RAIB has today released its report into trap and drag accidents at Archway and Chalk Farm stations, 18 February and 20 April 2023.

Summary

On Saturday 18 February 2023 at around 15:50 hrs, a passenger became trapped in the door of a Northern line train at Archway station. The passenger was exiting the train using a single leaf door at the rear of the fifth car when the door began to close on them, and their coat became trapped. The train departed and the passenger was dragged for approximately 2 metres along the platform before falling to the ground and the coat became free of the door. The passenger’s companion, who was holding on to them at the time, also fell to the ground. The train travelled approximately 20 metres until it stopped after the train operator became aware of the passenger being dragged and applied the brakes. The passenger sustained serious injuries and their companion was uninjured.

The accident occurred because the passenger’s coat had become trapped in the door as the passenger alighted, and because the train’s door control system did not detect the presence of the coat trapped in the door. Although the train operator was aware of the passenger and their companion, they were not aware that the passenger’s coat was trapped before they initiated the train’s departure. The train operator was not aware that the pilot light, which indicates that the train’s doors are closed, could still illuminate with something trapped in closed doors.

On Thursday 20 April 2023 at around 23:03 hrs, a passenger’s coat became trapped in the doors of a Northern line service at Chalk Farm station. The passenger had attempted to board the train but stopped as the doors began to close. The doors closed while the passenger was still close to the train, trapping their coat. The train then departed, dragging them along the platform. The train travelled for approximately 20 metres until the coat became free and the passenger fell to the ground. The train operator was unaware of the accident and continued the journey. The passenger sustained minor physical injuries to their left elbow and both knees and psychological distress.

This accident also occurred because the passenger’s coat became trapped in the train doors as they boarded the train and because the train’s door control system did not detect the presence of the trapped coat. However, in this accident, the train operator was not aware of the passenger nor that their coat was trapped in the doors before initiating the train’s departure. They were also unaware that the passenger was subsequently being dragged along by the train.

The investigation identified underlying factors associated with both accidents. It is possible that the train operators’ actions may have been affected by the automatic train operation system in use on the Northern line. Also, the methods for managing the safety of the platform‑train interface were not sufficiently effective at controlling the risks to passengers by getting their clothing trapped in closing doors.

Recommendations

RAIB has made four recommendations addressed to London Underground Limited and made three learning points. The recommendations concern the understanding of risk arising from trap and drag events, the risk mitigation options, the minimum station dwell times and how the design of the task and the cab environment can influence train operators’ attention and awareness.

The first learning point concerns the importance of documenting action plans in accordance with company procedures and recording when safety briefings have been undertaken. The second learning point concerns the importance of promptly reporting notifiable accidents to RAIB. The third concerns the importance of trainers and managers ensuring the risks of relying on the pilot light when deciding whether it is safe to start the train from platforms are completely understood by train operators.