MJR MSE lll DSL Book PDF

 ,u ,l ifV;ky उत्‍तर ‍श्चिम ‍र ल वेल, अज लर North Western Railway Ajmer funs ' kd] ,lVhlh] vtes j Rly. (O). 44550, BSNL (O). Tel/FAX: 0145-242...

 ,u ,l ifV;ky उत्‍तर ‍श्चिम ‍र ल वेल, अज लर North Western Railway Ajmer funs ' kd] ,lVhlh] vtes j Rly. (O). 44550, BSNL (O). Tel/FAX: 0145-2429498 N.S Patiyal Director, STC Ajmer E-mail: [email protected] Mob: 9001196582 FOREWORD Mechanical Department is most responsible towards Safety of Railways. In this regard, Railway Board framed Training Module for Direct Recruited trainee Supervisors, who are required systematic and gravitational knowledge of their field as they are the backbone of Mechanical Department. STC/Ajmer plays a vital role in imparting qualitative & effective theoretical & practical training to develop their professional aptitude. The main thrust of this book is application oriented with the appropriate theoretical inputs and trainee can develop self-reliance in training and taking problems in their work related field. I am pleased that STC Ajmer is constantly publishing course books as per module prescribed by Railway Board. We take an opportunity with the inspiration of our CWE, Shri Sudhir Gupta to present a course book for trainee MSE/MJR (Diesel) of IIIrd Session separately. The object of this book is to present the subject matter prescribed by Railway Board module in a most concise, compact and in lucid manner. I would like to thank our Hon’ble PCME, Shri Virendra Kumar for their benevolent guidance in this regard. I acknowledge and appreciate sincere efforts done by our experienced faculty Shri Prakash Kewalramani in bringing out this book. I would like to express thanks to Shri Amar C. Gaharwal Sr. Instructor, Shri Surendra Tak, Chief Typist and Smt. Manisha Khandey, PS as chief coordinator of this edition. Any errors, omissions and suggestions for the improvement of this book brought to our notice will be gratefully acknowledged and incorporated in the next edition. (N.S PATIYAL) Director, STC AII NWR  INDEX PAGE NO. SR. NO. DESCRIPTION From To 1. Diesel Locomotive-Introduction 1 2 2. Transmission System of Diesel Locomotives 3 4 3. Constructional Details of Diesel Locomotives 5 18 4. Lube Oil System of Diesel Locomotives (ALCO) 19 24 5. Fuel Oil System of Diesel Locomotives (ALCO) 25 29 6. Water Cooling System of Diesel Locomotives (ALCO) 30 34 7. Turbo-Supercharger 35 39 8. Air Compressor 40 47 9. Brake System of Diesel Locomotives 48 55 10. Bogie of ALCO Loco 56 60 11. Safety Devices in ALCO Loco 61 62 12. Rotating Equipments 63 67 13. Excitation System 68 69 14. Transition System 70 73 15. Dynamic Braking 74 77 16. Control System 78 83 17. Load Box Testing 84 89 18. Traction Motor 90 91 19. Microprocessor Control System 92 98 20. New Developments in Diesel Locomotives 99 101 21. Shed Layout 102 107 22. GM / EMD Locomotive 108 111 23. General Engine Arrangement 112 115 24. Lubricating Oil System of Diesel Locomotive (GM Loco) 116 117 25. Cooling System of Diesel Locomotive (GM Loco) 118 118 26. Fuel Oil System of Diesel Locomotive (GM Loco) 119 120 27. Compressed Air System 121 122 28. Difference Between WDG4 And WDP4 GM Locomotives 123 123 29. HTSC Bogie (High Tensile Steel Cast) 124 128 30. Electrical System 129 129 31. EM 2000 Computer 130 130 32. Rotating Equipment 131 135 33. Computer Controlled Brake System 136 140  DIESEL LOCOMOTIVE INTRODUCTION A diesel engine can be either two-stroke or four-stroke and, except for its ignition, is much like any other internal combustion engine. It is one of three types--V, vertical in-line, or horizontal--depending on the arrangement of its cylinders. The fuel system includes the fuel tank, fuel and ignition pumps, filters, injection nozzle, and emergency fuel cut-off valve. The fuel tank has baffle plates to prevent surging and a pit to catch sediment so that it can be drained out. In some locomotives, the fuel tank is above the pump and fuel enters the pump by gravity. In others, fuel is pumped from the tank into the main pump by an auxiliary pump. The fuel pump creates the injection pressure and determines the amount of fuel injected into the cylinders by the injectors. In an engine with a water-cooling system, water is run through water jackets between the cylinders and cylinder liners. The water is directed through a radiator to cool it. Louvers on the front of the radiator can be opened and closed to regulate the heat escaping from it. Occasionally, an engine is designed so that the pistons are cooled also by their lubricating oil. When this is done, a special oil radiator, with its own cooling fan, is provided in addition to the water cooling radiator. Lubricating oil should have some detergent properties so that contaminating materials can be kept in suspension and filtered out by strainers made of gauze, steel wool, or closely spaced plates. Brakes for a locomotive can be the kind that controls the locomotive, the train, or both. Air pressure for the brakes is supplied by a compressor. The weight of the locomotive is carried by the trucks, which also absorb lateral thrusts and oppose the tilting tendency. A truck is made of frames, wheels, axles, journals and journal boxes, bolsters, springs, bearings, and brake rigging. Most locomotives are equipped with chains to limit the swing of the trucks in case of derailment. Locomotives larger than 40 tons use four-wheel rigid trucks, four wheel swing bolster trucks, or six-wheel swing bolster trucks. Accessories supported by the locomotive engine include a bell, horn, speed recorder, wipers, sanding system, temperature controls, and engine and cab heaters. Measures of electrical pressure, resistance, and quantity are called volts, ohms, and amperes. A volt is the unit of pressure leaving the generator or battery; an ohm is a unit of resistance; and an ampere is the unit used to measure power available to the receiving mechanism, such as one of the traction motors. Ohm's law states the relationship between these: current equals to voltage divided by resistance. Voltage is measured by a voltmeter and amperage by an ammeter. Wiring diagrams, using lines and standardized symbols and abbreviations, are used in tracing circuits and locating troubles on diesel-electric locomotives. Wiring in the electric system is built to carry a specific load of current; current heavier than that specified is called an overload. Since an overload in the wiring can harm equipment, fuses and circuit breakers are provided to break the circuit before damage occurs. Mechanical energy can be changed into electrical energy, or electrical into mechanical, by a dynamo. If the mechanical energy is changed into electrical, the dynamo is called a generator; if the electrical energy is changed into mechanical, the dynamo is a motor. A generator can be either the alternating current or the direct - current type. Current is set up in the generator's armature coil whenever the coil cuts across the lines of magnetic force between the generator's poles. With an alternating-current generator, the current flows through the coil first in one direction then the other unless the generator has a commutator to turn the alternating current into a direct current. If a generator has many coils, connected to form a closed circuit, a direct current is supplied. Direct current generator coils can be connected in series, in shunt, or in a combination of series and shunt. Like a generator, a motor can also be connected in shunt or in series. Mechanical transmission is not preferable/suitable in locomotive because of the locomotive's size and weight, gears large enough to control it would be too large and bulky to be practical. Mechanical gear transmission of power to the wheels is therefore replaced by electrical transmission. To change the mechanical force from the engine into electrical power, an alternator is operated by the engine's crankshaft. The output of the alternator is rectified with the help of static rectifiers and cables transmit the power to traction motors and the traction motors turn the wheels. Traction motors are series-wound, direct current motors and are provided with a shunt. Their function is to convert electrical energy from the generator into mechanical force to turn the locomotive wheels. Electrical circuits in the locomotive are connected in series, in parallel, or in series- parallel, a combination of the two. Circuits are opened and closed by contactors, operated either by compressed air in heavy circuits, or by current from the battery in circuits where the current is low. Auxiliary switches to control the connecting or breakings of circuits are called interlocks. A relay is a device that changes connections in one part of a circuit in response to changes taking place in another part. Changing traction motors from series connection to series-parallel or parallel connection is known as transition. It can be done by connecting the motors in parallel or by shunting off part of the current drawn into the circuit, forcing more current to be drawn from the generator. A traction motor cut out switch is used to take the motors out of circuit if there is an electrical failure. In dynamic braking, the locomotive's wheels are used to drive the traction motors, which acting like generators, slow the locomotive's speed without causing wear of the wheels. When brakes are applied, a pneumatic switch stops the engine, stops the fuel pump, and turns on indicating lights. ****************  TRANSMISSION SYSTEM OF DIESEL LOCOMOTIVES A diesel locomotive must fulfil the following essential requirements- 1. It should be able to move a heavy load and hence should exert a very high starting torque at the axles. 2. It should be able to cover a very wide speed range. 3. It should be able to run in either direction with ease. Further, the diesel engine has the following drawbacks:  It cannot start on its own.  To start the engine, it has to be cranked at a particular speed, known as a starting speed.  Once the engine is started, it cannot be kept running below a certain speed known as the lower critical speed (normally 35-40% of the rated speed). Low critical speed means that speed at which the engine can keep itself running along with its auxiliaries and accessories without smoke and vibrations.  The engine cannot be allowed to run above a certain speed known as high critical speed. It is 112 to 115% of rated speed. The high critical speed is the speed at which the engine can keep itself running without damaging itself due to thermal loading, and centrifugal forces.  It is a constant torque engine for a particular fuel setting irrespective of its speed. It can develop rated power at rated speed and fuel setting only.  It is unidirectional.  