Electrical

Traction Rolling
Stock
 History of electric traction in India

February 3, 1925 : The first electric train ran between Bombay's

Victoria Terminus and Kurla along the Harbour Line
of CR.

‘Sir Leslie Wilson’ was the first electric locomotive in India and it
is now displayed at CSTM.
This EF/1 class was made by the Swiss Locomotive Works,
Winterthur

1957: Indian Railways decided to adopt 25 kV 50 Hz AC traction based on French Railway (SNCF) technology.

1957: The first 25kV AC electrified section Burdwan-Mughalsarai completed.

1957: Tatanagar-Rourkela section on the Howrah-Bombay route also completed…..

1976: Entire Howrah-Delhi route electrified.

1988: Bombay-Delhi (via WR) route electrified.

1995: 2 x 25kV AC system commissioned between Bina and Katni.

 Traction Rolling Stock

TRS deals with Maintenance of Traction Rolling stocks

Loco Sheds EMU/MEMU Sheds POH shops

 Function of Loco Shed

Each loco is assigned a shed for :

• Primary Maintenance.
• Implementation of modifications
• Planning of maintenance work for least break downs i.e. more availability for service.
• Maintaining of Equipment History
• Planning of Scheduled Maintenance dates
• Data Analysis for loco failures

Types of Locomotives:
Passenger Locomotive: Less Self Weight designed for higher speed potential i.e. 110,130 & 160 kmph

Goods locomotives: More Self Weight and designed for higher haulage capacity i.e. 6000 HP, 9000 HP etc.
 Method of Naming a Locomotive

Fifth Letter indicates modification

Fourth Letter indicates version

Third Letter indicates service type

P – Passenger Service
G – Goods Service
M – Mixed Service S – Shunting Service

Second Letter indicates traction type

A – AC traction ; D – Diesel
C – DC traction (Continuous Current)
CA – DC-AC traction or Dual traction

First Letter indicates gauge

W – Broad gauge
Y – Meter gauge
Z – Narrow gauge
Examples of Naming a Loco

WAP - 5 BG, AC, Passenger service, version 5

WCAM - 2 BG, DCAC, Mixed service, version 2

WAG - 9 BG, AC, Goods service, version 9

YAM - 1 MG, AC, Mixed service, version 1

Traction Rolling Stock

Bogie Nomenclature

• B --Two axle bogie with one Traction Motor for both the axles.

• BO--Two axle bogie with one Traction Motor for each axle.

• CO--Three axle bogie with one Traction Motor for each axle.

Loco Nomenclature

• B-B Loco : two 'B' bogies

• CO-CO Loco : two 'CO' bogies
• BO-BO-BO Loco : three 'BO' bogies
B-B Bogie

Motor

Axle
 Bo-Bo Bogie

Motor

Example : WAP5 Axle

 CO-CO Bogie

Motor
Examples:
Axle
WAG-5, WAP-7, WAG-9
 History of Electric Locomotives
SNo Class of Loco Year of Manufacturing Horse Power Technology

DC Locomotives
1 WCM1 1954 3170 English Electric
2 WCM2 1956 2810 English Electric
3 WCM3 1957 2460 English Electric
4 WCM4 1960 3290 Hitachi
5 WCM5 1961 3700 CLW
6 WCM6 1996 5000 CLW
7 WCG1 1925 2400 Swiss Loco works
8 WCG2 1970 1640 CLW
AC/DC Locos
9 WCAM1 1975 3640(AC) CLW
2930(DC)
10 WCAM2 1995 4720(AC) CLW
3780(DC)
11 WCAM3 1997 5000(AC) BHEL
4600(DC)
 History of Electric Locomotives
SNo Class of Year of Horse Technology
Loco Manufacturing Power
1 WAM1 1959 2870 KM-KRUPP-SFAC
2 WAM2 1960 2790 Mitsubishi
3 WAM3 1964 2790 Mitsubishi
4 WAM4 1970 3640 Mitsubishi
5 WAP1 1980 3760 CLW
6 WAP3 1987 3760 CLW
7 WAP4 1994 5000 CLW
8 WAP5 1993 6000 ABB
9 WAP6 1998 5000 CLW
10 WAP7 2000 6350 CLW
11 WAG1 1963 2900 SNCF
12 WAG2 1964 3180 Hitachi/ Mitsubishi
13 WAG3 1965 3150 Europe
14 WAG4 1966 3150 CLW
15 WAG5 1984 3900 CLW/BHEL
16 WAG6 1987 6000 ASEA
17 WAG7 1992 5000 CLW
18 WAG9 1996 6000 ABB/CLW
19 WAG9H 2006 6000 CLW
 Mechanics of Train Motion

• The tractive effort developed by the traction motor is the force available at
the wheel-rims for moving the Loco and trailing load.

