Indian Railways has commissioned Kavach 4.0, the latest version of its indigenous Automatic Train Protection (ATP) system, on 738 route kilometres across two major corridors. The system has been deployed over 633 route kilometres in the Palwal-Mathura-Nagda section on the Delhi-Mumbai route and 105 route kilometres in the Howrah-Bardhaman section on the Delhi-Howrah route. The update was shared by Railway Minister Ashwini Vaishnaw on Friday in a written reply to the Rajya Sabha.
Kavach is a safety-certified SIL-4 technology designed to assist loco pilots by automatically applying brakes if speed limits are exceeded and by ensuring safer operations in adverse weather. Field trials for the system began in 2016, followed by independent safety assessments. Version 3.2 was approved for supply in 2018–19, and Kavach was adopted as India’s national ATP system in 2020.
The implementation process involves installing station and trackside equipment, Radio-frequency identification (RFID) tags, telecom towers, optical fibre cable, and onboard units for locomotives. Based on experience from deploying version 3.2 on 1,465 route kilometres in the South Central Railway zone, Indian Railways introduced improvements that led to the approval of Kavach version 4.0 in July 2024.
Kavach 4.0 offers higher location accuracy, improved relay of signal aspects in large yards, an OFC-based interface between stations, and direct integration with electronic interlocking systems. These features support wider deployment across the national network. Extensive trials preceded commissioning on the two major corridors, and work is underway to equip the remaining sections of the Delhi–Mumbai and Delhi-Howrah routes.
Indian Railways reported significant progress in installing supporting infrastructure. Optical fibre cable has been laid along 7,129 kilometres of track, 860 telecom towers have been installed, 549 stations have been equipped with Kavach, and trackside equipment has been deployed across 2,674 route kilometres. A total of 4,154 locomotives have been fitted with onboard Kavach units.
Trackside work is ongoing across 15,512 route kilometres covering the Golden Quadrilateral, Golden Diagonal, High Density Network and other identified sections. Bids have been issued to equip an additional 9,069 locomotives with Kavach 4.0 as part of the phased rollout.
Training for the system is being provided at centralised railway institutes, and more than 40,000 personnel – including 30,000 loco pilots and assistant loco pilots – have been trained so far, with courses developed in collaboration with IRISET.
The approximate cost of installing trackside and station equipment is ₹50 lakh per kilometre, while fitting Kavach on locomotives costs about ₹80 lakh per unit. Expenditure on Kavach up to October 2025 has reached ₹2,354.36 crore, and the allocation for 2025-26 stands at ₹1,673.19 crore. Funds are being released in line with project progress.