To de-clutch power, the engine has to be shut down, or a separate mechanism has to be introduced. To satisfy the above operating requirements of the locomotive, it becomes necessary to introduce an inter-mediate device between the diesel engine and the locomotive wheels. This device, called transmission, should accept whatever the diesel engine gives, with all its limitations mentioned above and be able to feed the axles in such a way that the locomotive fulfils the essential requirements. FUNCTIONS OF AN IDEAL TRANSMISSION  It should be able to multiply the torque and reduce the speed to such a level that the train can be started without a jerk.  Once the train has started, it should decrease the torque and increase the speed as required, automatically.  The torque & speed characteristics should be verified uniformly throughout the traction depending upon the road requirements, so that the power transmission is jerk free.  It should be capable of reversing the power transmission easily, with identical torque & speed characteristics in both the directions.  It should be light, robust, and should occupy very little space.  It should be reliable and ask for minimum maintenance.  It should be approachable easily for maintenance and ask for minimum nos. of consumable.  It should not transmit road shocks and vibrations to the engine.  It should have good efficiency, good utilisation factor, and good degree of transmission.  It should be capable of starting the engine, if required.  It should be able to apply brakes, if required. Keeping in mind the above requirements, following transmission systems are used in diesel locomotives: a) Hydraulic transmission b) Electrical transmission Hydraulic Transmission - In this, hydraulic torque converter act as a clutch and gear box combined into one with infinite gear ratio. The output torque can be varied infinitely from zero to more than engine torque. One side of the torque converter (impeller end) is connected to the engine and continuously rotates while other side (turbine end) is connected to wheel by suitable gear train. The hydraulic transmission attains peak efficiency at specific speed and fall steeply on either side of it. By multi-staging, high efficiency can be maintained in the entire working range. This transmission system has advantages of having very high starting torque at zero speed, uniform torque curve and high power to weight ratio. Hydraulic transmission system is suitable for relatively low horse power and high speed engines. The transmission efficiency of this system is less than mechanical transmission system and only 70% of the engine speed can be achieved. Electrical Transmission - Most of the diesel loco-motives have electrical transmission system. In this, engine is permanently connected to generator/alternator. The output of the generator/alternator is fed to traction motors through a control circuit which varies the torque- speed relationship. The traction motors are directly mounted on the axles and rotates the axle through gear. The advantages of this system are that speed control is easy as current through motors is to be controlled for speed control of the locomotive, the system has low maintenance cost and separate reservoir is not required. Transmission efficiency of this system is higher than hydraulic transmission system but less than mechanical transmission system. However, this transmission system is heavier than hydraulic transmission system and not suitable for very high speed engines as compared to hydraulic transmission system. ****************  CONSTRUCTIONAL DETAILS OF A DIESEL LOCOMOTIVE A diesel locomotive consists of truck / bogie, loco chassis and superstructure. The bogies are of 4 or 6 wheel type depending on the horse power and overall length of the individual locomotive unit. The truck assemblies are made up of cast-steel or welded steel frame, axle- mounted traction motors, wheel brakes, axle suspension and springs. The construction may also provide for air duct to the motors for forced ventilation from a blower. The chassis of loco is robust steel structure fabricated of steel plates which supports and carry all the assemblies of super structure. Super structure of the locomotive can be divided into six main compartments: 1. Nose compartment 2. Driver's cab 3. Main Generator compartment 4. Engine room 5. Compressor compartment 6. Radiator fan compartment Nose Compartment - This compartment houses dynamic grid resistance, grid blower motor, sand box, panel mounted brake system, head light etc. Driver's Cab - Driver drives the locomotive from control stands on which air brake control valves, pressure gauges indicating lube oil, fuel oil & booster air pressure, mechanical & electrical speedometer and load meter etc. are provided. Main Generator Compartment - Traction generator, excitation gen., auxiliary generator and front traction motor blower are housed in this compartment. Engine Room - Diesel engine is kept in this compartment. Other important items of this compartment are after cooler, turbocharger, governor, fuel injection pump, fuel oil filter, lube oil filter, compressor spline coupling, extension shaft, lube oil pump and water pump. Compressor Compartment - Compressor is kept here. It produces compressed air which is used for braking purpose. Fuel booster pump and motor are also kept here. Radiator Compartment - Radiator compartment has two (left and right) radiator panels, lube oil cooler, radiator fan, right angle gear box for driving radiator fan, eddy current clutch which connects right angle gear box to diesel engine's extension shaft. Driver cabin end of the locomotive is known as Short Hood and the radiator room end is known as Long Hood. When the driver stands in the cabin facing the Nose compartment, his right hand side is the right hand side of the locomotive and the left hand side is the left hand side of the locomotive. Generator room end of the engine block is called Power take off end and the Compressor Room end of the engine block is called Free End. Parts List: DIESEL LOCOMOTIVE: POWER PACK AND ITS COMPONENTS Diesel engine of the diesel locomotive is also known as power pack. ALCO locomotive Engine has following major components: 1. Engine base 2. Engine block 3. Crank shaft 4. Cam shaft 5. Cylinder head 6. Valves 7. Piston 8. Piston rings 9. Cylinder liner 10. Connecting rod 11. Exhaust manifold 12. Governor (WW/MCBG) 13. Turbo supercharger 14. After-cooler assembly 15. Fuel injection Pumps & injectors 16. Lube oil pump 17. Water pump Assembly Engine Base - The engine base is a welded steel structure which provides the following: a mounting surface for the cylinder block, lubricating oil pump, water pump and four ending mounting pads: in addition it acts as a lubricating oil reservoir. Screens are fitted across the base at each cylinder location. Openings on each side of the base give access to the connecting rod bearings, crankshaft and main bearings; provides means for inspecting oil lines, piston skirts and cylinder liners. Removable doors enclose these openings. Also explosion doors are mounted on the right and left side of the base at the power take-off end Lubricating oil is carried in the base below the base screens. A lubricating oil drain plug, bayonet gauge with high and low level markings and a filler pipe are located in the base. A crankcase exhauster is used to vent the base. The engine base of the locomotive is made from weldable quality steel having 0.2% carbon. The engine base has following functions:- - To support the locomotive - To serve as oil sump - To take lube oil and water pump - To transmit load to chassis - To allow openings for crank case inspection. Foundation pads are provided for transmitting load to the chassis and also to take lower bolts of the main generator magnet frame. Engine Block - The engine block is the most important and highly stressed structure on which a number of important fittings like crank shaft, cam shaft, cylinder heads, cylinder liners, fuel injection pump, cross head, turbo support, governor etc. are fitted. Like engine base, this structure is also fabricated from low carbon steel. The cylinder block, constructed from steel weldments, houses and supports the major components of the engine: crankshaft and main bearings, camshaft, pushrods and lifters, connecting rods and pistons, cylinder liners, cylinder heads, crankcase exhauster, fuel pump crossheads and levers, and governor. It also provides mounting surfaces for the turbo supercharger support, exhaust manifold, air intake elbows, water elbows, and generator. A replaceable liner sleeve is fitted into the lower liner bore of the cylinder block. It provides a wear surface for the lower fit of the liner. On salvaged blocks, a replaceable upper liner sleeve, with an "O‖ ring (the same type used in the upper portion of the cylinder liner itself), is also fitted into the re-bored upper liner bore. Dimensions of the liner bore, without the upper sleeves. The crankshaft main bearing saddles, camshaft bearing supports, and the air intake manifold are integral parts of the block. Cooling water, circulated by the water pump, flows through the oil cooler, into a passage in the cylinder block. There, it circulates around the cylinder liners. Water from the block is conducted to the cylinder heads by water jumpers. Crank Shaft - The engine crank shaft is probably the singular costliest item of the locomotive. It is the medium of transforming reciprocating motion to rotary motion. The crank shaft may be assembled type or two piece bolted type or maybe a single piece forging. ALCO locomotive crank shafts are made of forged steel alloy, with its main bearing journals and crankpins machined to a high degree of smoothness. The shaft is slung under cylinder block and rotates on the main bearings (shells). It is supported by the bearing caps that are mounted to the saddles in the block with the stud bolts and nuts. The crank shaft for the 12 and 16 cylinder "V" type engines is made of one piece of forged steel alloy, with its main bearing journals and crankpins machined to a high degree of smoothness. The shaft is slung under the cylinder block and rotates on the main bearings (shells), it is supported by bearings caps that are mounted to saddles in the block with stud bolts and nuts. The shaft's main bearings and crankpins are joined by a series of crankshaft webs, to which counterbalances are welded at intermittent locations for balancing purposes. Two rods (right and left bank of the same cylinder number) are mounted side by side on each of the shaft's crankpins. The shaft is designed so that every two symmetrically opposite pins have the same radial throw position. A crankshaft gear, which drives the left and right camshaft gears, is applied to the power take-off end of the shaft. The free end of the shaft provides the drive for