Exploring the Significance of Electronic Interlocking Systems in Railways for Safe Train Operations

Exploring the Significance of Electronic Interlocking Systems in Railways for Safe Train Operations

The electronic interlocking system used in railways has gained attention due to its involvement in a recent train crash in Odisha's Balasore district. The crash, resulting in numerous casualties, led to investigations that revealed a change made in the electronic interlocking and point machine as the cause of the accident. In this article, we will explore the electronic interlocking system in railways and its significance in ensuring safe train operations.

Interlocking system: The interlocking system is a vital safety mechanism employed in railway signalling systems to manage train movements on tracks. It consists of a mechanism that controls the movement of trains, ensuring they traverse a controlled area safely. This system comprises signals and points that are interconnected mechanically or electrically, or both, enabling trains to switch tracks or junctions without interfering with other trains.

Electronic interlocking (EI): The electronic interlocking system, also known as EI, is an advanced computer-based signalling system that utilizes electronic components to regulate train movements and track configurations. Based on software, this system prevents two trains from operating on the same track simultaneously and grants permission to proceed only when the route ahead is clear. EI serves as an alternative to the conventional Relay Interlocking system and is typically operated and monitored by trained personnel from the signalling and telecommunications department, commonly referred to as "signallers" or signal operators.

Crucial elements of EI:

1. Signal: Signals indicate whether a train should stop (red light), proceed (green light), or exercise caution (yellow light) based on the track's status ahead.

2. Track circuit: These electrical circuits on the tracks detect the presence of vehicles or trains on specific sections of the track. They help verify whether a route is clear or occupied, ensuring safe train movement.

3. Point switch: Trains can switch tracks using movable sections called points. Switches guide the wheels towards the straight or diverging track, and point machines play a critical role in locking the switches for safe train operations.

Functioning of EI: The EI system determines when a train can proceed based on the track's direction and the availability of an alternate track. It guides the train to the appropriate track at a junction while ensuring that no other train can enter the same section simultaneously. The system records all activities in a microprocessor-based data logger, functioning as a black box to store and process signal data for generating reports.

Track occupancy sensing: Various sensing devices, such as axle counters, are installed on the tracks to detect the passage of wheels. These sensors count the number of wheel sets or axles that have passed over them, determining whether the entire train has traversed the track.

Safety of the system: The electronic interlocking system operates on a fail-safe mechanism, meaning that if any component (signals, points, or track occupancy sensors) deviates from the predefined safe logic, the system automatically stops the approaching train. In case of failure, all signals turn red, and train operations come to a halt.

Implementation status: As of 2022, approximately 45.5% of the Indian Railways network, comprising 2,888 stations, were equipped with the electronic interlocking system.

In conclusion, the electronic interlocking system plays a crucial role in ensuring the safe movement of trains on railway tracks. It relies on electronic components and software-based controls to prevent collisions and guide trains to their designated tracks. By employing fail-safe mechanisms and monitoring track occupancy, this system enhances the safety and efficiency of railway operations.

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