Railway Safety & Kavach

Kavach was developed by the Research Designs and Standards Organisation with Indian industry, and the first field trials on passenger trains started in February 2016. After an Independent Safety Assessment, three firms were approved in 2018-19 to supply Kavach Version 3.2, and in July 2020 Kavach was adopted as the National Automatic Train Protection system. On 4 March 2022, in a trial between Gullaguda and Chitgidda on South Central Railway, two locomotives were run towards each other; Kavach applied the brakes itself and halted them 380 metres apart. Version 3.2 was deployed on 1,455 route km on South Central Railway by December 2022 and 1,465 route km by February 2024; with 80 route km on North Central Railway, the Ministry stated a total of 1,548 route km as of October 2024. Alongside Kavach, the Rashtriya Rail Sanraksha Kosh was created in 2017-18 with a corpus of ₹1 lakh crore over five years to renew critical safety assets, and all unmanned level crossings on the broad gauge were eliminated by January 2019 — there were 8,948 of them on 31 March 2014.

Kavach specification Version 4.0 was approved by RDSO on 16 July 2024, adding higher location accuracy, better signal information in large yards, a station-to-station link over optical fibre and a direct interface to existing electronic interlocking. After extensive trials it was first commissioned on 738 route km — Palwal–Mathura–Nagda (633 Rkm) on the Delhi–Mumbai route and Howrah–Bardhaman (105 Rkm) on the Delhi–Howrah route — as stated in the Rajya Sabha on 5 December 2025. On 30 January 2026 Indian Railways commissioned 472.3 route km in a single day, the highest ever in a day and in a month, taking Version 4.0 to 1,306.3 route km across five zones. The figure was 1,452 route km on 11 March 2026, 2,490 route km as on 13 July 2026 and 2,633 route km as on 31 July 2026 — 1,423 Rkm on the Delhi–Mumbai route and 1,210 Rkm on the Delhi–Howrah route.

Kavach keeps a constant radio conversation between the track and the locomotive. RFID tags laid along the track tell the train exactly where it is; UHF radio and telecom towers carry the messages; and a wayside unit at each station reads the interlocking — signal aspects, point positions, track occupancy and route status. From that, plus the train's speed and the gradients and speed limits ahead, the wayside unit computes a movement authority, the distance the train may safely run, and sends it to the loco unit. The cab display shows the loco pilot the signal ahead, the target speed and the distance to it, and the onboard unit draws braking curves. If the train approaches a signal at danger, exceeds the permitted speed or enters a conflicting route, Kavach applies the brakes itself. If two trains are detected moving towards each other in a block section, it issues an automatic Stop-on-Sight command to both. It also sounds the horn automatically at level crossing gates, guards against roll-back and roll-forward, and reports every critical event to a central Network Management System. Kavach is certified to Safety Integrity Level 4 (SIL-4), the highest level in railway signalling. It sits on top of the conventional system, not in place of it: electronic interlocking at 6,671 stations, complete track circuiting at 6,671 stations and 10,395 interlocked level crossing gates (all up to 30 June 2026) remain the base layer, with GPS-based fog safety devices and vigilance control devices on every locomotive.

Track-side Kavach work has been taken up on 21,794 route km covering all Golden Quadrilateral, Golden Diagonal, High Density Network and identified sections, as stated in the Lok Sabha on 5 August 2026; against that, track-side equipment was installed on 7,726 route km, optical fibre laid over 11,547 km, 1,721 telecom towers raised, 1,009 station data centres built and 6,290 locomotives fitted. Work has been taken up for Kavach in a further 7,190 locomotives and 1,200 EMU/MEMU. The stated ambition dates to March 2022, when the Ministry said "Around 34,000 Kms of network will be brought under Kavach"; more than 94,000 technicians, operators and engineers have since been trained, including about 57,000 loco pilots and assistant loco pilots. ₹3,875 crore had been spent on Kavach works up to June 2026, with ₹2,066 crore allocated for 2026-27. Kavach trials at 160 kmph have been held on the Chipyana Buzurg–Tundla section with a Vande Bharat trainset, and Kavach 5.0, for suburban sections, was announced in April 2025. Freight loading, a supporting measure of how hard the network is worked, rose from 1,098 million tonnes in 2014-15 to 1,670 million tonnes in 2025-26.