emd loco shubhranshu bnc2009

GM-EMD LOCOMOTIVES

ShubhranshuChief Motive Power Engineer/DieselSouth Western Railway

SCHEME OF PRESENTATION

• Brief History

• Specifications and features

• How it Works

• Performance in the Field

• Recent Developments

EMD LOCOMOTIVESA BRIEF HISTORY

DIESEL TRACTION– A Journey

- 1961 Setting-up of DLW

- 1964 First Diesel Locomotive with DC-DC traction arrangement

- 1994 Introduction of AC-DC technology

- 1999 Introduction of EMD Locos AC-AC technology with GTO based TCC’s

- 2006 Introduction of AC-AC technology with IGBT based TCC’s

EMD MILESTONES IN INDIA

127 YDM3 Locomotives in 1961 – at Sabarmati


72 WDM4 Locomotives in 1961 at MGS


Contract for 21 EMD Loco’s GT46MAC signed in 1995The First WDG4 with EMD Colour Scheme


The First WDP4- 2002


DLW sets-up a State of the Art Technology Centre in 1996


First WDG4 made indigenously in DLW in 2000


First WDP4 made indigenously in DLW - 2003


First 4500hp IGBT WDG4 made in DLW in 2006. Also known as GT46ACe

TRANSFER OF TECHNOLOGY

• GM-EMD selected after a world-wide search through Global Tender

• Contracts signed in October 1995

– For supply of 13 Assembled and 8 PKD kits for

assembly at DLW

– Transfer of Technology for design, manufacture

and maintenance of GT46MAC locos and Family

of 710 series of Diesel Engines

DIESEL LOCOMOTIVE WORKS

TRANSFER OF TECHNOLOGY- SCOPE

• DURATION: 10 YEARS FROM JAN `96

• FOR GT 46 MAC LOCOMOTIVES AND FAMILY OF

710 ENGINES ( 3000 HP, 4000 HP AND 5000 HP)

• FOR ALL ITEMS MADE IN-HOUSE BY GM

• TRAINING OF INDIAN RAILWAYS PERSONNEL IN– SYSTEM INTEGRATION DESIGN

– MANUFACTURE OF LOCOMOTIVES

– MAINTENANCE OF LOCOMOTIVES

• MUTUAL EFFORTS FOR SUPPL DEVELOPMENT

MODALITIES FOR TOT ABSORPTION

• Training of IR personnel in GM-EMD factories in USA and Canada

• Training by GM-EMD experts in India – DLW and Hubli

• Supply of Documents – Drawings/Specs

• GT46 MAC manufacturing video tapes

• Teleconferences

GT46MAC

Single Cab

Turbocharged16 Cylinder

Full Width Cab

A C

GT46 - A VARIANT OF SD70

DC-DC TRACTION

• The prime mover, i.e., Diesel engine drives an electric generator directly coupled to it and produces direct current output.

• The traction motors are of direct current type and are supplied the DC output of the electric generator.

• Thus the generation as well as utilisation ends deploy DC machines in this system.

DC-DC TRACTION - DISADVANTAGES

• Not amenable to high degree of control of traction characteristics.

• Maintenance intensive electrical machines

• Lower reliability

• Commutator-carbon brush system

• Heavier Equipment

AC-DC TRACTION

• In this system, the generator was replaced with an alternator.

• The maintenance requirements at the generation end were brought down considerably.

• This facilitated the development of higher capacity locomotives without much increase in size.

• However, the utilisation end still posed a constrained wherein DC motors were still in use.

AC-AC TRACTION

• AC machines introduced both at the generation end and the utilisation end.

• Made possible with advances in power electronics, which led to development of high capacity switches with very precise control.

• Deploys variable voltage, variable frequency system to meet all the traction needs.

• Initial locos were equipped with GTO based traction control converters for converting the DC into controlled AC supplies.

EMD LOCOMOTIVESSPECIFICATIONS AND

FEATURES

BASICS

• 710 G3B type 16 cylinder, 2-stroke diesel engine• Main Computer- EM2000• Computer controlled traction system• Computer controlled Brake system• High adhesion• Fuel efficient• Low maintenance

Continued….

