 The subsequent enquiry found that the derailment occurred at a trailing crossover which was being worked on by three platelayers.The three maintained they had just been clearing and repacking the ballast which would not have impaired the stability of the track; and the only contributing cause was the high speed of the train.However six weeks later a further witness was found, a shunter who was waiting for the express to pass before reporting to the signal box, who stated he saw that 'key was out of the rail' and saw the rail jump up as the locomotives passed the crossover and the leading coach plough into the ballast.