanged. Air intake filter and vacuum oil bath filter are cleaned and oiled. (24). Radiators arereconditioned, 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 loadingpads 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 ofslack adjusters is done. Inspection for fatigue, crack and distortion of center buffers couplers, side buffersare done. (30). Traction motor suspension bearing- cleaning of wick assembly, checking of wear in motornose suspension. Correct fitment of felt wick lubricators is

59. ensured. Axle boxes are refilled with fresh oil. Testing of all pressure vessels is carried out.Examination while Engine is running. (32). Expressor orifice test is performed. Engine over sped tripassembly operation, LWS operation are checked. Checking of following items is done: Water and oilleakage at telltale hole of water pump, turbo return pipes for leakage and crack, air system for leakage,fuel pump and pipes for leakage, exhaust manifold for leaks, engine lube oil pressure at idle, turbo forsmooth run down as engine is stopped. Difference in vacuum between vacuum reservoir pipe andexpressor crankcase & and pressure difference across lube oil filters at idle and full engine speed arerecorded. (33). Brakes at all application positions are checked. Checking of fast and flexible coupling isdone and the expressor is properly aligned. Inspection of camshaft. Lubrication of hand brake lever andchain. (37). Speedometer- Overhaul, testing of speed recorder and indicator, pulse generator is done. (38).Additional items for WDP1:-Overhauling and operation of TBU is done, center pivot pin is checked, andCPP bush housing liners are checked for wear, inspection of vibration dampers for oil leakage and theiroperation. RDP test is done to check for cracks at critical location in the bogie frame. Checking of coilsprings for free height. (39). Additional items for WDP2 locos:-Checking for cracks bogie frame andbolster. Checking of hydraulic dampers for oil leakage. Check coil spring for free height. Zyglo test ofguide link bolts is performed. Examination of taper roller bearing for their condition and clearance isdone. Check and change center pivot liners. Checking of tightness of nuts on brake head pin. Disassembly,cleaning, greasing, repairing, replacement of brake cylinder parts is done. Ultrasonic test of axles isperformed. Visual Examination of suspension springs for crack and breakage. Checking of free andworking height of spring. Inspection of bull gear for any visible damage is done and the teeth profile ischecked. Test loco on load box as per RDSO standards.

60. PROJECT STUDY Project title :- To study about turbo supercharger of locomotiveTURBOSUPERCHARGERS A turbosupercharger, or turbo, is a gas compressor that is used for forced-induction of an internal combustion engine. It increases the density of air entering the engine to createmore power. A turbosupercharger has the compressor powered by a turbine, driven by the engine's ownexhaust gases. The turbine and compressor are mounted on a shared shaft. The turbine converts exhaustheat and pressure to rotational force, which is in turn used to drive the compressor. The compressor drawsin ambient air and pumps it in to the intake manifold at increased pressure, resulting in a greater mass ofair entering the cylinders on each intake stroke. Turbosupercharging dramatically improves the engine'sspecific power, power- to-weight ratio and performance characteristics which are normally poor in non-turbosupercharged diesel engines. TURBOS USED IN DIESEL LOCOMOTIVE In diesel locomotives,different turbos are used for different engines on the basis of their horsepower and make. Still, theirgeneral function remains the same i.e. to provide compressed air to the engine by employing the energy ofexhaust gases. The exhaust manifold is connected to the inlet of the turbocharger. The exhaust gases enterthe gas inlet casing where they are directed towards the nozzle ring. The function of the nozzle ring is toguide the exhaust gases and reduce shock on the turbine blades. The exhaust gases

61. impinge on the turbine blades and cause the turbine to rotate on their way out to the atmospherethrough the chimney. The rotating turbine causes the impeller of the compressor to rotate along with itsince they are mounted on the same shaft. The compressor starts sucking air through the air inlet casingand compresses it due to the centrifugal action of the impeller. After leaving the impeller, the air getscompressed further in the diffuser vanes. From here the compressed air is passed into the blower casing,which guides the air to an aftercooler. The function of the aftercooler is to cool the compressed air andconsequently reduce its specific volume. The pressure of this compressed air is in the range of 1.2-1.8kg/cm2, and this is known as BOOSTER AIR PRESSURE (BAP). This compressed air is then introducedinto the air gallery, which is connected to the intake valves of all the cylinders. Turbosuperchargers fromthe following manufacturers are used in diesel locomotives: ABB ALCO NAPIER GENERALELECTRIC (GE) HISPANO SUIZA ELGI COMPARISON OF DIFFERENT TURBO MAKES Thespecifications of the turbos used in diesel locomotives are as follows: 1. ALCO-2600 Power Rating: 2600HP Cooling System: Water Cooled Rundown Time: 80-190 seconds