• High adhesion levels – controlled creep >> high tractive effort

• Excellent dynamic brake

• High availability and reliability

• Operator friendliness

• Ergonomic control stand

• Fool-proof, non-fatiguing computer control alerter system

• Sealed twin beam headlight

• Easy interaction and guidance for trouble shooting (through EM2000)

• Ease of verification of safety devices

Unit exchange type Power assembly

BENEFITS OF GM LOCO

• Lower Maintenance means smaller

shed infrastructure

• Fewer locos mean fewer running staff

• Higher HP and tractive effort mean

longer and faster trains

• Longer trips mean greater operational flexibility

MAIN FEATURES

• AC-AC Traction

• High Tractive Effort due to state of the art Creep Control

• 4000hp – 54t Tractive Effort

• Highly effective Dynamic Braking System available up to near stand still.

• High Fuel Efficiency, Low Lube Oil Consumption

• Longer trips – 90 days

The locomotive is designed to achieve:

• Maximum stall starting torque of 54 Tonnes.

• Maximum dynamic braking effort of 27 Tonnes.

• The despatchable adhesion of 43%.

• Very low engine idle RPM 200.

• Higher fuel and lube efficiencies

• Low Maintenance requirement

MAIN FEATURES

• On-board fault diagnosis system and fault recording system.

• Computer controlled brake system with facility for self testing and self diagnostic features.

• On-board self test feature for working of important loco systems like relays and contactors, fans, blowers etc.

• Self test feature for ‘Available Traction Power’ from the locomotive through ‘Self Load Test’.

MAIN FEATURES (contd..)

• Sturdy, Bolsterless bogie design with Huck fastening arrangement leaving the undertruck virtually maintenance free.

• Use of hydraulic dampers ensures good ride index and availability of yaw dampers ensures smooth running at high speeds.

• Amenable for upgradation to haul longer trains in undulating terrains with installation of IDP or LOCOTROL Systems.

MAIN FEATURES (contd..)

WDG4/WDP4 locomotives are equipped with 4000HP, 2 stroke Turbocharged diesel engines.

Locomotive consists of four microprocessors.

1. One loco control computer EM2000

2. Two Traction computers ASG

3. One Air brake computer CCB

1) Head light2) Inertial Filter Air Inlet3) Starting Fuse and Battery Knife Switch4) Handrails5) Cooling System Air Inlet6) Radiator and Fan Access7) Coupler “E” Type8) Sanding Box (8)

9) Jacking Pads (4)10) Wheels (6)11) Fuel Tank12) Compressed Air System Main Reservoirs13) Battery Box14) Trucks (3 axle 3 motor HTSC type) Qty. 215) Underframe16) Dynamic Brake Grids17) Dynamic Brake Fans (2)

GT46MAC - LAYOUTGT46MAC - LAYOUT

14. Primary Fuel Filter15. Air Compressor16. Radiators17. AC Radiator Cool. Fans (Qty. 2)18. Draft Gear19. Compressor Filter20. Lube Oil Filter Tank21. Lube Oil Strainer22. Lube Oil Sump23. Main Generator Assembly24. No.1 Elect. Cntrl. Cab’t Air Filt.25. Traction Motors (Qty. 6)

1. #1 Electrical Control Cabinet2. Fuel Pump3. Engine Starting Motors (Qty. 2)4. Traction Control Cabinet5. Traction Motor Cooling Blower6. Main Gen. Assembly Blower7. Engine Exhaust Stack8. Engine Exhaust Manifold9. Diesel Engine10. Governor11. Engine room Vent12. Engine Water Tank13. Lube Oil Cooler

GT46MAC - LAYOUTGT46MAC - LAYOUT

EMD LOCOMOTIVESHOW IT WORKS

THE ENGINE – 710G3B

ENGINE ROOM

THE ENGINE

16 Cylinder two stroke 45 degrees V Engine.

Compression ration 1:16.

Swept volume 710 cubic inches.

Engine control through Woodward Governor.

Equipped with mechanical unit injectors.

Unit replacement facility for power assemblies.

