At 01:29 hrs on 2 March 2016, the leading bogie of a London Underground District line train derailed just outside Ealing Broadway station.
The train was travelling at less than 5 mph (8 km/h) when it derailed. There were 19 passengers and two members of staff on board the train at the time of the accident. There were no injuries.
The train had been held at a red signal since 00:35 hrs as a result of a track circuit failure. During that time, staff had been establishing which points needed to be secured in order for the train to safely pass the signal at danger and proceed to Ealing Broadway platform 7, where it could terminate.
Due to the inadequate level of information available to the service control staff, the poor relationship between the two control rooms involved, and a lack of understanding of the way in which the type of points involved were shown on the various available diagrams, the operational control staff did not identify the correct positions of all the sets of points that needed to be secured in the route. Consequently, the train was authorised to pass the signal at danger with a set of points in the wrong position for the route the train was due to follow.
The service control staff were not completely clear, from the information available to them within the control rooms, which points they needed to set in which positions and so they asked the maintenance team for assistance. The two teams did not communicate effectively and did not reach a complete understanding of the requirements for the route.
The RAIB has made three recommendations to London Underground Limited. The first covers possible ways of improving the quality and amount of information provided to control room staff to help them make decisions. The second relates to ensuring that a complete and full understanding is reached when passing messages, and ensuring that all those who may need to provide information for operational purposes are appropriately trained; and the third involves ensuring control room staff are able to respond appropriately in the event of conflict or confusion, to enhance team working and effective decision making.
The RAIB has also identified two learning points, relating to the importance of having proper arrangements for safety in place if work needs to be done near live electrical conductors, and avoiding confusion when passing messages by keeping the chain of communication short.
Response to recommendations:
- RAIB will periodically update the status of recommendations as reported to us by the relevant safety authority or public body
- RAIB may add comment, particularly if we have concerns regarding these responses.