Electronic Interlocking: Cause Behind Odisha 3-Train Crash Explained

The tragic train accident that left 275 people dead and over 1,000 injured in Odisha's Balasore district was caused due to a technical malfunction, according to Railway Minister Ashwini Vaishnaw.

During his interaction with the media, the minister confirmed that the root cause of the train accident was directly associated with the point machine and electronic interlocking system. He explained that the electronic interlocking system, which serves as a safety mechanism to prevent collisions and conflicting movements between trains, experienced a malfunction, ultimately resulting in the tragic incident.

Railway Minister Ashwini Vaishnaw said, "It is about point machine, electronic interlocking. The change that occurred during electronic interlocking, the accident happened due to that. Whoever did it and how it happened will be found out after proper investigation."

What is electronic interlocking?

Electronic interlocking is an advanced system of signal equipment that plays a crucial role in managing the configuration of railway tracks to prevent conflicts between trains. Its primary function is to maintain the safety of train operations by ensuring that signals are not changed in an incorrect sequence. The main goal of this system is to hold back the signal for a train to proceed until the route has been thoroughly confirmed as safe.

 In other words, electronic interlocking decides which track a train should use by determining where it is already occupied. The electronic interlocking system utilises electronic control systems and computer technology to monitor and regulate train movements. In this system, sensors and feedback devices are employed to detect the presence and location of trains on the tracks. It seamlessly integrates with various other railway systems such as train detection systems, signals, points, and track circuits to ensure the safe operation of trains.

It serves as a modern replacement for traditional mechanical interlocking systems, which relied on physical levers and rods for signal and switch control.  

Thus, by utilising electronic interlocking, the potential risks of accidents and collisions are meant to be greatly reduced, leading to improved safety and efficiency in railway operations. As per the railway department, the machine has a 0.1% chance of failure.

As per the Government Of India, Ministry Of Railways' Handbook 2021 on Interlocking & Functional Testing of Panel, Route Relay & Electronic Interlocking, “Signal interlocking is supposed to be the brain of a signalling system and it is highly important in terms of safety in train operation. All the commands for the operation of signalling gears are processed through the complex network of interlocking. However, safety to the train movements is not ensured unless safety and integrity checks for signal interlocking are performed, whether it is Mechanical, Electro-mechanical or Electronic Interlocking.”

The minister also said that an investigation into the incident was conducted by the Commissioner of Railway Safety.