‘Trap and drag’ incidents point to issues with door-close alarms

Train operators need to do more to make passengers aware of the hazards of trying to board a train while the doors are closing.

That's one of three safety messages the Rail Accident Investigation Branch (RAIB) has issued to the industry, after a trio of ‘trap and drag' incidents on London Overground services in north London during June.

In all three cases, passengers chose to put an object in the doors as they were closing, treating them like a lift in an attempt to make the doors reopen.

But because the items were thin (a hand, a walking stick and an umbrella), they did not stop the interlocks operating, as the door closing system only detects objects thicker than 30mm to ensure reliability (and, unlike a lift, does not use a light beam).

Each train started to leave the platform before the drivers, all of whom were experienced with at least ten years' service, spotted the passenger was running alongside the train.

The trains stopped within a few metres, and no one was injured. The passengers were not identified.

In all three cases, the drivers relied on the door interlock, rather than carefully checking the in-cab monitors as a final safety check before starting the train, as required in the Rule Book. They “did not realise that a passenger was in a potentially unsafe position when making the decision that it was safe to start”, said RAIB.

Arriva London Rail, which runs the driver-only operation Class 710 electric multiple units under contract to Transport for London, was found not to have made its driver briefings clear enough, or provided sufficient information about the limitations of some systems and the need for extra vigilance.

In all three incidents, passengers were attempting to use the rearmost door, furthest away from the perspective of the relevant camera. This means that they would be less conspicuous on the monitors than one standing closer to the camera, due to their relative image size.

In two cases, the drivers had observed people close to the train, but were not aware that they were trapped in the doors.

And in one case, an on-train CCTV camera was misaligned, so the trapped passenger was only visible from the neck downwards.

RAIB said the incidents demonstrate the importance of “ensuring that drivers are properly supported in the task of train dispatch through suitable training, briefings and maintenance of equipment”.

Dealing with the root cause passenger behaviour - will be a challenge.

A 2017 report by the Rail Safety and Standards Board found that the majority of passengers did not understand the meaning of the door-close alarm. Most people believed that train doors would reopen if they were obstructed, in the same way as lift doors.

The incidents happened at Seven Sisters (June 23 at 0911, trapped fingers/hand), Wembley Central (June 27, 0626 walking stick or pole), and Crouch Hill (June 29 1346, umbrella).

A previous incident at Wood Street on January 14 resulted in RAIB issuing a safety digest on May 11 making the same observations, with the exception of the passenger education message.