ON
TO THE DEPARTMENT OF MECHANICAL ENGINEERING
JAYPEE UNIVERSITY ANOOPSHAHR NAME-DIGVIJAY SINGH rd
TH
B.TECH 3 YEAR (5 sem) MECHANICAL ENGG. ENROLLMENT NO.- 8814105011 (E1)
ACKNOWLEDGEMENT This Project Report is combined effort of many people who have contributed in their own ways in making this report effective and purposeful. In my report, I would like to take the opportunity of thanking all those who have been instrumental in preparing this report. Firstly, I would like to thank Prof. Ghanshyam Singh (Student welfare Dean and H.O.D) and R.K Baghel Sir (Asst. Proffesor), Jaypee University Anoopshahr, for giving me an Opportunity to carry out this Training. I would sincerely like to thank the employees and the officers of DLW, Varanasi for their help and support during the vocational training. Despite their busy schedule, they took out time for us & explained to us the various aspects of the working of the plant, from the production shops.
I would sincerely like to thank Mr. Manoj Kumar Singh (JE/L.M.S.) ,Mr. Rahul Madaan (JE/E.T.S.) and Mr. Satya (JE/T.T.C Instructor), Mr.A.K.Mandal (JE/T.M.S.) who was instrumental in arranging the vocational training at DLW Varanasi, and without whose help and guidance the training could not have materialized. I express my deep sense of gratitude to Mr.Vipin Srivastava (Principal, TTC) for given me such a great opportunity. I would also thank my institution & my faculty members without whom this report would have been a distant reality. I also extend my heartfelt thanks to my family & well wishers.
Preface The objectives of the practical training are to learn something about industries practically and to be familiar with the working style of a technical person to adjust simply according to the industrial environment. It is rightly said practical life is far away from theoretical one. We learn in class room can give the practical exposure or real life experience no doubt they help in improving the personality of the student in long run of life and will be able to implement the theoretical knowledge. As a part of academic syllabus of four year degree course in Mechanical Engineering, every student is required to undergo a practical training. I am student of the Third Year Mechanical Engineering & this report is written on the basis of practical knowledge of acquired by me during the period of practical training taken at Diesel Locomotive Works, Varanasi. This report is presented in very simple & understanding language. This is a short report prepared by me during training period and not cover all of the aspects due to time constraint.
Digvijay Singh M.E.(3rd Year) 8814105011
DECLARATION I Digvijay Singh, Enrollment No.-8814105011, student of B.Tech.(Mechanical. Engg.) 3rd year of Jaypee University ,Anoopshahr hereby declare that my project report on “DIESEL LOCOMOTIVE WORKS ” is an srcinal and authenticated work done by me.
I further declare that it has not been submitted elsewhere by any person in any of the institutes for the degree of bachelor’s of technology.
(Digvijay Singh)
VISION & MISSION Vision & Mission Our Vision -
To be a world class manufacturer of Diesel - electric locomotives."
”
Our Mission - "We shall achieve our vision through Continuous Improvement in the
areas of Product Quality, Research and Development, Supplier Partnership, Human Resource Development and Team Work with emphasis on Core Competence leading to Customer Satisfaction and Business Excellence."
CONNECTING ROD
S.No.
Topic
Page No.
1.
Introduction to DLW
3
2.
Classification of Locomotives
6
3.
Products of DLW
7
4.
EMD(Electro Motive Division) or GM loco
9
(i).
WDG-4000 HP GOODS LOCOMOTIVE
9
(ii).
WDP4-4000 HP PASSENGER LOCOMTIVE
10
5.
ALCO (American Locomotive Company)
13
(i).
1350 HP CAPE GAUGE LOCOMOTIVE VDM4
13
(ii).
2300 HP CAPE GAUGE LOCOMOTIVE
14
(iii).
2300 HP METER GAUGE LOCOMOTIVE
14
(iv).
BROAD GAUGE MAINLINE FREIGHT LOCOMOTIVE WDG3A
15
6. 7.
Diesel’s Advantages over steam BASIC CONCEPT
16 17
8.
PRODUCTION SHOPS
17
9.
Training Period
20
(i).
Light Machine Shop (LMS)
20
(ii)
Engine Erection Shop (EES)
21
(iii).
Loco Assembly Shop (LAS)
75
(iv).
Heavy Machine Shop (HMS)
82
10.
DLW SNAPSHOTS
84
11.
Learning Experience
102
Diesel Locomotive Works, Varanasi Brief History: August
1961
DLW set up as green field project in technical collaboration with ALCO, USA for manufacture of Diesel Electric Locomotives
January
1964
First Locomotive rolled out and dedicated to the Nation
January
1976
Entered in export market, first locomotive exported to
December
1977
Tanzania First diesel generating set commissioned
October
1995
The Transfer Of Technology (T-O-T) agrrement was signed
March
2002
The first indigeneous EMD WDG4 freight Loco manufactured
November
2002
3600 HP Engine produced
March
2003
The first indigeneous passenger version of EMD loco WDP4 manufactured
September
2003
Development of 16 cylinder 3300 HP Power upgraded DLW engine, WDM3D locomotive
November
2006
DLW manufactured first WDG4 locomotive equipped with IGBT based converter.
March
2007
First WDP4 locomotive equipped with IGBT based converter
April
2007
DLW has successfully switched over to use of microprocessor based control system on all its locomotives
March
2009
257 locomotives manufactured in 2008-09, highest ever locomotive production
November
2009
5690 locomotives upto 30th Nov’ 2009 (including 348 EMD locos)
INTRODUCTION TO DLW Diesel Locomotive Works (DLW) is a production unit under the ministry of railways. This was setup in collaboration with American Locomotive Company (ALCO), USA in 1961 and the first locomotive was rolled out in 1964. This unit produces diesel electronic locomotives and DG sets for Indian railways and other customers in India and Abroad. Subsequently a contract for transfer of technology of 4000 HP Microprocessor Controlled AC/AC Freight (GT 46 MAC) / passenger (GT 46 PAC) locomotives and family of 710 engines has been signed with electro motive division of GENERAL MOTORS of USA for manufacture in DLW. The production of these locomotives has now started and thus DLW is the only manufacturers of Diesel Electric Locomotives with both ALCO and General Motors technologies in the world.
Brief History: Set up in 1961 as a green-field project in technical collaboration with ALCO/USA to Manufacture Diesel Electric Locomotives. First
locomotive rolled out and dedicated to nation in January, 1964.
Transfer-of-Technology
agreement signed with General Motors/ USA in October, 95 to manufacture state-of-the-art high traction AC-AC diesel locomotives. A
flagship company of Indian Railways offering complete range of flanking products in its area of operation.
State-of-the art Design and Manufacturing facility to manufacture more than 150 locomotives per annum with wide range of related products viz. components and subassemblies.
Unbeatable trail-blazing track record in providing cost-effective, eco-friendly and reliable solutions to ever-increasing transportation needs for over three decades.
Fully geared to meet specific transportation needs by putting Price-Value-Technology equation perfectly right.
A large base of delighted customers among many countries viz. Sri Lanka, Malaysia, Vietnam, Bangladesh, Tanzania to name a few, bearing testimony to product leadership in its category.
SALIENT FEATURES: Annual production capacity Annual turn-over Total number of staff Workshop land Township area Covered area in shops Covered area of other service buildings Electrical power requirement (Average maximum demand) Electrical energy consumption (units/year) Standby power generation capacity
295-300 Locomotives 12000million 7223 89 Hectares 211 Hectares 86300 m2 73700 m2 3468 KVA 19.8 million 3000 KW
SOME FACTS ABOUT DIESEL ELECTRIC LOCOMOTIVE Cost of one loco Weight of one Loco Fuel Consumption; Max. Speed Dia of Wheel Wheel to Wheel Distance Length of Under Frame
12 to 14 crore (EMD) 8 crore (Alco) 121 Ton At Full Load - 540 lt/hr. ,Idle Load - 40 lt/hr. 160 Km/hr. 1092 mm 1596.5 mm 19962 mm
Diesel electric locomotive
In a diesel-electric locomotive, the diesel engine drives an electrical generator or alternator whose output provides power to the traction motors. There is no mechanical connection between the engine and the wheels.
