Kavach 4.0 explained: What’s new in Indian Railways’ upgraded train safety system

As per the latest business developments, Indian Railways has commissioned Kavach Version 4.0 for the first time on the South Central Railway (SCR), marking an upgrade from Kavach Version 3.2. A PIB release informs that the latest version has been commissioned over 108 route kilometres on the Malkajgiri-Kamareddi section of the Hyderabad Division.

But what exactly is Kavach, and what has changed with Version 4.0?

What is Kavach?

Kavach is an indigenously developed Automatic Train Protection (ATP) system designed to assist loco pilots in maintaining prescribed speed limits and automatically apply brakes in critical situations, if required.

The system is aimed at preventing Signal Passing At Danger (SPAD), controlling train speeds during emergencies and reducing the risk of collisions. It additionally supports safer train operations during adverse weather conditions.

Kavach is not a single piece of equipment. Its implementation involves multiple components, including:

– Station Kavach at stations and block sections

– RFID tags installed along railway tracks

– Telecommunication towers

– Optical Fibre Cables (OFC)

– Loco Kavach equipment installed on locomotives

Together, these components enable the train protection system to function across railway sections.

What is Kavach 4.0?

Kavach 4.0 is the latest version of the system commissioned by Indian Railways. It builds on the operational experience advanced from deploying Kavach Version 3.2 across 1,465 route kilometres on South Central Railway, according to Indian Railways.

The latest version incorporates technological improvements aimed at enhancing safety, reliability and the system’s technological capabilities.

The first commissioning of Version 4.0 covers 108 route kilometres on the Malkajgiri-Kamareddi section.

How is Kavach 4.0 different from earlier versions?

The PIB release chalks out several specific improvements in Version 4.0 over the earlier Version 3.2 —

1. More accurate train positioning: Kavach 4.0 brings increased location accuracy, allowing for more precise positioning of trains. This is important because the system relies on knowing where a train is in relation to signals and other railway infrastructure.

2. Better signal information in larger yards: The latest version provides improved information on signal aspects in larger yards. This is an enhancement over the capabilities of the earlier version and is intended to improve the information available to the train protection system in more complex railway environments.

3. Station-to-station communication through OFC: Kavach 4.0 introduces station-to-station communication through Optical Fibre Cable (OFC). This provides a communication link between stations as part of the upgraded system architecture.

4. Direct integration with Electronic Interlocking Systems: Another key change is the direct integration of Kavach 4.0 with existing Electronic Interlocking Systems. This allows the upgraded train protection system to work more directly with the railway signalling and interlocking infrastructure already in place.

The fundamental purpose of Kavach stays unchanged. Like earlier versions, Version 4.0 is designed to assist loco pilots in maintaining prescribed speeds and intervene by automatically applying brakes in critical situations.

Its objectives keep include preventing SPAD, controlling train speed during emergencies and reducing collision risks.

So, the move from Version 3.2 to Version 4.0 is primarily an upgrade in accuracy, communication, integration and reliability, rather than a change in the basic purpose of the system.

The commissioning of Version 4.0 on South Central Railway marks the first deployment of the upgraded version and follows operational experience with Version 3.2 across 1,465 route kilometres on the zone.

Indian Railways has stated the upgraded system is scheduled for large-scale deployment across its network.

The release states that Kavach 4.0 requires Safety Integrity Level-4 (SIL-4) certification – which is the highest order of safety certification — reflecting the system’s critical role in operations. A new lift to rail safety!

KAVACH 4.0 now covers 108 Route Kilometres between Malkajgiri and Kamareddi rail section in Telangana enabling safer and seamless train operations across the region.

#KAVACH4.0 #RailInfra4Telangana https://t.co/C3JP6FLuid

— Ministry of Railways (@RailMinIndia) September 23, 2026