Alert Motorman Prevents Collision After Signal Failure Near Chennai, Probe Ordered
A potential disaster was narrowly avoided in Southern Railway's Chennai Division after a vigilant motorman applied emergency brakes upon spotting two trains stationary on the same track ahead. The incident occurred on March 5, 2026, in the Ambattur–Avadi section, prompting a multi-departmental inquiry, official sources confirmed on Friday.
According to sources, an Electric Multiple Unit (EMU) suburban train approaching Automatic Signal S192 received a 'Double Yellow' aspect—a cautionary signal authorising the train to proceed at reduced speed. As the train advanced, the motorman observed two trains standing on the same line within visible distance. Realising the grave danger, he immediately brought the train to a halt just short of the signal, averting what could have been a catastrophic collision.
Preliminary investigations indicate that the signalling system malfunctioned, displaying an incorrect aspect that allowed the approaching suburban train to proceed despite the track ahead being occupied. Railway officials suspect the incident was triggered by the unauthorised resetting of a Multi Section Digital Axle Counter (MSDAC) by a member of the technical staff, sources added.
In a similar signalling failure on June 28, 2026, an express train carrying approximately 900 passengers was cleared to proceed from Arakkonam towards Renigunta. However, due to an incorrect setting of points, the train was inadvertently diverted towards Katpadi. After realising the mistake, the loco pilots brought the train to a halt and cautiously reversed it back to Arakkonam, avoiding any mishap.
The All India Loco Running Staff Association has voiced concern over recurring signalling failures, emphasising that loco pilots and motormen operate trains solely based on signal aspects displayed on the track. Any incorrect signal—whether caused by technical malfunction or human error—could compromise passenger safety and disrupt train operations.
The association noted that signalling failures have been identified as a contributing factor in several major train accidents in recent years. “Such incidents undermine the confidence of loco pilots and motormen, who depend entirely on the integrity of the signalling system while operating trains. The crew cannot be expected to work with peace of mind if the reliability of the signalling system itself becomes doubtful,” a senior loco pilot said, quoting from a letter submitted by the association to Southern Railway.