Classification of locomotives Locos, except the older steam ones, have classification codes that identify them. This code is of the form WDG5A “ [ gauge ][ power ][load ][ series ][ sub type ]”
The first letter (gauge)
W- Indian broad gauge Y- meter gauge Z- narrow gauge(2.5 ft) N- narrow gauge (2 ft) The second letter (motive power)
D- Diesel C- DC electric (can run under DC traction only) A- AC electric (can run under AC traction only) CA- Both DC and AC (can run under both AC and DC tractions) B- Battery electric locomotive (rare) The third letter (load type)
G-goods P-passenger M-mixed traffic ; both goods and passenger S-Used for shunting U-Electric multiple units (E.M.U.) R-Railcars The fourth letter (series)
The series digit identifies the horsepower range of the locomotive. Example for the series letter ‘3’ means that the locomotive has power over 3000 hp but less than 4000 hp. The fifth letter (subtype) an optional letter or number that indicates some smaller variations in the basic model.
For ex: ‘A’ for 100 hp, ‘B’ for 200 hp and so on……..
For example, in “WDM 3A”:
“W” means broad gauge “D” means diesel motive power “M” means suitable for mixed (for both goods and passenger) service “3A” means the locomotive’s power is 3,100 hp (‘3’ stands for 3000 hp, ‘A’ denotes 100 hp more)
Or, in “WAP 5”: “W” means broad gauge “A” means AC electric traction motive power “P” means suitable for passenger service “5” denotes that this locomotive is chronologically the fifth electric locomotive model used by the railways for passenger service
PRODUCT OF DLW: DLW is an integrated plant and its manufacturing facilities are flexible in nature. These can be utilized for manufacture of different design of locomotives of various gauges suiting customer requirements and other products. The product range available is as under:
WDG4
4000 HP AC/AC Freight Traffic Locomotive
WDP4
4000 HPAC/AC Broad Gauge High Speed Locomotive
WDG3D
3400 HP AC/AC Broad Gauge Mixed Traffic Micro Processor Controlled Locomotive.
WDM3C
3300 HP AC/DC Broad Gauge Mixed Traffic Locomotive.
WDM3A
3100 HP AC/DC Broad Gauge Mixed Traffic Locomotive.
WDP3A
3100 HP AC/DC Broad Gauge High Speed Passenger Locomotive.
WDG3A
3100 HP AC/DC Broad Gauge Freight Locomotive.
WDM2
2600 HP AC/DC Broad Gauge Mixed Traffic Locomotive.
WDP1
2300 HP AC/DC Broad Gauge Intercity Express Locomotive.
WDM7
2150 HP DC/DC Broad Gauge Mixed Traffic Locomotive.
WDM6
1350 HP DC/DC Broad Gauge Mixed Traffic Locomotive.
YDM4
1350 HP AC/DC & DC/DC Broad Gauge Mixed traffic Locomotive.
EXPORT LOCO
2300 HP AC/DC Meter Gauge/Cape gauge Mixed Traffic Locomotive.
Diesel
Generating Sets
800 KW to 2500 KW
Spare Parts for engines, locomotives and generating sets.
DIESEL TRACTION ASSEMBLY AT DLW
1. 2. 3. 4.
Following types of diesel loco are being produced in the DLW: WDM – Wide Diesel Mixed WDP – Wide Diesel Passenger WDG – Wide Diesel Goods WDS – Wide Diesel Shunter
Products Assemble d at DLW
There are two types of engines are assembled at DLW EMD (Electro Motive Division) ALCO (American locomotive Company) EMD is two stroke diesel engines and ALCO is four stroke diesel engines. EMD engine is known as HHP (high Horse Power) or GM (general motor).EMD engine has maximum power is 5500 HP (4000 HP-5500 HP) and ALCO engine has maximum power is 3300 HP (1350 HP- 3300 HP)
EMD(Electro Motive Division) or gm loco Broad Gauge freight traffic Co-Co diesel electric locomotive with 16 Cylinder 4000 HP, AC-AC transmission, microprocessor controlled propulsion and braking with high traction high speed cast steel trucks. First turned out in 1999 with transfer of technology from General Motor (USA), this locomotive has exceptional fuel efficiency and very low maintenance requirements. It is specifically designed for heavy haul freight traffic requirements of Indian Railways for the 21st Century. The heart of loco Traction Control Converter uses the GTO devices (obsolete technology). Now the IGBT devices, has been introduced from Oct 2006. It is the latest technology and will be cost effective and gives higher reliability.The locomotive power has been upgraded to 4500 BCV and the first Loco (Loco No 12114) was manufactured in May 07.
State-of-Art, Microprocessor controlled AC-AC, Passenger Locomotive Powered with 16710G3B 4000HP Turbo charged Two stroke Engine. Fabricated rigid design Under frame, two stage suspension, High Traction High Speed 3 axle (HTSC) light weight cast truck frame attribute to high adhesion performance. First turned out in 2003, this locomotive has exceptional fuel efficiency and very low maintenance requirements. It is specifically designed for heavy haul passenger traffic requirements for Indian Railways. The WDP4 fleet is being upgraded by provision of hotel load feature along with power up gradation to 4500 HP. The prototype will be manufactured in the year 2007.
Diesel Engine
Transmission
16 Cylinder 710 G3B, 2 stroke, turbocharged after cooled Fuel Efficient Engine
Electrical AC-AC
Injection System Direct Unit Injector Governor Woodward
Suspension Axle hung / taper roller bearing Gear Ratio 77:17
4 Traction motor ( 3 in parallel per bogie)
Compression Ratio- 16:1 Lube Oil Sump Capacity 1073 Lts Truck
Brakes
High adhesion HTSC ( High Tensile Steel Cast) truck or bogie Adhesion 0.42
Electronic Air Brake System (KNORR-NYABComputer Controllled Braking) Air , hand , dynamic brake with fully blended with automatic brakes Pure air brake
Installed power Axle Load Gauge Wheel arrangement
General Characterstics (WDP4-4000HP PASSENGER LOCOMOTIVE) 4000HP
19.5 T 1676 mm A-A-I I-A-A
Wheel diameter Height Width Overall Length (Over Buffer Beam) Weight Max tractive effort Maximum speed
1092 mm 4201mm 3127 mm 19964 mm
Fuel tank capacity Locomotive Control
4000 lts EM 2000 with SIBAS-16 Traction Control
117 T 27 T 160 Kmph
ALCO (AMERICAN LOCOMOTIVE COMPANY)
TECHNICAL INFORMATION 1350 HP Locomotive having fabricated cape gauge Co-Co bogie. These locomotives have been supplied to Angola and Sudan.
Wheel Arrangement
Co-Co
Track Gauge
1067 mm Cape gauge
Weight
72 t
Overall Length
15600 mm
Wheel Diameter
921 mm
Gear Ratio
18: 93
Maximum Speed
90 Kmph
Diesel Engine
Type :ALCO 251 D 6 Cyl. 1350
Transmission
Electrical AC/DC
Brake
28LAV-1 system
Loco
Air, dynamic, parking
Fuel Tank Capacity
3000 Litres
(2). 2300 HP CAPE GAUGE LOCOMOTIVE
TECHNICAL INFORMATION 2300 HP Main Line Locomotive, having fabricated cape gauge Co-Co bogies. These are provided with two driver’s cabs, one at each end. These locomotives have been supplied to Angola and Sudan. Wheel Arrangement Co-Co Track Gauge 1067 mm Cape Gauge Weight 102 T Overall Length 17620 mm Wheel Diameter 921mm Gear Ratio 18 : 93 Maximum Speed 100 Kmph Diesel Engine Type: ALCO 251-B 12 Cyl. V- Engine HP 2300 Transmission Electrical AC/DC Brake IRAB-1 Loco Air, Dynamic, parking Fuel Tank Capacity 3000 Litres
(3). 2300HP METER GAUGE LOCOMOTIVE
TECHNICAL INFORMATION 2300 HP Main Line Locomotive, having fabricated meter gauge Co-Co bogies. These are provided with two drivers cabs, one at each end. These locos have been supplied to Malaysia, Senegal and Mali. Wheel Arrangement Co-Co Track Gauge 1000 mm Meter Gauge Weight 102 t Overall Length 17620 mm
Wheel Diameter Gear Ratio Maximum Speed Diesel Engine HP Transmission Brake Loco Fuel Tank Capacity
921 mm 18 : 93 100 Kmph Type: ALCO 251-B 12 Cyl. V- Engine 2300 Electrical AC/DC IRAB-1 Air, Dynamic, parking 3000 Liters
TECHNICAL INFORMATION Diesel Electric main line, heavy duty goods service locomotive, with 16 cylinder ALCO engine and AC/DC traction with micro processor controls. Wheel Arrangement
Co-Co
Track Gauge
1676 mm
Weight
123 t
Length over Buffers
19132 mm
Wheel Diameter
1092 mm
Gear Ratio
18 : 74
Min radius of Curvature
117 m
Maximum Speed
105 Kmph
Diesel Engine HP Brake
Type : 251 B,16 Cyl.- V 3100 IRAB-1
Loco Fuel Tank Capacity
Air, 6000Dynamic liters
DIESEL’S ADVANTAGES OVER STEAM
They can safely be operated by one person, making them ideal for switching/shunting duties in yards. The operating environment is much more attractive, being much quieter, fully weatherproof and without the dirt and heat that is an inevitable part of operating a steam locomotive. Steam locomotives require intensive maintenance, lubrication and cleaning before, during and after use. The thermal efficiency of steam was considerably less than that of Diesel engines.
