Odisha train crash: A signalling error, change in electronic interlocking likely the root cause, initial reports suggest

Rail Minister Ashwani Vaishnav on Sunday said that the root cause of the incident has got nothing to do with Kavach. India Today had earlier reported that the primary reason behind the massive twin train collision was initially identified as a signalling error. Countering West Bengal Chief Minister’s allegations on the Balasore train accident, Vaishnaw said that the reason is not what Mamata Banerjee said yesterday. This incident happened due to changes in electronic interlocking.

What is electronic interlocking?

Interlocking is a vital component of railway signalling that controls activities in a yard to enable the safe passage of a train through the controlled area. Railway signalling has progressed from the un-interlocked signalling system, mechanical and electro-mechanical interlocking, to modern signalling. Electronic Interlocking (EI) is one sort of signalling arrangement that has various advantages over Electro-Mechanical or Conventional Panel Interlocking.

The interlocking logic in the EI System is based on software and any adjustments are easy to make without the need for any wiring changes. The EI System is a processor-based system with numerous diagnostic checks built in. This improves system stability and results in minimum system downtime even in the event of a failure.

How does it malfunction?

In general, the signal turns red when the system fails. Since electrical signal interlocking is a fail-safe technique, problems could arise due to external interference such as human mistakes, malfunction, and so on.

"The set conditions have to be met. In this case, the point should have been set on the normal line and not on the loop line. The point was set on the loop line, it is something that cannot happen without human interference. "said a signalling expert in the Indian railways on the condition of anonymity.

 “There was some construction work going on in the same area related to the Level crossing gate. If there was a cable faulted supply to point, that needs to be checked. If the point was in the reverse direction then where it should have been, that needs to be checked,” India Today quoted sources as saying.

This Bahanaga Bazar railway station was equipped with electronic interlocking systems. The railways data also revealed that - Panel Interlocking/Route Relay Interlocking/Electronic Interlocking (PI/RRI/EI) along with Multiple Aspect Colour Light Signals were provided at 6,396 Stations out of 6,506 Stations on BG Routes, upto 31.03.2023.

Also Read: Odisha train accident happened due to electronic interlocking, has nothing to do with Kavach: Ashwini Vaishnaw