On 12 May 2010, the leading wheelset of a locomotive that was hauling an engineering train derailed when it was travelling westbound between Gloucester Road and Earl’s Court stations on the Piccadilly Line of the London Underground system.
As a result of the derailment, the locomotive and infrastructure were damaged and the driver of the engineering train reported suffering from trauma. The westbound Piccadilly Line was closed between Gloucester Road and Earl’s Court stations until the start of the passenger service the following day while the locomotive was re-railed and infrastructure repairs were undertaken.
The derailment occurred because the track was not able to maintain gauge within safe limits as the train passed over it. A combination of factors led to this situation occurring, including:
- the non-identification and misclassification of track faults which led to those faults not being rectified
- no action being taken in response to the identification of dynamic wide gauge at the location of the derailment in the previous months
- there were insufficient staff to maintain the track in good condition
- the Piccadilly Line team within Tube Lines was mainly focused on managing safety faults and had not identified the safety risks from combined groups of less serious faults.
RAIB has made nine recommendations. The recommendations include changes to how data from asset inspection equipment is presented, an analysis of the tasks involved in track patrolling and inspecting, changes relating to the training and assessment of track patrollers and inspectors, improvements to assurance processes and consideration of the use of available technologies that can assist track patrollers and inspectors in recording and classifying track faults.
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.