PRODUCTION SHOPS:-
Production shops are divided in three divisions1. Block Divisions 2. Engine Divisions 3. Loco Divisions BLOCK DIVISION: 1. Heavy Weld Shop (HWS) 2. Heavy Machine Shop (HMS) ENGINE DIVISION: 1. Engine Erection Shop (EES)
2. Engine Testing Shop (ETS) 3. Light Machine Shop (LMS) 4. Sub Assembly Shop (SAS)
5. Rotor Shop (RS) 6. Heat Treatment Shop (HTS) LOCO DIVISION: 1. Loco Frame Shop (LFS) 2. Pipe Shop (PS) 3. Truck Machine Shop (TMS) 4. Traction Assembly Shop (TAS)
5. 6. 7. 8.
Sheet Metal Shop (SMS) Loco Assembly Shop (LAS) Loco Paint Shop (LPS) Loco Test Shop (LTS)
SERVICE SHOPS: 1. Maintenance Areas#1, 2, 3 (MA1 ,MA2 ,MA3) 2. Tool Room 3. Central Transport Shop RESEARCH &DEVELOPMENT:
1. R & D - a Customer centric Activity Committed to Innovation and Continuous Improvement; 2. Highly skilled Manpower capable of handling complete R&D activities; 3. A sophisticated design center with modern CAD/ CAE workstations equipped with Unigraphics and Ansys; 4. Back-up support from RDSO, a centralized R&D organization at corporate level; 5. Several milestones in the past - an enviable pedigree viz. a. srcinal ALCO design made 7% more fuel efficient; b. many design improvements leading to better performance, incorporated in the srcinal ALCO design; c. many new designs for locomotives such as WDP1, WDG2, WDP2 to name a few;
In Diesel Locomotive Works (DLW) there are many Workshops for learning and visiting. These workshops are HWS, HMS, EES, ETS, LMS, LAS, SAS, RS, HTS, LFS, PS, TMS, TAS, SMS, LAS, LPS and LTS e.t.c. These are the workshops in the Diesel Locomotive Works (DLW) where student get knowledge about practical experience. There are some workshops in TTC (Technical Training Center) like Fitting shop, Machine Shop and Welding Shop. In Diesel Locomotive Works (DLW) I have visited 4 Work shops in four week. These workshops are Light Machine Shop (LMS), Engine Erection Shop (EES), Loco Assembly Shop(LAS) and Heavy Machine Shop (HMS).
Following four workshop were assigned to me during my training period of four weeks: Light Machine Shop (LMS) Engine Erection Shop (EES) Loco Assembly Shop (LAS) Heavy Machine Shop (HMS)
This shop deals with the matching of various small components required for the power pack unit such as cam shaft, connecting rod, liners, gears levers, Piston pin, nuts and bolts bushes, various shafts, Damper, Clutch gear etc. 1. Grinding section 2. Gear section
3. Cam shaft section 4. Automatic turret lathe section 5. Vertical turret lathe section 6. Connecting rod section 7. Lathe section 8. Liners section 9. Drilling section 10.Milling section
Pre-inspected engine block, crankshaft, cylinder liners, pistons, connecting rods, cylinder heads, exhaust manifold, turbo supercharger and all related piping are used in assembly of engine. Electrical machines like traction alternator, auxiliary generator and exiter are there after coupled on the engine.
After this in Engine Testing Shop, The complete power pack with electrics are tested on computerized Engine Test Bed to verify prescribed horsepower output. Vital parameters of engine health are checked to assure the quality of product.
Diesel Engine: This is the main power source for the locomotive. It comprises a large cylinder block, with the cylinders arranged in a straight line or in a V. The engine rotates the drive shaft at up to 1,000 rpm and this drives the various items needed to power the locomotive. As the transmission is electric, the engine is used as the power source for the electricity generator or alternator, as it is called nowadays.
Main Alternator: The diesel engine drives the main alternator which provides the power to move the train. The alternator generates AC electricity which is used to provide power for the traction motors mounted on the trucks (bogies). In older locomotives, the alternator was a DC machine, called a generator. It produced direct current which was used to provide power for DC traction motors. Many of these machines are still in regular use. The next development was the replacement of the generator by the alternator but still using DC traction motors. The AC output is rectified to give the DC required for the motors.
Auxiliary Alternator: Locomotives used to operate passenger trains are equipped with an auxiliary alternator. This provides AC power for lighting, heating, air conditioning, dining facilities etc. on the train. The output is transmitted along the train through an auxiliary power line. In the US, it is known as "head end power" or "hotel power". In the UK, air conditioned passenger coaches get what is called electric train supply (ETS) from the auxiliary alternator.
Motor Blower: The diesel engine also drives a motor blower. As its name suggests, the motor blower provides air which is blown over the traction motors to keep them cool during periods of heavy work. The blower is mounted inside the locomotive body but the motors are on the trucks, so the blower output is connected to each of the motors through flexible ducting. The blower output also cools the alternators. Some designs have separate blowers for the group of motors on each truck and others for the alternators. Whatever the arrangement, a modern locomotive has a complex air management system which monitors the temperature of the various rotating machines in the locomotive and adjusts the flow of air accordingly.
Air Intakes: The air for cooling the locomotive's motors is drawn in from outside the locomotive. It has to be filtered to remove dust and other impurities and its flow regulated by temperature, both inside and outside the locomotive. The air management system has
to take account of the wide range of temperatures from the possible +40°C of summer to the possible -40°C of winter.
Rectifiers/Inverters: The output from the main alternator is AC but it can be used in a locomotive with either DC or AC traction motors. DC motors were the traditional type used for many years but, in the last 10 years, AC motors have become standard for new locomotives. They are cheaper to build and cost less to maintain and, with electronic management can be very finely controlled. To convert the AC output from the main alternator to DC, rectifiers are required. If the motors are DC, the output from the rectifiers is used directly. If the motors are AC, the DC output from the rectifiers is converted to 3-phase AC for the traction motors.
Turbo Charging: The amount of power obtained from a cylinder in a diesel engine depends on how much fuel can be burnt in it. The amount of fuel which can be burnt depends on the amount of air available in the cylinder. So, if you can get more air into the cylinder, more fuel will be burnt and you will get more power out of your ignition. Turbo charging is used to increase the amount of air pushed into each cylinder. The turbocharger is driven by exhaust gas from the engine. This gas drives a fan which, in turn, drives a small compressor which pushes the additional air into the cylinder. Turbocharging gives a 50% increase in engine power. The main advantage of the turbocharger is that it gives more power with no increase in fuel costs because it uses exhaust gas as drive power. It does need additional maintenance, however, so there are some type of lower power locomotives which are built without it.