the engine's cooling water and lubricating oil pumps. The crankshaft forms an integral part of the engine's lubricating system. A continuous flow of oil passes under pressure from the main lubricating header in the engine's base to the bearing caps and bearings; through drilled passages in the shaft to the crankpins; and on the connecting rod bearings oil slingers and catchers are provided at both ends of the shaft to prevent oil leakage. The crankshaft end thrust is restricted by the use of either: (a) individual installed in both sides of the center main bearings saddle an upper main thrust bearing shell or upper and lower main bearing thrust shells located at the journal nearest to the power take-off end of the shaft. All shells, thrust or otherwise, are of the lead-tin overlay type and are suitably strengthened by a steel backing. Engine Crank shaft mounted on V-blocks Cam Shaft - In diesel engine, the cam shaft performs the vital role of opening and closing inlet and exhaust valves and allowing timely injection of fuel in-side the cylinder. There are three cam lobs for each cylinder for operating inlet valve, fuel injection pump & exhaust valve respectively. ALCO cam shafts are made of steel having carbon content between 0.48 to 0.58%.The camshaft on ―V‖ type engine is located on either side of the cylinder block and extends the entire length of the engine. The camshaft is divided into sections one for every two cylinders and is joined at the section flanges by studs or stud bolts and nuts. A locating dowel is used to position each section. These shaft assemblies are completely inter changeable when complete, but sections of the two design cannot be inter-mixed because of different end fastening methods. The camshaft rotates on bearings which are pressed into supports in the cylinder block. Lubrication is delivered to the bearing through an oil hole which runs the length of the camshaft. This hole feeds oil into smaller holes, located at each bearing journal. Each section of the camshaft has three integral cams for each cylinder. As the rollers for the fuel pump crosshead and valve pushrod lifters ride on the cams, the rotation of the camshaft actuates the engine's inlet and exhaust valves and fuel pumps.  CAMSHAFT SEGMANT Cylinder Head – The cylinder head is held on the cylinder liner by seven hold down studs provided on the cylinder block. It is subjected to very high shock stress and combustion temperature at the lower face which forms a part of the combustion chamber face. It is a complicated steel casting where cooling passages are cored for the purpose of cooling the cylinder head in addition to this provision is made for space for passage of inlet air and outlet gas. Further, space has to be left for fuel injection nozzles, valve guides and valve seat inserts. The cylinder shown head is secured to the cylinder block by seven studs. Individual water jumpers from the cylinder block to each cylinder head, conduct water from the cylinder block to water cooling passages in the cylinder heads. The cooling water discharge from each head is carried to the water outlet header by individual elbow connections. Cored passages permit the admission of scavenging air and expulsion of exhaust gases. Metal-to-metal joints of the flat lap type form the gas seal between the cylinder heads and cylinder liners and prevent the escape of gases from the cylinders. No gasket is required between cylinder head and liner. Each head has suitable chambers for two air inlet valves, two exhaust valves and a fuel injection nozzle. The valve lever bracket assembly, consisting of a bracket and two valve levers mounted on a valve lever shaft, is applied to the top of the cylinder head along with the equalizing yokes. The valve mechanism assembly and fuel injection nozzle on top of the head are enclosed by Aluminium cover. Valves - Valves are the most important of the small components of the diesel engine. Valves operate at a very high temperature varying from 1250 to l700 degree F. So the valve head is made from heat resistant austenitic material while stem is made from steel of specification SAE 4140. Piston - The piston is the most important component in the diesel engine as it takes direct part in transmission of power. The combustion of fuel results in large amount of heat being developed, 18% of which is absorbed by piston only. To dissipate such a large amount of heat, pistons are generally made of aluminium alloy. The functions of the pistons are: - It compresses the air to required pressure & temperature. It receives the thrust of expanding gases and transmits the force through connecting rod (for rotating crankshaft). It forms the crosshead through which side thrust, due to angularity of connecting rod, is transmitted to the cylinder wall. With the help of piston rings, it prevents leakage of gas from combustion chamber to crank case. Piston Pin - The piston pin has a floating fit in the piston and a running fit in the steel- backed, bronze lined connecting rod bushing. A rolled sleeve is installed in the pin bore to seal in the cooling oil. Special snap rings are provided at each end of the pin to hold it in place. Piston Rings - Main functions of piston rings are Preventing blow by air and combustion gases from getting into crank case. Scraps down excess lube oil from walls of cylinder liner and thus preventing excessive amount of lube oil from reaching combustion chamber. The piston rings are made from cast iron having open graphite structure. Cylinder Liner - Cylinder liners are mainly of two type i.e. Dry liner and wet liner. Dry liners are those which never come in contact with coolant but fit in sleeve inside and already completes cylinder. Wet liners are those which not only form the cylinder wall but also form a part of the water jacket. ALCO liners are made of high strength close grain alloy cast iron. Cylinder liner fit in the cylinder block with a metal to metal fit in ALCO Locos. Each liner has a collar on its upper end which seats in a counter bore in the cylinder block. One seal ring in grooves near the bottom of the liner, seal the fits between the liner and cylinder block. LINER BORE WITH SLEEVE Connecting Rod - Connecting rod is a member connecting piston and crank shaft and is a medium for converting the reciprocating motion to rotary motion. Connecting rod is mostly made of carbon steel or alloy steel forging. Exhaust Manifold - It collects exhaust gases from all the cylinders and supply to turbo supercharger. After-cooler - The engine is equipped with an after-cooler to cool inlet air to the engine after it is discharged from the turbo supercharger. The cooler consists of a tube bundle mounted in the air intake passage of the turbo supercharger support. The header contains the inlet and outlet cooler connections. The tube bundle consists of a series of finned tubes. A water connection at the base of the after-cooler cavity assures complete draining of the tubes. A tell- tale pipe is provided to indicate after cooler tubes leakage. Turbo Supercharger - The turbo supercharger is a self-contained unit, composed of a gas turbine and centrifugal blower mounted on a common shaft with the necessary surrounding casing. The exhaust gases gas from the cylinders of the engine is conveyed through the exhaust manifold to the turbine, which utilises some of the velocity energy in the exhaust gas otherwise wasted. This energy in the gas is used to drive the blower, which furnishes all the air required by the engine, through the air intake manifold at a pressure above atmospheric. The turbo supercharger unit is used in conjunction with a multiple pipe exhaust manifold. In this system the compressed air delivered by the turbocharger accomplishes two ends: first, it scavenges the hot residual gases otherwise left in the cylinder at the end of exhaust stroke, and replaces these with cool fresh air, second, it fills the cylinder with an air charge of higher density during the suction stroke. The provision of greater amount of fresh air permits the combustion of a correspondingly higher amount of fuel and consequently a higher output from a turbocharged engine than one not so equipped. Fuel Injection Pumps & Injectors - Fuel injection pump are of single acting, constant stroke and plunger type with the effective working stroke, however being adjustable. The pump consists primarily of a housing, delivery valve and spring, delivery valve holder, element (plunger and barrel assembly), plunger spring, a general control sleeve and control rack (Rod) assembly. The pump element comprises a barrel and a plunger, which are match assembled to a very close tolerance. The fuel injection pump has three functions:  To raise fuel oil pressure to a value, this will efficiently atomise the fuel.  To supply the correct quantity of fuel to injection nozzle commensurate with the power and speed requirement of the engine.  To accurately time the delivery of the fuel for efficient and economical operation of the engine.  Fuel oil enters pump from fuel oil header and fills The sump surrounding the plunger barrel. When the plunger is at the bottom of its stroke, fuel flows through barrel ports, filling the space above the plunger and the cut away area of the helix. As the plunger moves upward, fuel is pumped back into the sump until barrel ports are closed. Further upward motion of the plunger raises the pressure of the trapped fuel. When the pressure is sufficient to overcome the force exerted on delivery valve by valve spring, delivery valve opens and fuel is discharged into high pressure pipe, leading to injector. Fuel Oil Inlet Header: The fuel oil inlet header supplies fuel to the injection pumps, and is located in the control shaft compartment of the cylinder block. Fuel is drawn from the supply tank by a fuel booster pump, filtered, and discharged under pressure through a secondary filter into the header at the free end. From the header the fuel is distributed to the individual fuel injection pumps. Excess fuel drains to the supply tank. Fuel Pump rack Control Shaft: Two fuel pump control shaft are provided and located in passage extending the full length of the cylinder block. It is made up of sections of shafting on which are mounted spring levers, bearing brackets and section couplings. Fuel rack control haft is connected to governor through linkage at power take off end of the engine. Rotation of the shaft controls the fuel pump rack settings through spring loaded control levers mounted on the shaft. Individual levers permit any fuel pump to be manually cut out without affecting the control of the governor over the remaining fuel pumps. They also permit the engine to be shut down with one pump rack stuck in the open position. Crossover linkage between the right and left side pump