The Rail Accident Investigation Branch announces preliminary findings pointing towards driver error as the likely cause of the accident.
The investigation, which is entitled “Investigation into the derailment of an electric locomotive at Bletchley Junction, Bletchley, on 3 February 2012”, has not yet been formally fully compiled, but at the present time, a “preview” has been released without full technical details.
In the early hours of Friday, February 3rd, at 02:28, Virgin Trains operated 0A90, the 01:03 from Crewe to Wembley, was running around 80 minutes ahead of schedule, and derailed over pointwork south of Bletchley station. All four lines on the West Coast Main Line were closed for a large swathe of Friday, owing to overhead wires being brought down, and extensive damage to rails, sleepers with a loss of track alignment.
It is believed that the reason for the 80 minute early running will also be investigated, to see if speeding was a factor throughout other parts of the journey.
RAIB’s preliminary examination found that the derailment occurred because the locomotive was driven significantly faster than the permitted speed over the junction. This resulted in its wheel flanges climbing over the outer rail of a curve just before it would have reached the up fast line.
The Investigation Branch is quick to point out that their was no evidence that track or pointwork, despite being due for renewal at the end of the year, was to blame. The infrastructure here permits a maximum speed of 15mph when crossing to the Fast line, as 0A90 started to do, but the driver may have been doing in excess of 40mph across a tight radius. The driver should also have been bringing the speed of his train to a slower, more controlled amount for a 20mph restriction in the Leighton Buzzard direction.
The investigation will identify the sequence of events that led to the locomotive exceeding the permitted speed for the route it was taking. It will also include an examination of the factors that influenced the behaviour of the driver, the train operating company’s competence management system and the signalling arrangements at the junction. It will also review the history of the junction signal and any risk assessments that were carried out.
The West Coast Main Line has continued to suffer from Signal Failures since the derailment and moving annual average performance statistics are sure to be adversely affected for some time.