Axle mounted gear

Motor mounted gear

Axle

Tractive effort is required to move a train to overcome -

train resistance
gradients
Curvature and
To provide acceleration
 Traction Rolling Stock

Basic Components of Electric Loco

Pantograph
Roof Equipments DJ/VCB

Tap changer
Superstructure RSI block
Compressor

Traction Motor
Under frame Transformer
Battery
Bogie
Basic Components of Electric Loco Roof Equipments

Pantograph – collects current from contact wire for the Electric locomotive. The pan
has strips made up of carbon.

DJ/VCB (Dis-Jointer/ Vacuum Circuit Breaker)

 ON/OFF switch & makes OHE supply collected by pantograph available

to the main transformer
 designed to operate on load for normal or abnormal conditions i.e. It
opens automatically in case of over current or earth fault in the loco.
 Basic Components of Electric Loco

Transformer

This reduces and controls the incoming feeder voltage as per requirement.

Rectifier: converts transformer’s output to DC supply for DC

traction motors.

Smoothing reactor: Smoothing Reactors are used to reduce undulation of the current and to make
current smoother.

Tapchanger An on-load tap changing arrangement is provided on the primary winding of

the loco to achieve variation of the AC input voltage to the rectifier.
This helps to control speed/ torque of the train.

Loco Cab
 Basic Components of Electric Loco

Traction motors – Each loco has traction motors for driving the
locomotive. These are the main devices that run
the locomotive.

Static Inverter unit

This unit is connected to Auxiliary winding of the
Transformer.
It converts single phase 400 V AC supply to 3 phase 400
VAC voltage for Auxiliary machines in the Locomotive.

Auxiliary Machines
Required for supplying compressed air and for cooling of electrical equipment.
 Auxiliary Machines

Compressor - provides compressed air for all pneumatic operations required by

locomotive.
Compressed air is used for Electro - pneumatic contactors, Switching on & off of
circuit breaker, Pantograph, operation of the tap changer servomotor, Horns /
wipers / Sanders, Air brakes on the locomotive / train.

baby compressor : When the loco is dead, a baby compressor works from
battery - it builds up a pressure of 7 to 8 Kg which enables the driver to raise the
pantograph and switch-on OHE power.

Vacuum Exhauster (PV) for vacuum brakes of passenger & goods trains.
 Auxiliaries for cooling purpose
1. Traction Motor blower (MVMT)

2. Blower for colling of Smoothing reactor (MVSL)

3. Blower for cooling of Rectifier (MVSI)

4. Pump for circulation of Transformer oil (MPH):

It withdraws hot oil from the transformer & making it pass through radiator
tubes across which radiator blower (MVRH) blows the air and cools the oil which
again enters the transformer.

Battery – provides source of energy for charging the locomotive when loco is dead.

Relays – Provides the all protection against abnormal working.

Battery Charger (CHBA)- Battery charger is provided for charging the batteries.
 How does locomotive work ?

Panto Charged
DJ Closed

Silicon Silicon
Rectifier Rectifier

Reactor Reactor

Xmer Charged

Rectifier: Converts AC in DC
Reactor: Smoothens ripples in rectifed DC
CIRCUIT for AUXILIARY Motors
 Protections in Locomotives

∙ High current in main transformer winding

∙ Over current in silicon rectifiers
∙ Traction power circuit earth fault.
∙ Over voltage to traction motors.
∙ No voltage / low voltage protection.
∙ Auxiliary power circuit earth fault.
∙ Lightening Arresters for external lightening/line surges
 Shortcomings of D.C. traction motors

• The existing design of DC drive locos is capable of giving power upto 5000 HP.

• Unavoidable stepped jumps in the tractive effort due to notch control

• DC motor has inherent problem of brush gear & commutators and is maintenance
intensive.