No valve seat inserts

SALIENT FEATURES

710 G3B ENGINE

710 cu indisplacement

Turbo Model G Railroad Application

16 cylinders

THE ENGINE

• Engine Model(s): 710G3B• Number of Cylinders: 16• Engine Type: Two-Stroke, Turbocharged• Cylinder Arrangement: 45° “V”• Compression Ratio: 16:1• Displacement per Cylinder: 710 Cu inches (11 635 cc)• Cylinder Bore: 230.19 mm (9-1/16”)• Cylinder Stroke: 279.4 mm (11”)• Rotation (Facing Flywheel End): Counterclockwise• Max. Speed: 904 RPM• Normal Idle Speed: 269 RPM• Low Idle Speed: 200 RPM

710 G3B ENGINE

DIRECTLY DRIVES

- TRACTION ALTERNATOR

- COMPANION ALTERNATOR

- AUXILIARY GENERATOR

- AIR COMPRESSOR

- TRACTION MOTOR BLOWER

ENGINE SCHEMATIC

PISTON AND CON-ROD

Cast Steel PistonsSimple DesignSplash Lubrication

CYLINDER LINER

Cast IronLaser Hardened Water JacketedSide Ports for 2-stroke Design

GEAR TRAIN

THE CRANKSHAFT

TRACTION ALTERNATOR

Out put voltage ranges from 600 to 2600 Volts.

Consists of two independent stator windings and a rotating field common to both the windings.

AC output rectified to DC by rectifier banks and permanently connected in series.

The output of traction alternator is used only for traction power.

COMPANION ALTERNATOR

Built in the same housing of the traction alternator but electrically independent.

Rated at 250 KVA - produces maximum of 230 volts at 900 engine rpm.

Output is used to drive Radiator fans, exciting Traction alternator field and other AC blower motors.

Engine power is generated based on the following signals :

Barometric measure.Engine protection power limit (Dirty engine air filters).Turbo over speed power limit (surges)Engine overload protection limit through load regulator of Woodward Governor.Engine temperature power limit based on temperature signal from Engine temperature probes.

TRACTION CONTROL CABINET

– ONE INVERTOR PER BOGIE

– CONVERTS DC INTO VARIABLE VOLTAGE VARIABLE FREQUENCY 3-PH POWER FOR TRACTION MOTORS

– CONVERTS AC FROM DYNAMIC BRAKING INTO DC

– SIBAS 16 TRACTION CONTROL COMPUTER

TRACTION CONTROL COMPUTER

TCC COMPUTER

• This computer controls the actions of traction control converter.

• It interacts with the main locomotive control computer, i.e., EM 2000 through RS 485 serial link.

• The control of traction power is established through this computer in coordination with EM 2000. It also monitors various other parameters like temperature of various components, voltages, current, status of relays etc.,

• The computer performs all these functions through a set of 28 electronic modules. Each electronic module performs different functions & monitor different parameters.

• Two GTO based traction control converters for inverting the DC output of main generator into controlled AC supply for traction motors.

• Six AC traction motors in GT46MAC and 4 AC traction motors in GT46PAC locos at the utilisation end.

GATE UNITS & PHASE MODULES

The units actually involved in the process of inverting DC into AC

THE AC-AC SYSTEM OF EMD LOCOS

DC LINK CAPACITORS

Ensures constant DC voltage supply to Inverters

TRACTION MOTOR Four pole, 3-phase AC squirrel cage

induction motor.

Eliminates complexities of commutator, brushes and brush holders of DC motors.

AC motors eliminates the requirement of conventional transition systems.

Rugged and virtually maintenance free. Overhauling periodicity at 6 years.

Externally cooled nose suspended.

Sensors for speed and temperature measurements.

Oil lubricated bearing at the drive end.

Grease lubricated sealed bearing at non drive end.

AC Traction Motor

vs

DC Traction Motor

Size is considerablysmaller

Much simpler

Coupled with suitablecontrol system givessuperior traction

THE LOCO CONTROLLER

EM2000 Computer

EM 2000 COMPUTER- FEATURES

Uses a 32 – bit microprocessor.

Information can be downloaded to a lap top computer.

Flexible and expandable to accommodate future system enhancements.

Complete self – diagnostics.

Archived unit history data.

Provides self test feature.

EM 2000• The main locomotive control computer. Interacts with the

two Traction Controller Computers and the CCB computer.

• Important functions

– Traction alternator excitation control.– Monitoring position of various control devices– Displays various data which includes fault related information,

running totals, locomotive details etc.

• Data interchange through DIO and ADA Cards.

• Interacts with other computers through COM cards.

EM 2000 BLOCK DIAGRAM

EM2000 - Features

EM2000 helps conduct

Self load test without an external load box wherever and whenever required.

Contactors and relay test for self diagnostics

Blower motor test.

