At around 02:00 hrs on 22 June 2007 wagon 16002, the 15th wagon in train 6L58, the 21:19 hrs Mountsorrel to Chelmsford, derailed on the approach to River Great Ouse underbridge near Ely. The derailed wagon was dragged onto the bridge, where it, and other wagons that subsequently derailed, caused considerable damage to the bridge structure. There were no casualties in the derailment.
RAIB’s investigation identified the immediate cause of the incident was the right-hand leading wheel flange on wagon 16002 running over the rail head. This was caused by the leading right-hand suspension sticking (frictionally locking up), with the result that only the tip of the wheel flange was in contact with the rail. As the wagon rounded the curve only very small guiding forces acted on the flange, which were insufficient to keep the vehicle on the track.
As a consequence of this accident, RAIB has made 16 recommendations, targeted at Network Rail, Lafarge Cement (the owners of the wagons), Wabtec Ltd (the maintainers of the wagons) and English, Welsh and Scottish Railway (now operating as D B Schenker), the operators of the train. These relate to the detection of out of balance wagons, standards and maintenance records for private owner wagons operating on Network Rail’s system, track maintenance standards and access times at Ely, and train preparation at Mountsorrel.
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.