Major accident averted after faulty signal brings trains too close on same track

A major accident was averted on the Southern Railway’s Chennai Division when an alarmed biker applied the brakes after noticing two trains already stationed on the same track.

A serious security breach occurred in the Ambattur-Avadi section on March 5, 2026. Official sources said a multi-departmental investigation has been launched into the incident. Hindu on Friday.

According to sources, the Electric Multiple Unit (EMU) suburban train approaching Automatic Signal S192 received a ‘Double Yellow’ image, allowing it to proceed with caution. As the train moved forward, the driver noticed two trains stopping within visible distance on the same track. He realized the potential danger and immediately stopped the train just before the signal, preventing a serious accident.

Preliminary investigations revealed that the signaling system was faulty and displayed an inaccurate image, allowing an approaching commuter train to proceed even though the track ahead was full. Sources said railway officials suspected that the incident was triggered by unauthorized resetting of the Multi-Section Digital Axle Counter (MSDAC) by a member of the technical staff.

In a similar case of signaling failure on June 28, 2026, an express train carrying around 900 passengers was allowed to proceed from Arakkonam towards Renigunta. However, due to incorrect setting of points, the train was diverted to Katpadi by mistake. Realizing that the train was going in the wrong direction, the locomotives stopped the train and cautiously reversed it towards Arakkonam.

Locopilots express concerns

Members of the All India Loco Working Personnel Association have expressed concern over repeated signaling failures, saying that loco pilots and motormen operate trains strictly according to the signal specifications displayed on the track. Any false signal due to technical malfunction or human error can compromise passenger safety and disrupt train operations.

The association noted that signaling failures have been identified as a contributing factor to many major train accidents in recent years. “Such incidents undermine the confidence of locomotives and drivers, who depend entirely on the integrity of the signaling system when operating trains. If the reliability of the signaling system becomes questionable, the crew cannot be expected to operate with peace of mind,” a senior locomotive pilot said, quoting a letter sent by the association to the Southern Railway.