Excitation test of main generator field and its controls.

Air brake self test.

EM2000 – Safety Features

Alerter vigilance control system.Opposite direction brake.Automatic sanding of wheels for correcting

wheel slips.Automatic emergency braking to prevent

overspeeding.Tractive effort limiting feature while passing over

weak bridges and tunnels.Locked wheel/slipped pinion detection.

EM 2000 INTERACTION

CONTROL CONSOLE

DIAGNOSTIC DISPLAY PANEL

• It is the display unit of EM 2000 wherein the required parameters & fault messages are displayed.

• It also accepts inputs through the keys provided on the display.

• It is used by maintenance & operational people for interacting with EM 2000.

ENGINE CONTROL PANEL

LOCOMOTIVE TRUCK ASSEMBLY

HTSC BOGIE

High Tensile Steel Cast Bogie

Bolster-less design

Supports the weight of the loco and transfers traction to rails

Loco weight is transferred directly to bogie frame through secondary rubber springs.

Three AC Traction Motors

Although the frame itself is rigid, the design allows the end axlesto move or "yaw" within the frame.

This movement will allow the wheels toposition themselves tangent to the rails on curves for reduced wheel and rail wear.



• Uniform traction motor orientation and stiff secondary suspension improves weight transfer within the bogie for optimal adhesion.

• Primary suspension with coil springs for good ride quality.

• Secondary rubber springs (pads) also permit yaw on curves

• Provision of yaw dampers & vertical shock absorbers for better ride quality and stability at higher road speeds.

• Reduced no. of wear rubbing surfaces for extended maintenance intervals.

AIR BRAKE SYSTEM

– KNORR-NYAB CCB

– COMPUTER BASED ELECTROPNEUMATIC

– INTERFACE WITH EM 2000

– SUPPORTED IN INDIA BY KBI

CCB COMPUTER

• It is an electro pneumatic micro processor based system.

• The CCB computer is also known as computer relay unit. Other units of CCB are known as voltage conditioning unit (VCU) and pneumatic control unit (PCU).

• The control of braking system is established through CCB computer directly with inputs by the Loco Pilot through the brake controller.

• CCB communicates with EM 2000 through RS 485 serial link for displaying the data & recognising demands put by EM 2000 on CCB system based on the inputs by the driver.

BATTERY CHARGING SYSTEM

• The locomotive is equipped with an AC Auxiliary Generator rated at 18 KW at 55V AC.

• The 3-phase 55V AC output is rectified through a full wave rectifier assembly to obtain 74V DC output for charging of batteries.

• The output regulation of Auxiliary Generator is established through a digital voltage regulator module which controls the current flow to the field winding of Auxiliary Generator.

STARTING SYSTEM

• The locomotive is equipped with two dedicated starting motors which come into action only at the time of cranking the engine.

• The starting motors get their power supply from the batteries of the locomotive through starting contactors.

• Charging of the batteries is accomplished through an Auxiliary Generator directly coupled to the diesel engine.

• STARTING MOTORS

Two series wound DC motors operating at 64V.

Starting current 800 Amps.

Running current 77-120 Amps.

EMD LOCO - SPECIAL FEATURES

• AC-AC Traction

• High Tractive Effort due to state of the art Radar-based Creep Control

• 4000hp – 54t Tractive Effort

• Highly effective Dynamic Braking System available up to near stand still.

• High Fuel Efficiency, Low Lube Oil Consumption

• Longer trips – 90 days

RADAR ASSEMBLY

Radar Transceiver

Looks at the ground and detects mismatchbetween the linear speed and the rotational speed of wheel

Ensures limited creepof wheel on rails

RADAR ASSEMBLYLooks down at the ground and compares the linearspeed of the loco with the Rotary speed of the wheels

Controlled creep of wheels on rail maximizes adhesionand makes it possible to utilise maximum torque of traction motor for traction

ENHANCED DYNAMIC BRAKES

Dynamic Braking Effort of 27 t

Available up to near stand-still

Makes operations on steep gradients safer & economical

(WHEEL) CREEP CONTROL

The locomotive radar interacts with the loco computer.

Two sub functions

Wheel Creep Control - operates at all times in motoring and dynamic braking.

Improves tractive effort under adverse rail conditions (wet or oily rails) by adjusting wheel speed to maximize motor torque.