The Diesel Engine: The diesel engine was first patented by Dr Rudolf Diesel (1858-1913) in Germany in 1892 and he actually got a successful engine working by 1897. By 1913, when he died, his engine was in use on locomotives and he had set up a facility with Sulzer in Switzerland to manufacture them. His death was mysterious in that he simply disappeared from a ship taking him to London. The diesel engine is a compression-ignition engine, as opposed to the petrol (or gasoline) engine, which is a spark-ignition engine. The spark ignition engine uses an electrical spark from a "spark plug" to ignite the fuel in the engine's cylinders, whereas the fuel incompressed the diesel engine's cylindersAt is this ignited by the caused by air being suddenly in the cylinder. stage, the heat air gets compressed into an area 1/25th of its srcinal volume. This would be expressed as a compression ratio of 25 to
1. A compression ratio of 16 to 1 will give an air pressure of 500 lbs/in² (35.5 bar) and will increase the air temperature to over 800°F (427°C). The advantage of the diesel engine over the petrol engine is that it has a higher thermal capacity (it gets more work out of the fuel), the fuel is cheaper because it is less refined than petrol and it can do heavy work under extended periods of overload. It can however, in a high speed form, be sensitive to maintenance and noisy, which is why it is still not popular for passenger automobiles.
Diesel Engine Types: There are two types of diesel engine, the two-stroke engine and the four-stroke engine. As the names suggest, they differ in the number of movements of the piston required to complete each cycle of operation. The simplest is the two-stroke engine. It has no valves. The exhaust from the combustion and the air for the new stroke is drawn in through openings in the cylinder wall as the piston reaches the bottom of the downstroke. Compression and combustion occurs on the upstroke. As one might guess, there are twice as many revolutions for the two-stroke engine as for equivalent power in a four-stroke engine. The four-stroke engine works as follows: Downstroke 1 - air intake, upstroke 1 compression, downstroke 2 - power, upstroke 2 - exhaust. Valves are required for air intake and exhaust, usually two for each. In this respect it is more similar to the modern petrol engine than the 2-stroke design.
Size Does Count: Basically, the more power you need, the bigger the engine has to be. Early diesel engines were less than 100 horse power (hp) but today the US is building 6000 hp locomotives. For a UK locomotive of 3,300 hp (Class 58), each cylinder will produce about 200 hp, and a modern engine can double this if the engine is turbocharged. The maximum rotational speed of the engine when producing full power will be about 1000 rpm (revolutions per minute) and the engine will idle at about 400 rpm. These relatively low speeds mean that the engine design is heavy, as opposed to a high speed, lightweight engine. However, the UK HST (High Speed Train, developed in the 1970s) engine has a speed of 1,500 rpm and this is regarded as high speed in the railway diesel engine category. The slow, heavy engine used in railway locomotives will give low maintenance requirements and an extended life. There is a limit to the size of the engine which can be accommodated within the railway loading gauge, so the power of a single locomotive is limited. Where additional power is required, it has become usual to add locomotives. In the US, where freight trains run into tens of thousands of tons weight, four locomotives at the head of a train are common and several additional ones in the middle or at the end are not unusual.
To V or not to V: Diesel engines can be designed with the cylinders "in-line", "double banked" or in a "V". The double banked engine has two rows of cylinders in line. Most diesel locomotives now have V form engines. This means that the cylinders are split into two sets, with half forming one side of the V. A V8 engine has 4 cylinders set at an angle forming one side of the V with the other set of four forming the other side. The crankshaft, providing the drive, is at the base of the V. The V12 was a popular design used in the UK. In the US, V16 is usual for freight locomotives and there are some designs with V20 engines.
Starting: A diesel engine is started (like an automobile) by turning over the crankshaft until the cylinders "fire" or begin combustion. The starting can be done electrically or pneumatically. Pneumatic starting was used for some engines. Compressed air was pumped into the cylinders of the engine until it gained sufficient speed to allow ignition, then fuel was applied to fire the engine. The compressed air was supplied by a small auxiliary engine or by high pressure air cylinders carried by the locomotive. Electric starting is now standard. It works the same way as for an automobile, with batteries providing the power to turn a starter motor which turns over the main engine (by rotating flywheel with help of a pair of DC starter motor and flywheel is coupled with the crankshaft). In older locomotives fitted with DC generators instead of AC alternators, the generator was used as a starter motor by applying battery power to it.
Governor BASIC DUTY: To maintain Engine RPM and HP constant at varying load
condition. ADDITIONAL FUNCTION OF woodward GOVERNOR
Starting & Stopping of Engine Limit the fuel during acceleration, retardation and low booster pressure Shutdown the engine in case of low lube oil pressure Reduces power in case of wheel slip, Transition etc.
Once a diesel engine is running, the engine speed is monitored and controlled through a governor. The governor ensures that the engine speed stays high enough to idle at the right speed and that the engine speed will not rise too high when full power is demanded. The governor is a simple mechanical device which first appeared on steam engines. It operates on a diesel engine as below.
The governor consists of a rotating shaft, which is driven by the diesel engine. A pair of flyweights are linked to the shaft and they rotate as it rotates. The centrifugal force caused by the rotation causes the weights to be thrown outwards as the speed of the shaft rises. If the speed falls the weights move inwards.
The flyweights are linked to a collar fitted around the shaft by a pair of arms. As the weights move out, so the collar rises on the shaft. If the weights move inwards, the collar moves down the shaft. The movement of the collar is used to operate the fuel rack lever controlling the amount of fuel supplied to the engine by the injectors.
In an automobile engine, the power is controlled by the amount of fuel/air mixture applied to the cylinder. The mixture is mixed outside the cylinder and then applied by a throttle valve. In a diesel engine the amount of air applied to the cylinder is constant so power is regulated by varying the fuel input. The fine spray of fuel injected into each cylinder to be regulated achieve required. Regulation achievedhas by varying the fuel to sent by thethe fuelamount pumpsof topower the injectors. The control is arrangement is shown in the diagram left.
The amount of fuel being applied to the cylinders is varied by altering the effective delivery rate of the piston in the injector pumps. Each injector has its own pump, operated by an engine-driven cam, and the pumps are aligned in a row so that they can all be adjusted together. The adjustment is done by a toothed rack (called the "fuel rack") acting on a toothed section of the pump mechanism. As the fuel rack moves, so the toothed section of the pump rotates and provides a drive to move the pump piston round inside the pump. Moving the piston round, alters the size of the channel available inside the pump for fuel to pass through to the injector delivery pipe. The fuel rack can be moved either by the driver operating the power controller in the cab or by the governor. If the driver asks for more power, the control rod moves the fuel rack to set the pump pistons to allow more fuel to the injectors. The engine will increase power and the governor will monitor engine speed to ensure it does not go above the predetermined limit. The limits are fixed by springs (not shown) limiting the weight movement.
Power Control The diesel engine in a diesel-electric locomotive provides the drive for the main alternator which, in turn, provides the power required for the traction motors. We can see from this therefore, that the power required from the diesel engine is related to the power required by the motors. So, if we want more power from the motors, we must get more current from the alternator so the engine needs to run faster to generate it. Therefore, to get the optimum performance from the locomotive, we must link the control of the diesel engine to the power demands being made on the alternator. In the days of generators, a complex electro-mechanical system was developed to achieve the feedback required to regulate engine speed according to generator demand. The core of the system was a load regulator, basically a variable resistor which was used to very the excitation of the generator so that its output matched engine speed. The control sequence (simplified) was as follows: 1. Driver moves the power controller to the full power position 2. An air operated piston actuated by the controller moves a lever, which closes a switch to supply a low voltage to the load regulator motor. 3. The load regulator motor moves the variable resistor to increase the main generator field strength and therefore its output. 4. The load on the engine increases so its speed falls and the governor detects the reduced speed. 5. The governor weights drop and cause the fuel rack servo system to actuate.
6. The fuel rack moves to increase the fuel supplied to the injectors and therefore the power from the engine. 7. The lever (mentioned in 2 above) is used to reduce the pressure of the governor spring. 8. When the engine has responded to the new control and governor settings, it and the generator will be producing more power. On locomotives with an alternator, the load regulation is done electronically. Engine speed is measured like modern speedometers, by counting the frequency of the gear teeth driven by the engine, in this case, the starter motor gearwheel. Electrical control of the fuel injection is another improvement now adopted for modern engines. Overheating can be controlled by electronic monitoring of coolant temperature and regulating the engine power accordingly. Oil pressure can be monitored and used to regulate the engine power in a similar way. Like an automobile engine, the diesel engine needs to work at an optimum temperature for best efficiency. When it starts, it is too cold and, when working, it must not be allowed to get too hot. To keep the temperature stable, a cooling system is provided. This consists of a water-based coolant circulating around the engine block, the coolant being kept cool by passing it through a radiator. The coolant is pumped round the cylinder block and the radiator by an electrically or belt driven pump. The temperature is monitored by a thermostat and this regulates the speed of the (electric or hydraulic) radiator fan motor to adjust the cooling rate. When starting the coolant isn't circulated at all. After all, you want the temperature to rise as fast as possible when starting on a cold morning and this will not happen if you a blowing cold air into your radiator. Some radiators are provided with shutters to help regulate the temperature in cold conditions.