control shafts required on V- type engines. Lubricating Oil Circulating Pump: The lubricating oil circulating pump is of the positive displacement gear type. It is mounted on the free end of the base and is driven by the diesel engine crankshaft extension gear. The oil suction line from the sump is built into the engine base and lines up with the inlet passage cast into the pump casing. The pump discharges into external piping through a flange on the pump casing. A pressure relief valve is provided to protect the pump from excessive pressure and is located in the discharge piping. Water Pump: The cooling water circulating Pump is located on the free end of the engine and is driven by the engine crank shaft extension shaft gear. The Pump frame is connected to the engine through a flanged connection and suction and discharge piping are connected directly to suction and discharge flanges of the pump. In order to eliminate packing and its inherent maintenance problem, a mechanical seal has been installed i the pump. The pump is lubricated by oil thrown off the lube oil pump gear into the water pump bearing frame. After-cooler: It is a simple radiator, which cools the air to increase its density. Scales formation on the tubes, both internally and externally, or choking of the tubes can reduce heat transfer capacity. This can also reduce the flow of air through it. This reduces the efficiency of the diesel engine. This is evident from black exhaust smoke emissions and a fall in booster pressure. FIRING ORDER IN A MULTI-CYLINDER ENGINE In case of four stroke cycle engines, there is only one power stroke in four strokes of piston or every two revolutions of the crank shaft. It is therefore necessary to have a flywheel, to give a ‗carry over‘ for the three ‗waste‘ strokes and to ensure smoother power output. To increase the power output and to make it smoother, multi-cylinder engines are used in which, the firing strokes on different cylinders are suitably spaced in relations to the crank angles so that during the revolutions of the crank shaft, firing of the cylinders takes place one by one at regular intervals. For even firing in a four stroke engine, each cylinder must be allowed to fire once in four strokes and for sixteen cylinder engine, it is 720/16=450. For our railway standard engines, the following fire order has been prescribed- WDM2 Locomotives 1R1L-4R4L-7R7L-6R6L-8R8L-5R5L-2R2L-3R3L YDM4 Locomotives 1-4-2-6-3-5 WDS6 Locomotives 1-5-3-6-2-4 WDP4/ WDG4 EMD Locomotives 1-8-9-16-3-6-11-14-4-5-2-12-13-2-7-10-15 DATA SHEET FOR WDG3A LOCO  Wheel Arrangement : Co-Co  Track Gauge : 1676 mm  Weight : 123 t ± 2%  Length over Buffers : 19110mm  Wheel Diameter : 1092 mm  Gear Ratio : 18: 74  Min radius of Curvature : 117 m  Maximum Speed : 100 Kmph  Diesel Engine : Type: 251 C, 16 Cyl.- V  HP : 3100  Brake : IRAB-1  Loco : Air, Dynamic  Train : Air  Fuel Tank Capacity : 6000 litres  Traction Alternator type : T A 10102 EV  Aux. Generator Type : A G 3101 AY-1  Exciter type : A G 3101 AY-1  Traction motor type : TM 4907BZ (With roller suspension bearings) Type  Eddy Current Clutch - Gear Box type : EC 9005/2M/GB 11 A/M 1.312 (Gear Ratio 1:1.312)  Tacho Generator type : T G 1404 AZ/M  Axle Generator type : A G 903 CX/M  Traction Motors combination used : 2S-3P 100% FF & 6-P 100% ENGINE DATA The locomotive is powered by DLW built 16 Cylinder. ALCO 251C (WDG3A) design uprated, fuel - efficient engine capable of producing 3100 HP at 1050 rpm under standard conditions. The engine shall deliver 2900 HP at site condition and power input to traction motors at site shall be 2750 HP. ENGINE CHARACTERSTICS AND RATING  Rated Power under standard condition * : 3100 HP  Engine Speed  Rated : 1050 rpm  Idle : 350 rpm  Cylinder formation : 45 Deg.Vee  Nos. of Cylinders : 16 Nos.  Bore and Strokes : 9"X10- 1/2‖ (228.6 mm x 266.7 mm)  Compression Ratio : 11.75: 1  Cycle : 4 stroke  Aspiration : Turbo supercharged and charge air cooling  Mean Piston Speed : 1837.45 fpm (9.33 m /sec)  BMEP : 218.69 psi (15.08 Bar)  Swept Volume per cylinder : 668 Cu-in (10.95 Lit.)  Total Swept Volume : 10688 Cu-in (175.2 lit)  Nos. of Valve / Cylinder -  Air Valve : 2 Nos.  Exhaust Valve : 2 Nos.  Crank Pin Diameter : 6"  Crank Journal Diameter : 8 1/2"  Wt. of Engine Dry : 40798 lbs. (18506Kg.) Wet : 44231 lbs. (20063 Kg.)  Overall dimension of engine : 210-7/8" x 66" x 92" (5355 x 1676 x 2336 mm)  Over speed trip set points. : 1180+20 rpm (Mech) OST  Fuel Injection timing : 22.0 Deg.CA before TDC 23.0  Firing order :1R-1L-4R-4L-7R-7L-6R-6L- 8R-8L-5R- 5L-2R- 2L-3R-3L  Peak firing pressure (Max.) : 1775 PSI  Specific fuel consumption at rated Load : 156 + 4 gm/BHP/hr  Booster pressure : 1.8 – 2.2 bar  Engine SAILENT FEATURES OF WDM2, WDM2C, WDG4 S No Description WDM2 WDM2C WDG4 1 Service Goods / Goods / Coaching Goods Coaching 2 Length in meters 17.12 17.12 21.24 3 Weight in Tonnes 112.8 112.8 128.5 4 Max. speed in KMPH 110 120 100 5 Engine RPM in Idle 400 400 269 6 Engine RPM(8notch) 1000 1050 904 7 OSTA Tripping RPM 1110-1150 1160-1200 960-1045 8 Air Filtration Panel type / Cyclonic with Cyclonic type Cyclonic with Bigger size filter primary and paper type and paper type baggy type secondary filter secondary filter secondary filter 9 Brake system IRAB- 1 IRAB-1 CCB-KNORR 10 Lube oil sump capacity 910 1150 950 11 Fuel oil tank capacity 5000 5000 6000 12 Horse Power under idle 2600 3100 4 condition 13 Input to Traction 2400 HP 2750 HP 3726 HP 14 Adhesion (Max. Tractive 24.5% / 30.4 T 24.5%/30.4T 43% / 55.1 T effort adhesive weight 15 Weight transfer to wheels Centre pivot Centre pivot 60% Side rubber through 60% Side bearer 40% Resilient Side bearer 40% pads 100% 16 Axle load (Tonnes) 18.6 18.6 21.42 17 Bogie Cast/ Cast/ High speed steel Fabricated Fabricated cast S No Description WDM2 WDM2C WDG4 18 Gear Ratio (Pinion: Bull gear) 18:65 18:65 17:90 19 Traction motor arrangements LLR/LRR LLR/LRR LLL/RRR 20 Electrical transmission type DC/DC AC/DC AC/AC 21 Cranking done by Generator Exciter and aux. Two starter Motor working as motor Gen. working as AC motor 22 Master Controller Alco model UIC model with Reverser handle throttle wheel and throttle / DB reverser handle Handle 23 Transition 3 with field 1 (No field No transition shunting shunting) 24 In case of TN Isolation D.B. Will not function Will not function Will function for working truck 25 TM Isolation Defective TM can Defective TM Particular truck to be isolated can be isolated be isolated. 26 Type of Engine 4-Stroke V-16 4-Stroke V-16 2-Stroke V-16 Turbo super Turbo super Turbo super - charge super charge super charge super engine engine engine 27 Type of Turbo used Exhaust Gas Exhaust Gas Gear/ Exhaust Gas Driven Turbo Driven Turbo Driven Turbo 28 Type of truck Tri mount CO-CO Tri mount Side load pads type CO-CO type centre pivot CO-CO type 29 Type of Air compressor Air compressor Air compressor Air compressor directly driven by directly driven by directly driven by engine engine engine through clutch type coupling 30 Compressor cooling Air cooled Air cooled Water cooled 31 Fuel Injection system Through separate Through separate Direct fuel fuel injection fuel injection injection by pump and injector pump and Unit injectors. injector 32 Engine lube oil system One lube oil One lube oil Four lube oil pump, gear driven pump, gear pumps for entire lube oil driven for entire  Scavenging oil system lube oil system pump gear driven.  Piston cooling oil pump gear driven.  Main lube oil pump gear driven.  Soak back pump for turbo, electric motor Driven. S No Description WDM2 WDM2C WDG4 33 Cooling water system One water pump One water pump Two water pump gear driven, one gear driven, one gear driven, two radiator fan and radiator fan and radiator fans riven drive from engine drive from engine by computer through ECC through ECC controlled electric motors. 34 LOC per every 100 ltrs. Of 1.5 ltr. 1.5 ltr. 0.5 ltr. Fuel oil consumption 35 Minimum radius of curvature 73.2 73.2 64.92 (Meters) 36 Minimum continuous speed 18 28.2 14.72 / 14.88 (kmph) 37 Displacement / cylinder 668.25 Cu.in. 668.25 Cu.in. 710 Cu.in (10950.66 cc) (10950.66 cc) (11634.82 cc) Engine Assembly (ALCO) ****************  LUBE OIL SYSTEM (ALCO LOCOS) The lubricating oil, besides providing a film of soft slippery oil in between two frictional surfaces to reduce friction and wear, also serve the following purposes :-  Cooling of bearings, pistons, etc.  Protection of metal surfaces from corrosion, rust, surface damage and wear.  Keen the components clean and free from carbon, lacquer deposits and prevent damage due to deposits. The system essentially consists of;  Gear type oil circulating pump  Relief valve  Lube oil cooler  Filters  Regulating valve  Strainer filters and associated pipelines. When the engine is started the pump draws oil from the engine sump and delivers it to the filters. The delivery pressure of the pump is to be controlled as the pump is driven by an engine of variable speed and would often have higher delivery pressures on load than actually required. Higher pressure may endanger the safety of filters, pipelines and joints. The relief valve set at 9.5 kg/cm2 releases the delivery pressure above its setting and bypasses it back to the oil sump. On line centrifuge filter is provided in between to cater filtration of lube oil of the line which (filtered oil) passes back to the sump. Oil then flows through the filter tank containing 8 paper type filter elements. After the filtration, the oil passes through the cooler, gets cooled by transferring heat to the water. A regulating valve adjusted at 7.5 kg/cm 2 is provided at the discharge side of cooler to regulate the pressure. Excess pressure is regulated by sending the oil back to the engine oil sump. The oil then enters the main oil header after passing through another stage of filtration in the strainer type filter from where it is distributed to various locations for lubrication. Direct individual connections are taken from the main oil header to all the main bearings. Oil thus pass through the main bearings supporting the crankshaft on the engine block, pass through the crank pin to lubricate the connecting rod, big end bearing and the crank pin journals, reach, the small end through rifle drill hole and after lubricating the gudgeon pin and bearings enters into pistons. The pistons are provided with spiral oil passages inside them for internal circulation of lube oil. This is done with the purpose of cooling the pistons which are thermally loaded components. After circulating through the pistons the oil returns to the sump, but in this process a part of the oil hits the running connecting rod and splashes on to the cylinder liners for their lubrication. A line from the main oil header is connected to a gauge in the driver's