BRITAIN: The investigation into the Potters Bar derailment was focusing on standards of track maintenance yesterday, as an interim report revealed four metal nuts on a set of points were detached.
The Health and Safety Executive's (HSE) initial findings showed that contractors discovered two of the bolt nuts were detached from the set of points - the mechanism that switches trains from one track to another - on May 1st, nine days before last Friday's crash in which seven people were killed.
The maintenance contractors, Jarvis plc, refitted the nuts - a single nut and a locking nut - and re-checked the points and a visual inspection was carried out on May 9th. According to Jarvis plc, no faults were discovered.
However, at some point the nuts and another pair of bolt nuts again became detached from the points causing a supporting metal bar to break under the weight of the train, derailing the fourth carriage as it approached Potters Bar station in Hertfordshire.
Publishing the HSE's interim report, Mr Frank Hyland, who is managing the investigation, said the information provided by Jarvis plc about the detached metal nuts was "very significant" and all four had been removed for forensic analysis. Points failure was the likeliest cause of the derailment, the report said, but the HSE would not say whether the detached nuts were replaced with a new set or whether they were replaced with the correct type of nuts. The HSE also refused to say whether the metal nuts were found in a position that indicated they had simply fallen off.
"The question is 'why did we find nuts missing or not in position?' We shall be working with British Transport Police to build up a detailed history of all the points in the area," said Mr Hyland. The HSE said that so far it had found no evidence to suggest that the derailment had been caused by signal failure, by driver error or an act of vandalism.
The report was published as Mr Bob Crow, the general secretary of the Rail, Maritime and Transport Union insisted photographic and written evidence supported the union's claim that two of its members had raised concerns at official level about the state of the track near Potters Bar. Clarifying earlier comments that the complaints had been passed to the rail operator, Railtrack, Mr Crow said he suspected a maintenance contractor had failed to inform Railtrack.
The Prime Minister, Mr Tony Blair, last night in a BBC interview said he acknowledged the scale of the work needed to improve the railways.