Kavach is an automatic train protection (ATP) system indigenously developed by Indian Railways. Kavach is a system which alerts when a loco pilot jumps a signal (Signal Passed at Danger -SPAD), which is the leading cause of train collisions.
The system can alert the loco pilot and take control of the brakes and bring train movement to a halt automatically. When it notices another train on the same line within a prescribed distance.
The installation of Kavach train collision avoidance system is currently going on in Delhi-Howrah and Delhi-Mumbai routes. However, the technology was not available on the route in Odisha where three train-crash took place on Friday night, according to a railway official.
Kavach (train protection system)
As per wikipedia, Kavach is an automatic train protection (ATP) system indigenously developed by Indian Railways. Through the Research Designs & Standards Organisation (RDSO), initial development of Kavach started in 2012 under the name Train Collision Avoidance System (TCAS).
 system indigenously developed by Indian Railways. It alerts when a loco pilot jumps a signal which lesds cause of train collisions.){kind=link}