cabin to indicate pressure level. Lube oil pressure drop to less than 1.75 kg/cm2 would automatically shut down the engine through a safety device called Oil Pressure Switch to protect it from damage due to insufficient lubrication. From the main oil header, two branch lines are taken to the right and left side secondary headers to lubricate the components on both banks of the V-shaped engine. Each branch line of the secondary header lubricate the cam shaft bearings, fuel pump lifters, valve lever mechanism and spray oil to lubricate the gears for cam shaft drive. A separate connection is taken to the TSC from the right side header for lubricating its bearings. After circulation to all the points, lubrication oil returns back to the sump for recirculation in the same circuit. MAJOR COMPONENTS OF LUBE OIL SYSTEM Lube Oil Pump: This is located at free end of the engine slightly towards the right. Supply of oil in adequate quantities and at desired pressure is vitally depending upon the pump. A gear driven type pump has been provided.This gear type pump has been provided. The suction line is in built into the engine base and the discharge is into the external piping. The pump develops a partial vacuum, causing the fluid to flow into the pump inlet under atmospheric pressure. The fluid trapped between the helical gear teeth and the pump housing is then pumped out at the outlet side with pressure. The delivery of the pump is directly proportional to the speed of rotation. Relief Valve: This valve is fitted at the delivery side of the lube oil pump to ensure that oil pressure does not exceed the pre-determined setting of about 9.5 Kg/cm2.This protects the system from damage due to excessive pressure on cold through by passing a portion of the oil to engine sump. Lube Oil Filters: Paper type, disposable cartridge filters are used for the engine lube oil system. The filters are located in radiator room.In some locos Moatti type filters are provided. On the top of this filter a condition indicating gauge is provided. It is having red and green zones. Whenever needle shows red LP has to inform shed Lube Oil Cooler: This is located in radiator room. Lube oil cooler is a heat exchanger, which removes heat from the lube oil and ensures supply of oil to the engine at a reasonable temperature. The viscosity of the oil is dependent on the temperature.The viscosity of the oil is dependent on the temperature.The viscosity of the oil is dependent on the temperature and mixing of combustion by products. The lube oil system can operate satisfactorily as long as the viscosity of the oil remains within the desired limit. Pressure Regulating Valve: This is located at the discharge of the cooler and before the strainer. It regulates the flow of oil through the cooler and the lube oil pressure in the system. The setting of the valve is 7.5 Kg/cm2. If the pressure is high, some of the oil is by passed to the sump (Regulating valve is not available in locos provided with Moatti type lube oil filter.) Lube Oil Strainer: The lube oil strainer is located at left side free end of the engine.The strainer removes minute particles. NOTE: Lube oil strainer is not available in loco provided with Moatti type lube oil filters. Low Lube Oil Pressure Trip Assembly: In the case of wood ward governor fitted locos an oil pipe is connected between the lube oil system and this assembly.This is constantly monitoring the lube oil pressure. If the lube oil pressure drops, this assembly senses it and trips a plunger with red band as an indication; simultaneously engine will shut down with an alarm indication (bell ringing and LED glowing).During cranking, if this is in tripped condition ,engine will crank but not fire. The lube oil trip button has to be rested to normal position before cranking. Crank Case Exhauster :This is provided to maintain certain amount of vacuum in the crank case by expelling the hot oil vapour (hot fumes).It is driven by an electric motor, which gets supply from the batteries before cranking and from auxiliary generator after cranking. In the event of failure exhaust motor due to tripping of CCEB an amber coloured lamp will glow on the control panel/stand.If CCEM is failed the diesel engine must be shut down after clearing the section. While taking over charge if it is found that the exhauster is not working, do not attempt to crank the engine. On run it must be ensured very frequently that only oil vapour pressure comes out and no water particle is coming out through crank case exhauster passage. If the water contamination is found with lube oil in the sump, immediately engine must be shut down and shed should be contacted. The possible sources for water entry into crank case may be due to ;  Slight crack in the cylinder liners or the ‗O ‘rings provided at the bottom of the cylinder liner are perished.  Damage to water seal in water circulating pump.  Lube oil cooler tubes cracked when engine is in shut down position. Crank Case Inspection Doors: The inspection covers are provided for the examination of crank shaft and other rotating parts by the maintenance staff in the shed. They are provided on both sides, 8 on each side. These doors must be secured tight. Crank Case Explosion Doors: These are provided on the diesel engine crankcase to avoid extensive damage due to positive pressure developed inside engine crankcase. This may happen due to failure developed inside crankcase. This may happen due to failure of CCEM when unnoticed by engine crew for considerably longer period and whenever there is a main bearing failure. Whenever the pressure inside the crankcase exceeds a certain limit these doors will open and prevent damage to the engine block. This is provided in place of one of the inspection doors, one of each side (L2& R7). This opens whenever the pressure inside exceeds a pre-set value and releases the excess pressure and again closes when the pressure drops down below the spring tension. When the explosion drops down below the spring tension. When the explosion doors open it indicates that a positive pressure is prevailing in the crankcase. Whenever this opens shut down the engine and inform PRC/shed. Moatti Lube Oil Filter: In place of paper lube oil an automatic self-cleaning filtration unit has been installed on few locos. The main advantage of Moatti is the increase in oil renewal periodicity and elimination of paper filters and its handling. Centrifuge Oil Separator: Centrifuge oil separator (COS) is provided in lube oil system to filter the carbon particles from the lube oil. Centrifuge oil separator is connected in the outlet of the lube oil pressure increases more than 2Kg/cm2. The carbon particles in the lube oil get deposited on the drum due to centrifugal action thereby reduces the load on the filter and increases its renewal periodicity. FAILURES/DEFECTS IN LUBE OIL SYSTEM Various causes leading to the failures of locomotive on account of lube oil system are as under:- External Leakage: External leakage resulting in failure of loco due to short of lube oil. The points of external leakage are as under:  Tappet cover-perishing of tappet cover gasket due to aging or improper material, improper fitment of gasket, improper tightening of tappet cover.  Crank case cover: - wrong material, improper fitment or use of hammer for tightening.  Crank case explosion cover.  Push rod grommets: - Defective material, aging effect.  Extension shaft oil seal:-worn out seal or building up of positive pressure inside the crank case.  Face joint of lube oil relief, regulating-defective gasket or improper joint.  From armored, dresser or metallic joint- due to misalignment, excessive gap between pipes or improper clamping.  Lube oil filter housing cover - perished ‗o‘ ring cracked broken fly nuts, cracked filter housing.  Lube oil filter housing drain cock and strainer drain cock.  Turbo lube oil filter housing due to working out center of bolt.  Bursting of flexible pipes.  Lube oil gauge pipes and pipe to Woodward governor Inadequate clamping, improper annealing.  Lube oil pump face joint or flange joint.  Leakage from Lube oil Cooler tubes, resulting in mixing of lube oil in water.  Defective Lube oil Pump:-pressure not building up or breakage of any of the components.  Excessive oil throw from CCE motor exhaust pipe- due to choking of return oil passage to the sump.  Quality of oil: - Due to contamination in any form by fuel oil, cooling water, soot, etc. Change in properties like viscosity, PH value, TBNE etc.  Improper setting of relief, regulating or by pass valve  Choking of filter elements. CORRECTIVE ACTIONS DURING MAINTENANCE Following corrective action is required during maintenance to avoid failures on lube oil system account. External leakage: Notch up the locomotive from idle to 8th notch and put CC motor in off condition for a small period of time and check the leakage at possible point. If leakage is a noticed from tappet cover, crank case cover, dummy plate, explosion cover gasket, face joint of valves, change the gaskets. The push rod grommets may also be changed if leakage is found. Apply silicon compound while fitting the grommet. The leakage in extension shaft seal can be due to either worn out seal on positive pressure inside the crankcase. Normally the seal damaged due to misalignment of compressor with engine crank shaft or excessive crankshaft deflection. In such cases replace the seal and check Compressor alignment and crankshaft deflection. In case extension shaft seal s found perfect then attention is paid adequately to the power pack. Following attention should be paid to avoid leakage from armoured and dressor couplings:- There should be no misalignment of pipes.  Minimum gap between the two pipes should be curtained. In case of excessive gap, suitable length of the pipe is welded to one of the pipes.  Ensure proper clamping at adequate distance. Lube oil filter housing:-  It must be ensured in every schedule that all fly nuts are intact and welding of the fly nuts is not cracked or broken.  Tighten fly nuts crosswise at the time of replacement of lube oil filter housing ‗o‘ ring.  In case of premature failure of lube oil filter housing ‗o‘ ring. Check warpage in housing cover on surface plate.  Check crack in e housing visually in every trip. 2  Test filter housing at 10Kg/Cm during yearly schedule.  Replace defective drain cock.  Every loco should have provided with X-head dowel.  Check lube oil cooler for leakages from welded j rivets in every trip. If lube oil is mixed in water, change cooler. Ensure hydraulic testing of lube oil cooler during yearly schedule.  Check crack in turbo lube oil filter housing in every schedule.  Replace all flexible pipes as per schedule.  Pay adequate attention to lube oil gauge pipes and pipe to Woodward governor. Ensure adequate clamping. Check for loose seat and anneal the pipes.  