TCAS ­ Kavach

TCAS ­ Kavach


  • The deadly collision between two passenger trains in southern India’s Vizianagaram district in Andhra Pradesh which killed 14 people and injured fifty persons could have been averted if Traffic Collision Avoidance Systems (TCAS) were in place.

  • East Coast Railway officials indicated that the indigenously developed TCAS called ‘Kavach,’ was not installed on the route where the Visakhapatnam-Palasa and Visakhapatnam-Rayagada trains collided.

What is TCAS ­ Kavach?

  • Kavach is a cab signalling train control system with anti­collision features.
  • Simply put, it plays the role of a watchdog over the existing signalling system.

  • It was developed over a period of 10 years, starting in 2012, by the Indian Railways Research Designs and Standards Organisation (RDSO).
  • Kavach is designed to give out warnings to the loco pilot in case he does not notice the ‘red signal,’ and instead of stopping, is going to overshoot the signal.
  • After giving warnings on the locopilot’s display, if the pilot does not slow down below 15 kilometres per hour, the Kavach system automatically applies brakes to bring the train to a halt.

How is the Kavach system deployed?

  • In the Kavach set­up, the railway stations along the route where this tech is sanctioned to be deployed are provided with three components.
  • First is Radio Frequency Identification (RFID) technology in the tracks.
  • RFID tech uses radio waves to identify people or objects.
  • It uses electromagnetic fields to automatically identify and read information contained in a wireless device from a distance without making physical contact or requiring a line of sight.
  • Secondly, the locomotive, which is the driver’s cabin, is provided with RFID readers, computer, and brake interface equipment.
  • Finally, radio infrastructure which are towers and modems are installed at railway stations.

How does Kavach infrastructure work?

  • The three components of Kavach on rail tracks, locomotives and at railway stations are communicating with each other to monitor train movements, and transmit signals ahead to locomotives.
  • Their function is not affected by visual interferences like hilly geography or haze.
  • There is direct loco­to­loco communication and information regarding location and track IDs are exchanged, in case it is noted that both trains are on the same line.
  • The locomotives have antennas which communicate with towers on railway stations and display warnings to the driver on his monitor.

Why did the A.P. train accident occur?

  • The Railways Ministry attributed the cause of the Andhra Pradesh accident to the deceased loco pilot, saying it was likely caused by a ‘human error.’
  • Railway officials said that the loco pilot of the Visakhapatnam­Palasa train did not stop or slow down the train despite a red signal given in the block section.
  • Experts say that if the Kavach system was in place it could have helped avoid this accident.
  • The system would have warned the loco pilot that he was overshooting the red signal, and would have automatically applied the emergency brakes.

How much does the Kavach system cost?

  • Deploying Kavach costs ₹50 lakh per kilometre for the Indian Railways.
  • Experts say present coverage for Kavach is only 1,500 km and at this rate, it may take many years to ensure Kavach even on high­density routes as Railways has a total route length of 68,000 kms.

Syllabus: Prelims