Grayrigg Derailment - Cause

Cause

Lambrigg ground frame, 660 yards (600 m) south-west of the accident site, controls two crossovers, each one comprising two sets of points allowing trains to cross from one running line to the other in emergencies or during track maintenance work. These points are used only occasionally, operated locally after a release is obtained from Carlisle power signal box. They are normally locked in the main line "running" position. Early statements by Chief Superintendent Martyn Ripley of British Transport Police suggested that investigations would focus on these points.

Investigations were launched by the Rail Accident Investigation Branch and Her Majesty's Railway Inspectorate. RMT rail union leader Bob Crow said on BBC News that a points failure was responsible for the incident. Experts compared the cause to that of the Potters Bar rail crash in 2002.

On 26 February, an interim report published by the Rail Accident Investigation Branch outlined the current progress of the investigation. The report contained a single conclusion, that the immediate cause of the accident was the condition of the stretcher bar arrangement at points 2B at Lambrigg crossover, which resulted in the loss of gauge separation of the point switch blades. The stretcher bars (components that hold the moving blades of the points the correct distance apart) had been found to be disconnected or missing. Of the three bars, one was not in position, another had nuts and bolts missing, and two were fractured. The points in question were facing the direction of travel of the train.

Following the RAIB report, Network Rail released a statement in which its Chief Executive, John Armitt, described how the organisation was "devastated to conclude that the condition of the set of points at Grayrigg caused this terrible accident". He apologised "to all the people affected by the failure of the infrastructure".

The RAIB report noted that the Network Rail New Measurement Train ran over the site on 21 February. This train uses lasers and other instruments to make measurements of the track geometry and other features such as overhead line height and stagger, and the track gauge, twist and cant. It is not used to inspect points, but it does make a video record of the track which can be reviewed later. Commenting on the possibility that the train's video might have been used to detect the points damage and thereby prevent the accident, a Network Rail spokesman said: "The train runs at speeds of up to 125 mph, or 95 mph on this stretch. There would be no point somebody watching it at that speed as they wouldn't be able to pick up any faults. It has to be run in super-slow motion to spot faults. The train runs for up to 18 hours a day, seven days a week. It would probably take someone most of the month to watch one day's worth of data. It's not what it's there for. It's a backwards reference tool."

Network Rail admitted it failed to carry out a scheduled visual track inspection in the area on the Sunday before the derailment.

Bob Crow of the RMT union said: "This is shutting the stable door after the horse has well and truly bolted. We argued this train should not replace visual inspections. Inspectors who walk the track are the eyes and ears of the railway. They don't just check the safety of the track, they look at the area surrounding it, check for signs of potential trouble such as gaps in the fence where vandals could get in." Labour Party Member of Parliament John McDonnell added: "The fact that Network Rail apparently had footage of a missing stretcher bar days before the fatal crash is very worrying."

As part of the investigation by the British Transport Police, three Network Rail employees were arrested and bailed, one in July 2007 and two in November 2007 All three were due to answer bail in March 2008 but this was extended until the end of June pending further inquiries. On 9 February 2009, the British Transport Police confirmed that none of the three Network Rail employees arrested in connection with the derailment will be charged following advice from the Crown Prosecution Service.