Ensure proper setting of OPS in specified schedule.  Test relief regulating and bypass valves as per schedules.  Ensure quality of lube oil through spectrographic analysis. Check its viscosity, TBNE, PH value and contamination regularly. Following addition point will help in reducing the lube oil consumption of the locomotive:  Heavy leakage of lube oil is also noticed from OST. It is essential that drain pipe of the OST housing to sump is cleaned, so that oil can go back into the sump freely without any obstruction. Moreover, adequate clearances in OST and vibration damper should be maintained.  In case of excess oil throw from the engine exhaust due to weak power pack, attend locos on programmed basis.  Ensure fitment of piston rings at 180° to each other avoiding the gudgeon pin side  Check valve guide internal bore diameter during overhauling of cylinder heads Bore be checked either through pilots or with the help of air gauge.  Check engine sump vacuum on load box at 8thnotch. It should be minimum 0.9" of water. Positive pressure or less vacuum will increase LOC.  Avoid water leakage in lube oil by providing proper quality ‗O‘ rings on the liners. Check pitting/corrosion of the mating surfaces of the liner or the block. If water contamination is more than 0.25%, it will require lube oil change.  Every filter change would amount to loss of some lube oil. If the filter life is less either due to poor filters material or due to poor engine condition, it will have adverse effect on lube oil consumption. ****************  FUEL OIL SYSTEM (ALCO) The fuel oil system is designed to inject correctly metered amount of fuel oil at correct high pressure into the engine cylinders at a stipulated time in a highly atomized form. High pressure of fuel is required for lifting the nozzle valve, penetration of fuel into pressurized combustion chamber and proper atomization. As the engine is a variable speed and load engine with variable fuel requirement within a particular range correct metered quantity is essential. Timing of injection is important to burn the fuel completely. After switching 'ON', the fuel booster pump starts sucking oil from the fuel tank, filtered through a primary filter. The capacity of the fuel tank depends upon the type of locomotive i.e. 5000 litres for WDM2, 6000 litres for WDP3A and WDM3A. Baffle walls are there inside the tank to arrest surge of oil during movement of loco. A strainer filter, an indirect vent, drain plug and glow-rod type level indicator are also provided in the fuel tank. The filter is having a socks type filter element. Because of the variable consumption by the engine the delivery pressure of the pump may increase, increasing load on the pump and its drive motor. A spring loaded relief valve is provided for by-passing the excess oil back to the fuel tank, thus releasing the excess load on pump and motor. It is adjusted to a pressure of 5.2 Kg/cm2. Then oil passes through the paper type secondary filter and proceeds to left side fuel header. The fuel header is connected to eight numbers of FIPs on the left bank of the engine and a steady oil supply is maintained to the pump at 3 Kg/Cm2. The fuel then passes on to the right side header through a fuel cross over pipe and reaches eight FIPs on the right bank. The regulating valve after the right side header takes care of the excess pressure of 4 Kg/Cm2 by by-passing the extra oil back to the tank. A gauge connection is taken from here to the driver's cabin for indicating FOP. The fuel injection pump used in diesel loco is a constant stroke plunger type pump with variable quantity of fuel delivery to suit the engine demand. The fuel cam controls the pumping stroke of the plunger. The High-pressure fuel is then passed on to respective fuel injector nozzles through a high-pressure tube. The fuel injection nozzle is fitted in the cylinder head with its tip projected inside the combustion chamber. Due to very high pressure range 3900 psi to 4050 psi, the nozzle valve is lifted passing the oil into the combustion chamber in highly atomized form. FAILURE OF LOCOMOTIVE DUE TO FUEL OIL SYSTEM The locomotive generally fails due to fuel oil pressure not building up, which may be due to following reasons:- 1. Fuel - Less than 700 Litres fuel in tank. 2. Clogging of fuel filters (a) Quality of primary and secondary filters-If the elements are not as per the RDSO specifications. (b) Quality of HSD oil-When the fuel is contaminated with water, rust, dirt, dust, fungi or any micro-organism. (c) Condition of HSD tank-The fuel in the tank is required to be free from water, dirt, dust, rust and other contaminations. It is known that some sort of micro-biological growth takes place inside the HSD storage tanks, but the condition worsens due to prolonged storage and the oil water inter phase becomes susceptible to infectious attack by micro-organisms. Such an attack would lead to constant build-up of bacterial and fungal cells, which can ultimately cause choking of filter pores.  FUEL OIL SYSTEM OF ALCO LOCO 3. Defective Fuel Booster Pump and Motor (a) Rotor or idler gear damaged. (b) Leakages from the cover gasket. (c) Leakages from the pump seals. (d) Breakage of spring (e) Broken booster pump coupling. (f) Breakage of carbon brush (g) Commutator flashover. (h) Improper wire connections securing of fuel pump motor. 4. Leakages (a) Suction pipe leaking. (b) Bursting of high pressure tubes. (c) Leakages from flexible and metallic pipes. (d) Leakages from banjo pipes. 5. Defective Fuel Injection Pump and Injector Nozzle (a) Excessive hot pump. (b) Broken delivery valve spring. (c) Broken guide cup spring. (d) Working out or breakage of FIP foundation bolts (e) Injection nozzle stuck open or closed. (f) Injector nozzle cap cracked.  6. Relief and Regulating valve (a) Sticking of relief and regulating valve 7. Battery switch not closed 8. Fuel pump circuit breaker defective Following steps should be taken to enhance the reliability of fuel oil system:- (a) Checking of fuel oil vacuum in monthly schedule. In case the vacuum is less, pump should be removed for overhauling. The delivery of the pump should be checked after overhauling (b) Check the leakage of fuel oil from the fuel pump seal after starting the motor (c) Proper securing of wire connections of fuel pump motor. (d) Checking of carbon brush sizes in every trip schedule. (e) Check commutator in every schedule for flash over. (f) Ensure timely replacement of both primary and secondary filter. (g) Tighten cover bolts of the filter housings as per procedure. (h) Drain out water and sludge from the fuel tank of goods locos during T1 schedule and after 20 days for mail locos. (i) Drain out primary and secondary filter housing during every trip schedule after opening the dummy samples of oil drained out from the housing may also be given to lab for testing. (j) Correct setting of relief and regulating valve during quarterly schedule. Careful examination of seat of relief and regulating valve to be done. (k) Fuel cross over pipe to be modified by providing straight elbow in HY schedule. Fuel cross over pipe to be provided with proper sleeve to avoid rubbing of pipe with CC motor and cylinder head. (l) Clamp all fuel system pipes to avoid rubbing of pipes. (m) Torqueing of cross head bolts and FIP foundation bolts in monthly schedule sequentially. (n) Pump alignment with fuel inlet to be ensured. Looseness of fuel inlet bolts to be checked in trip schedule. (o) Check depth of fuel inlet elbow gasket seat and thickness of the gasket. Reject the elbow if the depth of the gasket head is more than the gasket seat. (p) Check distortion of banjo pipe on each removal and anneal or replace copper washer. Orifice test is done to check the fuel feed system by simulating the fuel load conditions. Testing procedure is given below:- (a) An orifice plate of 1/8‖ is fitted in the system before the regulating valve. (b) A container to be placed under the orifice to collect the leak off oil. (c) The fuel booster pump to be switched on for 60 seconds (d) The rate of leakage should be about 9 Litres per minute through the orifice, with the engine in stopped condition. The system should be able to maintain 3 Kg/cm2 pressure with this leakage rate which approx. simulates the fuel load consumption by the engine. In case of drop in pressure the rate of leakage would also be less indicating some defect in the system. This test is very easy and reliable and saves time as well as fuel. Also the fuel feed system can be checked under simulated conditions, which is otherwise not possible with the normal testing of engine. Inspection And Maintenance of Fuel Injection Equipment’s (a) A dust proof room for overhauling and testing of fuel injection equipment‘s. (b) It must be remembered that certain components like plunger and barrel, the delivery valve and valve seat of FIP and the nozzle and valve body of the injector nozzle are matching components and never to be interchanged. Fuel Injection Pump It is essential to check the following items during overhaul: (a) Seizure and slackness in plunger and barrel. (b) Scratches and scuffmarks on the plunger due to abrasives in fuel oil. (c) Erosion of helix edges on the plunger beyond stipulated limits. (d) Corrosion and pitting marks on plunger or barrel. (e) Discolouration due to heating in plunger and barrel. (f) Delivery valve spring, the valve and the valve seat need careful checking. Grinding the valve and valve seat to proper angle and lapping may have to be done if necessary to ensure perfect contact between the valve and seat. (g) Slackness between control rack and bushing, control rack and control sleeve and plunger lug, which produces lost motion and makes it difficult to adjust the rack movement accurately. (h) Wear on top or bottom of the guide cup. (i) Lapping of surface between the barrel and delivery valve body and also between delivery valve body and holder is required to have leak proof joints. (j) Plunger spring for cracks and loss of tension. Calibration of FIP Each FIP is subjected to calibration test after overhaul to ensure that it delivers the same and stipulated amount of fuel at a particular rack position. The calibration and testing of FIPs are done on a specially designed machine. The blended test oil of recommended viscosity under controlled temperature is circulated through a pump at a specified pressure for feeding the pump under test. The oil discharged for 300 strokes of the pump is measured at idle and full load and should be as specified by the manufacturer. Maintenance and Inspection of Fuel Injection Nozzle Criteria for good nozzle are proper atomization, correct spray pattern, and no leakage or dribbling. (a) Before a nozzle is