On 12 June 2008, a wheelset on an FTA/FSA type wagon derailed as it passed through Marks Tey junction, located on Network Rail’s Great Eastern Mainline. A second wheelset on the same bogie subsequently also derailed. Two members of staff received minor injuries as a result of the derailment, which also caused damage to the infrastructure and rolling stock involved. The line was re-opened fully the following morning.
The immediate cause of the derailment was the left-hand wheel of the trailing wheelset of the rear bogie of the derailed wagon running over the cess rail head and derailing as the train traversed a section of plain line between a set of trailing points and a set of facing points at Marks Tey junction.
The causal factors were the unloading of the wheels of the rear axle of the trailing bogie of the derailed wagon; a dip in vertical alignment of the track caused by the incorrect replacement of the bearers at the heel of the points; the presence of cyclic top shortly after these points; and the permitted speed of the train.
RAIB has made seven recommendations relating to the following areas: reducing the risk of derailment of FSA and FTA wagons; the competence, management of track recording, and access to the line for Network Rail’s Colchester Maintenance delivery unit; the planning and briefing of preventative maintenance tasks; and the management of broken rails and timber bearer replacements.
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.