Enables the wheel to rotate at a rate slightly faster than ground speed.

(WHEEL) CREEP CONTROL

Second Function

Wheel Slip Control - operates if a wheel creep control failure occurs (radar failure, for example) or if rail conditions are too poor for successful wheel creep control.

The locomotive computer selects the appropriate wheel control to suit the operating conditions. It also applies sand if severe rail conditions exist.

Operation of the wheel control function may cause the control console WHEEL SLIP indicator to flash or light steadily.

PERFORMANCE

Greater requirements of traffic

Heavier and longer trains

Less time for maintenance - more utilization

Increase in Horse Power by several modifications

EMD LOCOS IN THE FIELD

COMPARE WITH WDM2

WDM2 GM LOCO

• Availability 81% >90% • Trip Schedule 7-10 days 90 days

• Starting Adhesion 27% 42%

• Starting Tract Effort 30.4 t 54 t

COMPARE WITH WDM2

WDM2 GM LOCO

• Balancing Speed (kmph)(4700t-level) 59 85

• Lube Oil Consumption (% of Fuel) 1.5 0.5

• SFC (gm/BHP Hr) 166 151

• Dynamic Breaking 48% applicable at all speeds

COMPARE WITH OTHER LOCOS

STARTING LOAD ON 1/150 GRADIENTCLASS LOAD

BOXN TONNES

WDM 2 33 2700

WDG 2 47 3850

WAG 5 38 3110

WAG 7 46 3767

WAG9 52 4258

WDG4 58 4750

COMPARISON OF WDG3A , WDG4 & WAG9

DescriptionDescription WDG3AWDG3A WDG4WDG4 WAG9WAG9

Length (Mtrs.)Length (Mtrs.) 19.1319.13 21.2421.24 20.620.6

Weight in TonsWeight in Tons 123123 126126 123123

Brake SystemBrake System PneumaticPneumatic Micro processorMicro processor Pneumatic/Pneumatic/

micro processormicro processor

HPHP 31003100 40004000 60006000

Starting Tractive effortStarting Tractive effort 398398 570570 520520

Continuous TEContinuous TE 313313 400400 325325

Slip controlSlip control Wheel Slip relay Wheel Slip relay controlcontrol

ComputerisedComputerised Relay control/Relay control/

ComputerisedComputerised

Starting capability in Starting capability in 1/200 gradient1/200 gradient

44004400 51905190 47004700

COMPARISON IN THE FIELD

PARAMETERS KSRA-IGP Ghat in CRly * QLM-CLR Ghat in S.W.Rly

Distance 15.95 km 26 km

Gradient 1 in 37 1 in 37

Curves Maximum of 5° Maximum of 7.8°

Load 59 BOXN loaded to CC+4t+2t

59 BOXN loaded to CC+8t+2t

Operational Speed

35 Kmph 40 Kmph

Locos Used 3xWAG7 leading + 3xWAG7 banking

2xWDG4 leading +3xWDG4 banking

Total HP 30,000 HP 20,000 HP*CRS/Central Circle Letter no. C-11(140)96-225 dated: 21-5-07

THE BRAGANZA GHAT (CLR-KLM)

HASSAN-MANGALORE LINE

SKLR-SBHR GHAT SECTION

GHAT OPERATIONS – UP THE GRADIENT

Earlier traction arrangement with ALCO (WDG-3)

3L + 44W + 3L + 14W + 2L

Current Traction arrangement with EMD (WDG-4)

2L + 59W + 3L

GHAT OPERATIONS – DOWN THE GRADIENT

Earlier traction arrangement with ALCO (WDG-3)

3L + 58W

Current traction arrangement with EMD (WDG-4)

5L + 59W

MOST DIFFICULT

MOST DEMANDING

AND THE MOST BEAUTIFUL

EMISSION STANDARDS• The 710 engine is NOx-reduction friendly

– NOx reduction is less than comparable four-stroke engines

– Exhaust gas recirculation reduces NOx with minimal fuel consumption increase

• Particulate matter is reduced through reducing oil consumption and improving combustion

• Bottom Line: EMD’s 710 engine has met every new set of emissions standards– UIC II (2003), EPA Tier 2 (2005)

– The 710 engine was the first locomotive engine to have EU Stage IIIA type approval

