- Category
- Digital Signalling & Railway Safety
- Used for
- Safe control of railway signals, routes and points at stations and junctions
- Benefits
- Improved signalling reliability, reduced human intervention, faster fault detection, safer route setting and easier integration with modern railway control technologies.
- Introduced
- Progressively introduced; large-scale adoption during the modern signalling programme
Electronic Interlocking, commonly abbreviated as EI, is an important part of the modern signalling infrastructure used by Indian Railways.
An interlocking system ensures that railway signals, points and routes are operated in a safe sequence. For example, it prevents conflicting routes from being authorised simultaneously when doing so could create an unsafe train movement.
Traditional railway networks used mechanical, panel and relay-based interlocking arrangements. Electronic Interlocking performs these safety functions using computer-based electronic equipment and specially designed fail-safe logic.
EI technology offers improved reliability, easier fault diagnosis and greater flexibility when railway layouts are modified or expanded. It can also provide a modern foundation for integration with technologies including Automatic Block Signalling, Centralised Traffic Control and Kavach.
Indian Railways has progressively expanded Electronic Interlocking across stations as part of its signalling modernisation programme.