Lubrication Like an automobile engine, a diesel engine needs lubrication. In an arrangement similar to the engine cooling system, lubricating oil is distributed around the engine to the cylinders, crankshaft and other moving parts. There is a reservoir of oil, usually carried in the sump, which has to be kept topped up, and a pump to keep the oil circulating evenly around the engine. The oil gets heated by its passage around the engine and has to be kept cool, so it is passed through a radiator during its journey. The radiator is sometimes designed as a heat exchanger, where the oil passes through pipes encased in a water tank which is connected to the engine cooling system. The oil has to be filtered to remove impurities and it has to be monitored for low pressure. If oil pressure falls to a level which could cause the engine to seize up, a "low
oil pressure switch" will shut down the engine. There is also a high pressure relief valve, to drain off excess oil back to the sump. Like an automobile, a diesel locomotive cannot start itself directly from a stand. It will not develop maximum power at idling speed, so it needs some form of transmission system to multiply torque when starting. It will also be necessary to vary the power applied according to the train weight or the line gradient. There are three methods of doing this: mechanical, hydraulic or electric. Most diesel locomotives use electric transmission and are called "diesel-electric" locomotives. Mechanical and hydraulic transmissions are still used for lighter locomotives. Diesel-Electric Types Diesel-electric locomotives come in three varieties, according to the period in which they were designed. These three are: DC - DC (DC generator supplying DC traction motors); AC - DC (AC alternator output rectified to supply DC motors) and AC - DC - AC (AC alternator output rectified to DC and then inverted to 3-phase AC for the traction motors). The DC - DC type has a generator supplying the DC traction motors through a resistance control system, the AC - DC type has an alternator producing AC current which is rectified to DC and then supplied to the DC traction motors and, finally, the most modern has the AC alternator output being rectified to DC and then converted to AC (3phase) so that it can power the 3-phase AC traction motors. Although this last system might seem the most complex, the gains from using AC motors far outweigh the apparent complexity of the system. In reality, most of the equipment uses solid state power electronics with microprocessor-based controls.
Bore......................................................................................................................230.19 mm (9-1/16") Stroke ........................................................................................................................... 279.4 mm (11") Angle between banks .......................................................................................................................45 Compression ratio .......................................................................................................................... 16:1 Displacement per cyl......................................................................................11 635 cm 3 (710 cu. in.) Rotation (facing rear end) .........................................................................................Counterclockwise Firing order 8-cyl. ..............................................................................................................................1,5,3,7,4,8,2,6 12-cyl. ..........................................................................................................1,12,7,4,3,10,9,5,2,11,8,6
12N-cyl..........................................................................................................1,7,4,10,2,8,6,12,3,9,5,11 16-cyl. ......................................................................................1,8,9,16,3,6,11,14,4,5,12,13,2,7,10,15 20-cyl. ..................................................................1,19,8,11,5,18,7,15,2,17,10,12,3,20,6,13,4,16,9,14 Exhaust valves (per cyl.) ......................................................................................................................4 Main bearings 8-cyl. ..................................................................................................................................................5 12-cyl. ................................................................................................................................................7 16-cyl. ..............................................................................................................................................10 20-cyl. ..............................................................................................................................................12 Governor (Woodward) ................................................................................................................PGEV OR Electronic engine control (EMD).............................................................................................EMDEC Scavenging ............................................................................................................................... Uniflow Type of scavenging blower ...................................................................................... Turbo-Centrifugal Cooling system ................................................................................................................... Pressurized Water pump(s)..................................................................................................................... Centrifugal Lubricating oil system.......................................................................................................Full pressure Lubricating oil pumps ............................................................................................... Helical gear type Fuel injection ..............................................Mechanical or Electronic Unit injector with needle valve Fuel pump ...........................................................................................................Positive displacement Engine starting 8-cyl. ................................................................................................................... Single electric motor 12, 16-cyl. ............................................................................................................Dual electric motors 20-cyl.......................................................................................................Dual electric/dual air motors RATINGS Full time low idle speed(s).......................................................................................200/235/255 RPM Normal Idle speed(s).........................................................................................269/274/290/299 RPM Full speed(s)...........................................................................................................904/950/1000 RPM Output (Traction) H.P. 8-cyl. ....................................................................................................................................1350 HP 12-cyl. ........................................................................................................................... 3000/3200 HP 16-cyl. ................................................................................................................. 4000/4300/4500 HP 20-cyl. ........................................................................................................................... 5000/5500 HP
CYLINDER HEAD The cylinder head, Figure (a), is made of cast iron alloy with cast passages for water and exhaust gases. Drilled water holes at the bottom of the cylinder head match the water discharge holes in the liner. Cooling water is circulated through the head and is discharged through an elbow mounted on the side of the head mounting flange. Exhaust passages in the cylinder head line up with elbows in the crankcase, which conduct the exhaust gases through the water discharge manifold to the exhaust manifold.
A well is located in the center of the cylinder head for application of the unit fuel injector. To ensure correct positioning of the injector, a mating hole for the injector locating dowel is located in the head. Figure (b) on page 37, shows the rocker arms, exhaust valves, valve bridges with springs, valve guides, overspeed trip pawl, fuel injector, and other related items making up a complete cylinder head assembly.
Fig (a) Cylinder Head With Valves
Fig (b) Complete Cylinder Head Assembly, Exploded View
EXHAUST VALVES The long stem exhaust valves, Figure on page 38, are fabricated from a forged nickelchromium alloy steel head and a tip hardened steel stem by means of friction welding. Single bead valve locks hold the valve in a tapered spring seat. Precision valve guides ensure proper valve seating.
Figure of typical exhaust valve EXHAUST VALVE BRIDGE ASSEMBLY
The valve bridge, Figure (A) & (B), operates two exhaust valves from one rocker arm. A spring and spring seat are held on the valve bridge stem by a lock ring. The spring seat
rests in a socket in the cylinder head and the spring applies pressure to maintain contact between the valve bridge and the rocker arm. The hydraulic lash adjuster maintains zero lash between the end of the valve stem and the valve bridge. Lube oil flows from the rocker arm through a drilled passage in the valve bridge to the top of the lash adjuster, past the ball check, and into the body. When the rocker arm depresses the valve bridge, a slight movement of the plunger in the lash adjuster seats the ball check, trapping the oil. Since the oil is practically incompressible, further movement of the rocker arm causes the lash adjuster plunger to force open the exhaust valve.
Fig (A) & (B) Valve bridge assembly -------------------------------------------------------------------------------ROCKER ARM ASSEMBLY
Three rocker arms, Figure. on page 41, are mounted on the cylinder head. Two rocker arms actuate the four exhaust valves, the third operates the injector. The rocker arms are operated directly by the camshaft through a cam follower roller mounted at the fork end of each rocker arm. The opposite end of each rocker arm has an adjusting screw and locknut for setting the injector timing and adjusting the hydraulic lash adjusters. The injector rocker arm, although similar in appearance to the exhaust rocker arm, is stronger than the exhaust rocker arm, and can be identified by the yoke at the cam follower end which is square-shaped on the injector rocker arm, but V-shaped on the exhaust rocker arm. Also, only the injector rocker arm has the machined notch for the overspeed trip. Injector and exhaust rocker arms are not interchangeable. Lubricating oil is supplied to the cam follower assembly and the adjusting screw end through drilled passages in the rocker arm.
Typical Rocker Arm
PISTON ASSEMBLY The piston assembly consists of a cast iron alloy piston, Figure a1., four compression rings, and two oil control rings. A “trunnion” type piston carrier, Figure a3., on page 43, is used with the piston assembly to allow the piston to rotate or “float” during engine operation. The carrier supports the piston at the internal piston platform. A thrust washer, Figure a2., is used between the platform and the carrier. The carrier is held in position in the piston by a snap ring inside the piston. Oil taken up by the two oil control rings passes through the oil holes at the bottom of the piston.