62. 2. ABB-2300 Power Rating: 2300 HP Cooling System: Water Cooled Rundown Time: 60-120seconds 3. ABB-2600 Power Rating: 2600 HP Cooling System: Water Cooled Rundown Time: 60-120seconds 4. ABB-3100 Power Rating: 3100 HP Cooling System: Water Cooled Rundown Time: 60-120seconds 5. ABB-TPR 61 Power Rating: 3300 HP Cooling System: Air Cooled Rundown Time: 60-120seconds 6. NAPIER-2300 Power Rating: 2300 HP Cooling System: Water Cooled

63. Rundown Time: 20-60 seconds 7. NAPIER-2600 Power Rating: 2600 HP Cooling System: WaterCooled Rundown Time: 20-60 seconds 8. NAPIER-3100 Power Rating: 3100 HP Cooling System: Water

Cooled Rundown Time: 20-60 seconds 9. GE-3100 SINGLE DISCHARGE Power Rating: 3100 HPCooling System: Water Cooled 10. GE-3100 DOUBLE DISCHARGE Power Rating: 3100 HP CoolingSystem: Water Cooled *Has two outlets for air in the blower casing and hence uses two aftercoolers.

64. 11. HISPANO SUIZA-3100 Power Rating: 3100 HP Cooling System: Air Cooled 12. ELGI PowerRating: 4000 HP ALCO FRONT VIEW

65. ALCO TOP VIEW

66. ALCO ASSEMBLY GE (DOUBLE DISCHARGE) FRONT VIEW

67. GE (DOUBLE DISCHARGE) TOP VIEW GE (DOUBLE DISCHARGE) BOTTOM VIEW

68. GE (DOUBLE DISCHARGE) ASSEMBLY TURBO OPERATING DIFFICULTIES: Operatingdifficulties can be prevented providing the daily turbocharger operating data is measured and regularmaintenance and inspection routines are adhered to. To assist in identifying causes of performancedeterioration, the following table has been formed: OPERATING DIFFICULTIES PROBABLE CAUSEREMEDIAL MEASURES Engine starts running but the turbocharger does not. Foreign matter/debriscaught between the turbine blade tips and the shroud ring. Blade tips rubbing the shroud ring. BearingDisorder Provide cleaning and eliminate the cause for the ingress of the foreign matter. Inspect andreplace with new bearing.

69. Turbocharger experiences surging during operating. Fouling of turbine nozzle, blades. EngineCylinder unbalance. Note: Rapid Changes of the engine load, particularly during shut-down can causeturbocharger surging. Cleaning of the turbine side of turbocharger as required. Refer to Engine BuildersInstruction Manual. Exhaust gas temperature higher than normal. Fouling or damage to turbine nozzle orturbine blades. Lack of air e.g.: dirty air filter. Exhaust back pressure too high. Charge air cooler dirty,cooling water temperature too high. Engine fault in fuel injection system. Cleaning the turbine side of theturbocharger or component replacement. Clean as required. Investigate cause. Clean and adjust as MakersInstruction Manual. Charge air (boost) pressure lower than normal. Pressure gauge faulty or connection toit is leaking. Gas leakage at engine exhaust manifold. Dirty Air filter, causing pressure drop. Dirtyturbocharger. Turbine blades or nozzle ring damage. Rectify. See Engine Builders Instruction Manual.Clean air as required. Cleaning of complete turbocharger required. Inspect and replace as necessary.Charge air pressure (boost) higher than normal. Pressure gauge reading incorrectly. Nozzle ring cloggedwith carbon deposits. Rectify. Clean as required.

70. TURBO OVERHAULING The overhauling and servicing of a turbosupercharger is broadly dividedinto five parts which are: Dismantling of the turbo Cleaning of the turbo Inspection of differentparts Repair and rotor balancing Assembly of the turbo Engine Overload, engine output higher thanexpected. Fault in engine fuel injection system. Consult Engine Builders Instruction Manual. ConsultEngine Builders Instruction Manual. Turbocharger Vibration Severe unbalance of rotor due to dirt ordamaged turbine blades. Bent rotor shaft. Defective bearings. Rebalance the rotor assembly. Inspect andreplace as necessary. Inspect and replace as necessary.

71. DISMANTLING OF THE TURBO Dismantling of a turbo requires trained personnel and special tools(allen keys, spanners, suspension yoke, support, etc). It is a complicated process and should be done verycarefully after referring to the manufacturers instruction manual. CLEANING OF THE TURBOCleaning work includes regular visual checks and the cleaning of parts to ensure the correct functioning ofthe turbo.