put to test the must be rinsed in fuel oil, nozzle holes cleaned with wire brush and spray holes cleaned with steel wire of correct thickness. (b) Replace the O ring around the nozzle holder. (c) The nozzle and the valve need grinding if wear has taken place.this should be done with utmost care to avoid loss of hardened surface more than actually required. The grinding of valve face is done on a specially designed machine at the recommended angle. The valve and seat must have proper line contact to ensure perfect sealing. Lapping is necessary to achieve better line contact after grinding. (d) Valve lift must be checked with the help dial indicator. It shows the amount of wear on the valve face and seat. Following tests are conducted on a specially designed machine:- Spray Pattern The spray of fuel should be properly atomized and uniform through all the holes. This can be judged with an impression taken on a blotting paper. Spray Pressure The stipulated correct pressure at which the spray should takes place is 3900-4050 psi for new and 3700-3800 psi for reconditioned nozzles. If the pressure is down to 3600 psi, the nozzle needs replacement. Shims are being used to increase or decrease the tension of nozzle spring, which increase or decrease the spray pressure. Dribbling There Should Be No Loose Drops Of Fuel Coming Out Of The Nozzle Before Or After The Injections. The dribbling can be checked by having injections manually done couple of time quickly and check whether the nozzle tip is dry or leaky. Raising the pressure within 100 psi of set injection pressure and holding it for 10 seconds may also give a clear idea of the nozzle dribbling. The dribbling may occur due to improper pressure setting or dirt stuck up between the valve and valve seat or valve sticking inside the valve body. Nozzle Chatter The chattering sound is a sort of cracking noise created due to free movement of the nozzle valve inside the valve body, it should be proper. Nozzle Leak of Rate Avery minute portion of the oil inside the nozzle passes through the clearance between the valve and the valve body for lubrication purpose. Excess clearance may cause excess leak off, thus reducing the amount of fuel actually injected. To check the leak off rate creates a pressure in the nozzle up to 3500 psi and hold the pressure till it drops to 1000 psi. The drop will be quicker in case of excessive leak off and the pressure drop will be quicker in case of excessive leak off rate. The leak off time recorded should be within stipulated limits. High Pressure Tubes (a) Zyglo testing of HP pipe before fitment. (b) These tubes are to be tested up to 5000 psi (c) The rubber ferrule to dampen the vibrations must be provided in these HP tubes. (d) Radius of HP pipes should be checked up on a fixture *****************  WATER COOLING SYSTEM (ALCO) After combustion of fuel in the engine, about 25 to 30% of heat produced inside the cylinder is absorbed by the components surrounding the combustion chamber i.e., Piston, cylinder, cylinder head, etc. Unless the heat is taken away from them, the components are likely to fail under thermal stresses. All internal combustion engines are provided with a cooling system designed to cool the excessively hot components, distribute the heat to other surrounding components to maintain uniform temperature throughout the engine and finally dissipating the excess heat to atmosphere to keep the engine temperature within suitable limits. The WDM2 loco is having closed circuit pressurized water-cooling system for the engine (earlier it used to be non-pressurized system). The system is filled in by 1210 litres of demineralised water treated with corrosion inhibitor in two inter-connected expansion tanks on the top of the locomotive. A centrifugal pump driven by the engine crankshaft through a gear, suck water from the system and deliver through the outlet under pressure. The outlet of the pump has three branch lines from a three-way elbow to the following locations: -  To the turbocharger through a flexible pipe to cool intermediate casing, turbine casing and bearings. After cooling, water returns to the inlet side of the pump through a bubble collector that is provided to collect the air bubbles formed due to evaporation and pass them on to the expansion tank to avoid air lock in the system.  The second line leads to the left bank of the cylinder block. A diversion is also taken from this line for circulation through the after cooler to cool the charge air for engine. Water from the after cooler then returns to the same line to enter the engine block and circulate around cylinder liners, cylinder heads on the left bank and then pass on to water outlet header. Individual inlet connection with water jumper pipes and outlet by water riser pipes are provided to each cylinder head for entry and outlet of water from the cylinder head to the water outlet header, Water then proceeds to the left radiator and release its heat to the atmosphere before recirculation to the engine.  The third connection leads to the right bank of the cylinder block. After cooling the cylinder liners, heads, etc. on the right bank, it reaches the right side radiator. Before it enters the radiator, a connection is taken to the water temperature manifold, where a temperature gauge is fitted to indicate the water temperature and the temperature of water is also shown on display unit. Two temperature sensors ETS- 1, ETS-2 are also provided. ETS l is for starting the movement of radiator fan at low speeds through eddy current clutch at 64°C. ETS-2 picks up at 68°C and accelerates the radiator fan to full speed. Audio- visual alarm at 92°C will start beeping to alert loco pilot to take corrective action to reduce engine water temperature. If water temperature rises further to 950 C, then control unit /Microprocessor will bring the engine to idle. Water temperature is controlled by controlling the movement of radiator fan. Cooled water from the left side radiator passes through the lube oil cooler and cools lube oil. After lube oil cooler, it unites with right side radiator outlet, to be back again to the suction of the pump for re-circulation. Apart from Hot Engine Alarm, another safety in the form of LWS is also provided. It shut down the engine if the water level falls below 1" from the bottom of the expansion tank. Expansion Tank This is located at the topmost level of the system and this serves as a reserve tank. An auxiliary tank is also provided above the radiator room. Both the tanks are interconnected. To indicate the water level, gauge is provided inside the radiator room on the right side of head light. While taking overcharge water level should be above the half mark of the gauge. The capacity of cooling water system is 1210 litres. Expansion tank and auxiliary tank are supplementing the loss in the system. A pipe is connected from the expansion tank to the system on the suction line. An overflow is provided in the auxiliary tank. A pressure cap is provided on the auxiliary tank which will operate and release excess pressure. This is provided to avoid complete siphoning of water. Expansion tank is connected with various vent pipes of the cooling i.e. after cooler, turbo supercharger, bubble collector, lube oil cooler and both side radiator for venting the steam. Low Water Switch This is an important safety device provided to protect the engine from the damages caused due to lack of cooling water. This will shut down the engine when the water level falls below 1‖ level from the bottom of expansion tank. A pipe connection is taken from the expansion tank to LWS float chamber, with a 3 way cut out cock. This cock is provided to facilitate testing of LWS without draining of water from the system. When the water level goes down, the float in the chamber drops and movable contact from the other end of the fulcrum is lifted which will make electrical contact and send signal to the governor to shut down the engine. Normally LWS COC must be in open position i.e. to connect the tank in the float chamber. While testing the LWS this COC is to be closed. In this position water flows from the expansion tank stops in water in the float chamber drains out which will operate the switch. Now a day‘s electronic water level indicator is provided in the cab. This is having 3 LEDs 1) Green which indicates water is full 2) Yellow which indicates water is half 3) Red which indicates water is to be added. Whenever LWS malfunctions this switch has to be operated after insuring sufficient water level. EDDY CURRENT CLUTCH (ECC ASSEMBLY) This is provided in the radiator room to start and stop radiator fan according to water temperature. Centrifugal Water Pump The water pump is situated on the left side free end of the engine.The pump circulates water in the cooling system.The pump is getting it‘s drive from the diesel engine crankshaft through a step gear 79:46 (79 drive shaft and 46 driven shaft).The capacity of water pump delivery is 2457 litres per minute, at a speed of 1720 RPM. Tell Tale Pipe To identify the defects in water and oil seal system, a tell-tale pipe is provided in the water pump. In case of leakage LPs may deal as below.  From shed Loco should not be taken with tell-tale pipe leakages.  If this is noticed en-route contact shed and the loco can be onwards carefully watching the water level. If the leakage is very heavy, loco should not be worked further.   If oil leak is noticed en-route, inform shed and work onwards duly checking the oil level in the sump and make the entry in the repair book. NOTE:-Under any circumstances tell-tale pipe should not be plugged. Water Pressure Sensor It is provided in the delivery side of water pump to ensure working of the pump. Its feedback is given to microprocessor. Oil Traces Found In Expansion Tank When oil traces are found in expansion tank that indicates the lube oil has entered into the water tubes in the lube oil cooler, that are cracked or burst, because the pressure of the lube oil is more than water in the cooler. If the contamination is not very heavy the loco pilot can work duly informing shed. If oil traces are very heavy it may greatly affect the cooling process. Working in these conditions may lead to continuous hot engine alarm and the performance of the loco will be badly affected.So it is not advisable for a loco pilot to work a train with a loco heavy lube oil contamination in the water system. Vent lines are provided from after cooler, lube oil cooler, radiators, TSC and bubble collector, etc. to maintain uninterrupted circulation of cooling water by eliminating the hazard of air lock in the system. Cooling water is subjected to laboratory test at regular intervals for quality control. Contamination, chloride contents and hardness etc. are checked to reduce corrosion and scaling. CAUSES OF FAILURES IN WATER COOLING SYSTEM Defective Water Pump Check water pump pressure at 8th notch. It should be 1.8 Kg/cm2 to 2.2 kg/cm2. The main problem in the maintenance of the water pump is the water seal. Other reasons for failure can be breakage of pump shaft, working out of castle nut and split sleeve, breakage of impeller, radial and thrust bearing defective and break age of gear teeth. Following steps must be taken during maintenance to avoid failures:-  Replace the water seals during yearly schedule.  