Fig (a1)Typical Cast Iron Alloy Piston
Figure (a2). Piston Carrier And Thrust Washer
Figure a3. Piston Pin, Insert Bearing, And Carrier
An insert bearing, Figure a3., on page 43, fits into a broached slot in the carrier.The highly polished piston pin, Figure a3., is applied in the carrier together with the insert bearing as a fitted assembly. Two retainers, one at each end, are bolted to the piston carrier to prevent the pin and bearing assembly from sliding out of the carrier. The assembly is bolted to the upper end of the connecting rod. The piston pin and insert bearing are of the “rocking” type design with offset piston pin center. This produces mechanical separations between the pin and bearing alternately
on the three bearing lands during the course of a power cycle. This provides a pumping action for oil circulation through the pin and bearing area. Internal parts of the piston are lubricated and cooled by the piston cooling oil. Cooling oil is directed through a drilled passage in the piston carrier, circulates about the underside of the piston crown area, and then drains through two holes in the carrier located at the taper as shown in Figure a3.
PISTON AND ROD INSPECTION Piston and connecting rod assemblies, Figure b1., can be inspected while installed in an engine provided the engine is shut down and the air box and oil pan inspection covers are removed. Precautions should be taken, before proceeding, to prevent the engine from being
started. Open all cylinder test valves to facilitate rotation of the crankshaft, using the turning jack.
Figure b1. Piston And Connecting Rod Assembly, Cross-Section
CONNECTING ROD ASSEMBLY The “trunnion type” connecting rods, Figurec1., are interlocking, blade and fork construction. The blade rod moves back and forth on the back of the upper crankpin bearing and is held in place by a counterbore in the fork rod. One end of the blade rod slipper foot is longer than the other and is known as the “long toe.” The blade rods are installed in the right bank with the long toe toward the center of the engine.
The fork rods are installed in the left bank. Serrations on the sides of the rod at the bottom match similar serrations on the fork rod basket, Figure c1.. The rod basket consists of two halves, held together at the bottom by three bolts and self-locking nuts. The fork rod and basket are bolted together at the serrations. Fork rods and baskets are not interchangeable since they are line bored as an assembly. Both the fork rod and basket are stamped with an identical assembly serial number for matching and identification purposes.
Figure c1. Connecting Rods, Bearing Shells, And Basket
CYLINDER LINER The cylinder liner, Figure (a)., consists of casting having two separate water jackets applied and brazed to the casting. A row of air inlet ports completely encircles the liner. A flange on the outboard side of the liner below the ports, provides a connection for the liner water supply line. A water deflector, Figure (b). on page 48, prevents the inlet water from impinging directly on the inner liner wall.
Figure (a). Cylinder Liner The inlet water circulates around the bottom of the liner, progressing upward to discharge
into the cylinder head through twelve drilled holes. A copper clad steel gasket provides a combustion seal between the cylinder head and the liner. The gasket is fitted with twelve seal assemblies, each consisting of a Teflon heat dam bonded to a Silicone rubber grommet. A counterbore around each drilled hole in the liner accommodates the seal assemblies, as shown in Figure (c). on page 48, to seal the water passages when the cylinder head is installed.
Figure (b). Water Inlet Deflector
Figure (c). Typical Water Seal Assembly In Counterbore
CYLINDER POWER ASSEMBLY:
Rocker Arm Oil Line Removal Basket Bolt Wrench Application
Piston Pin
Piston Pin Insert Bearing Installation
The crankshaft assembly is made up of the crankshaft, main bearings and caps, thrust collar, torsional damper, and the accessory drive gear. Although the accessory drive gear is part of the crankshaft assembly, it will be described as part of the accessory drive gear train. The accessory drive gear train provides power from the crankshaft to drive the oil pump(s), water pumps, and the governor (if applied). The crankshaft, Figure (i), is a CRANKSHAFT drop forging of carbon steel material with induction hardened main and crankpin journals. On 8 and 12-cylinder engines, the crankshaft is a one piece forging. On 16 and 20-cylinder engines, the crankshaft may be a one piece forging or made up of two sections whose center flanges are bolted together. Counterweights are provided to give stable operation and all crankshafts are dynamically balanced. Drilled oil passages provide for lubrication of the main bearings as shown in Figure (ii)., on page 52.
Figure (i). Typical Engine Crankshafts
Figure (ii). Crankshaft Oil Passages
The main bearing shells, Figure (iii), are precision type steel-backed lead-bronze, with a thin layer of lead-tin. Tangs in the bearings locate them in the proper axial position and prevent bearing turning. Upper and lower bearing shell halves are not interchangeable. Lower main bearing shells have two tangs on each side which fit into the main bearing cap. Upper main bearing shells have one tang which fits into a groove on the right side of the “A” frame bore. Upper shells can be rotated out, in a direction opposite to normal crankshaft rotation, when the lower bearing and cap are removed.
Figure (iii). Main Bearing Shell And Cap
THRUST COLLAR The two thrust collars, Figure (iv), are solid bronze and are semicircular in shape. One face of each collar has “thumb print” oil depressions to ensure adequate lubrication. They are placed in the counterbore of each center bearing “A” frame and are held in position by the bearing caps. Their purpose is to limit the longitudinal movement of the crankshaft.
Fig. (iv) Crankshaft Thrust Collars (Two Collars For Each Engine)
The gear type damper, Figure (v), is a hydraulic paddle wheel device which absorbs torsional vibrations of the crankshaft by forcing engine lubrication oil through narrow passages in the damper. The damper consists of a spider, with external spur teeth, an intermediate ring, with internal spur teeth, and two outer side plates secured with bolts and nuts. A continuous circulation of oil is provided to the damper through an oil passage in the crankshaft. Oil flows from the chamber in the center of the damper through radial holes, beginning in the spider hub and ending at the fillet radius at the base of each tooth. The passages contain a narrowed section at the spider hub to provide an oil flow restriction. The spider is designed so that each tooth is directly supplied with oil. An auxiliary circumferential oil groove is machined into each side face of the spider to supply oil for
the rubbing surfaces between the spider and outer plate. These grooves are supplied by means of passages connecting the grooves to the radial holes.
Figure (v). Gear Type Damper, Exploded View
The intermediate ring is ground on both sides to a uniform thickness, slightly thicker than the spider. This difference in thickness provides the axial clearance necessary for proper oil passage. In addition, clearance between the intermediate ring and the spider is provided to allow the ring to “float” on the oil film generated at the tips of the spider teeth.
The ring gear, Figure (vi)., on page 56, is used on engines equipped with starting motors. Engaging the teeth on the ring gear rotates the crankshaft for engine starting or selects a crankshaft position when using an engine turning gear device. The ring gear pilots on the engine side of the coupling disc and is bolted to the coupling disc. The coupling disc serves as the coupling between the engine crankshaft and the driven shaft. Degree and top dead center markings are stamped on the outer rim of the coupling disc. Holes are also provided around the circumference of the rim for insertion of a turning bar to manually rotate the crankshaft. Engine coupling discs of the same type are interchangeable, providing top dead center pointer location on the engines is the same. The serrated coupling is assembled without using body bound bolts and for this reason has no reamed holes. All rim bolts are the same size. The coupling disc should be applied to the crankshaft with
Figure (vi) Typical Ring Gear And Coupling Disc Installation
the small “0” marks on the coupling disc and the crankshaft coinciding. This will position the coupling with the point at the 0 mark on the rim when the No. 1 piston is at TDC.
Injector timing when piston is at T.D.C (16-cylinder 4500 HP ,GM loco or HHP engine) e.g. Cyl no. 1 ;Degree of flywheel 0 means piston of cylinder no.1 is at T.D.C position when flywheel degree is 0 Cyl. No. 8 ;Degree of flywheel 22 &1/2 means piston of cylinder no.8 is at T.D.C position when flywheel degree is 22&1/2
Firing order of ALCO 1350 HP engine (6-cylinder)
Power necessary to drive the camshafts, and the turbocharger before it becomes free wheeling, is supplied through the gear train at the rear of the engine. Figure 7-1 shows the gear train before the camshaft drive housing and turbocharger are installed, and Figure 7-2., on page 60 shows a cross-section of the gear train. The gear train, Figure 7-1, consists of a crankshaft gear mounted on the crankshaft, No. 1 idler gear, a clutch (or spring) drive gear assembly, and the left and right camshaft drive gears. The clutch (or spring) drive gear assembly is made up of the No. 2 idler gear, a clutch (or spring) assembly, and the turbocharger drive gear.
