On Tuesday 31 January a freight train was traversing the Cricklewood Curve at 7.5 mph when two wagons derailed. The wagons overturned and started to slide down the embankment, but were held by their couplings to the rest of the train. There were no injuries as a result of the accident, but residents of flats at the foot of the embankment were evacuated as a precaution.
The immediate cause of the derailment was a severe track twist, brought about by movement of the embankment at the site of repair works to address previous movements. Track maintenance staff had not appreciated the severity of the movement before the derailment and did not carry out remedial work. A risk assessment had identified embankment movement as the greatest risk during the works, but this was not fully considered by the Network Rail staff involved in planning the work.
RAIB has made six recommendations as a result of its investigation. They cover:
- application of construction regulations;
- project management systems and associated technical control; and
- technical standards regarding track deterioration.
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.