On Friday 04 November a train travelling on the West Coast Main Line derailed after running into a landslip at a cutting at Oubeck North. The trailing wheelset of the leading bogie derailed and the train travelled a further 1430m before coming to rest in an upright position. There were no injuries as a result of this derailment but track damage was sustained.
The immediate cause of the derailment was the train running into material deposited on the track as a result of the cutting landslip. This failed due to the volume of water flowing through a concealed field drain into the slope, which was greater than usual due to the wet period over the preceding two weeks and excessive rain during the previous day. The root cause was that the field drain was hidden from view and therefore the infrastructure owner was unaware of it.
RAIB has made six recommendations as a result of its investigation. The primary focus of the recommendations was on modifying existing drainage arrangements at Oubeck and identifying, prioritising and managing other cutting slopes prone to risks of earth flow due to drainage from neighbouring property.
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.