Zyglo testing of water pump shafts must be done. The shaft should also be checked for dimensional accuracy and run out.  Adopt correct procedure of checking and fitting the split sleeve and torquing the castle nut. The castle nuts to be torqued at 220 ft. lbs.  Check the condition of gear teeth during overhauling and keep the backlash within limits.  Test the pump on test stand after overhauling to check the condition of seal.  Water Leakage through Various Joints and Pipes Leakage of water through flexible pipes, metallic pipes, gaskets, dresser and Victaulic coupling, bubble collector, radiator equalizing pipes, etc. may lead to engine failure. Following steps should be taken to reduce incidences:- 1. Replace all the flexible pipes of the water system on time basis i.e. during yearly schedule and should be properly clamped at proper locations to prevent them from rubbing and getting punctured. 2. The metallic pipes should be aligned and clamped properly. 3. Replace all the gaskets during specified schedules. Water leakage through coupling joints should be checked in every schedule and in case of leakage gasket must be replaced. 4. Bubble collector support plate should be suitably strengthened to avoid leakage from armoured / Victaulic coupling of bubble collector due to vibration. 5. Pay proper attention while preparing armoured and dresser joints. There should be a minimum gap and alignment of the pipes should be proper. A gap of 1/8" to 1/4" is maintained in Victaulic coupling and 1‖ in dresser couplings. 6. Replace all three bolts dresser couplings with 4 bolt couplings. DATA SHEET FOR COOLING SYSTEM Chemical additives INDION1344 OR NALCO 2100, Indion–1344 be required For Jacket Water used 0.68 Kg. per 500 ltr. of DM / distilled water Water required for initial Filling 1500 liters Make – up Water Quantity 310 liters Maximum J.W. 900 C Temperature at 100% load Minimum permissible J.W. 40 – 60C temperature for starting engine Quality of Water De – mineralized *************  SUPER CHARGING In an internal combustion, compression ignition type engine, for burning every pound of fuel, a certain amount of air is required. For increasing the horsepower output of each cylinder, the size of the cylinder can be increased, but it will result in increased weight which is not possible because it will also occupy more space. The diesel engine, in which air under atmospheric pressure is supplied for burning the fuel inside the cylinder during the suction stroke, is called normally aspirated engine. If it is possible to increase the quantity of air available for combustion within the limited space of the combustion chamber (with the existing size of the cylinder) more fuel can be burnt and thereby increasing the horse power output. If the air is admitted into the cylinder at a pressure higher than atmospheric pressure, more quantity of air can be made available for combustion. So the process of admitting more air at a higher pressure in order to burn more quantity of fuel to increase the heat energy, in turn, more output of the engine, is called Super Charging. Some methods of super charging are: a. Electrically driven motor to rotate a blower. b. Gear driven blower (mechanically) where the blower is getting drive from the engine through gears. c. By means of exhaust gas driven turbine to rotate a blower. The last method is the most economical method, because we are utilizing the exhaust gas to drive the blower, which would have, otherwise, gone waste. ADVANTAGES OF SUPER CHARGING 1. The output of the existing engine can be increased, when there is a greater power demand. 2. The weight of the engine can be reduced so that the ratio, between the weight of the engine and the HP developed, can be increased. 3. The effect of altitude can overcome, as the air density is lower at higher places. 4. Better scavenging action can be ensured in the engine cylinders. 5. Due to cold fresh air forced into the cylinder, it will cool the combustion chamber well. TURBO SUPER CHARGER The function of a turbocharger is to use the exhaust gas energy of an internal combustion engine (which would otherwise be wasted) to drive a turbine wheel and hence a blower. The blower increases the pressure and density of the charge in the engine cylinder, thereby increasing the power above that of a naturally aspirated engine. Following are the advantages of a supercharged engine:-  A supercharged engine of given bore and stroke dimensions can produce 50% or more power than a naturally aspirated engine. The power to weight ratio in such cases is much more favourable.  Results in better scavenging and ensures carbon free Cylinders and valves and better health for the engine also.  Better ignition due to higher temperatures developed by higher compression in the cylinder.  Better fuel efficiency due to complete combustion of fuel by ensuring availability of matching quantity of air or oxygen.  Reduction in thermal loading of the engine components by reducing the exhaust gas temperatures. Working Principles of Turbo Supercharging System The exhaust gas discharged from all the cylinders accumulate in the common exhaust manifold at the end of which the TSC is fitted. The gas under pressure thereafter enters the TSC through the connector and the torpedo shaped bell mouth and then passes-through the fixed nozzle ring. The exhaust gases passing through the fixed nozzle ring is directed to the turbine blades at increased pressure and at a suitable angle to achieve rotary motion of the turbine at maximum efficiency. After rotating the turbine the exhaust gases go out to the atmosphere through the exhaust chimney. The turbine has a centrifugal blower mounted at the other end of the same turbine shaft and rotation of turbine drives the blower at equal speed. The blower connected to the atmosphere through a set of oil bath filters/cyclonic filters suck air from the atmosphere and deliver it at higher velocity. The air then passes through the diffuser inside the turbo, where the velocity is defused to increase the pressure of air before being delivered from turbo. TSC consists of following main components;- 1. Gas inlet casing 2. Turbine casing 3. Intermediate casing 4. Blower casing with diffuser 5. Rotor assembly with turbine and blower on same shaft. Gas Inlet Casing - It is made of heat resistant CH-20 stainless steel. Its function is to take the hot gases from exhaust manifold to the nozzle ring. Turbine Casing - It houses the turbine inside it and is cored to have water circulation through it for cooling purpose. This has oval shaped gas outlet passage at the top. It is fitted in between the inlet casing and intermediate casing. Intermediate Casing - This is also water cooled and is made of alloy cast iron like turbine casing. It is in between the turbine casing and blower casing and separates the exhaust and the air sides. It also supports the turbine rotor on two tri -metallic bearings which are interference fit in the intermediate casing. Blower Housing Assembly - It houses the blower. Air enters through the blower inlet axially and discharged radially from the blower through the diffuser. Rotor Assembly - The rotor assembly consists of the rotor shaft, rotor blades, thrust collar, impeller, inducer, centre studs, nose piece, lock nut etc. assembled together. The rotor blades are fitted into slots and locked by tab lock washers. This is a dynamically balanced component as this has a very high rotational speed. The cooling system is integral with that of engine. Circulation of water takes place through the turbine casing and intermediate casing which are in contact with exhaust gases. The cooling water after being circulated in turbo system returns back to the engine cooling system. One branch line of lubricating system is connected to ISC filter and then the lube oil enters the TSC for lubricating its hearings. Oil seals are provided on both the turbine and blower ends of the bearings to prevent oil leakage from bearing to the blower or the turbine housing. Lubricating System One branch line from the lubricating system of the engine is connected to the turbo supercharger. Oil from the lube oils system circulated through the turbo supercharger for lubrication of its bearings. After the lubrication is over, the oil returns back to the lube oil system through a return pipe. Oil seals are provided on both the turbine and blower ends of the bearings to prevent oil leakage to the blower or the turbine housing. Cooling System The cooling system is integral to the water cooling system of the engine. Circulation of water takes place through the intermediate casing and the turbine casing, which are in contact with hot exhaust gases. The cooling water after being circulated through the turbo- supercharger returns back again to the cooling system of the locomotive. Air Cushioning Pressurized air from the blower casing is taken through a pipe inserted in the turbo to the space between the rotor disc and the intermediate casing. This arrangement is called air cushioning and is used for following purposes:- 1. To prevent hot gases coming in contact with the tube oil 2. To prevent leakage of lube oil through the oil seal. 3. To cool the hot turbine disc. 4. To reduce thrust load on the thrust face of the bearing.  TURBOCHARGER AIR INTAKE SYSTEM WDM2 Turbocharger Surging Surging is defined as the operating point at which the compressor ceases to maintain a steady flow for a given booster pressure and reversal of the flow takes place. This is usually accompanied by noise in the form of pulsations, sometimes mildly and sometimes noisily with large amplitude. It is essential that surging during engine operation is avoided. Damage may be caused to the rotating parts with consequent damage to the complete turbocharger. Following may give rise to surge:-  A violent change of engine load or excessive overload.  An excessive rise of cooling water temperature in the charge air cooler.  Extreme fouling of the inlet or exhaust manifolds.  Mismatching of compressor and turbine components in respect of a particular engine.  The turbine nozzles and blades will accumulate carbon deposits from the burnt residue of fuel impurities and lubricating oil additives, resulting in high turbine speeds, high booster p