Interlocking System in Indian Railways | 13 Jun 2023
Why in News?
An investigation is underway to determine the cause of a devastating train crash in Odisha's Balasore district. The incident has raised concerns about the electronic track management system used by the railways.
- The Indian Railway Minister has highlighted a change in the electronic interlocking as the primary factor leading to the accident.
What is an Interlocking System in Indian Railways?
- About:
- Interlocking System refers to a crucial safety mechanism used to control train movements and ensure safe operations at railway stations and junctions.
- It is a complex network of signals, points (switches), and track circuits that work together to prevent conflicting movements and collisions.
- Electronic Interlocking (EI): It employs computer-based systems and electronic equipment to control signals, points, and level-crossing gates.
- Unlike conventional relay interlocking systems, EI utilises software and electronic components to manage the interlocking logic.
- EI ensures the synchronisation of all elements to facilitate uninterrupted train movement.
- As of 2022, 2,888 stations in India were equipped with an electronic interlocking system — comprising 45.5% of the Indian Railways network.
- Interlocking System refers to a crucial safety mechanism used to control train movements and ensure safe operations at railway stations and junctions.
Indian Railways Network
- The Indian Railways is the world's fourth-largest railway network, carrying an average of eight billion passengers annually.
- The network spans over 68,000 km and encompasses more than 7,000 stations, with a running track of 1,02,831 km.
- As of March 31, 2022, the total track length, including sidings, yards, and crossings, stands at 1,28,305 km.
- Components of Electronic Interlocking:
- Signal: Signals use light indicators to direct trains to stop (red), proceed (green), or exercise caution (yellow) based on the track's status ahead.
- Point: Points are movable sections of tracks that enable trains to change lines by guiding the wheels towards a straight or diverging path.
- Electric point machines lock and unlock point switches in the desired position.
- Track Circuit: Electrical circuits installed on tracks detect the presence of a train between two points, determining the safety of train movement.
- Additional Components: Electronic systems, communication devices, and other equipment control signalling components and are housed in relay rooms with dual-lock access control.
- A data logger records all system activities, serving as a record similar to an aircraft's black box.
- Functionality of the System:
- Command Reception and Route Setting: The electronic interlocking system receives commands from operators or automated control systems following which information is collected from the yard and processed to set a safe route for trains to follow.
- Alignment and Interlocking: Once the route is determined, the system aligns the necessary track switches (points) and interlocks signalling devices at appropriate positions to establish the desired route.
- Signal for Train Proceeding: Trains are given signals to proceed based on the track's direction and the absence of obstructions on diverging tracks.
- This ensures that trains can safely and smoothly navigate through the network.
- Collision Prevention: The system utilises track circuits to detect the presence of trains.
- By monitoring these circuits, the system prevents multiple trains from running on the same block or conflicting paths, thus minimising the risk of collisions.
- Point Locking: Points (switches) remain locked in position until certain conditions are met, such as the train crossing a specific section of the track or the signal to proceed being withdrawn.
- This ensures that the points are correctly aligned and secure for train movements.
- Failure Indication: In the event of a failure or malfunction, the system alerts operators or maintenance personnel.
- One common method is the use of a red light signal, indicating that the system has detected an issue and the route ahead is not clear or safe.
- This prompts appropriate actions to be taken to resolve the problem and ensure safe operation.