Figure 7-1. Camshaft Gear Train
Figure 7-2. Camshaft Gear T rain, Cross-Section
The clutch drive gear assembly, Figure 7-3, consists of the No. 2 idler gear, the turbocharger drive gear, and an overrunning clutch assembly mounted between the two gears to provide a mechanical connection of the turbocharger to the engine gear train during engine start up, light load operation, and rapid acceleration. The clutch drive gear assembly should be removed as an assembly and then disassembled for inspection.
Figure 7-3. Clutch Drive Gear Assembly
The camshaft assembly, Figure (a1)., on page 62, consists of flanged segments, front and rear stubshafts, and a spacer is used on 12, 16, and 20-cylinder engines between the center segments. Each segment spans three (12-cyl.), four (8 & 16-cyl.), and five (20-cyl.) cylinders. Segment flanges are marked as shown in Figure (a1) to aid in correct assembly. At each cylinder there are two exhaust cams, one injector cam, and two bearing journals.
Figure (a1). Typical Camshaft Assemblies (16 -Cyl.)
Exhaust valve timing is very important as it ensures correct relationship of valve operation with the other events in the cylinder power cycle. To check or adjust exhaust valve timing, it is necessary to know the top dead center of each cylinder as shown in Table 1 and 2., on page 63 and 64. Items which govern correct valve timing are given in the following procedures.
Table (a1). Firing Order And Top Dead Center
Table (a2) Firing Order And Top Dead Center - continued
The turbocharger assembly, Figure 1, is primarily used to increase engine horsepower and provide better fuel economy through the utilization of exhaust gases. The turbocharger has a single stage turbine with a connecting gear train. The connecting gear train is necessary for engine starting, light load operation, and rapid acceleration. Under these conditions there is insufficient exhaust heat energy to drive the turbine fast enough to supply the necessary air for combustion, and the engine is actually driving the turbocharger through the gear train assisted by exhaust gas energy. When the engine approaches full load, the heat energy in the exhaust, which reaches temperatures approaching 538C (1000F) is sufficient to drive the turbocharger without any help from the engine. At this point, an overrunning clutch in the drive train disengages and the turbocharger drive is mechanically disconnected from the engine gear train.
Figure 1. Typical Turbocharger Assembly On turbochargers for 8-cyl. engines, the turbine shaft is driven by the engine gear train
through a series ofgear gearsassembly, in the turbocharger. turbocharger drive gear, which is a part of the spring drive meshes withA the turbocharger idler gear, driving the carrier drive gear. The carrier shaft drives the sun gear on the turbine shaft through three planet gears when the turbocharger is being driven by the engine. The sun gear
meshes with the planet gears which, in turn, mesh with a ring gear in the overrunning clutch assembly. The ring gear is fixed, when the engine is driving the turbine, because the direction of torque at the ring gear locks the overrunning clutch. When the turbine is being driven entirely by exhaust gas energy, the direction of torque is reversed and the clutch overruns, allowing the ring gear to rotate .
The exhaust gases from the engine cylinders are discharged from the cylinder heads into the exhaust manifold, Figure (a), and to the turbocharger turbine. Going through the turbine, the gases expand to atmospheric pressure, pass through the turbocharger ducting, and are then expelled from the engine.
Figure (a). Typical Exhaust Manifold
The exhaust manifold is made up of chamber assemblies, expansion joints, and adapter assembly. The expansion joints, which are used between chamber assemblies and between the adapter and screen assembly and the turbocharger, provide the necessary flexibility to compensate for expansion and contraction of the manifold due to temperature changes. The adapter assembly contains a trap type screen to prevent the entry of foreign objects into the turbocharger. A trap box is attached to the outer body which collects small debris.
Figure (b). Typical Exhaust Manifold-To-Turbocharger Adapter Assembly .
Prelubrication of a new engine, an engine that has been overhauled, or an engine which has been inoperative for more than 48 hours is a necessary and important practice. Prelubrication alleviates loading of unlubricated engine parts during the interval when the lube oil pump is filling the passages with oil. It also offers protection by giving visual evidence that oil distribution in the engine is satisfactory. The engine cooling system consists of engine driven centrifugal water pumps, replaceable inlet water manifolds with an individual jumper line to each liner, cylinder head discharge elbows, and an outlet manifold through which cooling water is circulated. The centrifugal water pumps are mounted on the accessory drive housing and are driven by the governor drive gear (on 8, 12, and 16-cylinder engines) or by the accessory drive gear (on 20-cylinder engines). A representative illustration of the 8, 12, and 16-cylinder engine cooling system is shown in Figure (A). Cooling water is circulated in a counter-flow direction through each aftercooler, Figure(A), located in the turbocharger air discharge duct, to cool the air before it enters the engine air box. (NOTE: Aftercooler piping used on all 710G3B and 710G3C engines differs from that used on previous 645 and 710 engines in order to achieve water counter-flow through both aftercoolers).
The engine (and aftercoooler) discharge water flows through an external cooling system to dissipate the heat taken up in the engine. This system consists of a water tank, water level gauges, temperature gauges, radiators, and connecting piping. Figure (A). Typical Standard Jacket Water Cooling System Schematic
Refer to Figure 1 and Figure 2., on page 68 and 69 for piping details. Pump outlet elbows (or piping) conduct water from the pump(s) to the removable water inlet manifolds located in each air box. On engines with standard jacket water cooling systems, each water inlet manifold is connected at the rear end plate to an aftercooler water inlet pipe. The rear end flange of the inlet manifold is equipped with two seals which prevent the leakage of air from the air box. A flange at the front end of the inlet manifold contacts the outer face of the front end plate when the manifold is installed. On engines with separate aftercooling water systems, separate aftercooler piping is used on the outside of the engine. The water inlet manifolds in each air box are blocked off at the rear end flange.
Figure (1). Typical Standard Jacket Water Cooling System Piping
Figure 2. Typical Separate Aftercooling System Piping
Each liner is individually supplied with coolant from the water manifold through a water inlet tube assembly. A deflector is used at each liner water inlet to divert the water and prevent direct impingement on the inner liner wall. Water enters the cylinder head through 12 discharge holes at the top of the liner. WATER LEAKS
If loss of water in the cooling system is noticed, check for leakage at piping, pump seals, jumper tube connections, cylinder head discharge elbow, junction of head to liner, and check for liner or cylinder head cracks .
AFTERCOOLER An aftercooler is located on each side of the turbocharger to cool the air entering the air box for each bank of the engine. Cooling the air compressed in the turbocharger reduces the temperature of the air, which increases air density and improves engine operating efficiency.
The aftercoolers are heat exchangers of box-like construction consisting of a tube nest, through which water is circulated, and fins to aid in the transfer of heat from the compressed air entering the engine air box. On engines with standard jacket water cooling systems, the aftercoolers receive water from the rear (discharge) ends of the water inlet manifolds that pass through each air box. The water leaving the aftercoolers on these engines is piped through the engine discharge manifold to the engine jacket water cooling radiators.
The engine cooling water pump(s), Figure (i), and Figure (ii), on page 70 and 71, are selfdraining centrifugal type pumps which rotate in the opposite direction of the engine crankshaft. Pumps used may be either standard or high capacity in combinations, depending on application.
Figure (i).Typical Standard Jacket Water Pump
Figure (ii).Typical Water Pump Installation (8, 12 & 16-Cylinder Engines w/ Separate Aftercooling).
The pump(s) used on engines with standard jacket water cooling systems are basically the same pump, but are carried under two part numbers in order to identify the right and left bank pumps. The only difference between the pumps is the position of the impeller housing in relation to the support housing. The position of the impeller housing may be changed on either pump to permit use on the opposite bank.
