The Rail Accident Investigation Branch has released its report into the uncontrolled evacuation of a London Underground train at Clapham Common.

On the 5th May 2023, a London Underground train was departing Clapham Common at around 17:43 when it was brought to a halt following an activation of the emergency alarm. This was activated as passengers could see smoke and had a smell of burning.

The train stopped with two cars inside the tunnel and four cars adjacent to the platform.

With the doors remaining closed, around 100 of the 500 passengers onboard began to self evacuate the train onto the platform through the interconnecting doors between the carriages and also through the train windows.

Around four and a half minutes had passed before station staff began to open the train doors.

Passengers reported minor injuries, but it could have been a lot worse, especially as Clapham Common has a single island platform and the risk of passengers falling off the southbound platform and onto the conductor rails and into the path of oncoming trains.

Passengers had told the RAIB that there was a perceived significant risk of fire on the day and that the alarm bells began to ring when the train doors did not open and no effective action was seen by staff.

The RAIB has found three underlying factors that lead to the incident:

• Staff were not provided with procedures for incidents where passenger behaviour can rapidly escalate
• London Underground did not retain the learning from a previous incident at Holland Park station
• London Underground had not identified the risks of self evacuation of partially platformed trains

RAIB has made three recommendations, all addressed to London Underground. The first relates to procedures and training to ensure that staff have clear guidance on how to deal with out-of-course events.

The second relates to learning from previous incidents not being lost and to recommendations being tracked through to implementation.

The third recommendation is that London Underground review its risk assessment processes so that the risks associated with out-of-course events and at specific locations are effectively identified and assessed.

“Out-of-course events can rapidly escalate into emergencies if not responded to promptly and effectively.

“During this incident staff didn’t fully appreciate the emerging safety risk when passengers’ behaviour began to escalate as they became increasingly anxious. When passengers did not receive suitable information about the nature of the incident and the actions they should take, nor see action they would have expected to be taken, they turned to desperate measures to self-evacuate.

RAIB investigated a similar incident at Holland Park in 2013 and for a number of years that incident was used as an example to train staff about how to respond to such out-of-course events. However, it was subsequently removed from the training syllabus and since then knowledge of the lessons learnt may well have begun to fade. This incident again demonstrates that learning from past operational incidents needs to be retained by organisations.”

Andrew Hall, Chief Inspector of Rail Accidents