KAVACH 4.0 Goes Live First Time on South Central Railway

Indian Railways has switched on KAVACH Version 4.0 over the South Central Railway (SCR), the first time this edition of the country's own train protection system has carried live traffic anywhere. The stretch chosen runs between Malkajgiri and Kamareddi in the Hyderabad Division, where 108 route kilometres were moved up from Version 3.2 to Version 4.0.

Why this stretch

South Central Railway was already the zone with the deepest KAVACH experience. Version 3.2 runs there across 1,465 route kilometres, and the lessons drawn from operating that network fed straight into the design of the newer edition. Railways plans to take Version 4.0 to the rest of the country on a large scale, so the Hyderabad Division stretch works as the proving ground.

What Version 4.0 adds

• Train position is fixed more accurately than before.
• Signal aspects are reported better inside large yards, so crews know more about what lies ahead.
• One station's KAVACH now talks to the next through optical fibre cable.
• The system plugs straight into the electronic interlocking already installed, instead of needing a separate bridge.

How the system guards a train

KAVACH is an Automatic Train Protection system designed and built in India. It watches over the Loco Pilot: if the speed limit is crossed, or a signal showing danger is about to be passed, the equipment applies the brakes itself when the driver does not. That is how it works against Signal Passing at Danger, or SPAD, and against collisions, and it keeps trains running safely when fog or rain hides the signals.

Because so much rides on it, the equipment has to clear Safety Integrity Level-4 (SIL-4), the strictest of the safety grades.

What a KAVACH section needs

Fitting a section is not a single installation. Station KAVACH goes up at stations and on block sections, RFID tags are laid along the whole length of track, telecom towers are raised across the section, optical fibre cable is buried beside the rails, and every locomotive working the route carries Loco KAVACH on board.