How Electric Train Engine Works? – Indian Railway

Ever Wondered how electric train runs on the track? How it manages all the operation and what are there for safety? Let’s discuss the conventional methods briefly on

Below is the diagram of electric train engine taking supply from wire known as OHE cable having supply of 25kV.

Pantograph touches OHE
Pantograph touches OHE

OHE wire:

OHE cable
OHE Cable

There are two types of wires above the track. Catenary wire(Which is on the top) and Contact wire(which is below and having contact with Engine via Pantagraph). Both wire have same supply of 25kV.

Railway Track:

Railway track
Railway track

Train runs on the track made of highly concentrated iron. Track have combination of rail, balast, sleepers. The train/engine stands in between OHE and the Track.

How Engine takes Supply:

25kV from the live wire(contact wire) is given to the locomotive engine via a pantograph which is responsible to give feeding to the power circuit. Also there is a chamber known as VCB (Vaccum Closed Chamber) in which the connection is made similarly as a contact switch of high tension but using pneumatic pressure.
Once Pantagraph touches the OHE cable having supply of 25kV, loco pilot is ready to close the connection and power the engine.

What happens to 25kV supply after starting the engine:

The supply is initially given to three different power circuits via auto transformer and step-down transformer.

  1. Feeding Power Circuit
  2. Traction power circuit
  3. Auxiliary Power circuit
Block Diagram
Block Diagram

Feeding power circuit takes the feed from OHE wire and decides the amount of supply to be given to traction power circuit. It has mainly transformer section including-

  1. Auto transformer
  2. Step down transformer
  3. SMGR

Traction Power circuit is responsible for sending supply to the motors which are known as traction motors. Traction power cirtcuit includes-

  1. RSI block (to convert AC supply into DC)
  2. SL (to smooth the output of RSI)
  3. Line Contactor
  4. Traction motors (responsible for the movement of axle)

Since all of these elements in traction power circuit works on very high voltage & current, they get heated very quickly. Therefore motor fans/pumps are provided for cooling purpose of them. This part of circuit is known as Auxillary Power Circuit. And these all get supply from ARNO (i.e. Feeding power circuit -> ARNO-> Auxillaries). This includes the following –

  1. HPH (for cooling of transformer oil)
  2. MVSL (for cooling of SL)
  3. MVSI (for cooling of RSI)
  4. MVMT (for cooling of traction motors)
  5. MCP (Compressor for pneumatic circuit which is responsible for braking and other circuit operations)
  6. Battery Charger

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Keeping in mind the every possible means of failure there is always a relay or fuse or contactor which will stop the entire operation depending on the seriousness of the failure.

This is a brief on how the total operation is done in conventional method of the electric engine in Indian Railway.

Hope you have got idea about the working of the electirc engine.

For more specied details of the locomotive, please visit RDSO

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