72. Outline of cleaning work

73. The following figure explains the various symbols used in the previous figure:

74. GAS CASING: Deposits often form on the nozzle ring and the turbine blades. Impaired efficiency andperformance of the engine are the result. Thick and irregular deposits can also result in an un-permissibleunbalance of the rotor. Cleaning of the cooling water passage of gas outlet casing: Commercial HCL of5% concentration is used for cleaning and defurring. An inhibitor is added to reduce the corrosion of castiron. Neutralisation with 5% NaOH (alkaline) solution follows the acid wash. Fresh water is used foeflushing/rinsing. All casing gaskets are replaced. Gas inlet casing: Deposits are cleaned with soft wirebrush and with either diesel/kerosene + 20% mineral oil solution (80/20 solution). BEARING CASING:Cleaning of the sealing air ducts: The carbon deposits are dissolved and cleaning is done with the help offlexible wire for ensuring free passage. Compressed air is used to check that the sealing air ducts in thebearing casing are unobstructed / unchoked. Oil Passages: It is cleaned with 80% kerosene/diesel + 20%mineral oil solution (i.e. 80/20 solution).

75. AIR OUTLET CASING: The deposits are cleaned with soft wire brush and 80/20 solution. ROTOR

PARTS: The turbine blades can be cleaned by glass bead blasting. The seating areas for compressor wheelset, thrust bearing and floating bushes (Bearing compressor side + Turbine side) are protected by means ofrubber sleeve. The cleaning of the compressor wheel set is carried out with 80/20 solution and thereforewith malmal (piece of cloth). Rotating parts are thoroughly cleaned uniformly as uneven residual depositslead to unbalance. BEARING PARTS: All bearing parts, bearing covers are cleaned in 80/20 solution andwith malmal (piece of cloth). Special care is taken to clean the carbon deposits from the O ring groovesand the oil supply/oil drain lines. INSPECTION OF THE TURBO: After dismantling and cleaning of theturbo, it is inspected for any faults. All the clearances and blade conditions are checked and a note of allthe repair work needed is made.

76. REPAIR AND BALANCING OF ROTOR: Various parts of the turbo are repaired as necessary. Therotor is examined carefully and any distorted turbine blade is ground with a grinder so that it is smoothagain. The rotor is then checked if it is unbalanced and is balanced on a Rotor Balancing Machine ifneeded. In the course of manufacture, following parts are balanced individually: Shaft Sets of compressorwheel While the engine is running, many reasons may cause unbalance to the rotor: Mechanical damageson the rotor, i.e. foreign bodies. Uneven deposits of layer of dirt/carbon. Abrasion on the compressor orthe turbine caused by hard particles in the intake air or in the exhaust gas. Balancing must be done when:Rotating components feature mechanical damages. After reblading of turbine. After repairs on the induceror compressor wheel. After replacing the inducer or compressor wheel. Balancing is not required when: Anew bladed shaft is assembled into the turbocharger. If, due to a change of specification, the set of wheelshas to be changed for a new one.

77. ABRO ROTOR BALNCING MACHINE GE ROTOR ON BALANCING MACHINE

78. TURBO RUNDOWN TIME The Turbo Rundown Time (TRD) of a turbo is the total time taken by theturbo to come to a standstill, measured from the instant the crankshaft of the engine stops. This timeshould be within a certain limit prescribed by the manufacturer. If not so, it indicates a fault in the turbo.The rundown times of different turbos have been mentioned earlier. Turbo Rundown Test (for WDM-2Loco) This test is to be conducted if the Booster (Turbocharger in WDM-2 pidgin) is not developingproper pressure during a run. 1. Secure the loco: Keep the A9 (Train Brake lever) in released condition;keep the SA9 (Loco brake lever) in an applied condition; switch off the GF (Generator Field); keep thereverser in neutral condition; and put the ECS (Engine control switch) in the run mode. 2. Ensure that thewater temperature is higher than 49 degrees Celsius. 3. The driver should climb on top of the hood andsight the turbine of the turbocharger through the chimney. 4. The assistant should raise the engine to 4thnotch rpm and allow the engine to stabilize in speed. 5. The assistant should now shut the engine down byoperating the MUSD (Multiple Unit Shut Down) breaker on the control stand. 6. As the engine begins tostop turning, the assistant must quickly get down and come to the hood door to the Expressor.

79. 7. He must give a signal to the driver as to the instant the huge engine stops rotating by looking at thecrankshaft of the engine coupled to the expressor. 8. The driver must count the number of seconds theexhaust turbine takes to come to a stop, from the instant the engine has come to a standstill. 9. If theturbine (which revolves at 18,000 to 19,000 rpm) takes more than 90 seconds then it is a goodturbocharger, any reduction in the period of spinning down is an indication of a faulty turbo.|~|REFERENCES: I.R.I.M.E.E, JAMALPUR R.D.S.O, LUCKNOW TKD SHED LIBRARY INTERNET

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