• It is essentially high current, low voltage machine which requires large diameter cables &
heavy associated switch gears which are expensive.
3-Phase Loco
 Special features of 3- phase Electric Loco

• Three phase AC motors : (details in next slide)

• Regeneration (details in next slide)
• Unity Power Factor
• Increased Starting Tractive effort and increased Horse Power
• On Board Self Diagnostic features
• Less maintenance due to less moving components
• Variable Voltage Variable Frequency Drive: Desired Torque can be achieved easily by varition in the Voltage
and frequency.
• Triplate Pneumatic Brake panel to minimize piping and provide single place location of all pneumatic
equipments.
• Use of Underslug Compressors thereby eliminating oil fumes & oil spillage inside the loco which is potential fire
hazard
 Advantages of 3 phase Induction Motor

• Compact - high power density

• higher operational speed
• low maintenance
• Light weight
• high power/weight ratio (1500 kW/Axle)
• No commutation – No moving parts in side – more reliable
Regeneration

• Regeneration is available in electric locomotives. During braking, the motors become

generators and current is fed back to into the supply system. of bakes.

• This current can be used by other trains

• Saving of energy by around 25% in electric locomotives and in electric multiple units.

• Available in all 3 phase loco (WAP7 and WAG9) and has been developed in WAG7
conventional loco.
 Traction Motor Details

WAP-5 WAP7/WAG9
TYPE 6FXA 7059 6FRA 6068

Motor type 6-poles/AC asynchronous motor 6-poles/AC asynchronous motor

Insulation class 200 200

Cooling Forced Air Forced Air

Output 1150 kW 850 kW

Type of suspension Fully suspended Axle hung nose suspended motor

Continuous speed 1585 RPM 1283 RPM

Voltage 2180 V 2180 V

Continuous current 370 Amp 270 Amp

Gear Ratio 67:17 77:15

 Hotel Load Requirement

• WAP-7 with Hotel load are provided with 7775 kVA transformer with 2 X 500 kVA Hotel
Load Convertor

• WAP-5 loco are provided with composite convertor i.e single unit for Traction and
Hotel Load Convertor.

• WAP-5/ WAP-7 manufactured before 2012 donot have Hotel Load capability as
transformer rating is 7400 KVA.
 Block diagram of 3 phase system

Transformer

Converter DC Link Inverter AC T.M.

• A converter is used for Voltage source Invertor: Converts DC to AC to
converting the AC to DC. supply voltage from 0-2180 V, 0-160 Hz

• DC link is made of the DC link capacitor, series tuned filter and over voltage protection
circuit.
• DC link is reservoir of energy, which supplies periodic and nonperiodic energy requirement
of load and decouples it from supply source.
Layout of Equipment in 3-phase locomotive
 Frequency of Maintenance Schedules

WAG5 WAP7 (3 ph) WAG 9 ( 3 ph)

TI 15 days As per loco link 45 days
IA 45 days 90 days 90 days
IB 90 days 180 days 180 days
IC 135 days 270 days 270 days
AOH 18 months 18 months 18 months
IOH 54 months 4.5 yrs or 12 Lac km 6 years or 12 Lac km
POH 9 yrs or 12 Lac kM 9 yrs or 24 Lac km 12 years or 24 Lac km
MTR Rehabilitation once during life time
 TYPES of 3-PH LOCOMOTIVES

Type of Loco WAP-5 WAP-7 WAG-9

Service Type Pass Pass Goods

Bogie Type Bo-Bo Co-Co Co-Co

No. of Traction Motor (in Nos.) 4 6 6

Speed (Max) kmph 160 130 100

Weight (Tonnes) 78 123 123

WAG12 Locomotive

• Being made under ‘Make-in-India’ initiative.

• Power output of 12,000 HP is twice as powerful as its immediate predecessor, WAG-9

• One of the most powerful freight locomotives in the world.

• Being procured from Madhepura Electric Loco Pvt. Ltd. (MELPL) which has a capacity to
manufacture 110 loco/annum.

• Target: 800 locos (five assembled and 795 manufactured) over a period of 11 years.

• 106 Locomotives have been inducted in IR so far.

• 60XXX series will be used.

Purpose
• Decongest the saturated routes by improving average speed and loading
capacity of freight trains.
Salient Features of WAG12 B Locomotive

• Bo-Bo + Bo-Bo configuration

• Design Max speed : 120 KMPH,

• Can start freight trains weighing 6,000 Tonnes on gradient of 1 in 150 with Max Tractive
Effort of 706 kN.
• The original design of 22.5 T axle load has been upgraded to 25 Tonnes

• It can be tracked through GPS through embedded software through microwave link.
END OF THIS PART….