Isolated safety systems let train move with doors open

A passenger train was able to start moving with several doors open and before the conductor had completed the dispatch process because safety systems had been isolated in an attempt to correct a fault.

Accident investigators from RAIB have made several recommendations to Northern Trains following the incident on the afternoon of May 3 2023, which happened as the train - a three-car class 323 electric multiple unit - was departing from Styal station, Manchester.

On the same journey, the train had already been delayed by a fault while at Alderley Edge which had prevented the driver from releasing the brakes and taking power. This had eventually been resolved after a final attempt to open and close the doors, but the situation recurred two stations further along, at Styal, where the fault proved more recalcitrant.

Here the train stood for 25 minutes while the driver and conductor dealt with the situation in consultation with Northern’s maintenance controller.

The MC instructed the driver to isolate safety systems relating to the doors to allow the train to move. These isolations did not resolve the issue, but after further checks, the train became able to move. By this time several passengers had opened the doors and were standing on the platform.

The train then started to pull away unexpectedly before the conductor had reboarded or carried out the dispatch process, and travelled for approximately 10 seconds with five doors open. Once it reached 3.1 mph (5 km/h), a safety system caused the open doors to close automatically. No one was hurt in the incident, although people were moving towards the train and a passenger was standing in an open doorway when the train started to move.

Because engineering safeguards relating to open doors had been bypassed, the train was able to depart without the driver receiving an indication that the dispatch process was complete and without confirmation that the doors were closed.

The conductor alerted Northern Trains Control through the MC, who in turn notified the signaller. The signaller stopped the train at the last signal before Manchester Airport and asked the driver to confirm that all the doors on the train were closed and that the conductor was on board. The driver confirmed this, and the train was then signalled to proceed to Manchester Airport, a terminal station.

When it arrived, 42 minutes late, the doors did not open. The driver walked to the rear cab to investigate and realised that the conductor was not on board the train, which was then taken out of service. The conductor and remaining passengers at Styal completed their journey on the next scheduled train.

Following its investigation, RAIB has made three recommendations to Northern Trains Ltd. The first seeks to improve the management of the risk of trains being in operational service with known intermittent faults. The second considers how the operational risk of trains being in service with safety systems isolated is managed, and the third looks to provide operational staff with the skills and strategies to manage out-of-course incidents and stressful situations.