The Indian Railways’ indigenous Automatic Train Protection (ATP) system — Kavach — is not operational on the Kharagpur-Bhadrak-Cuttack route, where the ill-fated collusion of two passenger and one goods train took place on Friday.

The collusion of Shalimar-Chennai Coromandel Express with a goods train and then with Sir M Visvesvaraya-Howrah Superfast Express near Bahanaga Bazar railway station under the Kharagpur railway division has led to more than 280 casualties as well as 56 grievously injured and another 747 passengers with minor injuries.

An India Railways spokesperson clarified that Kavach is route specific and at present it is under installation on the Delhi-Howrah and Delhi-Mumbai routes. It is not operational on the Kharagpur-Bhadrak-Cuttack route.

Sources have also indicated that prima facie it appears to be a signalling issue. The initial joint inspection report by Kharagour railway division suggests that signal was given and taken off for the up main line for the Coromandel Express but the train entered into a loop line and clashed with goods train which was on the up loop line and derailed.

“A thorough investigation is required to ascertain how the Coromandel Express took the loop line and hit the goods train. It seems the track joints were not properly positioned,” an official explained.

Anti-collision system

Kavach, the Train Collision Avoidance system (TCAS) aids engine drivers to avoid Signal Passing At Danger (SPAD), over speeding and train running during inclement weather such as dense fog.

It works on the principle of continuous update of movement by using radio communication and includes non-signalling based additional features for collision prevention.

“Kavach is certified at the highest level of safety integrity which implies that possibility of hazardous error happening is less than once in more than 10,000 years,” Railways officials said.

Also read: What is KAVACH? Could it have prevented the Odisha train tragedy?

It is already functioning on 1,455 Route km on South Central Railway. Besides, Kavach tenders have been awarded on 2,951 Rkm on Delhi-Mumbai and Delhi Howrah sections, which are targeted for commissioning in 2024.

Kavach has been sanctioned on 35,736 Rkm of High Density Network (HDN) and High Utilised Network (HUN) of Indian Railways. Further preparatory survey is in progress on 6,000 RKm of remaining Golden Quadrilateral/ Golden Diagonal (GQ-GD) for next phase of Kavach rollout.


Railways moved from mechanical signalling to electro-mechanical relay based signalling and finally to relay based signalling. At present, it has covered 97 per cent stations with a modern signalling system with 2,325 electronic and 3,917 relay-based interlocking and 649 ISB block stations.

Automatic Block signalling enhances line capacity within existing track infrastructure allowing more than one train to be moved in a block section between two stations without affecting safety. Currently, it is functional on nearly 3,600 Rkm including 2,521 Rkm on High Density Network.