The Rail Accident Investigation Branch is carrying out an investigation into the high speed derailment of one pair of wheels on train 1F45, the 14.55 service from St Pancras to Sheffield, at about 15.46 on 20 February 2010.

The train comprised a seven-car Class 222 ŒMeridian¹ diesel-electrical multiple-unit operated by East Midlands Trains and was carrying approximately 190 passengers and a number of train crew.  On approaching the site of the derailment the train was travelling at close to 100 mph.  No other wheels derailed and the train remained upright.

No injuries were caused to the passengers or train crew although significant damage was caused to the track and signalling equipment over a distance of two miles. There were also reports that one or more road vehicles on an adjacent highway were struck and damaged by debris as the derailed train passed.

The evacuation of the passengers into another train was completed about four hours after the derailment.  The line was then closed for a period of three days to enable train recovery and repairs to the infrastructure.

The RAIB¹s preliminary examination has identified that the derailment is likely to have been the result of the failure of an axle in proximity to the final drive.  The exact nature of this failure and associated factors will be the subject of detailed examination by the RAIB, with the cooperation of the operator and rolling stock maintainer, Bombardier.  Any urgent safety issues arising during this investigation will be the subject of a notification to all the industry parties affected.

To date, there is no evidence that the condition of the railway infrastructure or signalling contributed to the derailment.

The RAIB¹s investigation is independent of any investigations by the safety authority.

The RAIB will publish a report, including any recommendations to improve safety, at the conclusion of its investigation.