Kolkata-Sairang train derailment: Preliminary probe points to faulty braking system

New Delhi: A preliminary probe into the derailment of the Kolkata-Sairang Express at Digaru Railway Station in Assam on November 11 has pointed to a malfunctioning main braking system on the train.

A six-member probe team, in its report, found that the system primarily responsible for applying brakes in the coaches, technically known as the BP angle cock, was in an isolated condition in the locomotive.

"This may be the reason for this accident, as the brakes may not have been applied when the FP/BP angle cock of the loco was in an isolated condition," a joint note prepared by the probe team on the day of the accident said.


It further stated that the train crew applied the brakes, "but the brakes may not have been applied as the angle cock was previously in the closed position".

Read more: Kolkata-Sairang Express derailment in Assam: Six coaches go off tracks at Digaru station

The probe report does not identify who rendered the braking system dysfunctional or whether the train crew overlooked safety procedures to check its functionality before operating the train.

However, in their statements, the train's crew members -- the loco pilot, assistant loco pilot and guard -- said that the braking system was functioning properly when they took charge of the train at Guwahati around 5.30 am on November 11.

According to the report, the train was stopped at Panbari (PNB) station at 6.16 am after the wheels of one of the coaches were found to have overheated due to jammed brake pads.

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The crew attended to the problem, following which the train remained halted at the station for about 30 minutes.

When the train left PNB at 6.46 am and was approaching Digaru station, the station master concerned signalled it to enter the loop line and stop there to allow another train to pass first.

According to the report, the brakes failed to work when the crew applied them to stop the train. It overshot the red signal, hit a dead end, and came to a halt after derailing.

Some safety experts said the crew might have been using the alternative braking system available on the train, known as the regenerative braking system, to control its speed during the journey. They might have applied the main braking system while attempting to stop the train near the loop line, only to find that it was dysfunctional.

"Who isolated the main braking system? Did railway staff do it and forget to restore it later? Looking at the sequence of events, the possibility of involvement of some outsider is highly unlikely. The incident raises several questions and warrants a thorough probe," a safety expert said.

Advisories issued by some railway divisions after the incident suggest that railway staff might have closed the angle cock while attending to the jammed braking pad at PNB station and forgot to reopen it before the train resumed its journey.