Kavach Train Collision Avoidance System (TCAS)

Overshoot and Importance of the KAVACH System

• Context (TH | TH | IE): The Vizianagaram train accident may have occurred due to overshot.
• The anti-collision KAVACH system is not available on either of these trains.

Overshot

• Overshot is technically called Signal Passing at Danger (SPAD).
• It occurs when a train doesn’t stop at a red signal and keeps moving forward.
• It is a serious safety hazard that can lead to train collisions and other accidents.

Reasons of Overshot

• Human error: Due to fatigue, distraction, or signal misinterpretation.
• Technical failure: It includes problems with the train’s brakes, signalling system, or track.
• External factors: Such as bad weather or obstructions on the track.

KAVACH System: Solution to Overshot

• The KAVACH is an indigenously developed Automatic Train Protection (ATP) system.
• It was developed by the Research Design & Standards Organisation (RDSO) of the Indian Railways.
• It has been adopted as the National ATP System for Indian Railways.
• It is a state-of-the-art electronic system developed under the Atmanirbhar Bharat initiative.
• It is one of the cheapest systems with Safety Integrity Level-4 (SIL-4) certification.

Under SIL-4, the probability of error is 1 in 10,000 years.

Key Features/Advantages of the KAVACH System

• Avoid SPAD: When a red signal is ignored, and two trains approach each other on the same track, the system applies sudden brakes.
• Overspeed protection: It will automatically apply the brakes if the train exceeds the speed limit.
• Collision avoidance: Through direct loco-to-loco communication.
• Signal information: The system offers the driver real-time signal information. It provides a line-side signal display in the cabin for better visibility in fog and at high speeds.
• Automatic whistling at level crossings: A big boon during fog conditions.
• SOS feature: To control trains in emergency situations.

Where has KAVACH been Implemented?

• The South Central Railway (SCR) Zone pioneered implementing the KAVACH.
• Trials of Kavach were conducted on the Lingampally–Vikarabad–Wadi and Vikarabad–Bidar sections of the South Central Railway, covering a distance of 250 km.