Odisha train accident: what is an electronic interlocking system? 'Root cause' of mishap

Railway minister Ashwini Vaishnaw has said that the 'root cause' of the triple train collision in Odisha's Balasore on June 2 was a change in 'electronic interlocking'.

What is an interlocking system?

An interlocking system is a safety mechanism that ensures the safe and efficient movements of trains at railway junctions, stations and signalling points.

The interlocking system makes sure that movable sections of track that allow trains to change direction from one track to another are properly aligned and locked in the correct position before a train can pass over them.

There are circuits installed on the track that detect the presence of a train. The circuits help to determine whether a section of track is occupied or empty, enabling the interlocking system to control train movements.

Electronic interlocking is a modern form of interlocking technology in which the control and supervision of train movements are carried out through software, computers, programmable logic controllers , and communication networks.