Why in news?

Nine people were killed, and at least 40 were injured when the Sealdah-bound Kanchanjunga Express from Agartala was hit from the rear by a goods train. The accident occurred in West Bengal’s Darjeeling district, 11 km from New Jalpaiguri station.

A combination of a signalling fault on the tracks before the New Jalpaiguri station and human error by the driver of the freight train are likely to have led to a deadly collision. In this context, experts highlight the importance of installing the anti-collision system 'Kavach' to control human errors.

What’s in today’s article?

• T/A912 Authorization
• Kanchanjunga express accident
• Kavach - Train Collision Avoidance System

T/A912 Authorization

• About
  • Also known as paper line clearance, T/A912 authorization is a specific instruction given to train drivers in the event of a failure or defect in the automatic signalling system.
  • It outlines the procedures and speed restrictions that must be followed to ensure safe train operations under such conditions.
• Procedures and speed restrictions
  • Signal Procedure
    • When encountering an automatic signal displaying the "ON" aspect (red signal), the driver must stop the train.
    • The train must wait for the prescribed duration at the red signal: one minute during the day and two minutes at night.
  • Proceeding with Caution
    • After the waiting period, the driver may proceed with extreme caution.
    • The maximum speed allowed is 15 kmph where visibility is good.
    • The maximum speed allowed is 10 kmph where visibility is poor (e.g., in case of rain).
    • The driver must maintain these restricted speeds until reaching the next stop signal or clear signal indication.

Kanchanjunga express accident

• The accident
  • 
• Combination of faulty automatic signalling system and human error - possible reasons behind the accident
  • Faulty automatic signalling system
    • The automatic signalling system between Ranipatra railway station and Chattar Hat junction in West Bengalwas not working.
    • This prompted the Rangapani station manager to issue a cautionary note known as T/A912 to all drivers passing through the section.
  • Human error
    • The driver of the Kanchanjunga Express followed the correct procedures during the defect in the automatic signalling system.
      • It stopped at all red signals for one minute and proceeding at 10 kmph.
    • However, the goods train's driver ignored these norms and hit the stationary passenger train from behind.

Kavach - Train Collision Avoidance System

• About
  • 
  • It is India’s very own automatic protection system in development since 2012, under the name Train Collision Avoidance System (TCAS).
    • Later, it got rechristened to Kavach or “armour”.
  • Basically, Kavach is a state-of-the-art electronic system which was designed to help the Indian Railways achieve Zero Accidents.
• Development
  • It has been indigenously developed by the Research Design and Standards Organisation (RDSO) in collaboration with the Indian industry.
  • Trails were facilitated by South Central Railway to achieve the corporate objective of safety in train operations.
• Functioning
  • A set of electronic devices and Radio Frequency Identification devices installed in locomotives, in the signalling system as well the track.
  • This enables the locomotives, signalling system and tracks to talk to each other using ultra high radio frequencies to control the brakes of trains and also alert drivers.
• Features
  • It activates the train braking system automatically if the driver fails to control the train as per the speed restrictions.
  • In addition, it prevents collision between two Locomotives equipped with a functional KAVACH system.
  • It is designed to assist locomotive pilots in avoiding Signal Passing At Danger (SPAD) and over speeding.
    • SPAD - when a train passes a stop signal when not allowed to do so.
    • SPADs are one of the potential precursors to railway accidents.
  • It will also provide support for train operations during adverse weather conditions such as dense fog.
  • It is a Safety Integrity Level 4 (SIL-4) certified technology with the probability of error being one in 10,000 years.
• Other features
  • Automatic Braking for Prevention of Over Speeding
  • Auto Whistling while approaching Level Crossing Gates
  • SoS Messages during emergency situations
  • Centralised live monitoring of Train movements through Network Monitor System
• Deployment strategy
  • Indian Railways had plans to implement KAVACH protection system to an extent of 2000 km during 2022-23.
  • Around 34,000 km of network will be brought under KAVACH.
• Benefits
  • Enhanced safety for Indian railways
  • World’s cheapest automatic train collision protection system
    • It costs ₹50 lakh per kilometre to operate compared to about ₹2 crore worldwide.
  • Opens avenues of export of this indigenous technology for Railways.