RECENT DEVELOPMENTSin

EMD LOCOMOTIVES

GTO TO IGBT UPGRADE

• Switchover to IGBT from GTO Thyristors

• IGBT overcomes following shortcomings of GTO

– Bulk

– Need for Excessive Cooling, Chlorinated coolants

– Slower Switching, need for absolute surge protection

– Prone to Failures, very expensive

• Insulate Gate Bipolar Transistor (IGBT)

– Provides high frequency switching

– More rugged/reliable

– Compact

– Purer sinewave

UPGRADE to 4500hp

• Achieved without any additional costs

• First 4500 Loco WDG4 (12114) made with EMD IGBT modules in May 2007

• Provides sustained high tractive effort for considerably longer than 4000hp locos.

• New Indigenous efforts have yielded encouraging resuts.

• First indigenously developed 4500hp IGBT based loco with traction convertors from M/S Medha, Hyderbad

• Commissioned in Dec 2008. WDG4 -12169

• ENABLES SINGLE-HEADING IN BORDERLINE CASES OF HEAVY LOAD, PREVENTS STALLING

ADVANTAGES OF 4500 HP WDG4

• LATEST UPGRADE MAKES IT POSSIBLE TO ACHIEVE 4500hp WITHOUT ANY ADDITIONAL COSTS

PROVIDES HIGHER PROVIDES HIGHER TRACTIVE EFFORT EVEN TRACTIVE EFFORT EVEN AFTER STARTING, UP TO AFTER STARTING, UP TO 15 kmph – 15 kmph – AN INNOVATION IN AN INNOVATION IN TRACTION CONTROL TRACTION CONTROL

4500 hp enableS WDG4 operations with 2+2 configuration without stalling in SKLR-SBHR Section.

Earlier need was 6+6 ALCO

INDIGENOUS TCC/LCC

Special Enabling Features of Medha

• LCC – MS696 – REPLACES EM2000

• INDIVIDUAL AXLE CONTROL – ONE PER MOTOR

• DISTRIBUTED POWER CONTROL (LOCOTROL)

• HOTEL LOAD

• OPTICAL FIBER COMM – BETTER REIABILITY

• HEAT TUBE COOLING INSTEAD OF EVOPARTIVE

• INTEGRATED EVENT RECORDER

• IDENTICAL TO THE EMD DESIGN IN DRIVER INTERFACE

ALCO IS NOT FAR BEHIND

UPGRADES ON ALCO

• UPGRADED POWER FROM 2600hp to 3300hp

• MICROPROCESSOR CONTROL OF EXCITATION AND LOCO SYTEMS

• MICROPROCESSOR BASED ENGINE GOVERNOR

• LCD GAGE PANEL

• ENABLED FOR DISTRIBUTED POWER/LOCOTROL

• REMOTE MONITORING – GPRS BASED

• END OF TRAIN TELEMETRY

• POWER SETTER FOR MU OPERATIONS ECONOMY

• INTELLIGENT LOW IDLE – FUEL ECONOMY

ALCO LOCOS ARE NOW INTELLIGENT MACHINES

General Electric

MedhaSiemens

MEDHA MEP 660 Microprocessor based diesel loco control

system: Loco No 13037

TFT LCD panel on control desk for communication with the loco pilots

Maintenance

MAINTENANCE AND TRAINING

• Diesel Shed at Hubli – 162 (153 G4, 9 P4)

• Diesel Shed at KJM – 36 P4 (Also homes ALCO)

• Diesel Loco Service Centres – Hospet, Sakleshpur

• Elsewhere on IR – Siliguri, Sabarmati

• Also being planned at

DIESEL SHED - UBL

• Trip Schedules: 30/90 Days

• Six Monthly Schedules

• Annual Schedules– Primarily Filter Change, Consumables, Bogies,

Compressor, Wheel Turning, Carbon Brushes

• Six Yearly – The first major schedule– Change of Power Assemblies, turbo,

Crankshaft Main Bearings etc.

DIESEL SHEDS – UBL, KJM

TRAININGA well equipped training school

LOCO SIMULATOR

SIMULATOR – TRAINING ROOM

TRAINING MODELS

PLANS OVER IR

AND FINALLY

UNITED COLOURS OF EMD

THANK YOU

emd loco shubhranshu bnc2009

Documents

secondary

high fuel

current traction

earlier traction

wdm2wdm2 gm

ac traction

ac traction

traction motor