The basic engine fuel system, Figure (a), consists of the fuel injectors, the engine mounted fuel filter, fuel supply and return manifolds, and engine mounted fuel lines. Components external to the engine such as the motor driven fuel pump, fuel tank,
fuel suction strainer, the primary fuel filter, and connecting fuel lines complete the system. In operation, fuel from the fuel tank is drawn up by the fuel pump through a suction strainer and primary fuel filter for delivery to the engine mounted (secondary) filter. It then passes through the filter elements to the engine fuel supply lines and injector inlet filter at each cylinder - into the injector. A small portion of the fuel supplied to each injector is pumped into the cylinder, at a very high pressure, through the needle valve and spray tip of the injector.
Figure (a). Basic Fuel System (Governor Controlled Engine Shown)
MECHANICAL UNIT INJECTOR (MUI) The MUI injector, Figure (A), is located and seated in a tapered hole in the center of each cylinder head, with the spray tip protruding slightly below the bottom of the
head. It is positioned in the head by a dowel and held in place by an injector crab and nut.
Figure (A). MUI Fuel Injector .
The oil filter, Figure (i), is used on the governor to protect the servo bellows assembly screen and orifice stack. The filter is contained in a housing that is mounted on the side plate.
Figure(i). Oil Filter .
FLUSHING GOVERNOR Governor flushing in not recommended as a regular maintenance item. Instead, the governor should be disassembled and cleaned if operation is impaired due to dirt or other foreign particles in the governor. OVERSPEED CONTROL An overspeed trip mechanism, normally provided on governor controlled engines, is used to mechanically prevent the injection of fuel into the cylinders should the engine speed become excessive. If the engine speed should increase to the specified limits, the overspeed mechanism will shut down the engine. STARTING SYSTEM The engine starting system consists of either dual electric starting motors (12 & 16cyl. engines), or a single electric motor (8-cyl. engines) with heavy duty sprag drives, or a combination of dual electric starting motors along with dual air starting motors (20-cylinder engines), as well as associated electrical wiring and/or air piping and controls. The dual electric (and the dual air) starting motors are mounted one above the other and bolted to bracket assemblies which, in turn, are attached to the rear end plate at the sides of the engine, Figure (a). A single electric starting motor will mount in the upper position on a bracket assembly. A flywheel pointer is bolted on
the face of the bracket assembly.
Figure(a).Typical Dual Electrical Starting Motor Application
Tested engines are receives from Engine Division. Similarly under frames are received from Loco frame shop and assembled trucks from Truck machine shop.
Super structure compartments and contractor compartment are received from respective manufacturing and assembly shops of Vehicle Division.
Important alignments like crank shaft deflection, compressor alignment and Eddy Current clutch/radiator fan alignment are done during assembly stage.
Electrical control equipments are fitted and control cable harnessing is undertaken.
The complete locomotive is thus assembled before being sent onwards for final testing and spray painting.
All locomotive are rigorous tested as per laid down test procedures before the locomotive is taken up for final painting and dispatch for service.
Main Alternator The diesel engine drives the main alternator which provides the power to move the train. The alternator generates AC electricity which is used to provide power for the traction motors mounted on the trucks (bogies). In older locomotives, the alternator was a DC machine, called a generator. It produced direct current which was used to provide power for DC traction motors. Many of these machines are still in regular use. The next development was the replacement of the generator by the alternator but still using DC traction motors. The AC output is rectified to give the DC required for the motors.
Auxiliary Alternator Locomotives used to operate passenger trains are equipped with an auxiliary alternator. This provides AC power for lighting, heating, air conditioning, dining facilities etc. on the train. The output is transmitted along the train through an auxiliary power line. In the US, it is known as "head end power" or "hotel power". In the UK, air conditioned passenger coaches get what is called electric train supply (ETS) from the auxiliary alternator.
Air Intakes The air for cooling the locomotive's motors is drawn in from outside the locomotive. It has to be filtered to remove dust and other impurities and its flow regulated by temperature, both inside and outside the locomotive. The air management system has to account-40°C of theofwide range of temperatures from the possible +40°C of summer to take the possible winter.
Rectifiers/Inverters The output from the main alternator is AC but it can be used in a locomotive with either DC or AC traction motors. DC motors were the traditional type used for many years but, in the last 10 years, AC motors have become standard for new locomotives. They are cheaper to build and cost less to maintain and, with electronic management can be very finely controlled. To convert the AC output from the main alternator to DC, rectifiers are required. If the motors are DC, the output from the rectifiers is used directly. If the motors are AC, the DC output from the rectifiers is converted to 3-phase AC for the traction motors.
Batteries Just like an automobile, the diesel engine needs a battery to start it and to provide electrical power for lights and controls when the engine is switched off and the alternator is not running.
BATTERIES
Traction Motor Since the diesel-electric locomotive uses electric transmission, traction motors are provided on the axles to give the final drive. These motors were traditionally DC but the development of modern power and control electronics has led to the introduction of 3phase AC motors. For a description of how this technology work. There are between four and six motors on most diesel-electric locomotives.
Traction motor
Pinion/Gear The traction motor drives the axle through a reduction gear of a range between 3 to 1 (freight) and 4 to 1 (passenger).
Fuel Tank A diesel locomotive has to carry its own fuel around with it and there has to be enough for a reasonable length of trip. The fuel tank is normally under the loco frame. The capacity of fuel tank is between 4500 ltrs. to 6000 ltrs(20-cylinder) it is vary according to the model of engine.
Air Compressor The air compressor is required to provide a constant supply of compressed air for the locomotive and train brakes.
Drive Shaft The main output from the diesel engine is transmitted by the drive shaft to the alternators at one end and the radiator fans and compressor at the other end .
Radiator and Radiator Fan The radiator way as inwithin an automobile. Water isrange distributed engine block works to keepthe thesame temperature the most efficient for thearound the engine. The water is cooled by passing it through a radiator blown by a fan driven by the diesel engine.
Sand Box Locomotives always carry sand to assist adhesion in bad rail conditions. Sand is not often provided on multiple unit trains because the adhesion requirements are lower and there are normally more driven axles.
Truck Frame This is the part (called the bogie) carrying the wheels and traction motors of the locomotive.
TRUCK FRAME
A diesel-mechanical locomotive is the simplest type of diesel locomotive. As the name suggests, a mechanical transmission on a diesel locomotive consists a direct mechanical link between the diesel engine and the wheels. In the example below, the diesel engine is in the 350-500 hp range and the transmission is similar to that of an automobile with a four speed gearbox. Most of the parts are similar to the diesel-electric locomotive but there are some variations in design mentioned below.
Wheels slip is the bane of the driver trying to get a train away smoothly. The tenuous contact between steel wheel and steel rail is one of the weakest parts of the railway system. Traditionally, the only cure has been a combination of the skill of the driver and the selective use of sand to improve the adhesion.
These wheels are having wear adapted profile to RDSO drawing .
ECC 1 –Power distribution and converts DC current into AC current for traction motors. ECC 2 – For battery charging assembly ECC 3 – Radiator controlling system ECC 4 –For communication between CAB1 and CAB2 , In twin cab engines Engine can be started from both of the cabs TCC 1 –Control traction motors of bogie 1 TCC 2 – control traction motors of bogie 2
As the name suggests in heavy machine shop the finished engine blocks are
prepared then machined upon to produce holes for power pack assembly.
This shop carries out the machining of Cylinder block of ALCO and HHP engines
main base ,bearing cap and alignment of “A” frame which holds the crankshaft.
Planning, Milling, Drilling, Tapping, Boring, etc. The main machines in HMS are:
1. Angular boring machine (TAL/HMT)
1. CNC Portal milling (Waldrich Coburg) 2. Radial Drill (max. 25 ton)
4. Hydraulic press
DLW SNAPSHOTS
FORK(LEFT) AND BLADE(RIGHT) TYPE PISTONS FOR 16-CYLINDER ENGINE
Learning Experience Working on this project was a pleasure for me as I learned lot of things which was unknown to me before doing this project. I worked In, Light Machine Shop(LMS), Engine Erection Shop (EES),Loco Assembly Shop(LAS) ,Heavy Machine Shop (HMS) and my job description includes regular updating status to know about all related to Production Unit, Diesel Generating sets and their spares for Indian Railways and NonRailways customer. I tried to give my best effort on this project but it could be more better if I would have theoretical knowledge about workshops before taking this project. As this topic was new to me and due to time constraint I was not able to through each and every Procedure.
DIGVIJAY SINGH B.TECH 3rd YEAR (5th sem) ENROLLMENT NO. – 8814105011
