"Inappropriate Inspection Regime'' Causes Derailment
11 December 2014, 13:00
A passenger train traveling to Norwich derailed after an "inappropriate inspection regime'' had failed to detect that track fixings had deteriorated over time, an accident report has said.
Nineteen wheels on the Greater Anglia train came off the rails on a tight curve 260 metres after it left London's Liverpool Street station, the report from the Rail Accidents Investigation Branch (RAIB) said.
All the wheels came back on to the correct rail within a distance of 40 metres, with the driver unaware of any problem until the senior conductor told him that passengers had reported a rough ride with dust falling from the ceiling.
At the same time, the signaller advised him that the signalling system had identified a problem at a set of points used by the train when leaving Liverpool Street bound for Norwich at 10am on January 23 2013.
The driver then stopped and examined his train at Shenfield in Essex, but saw nothing unusual.
In fact some of the wheels had been damaged but the driver was not looking for such damage as it was not yet realised that a derailment had occurred, the report said.
The signaller gave the driver permission to proceed and the train continued to Norwich at normal speeds of up to 100mph.
The report said: ``No one appreciated that there had been a derailment until the train was examined by a specialist inspector when it arrived at Norwich and, at about the same time, a signal maintenance team found track damage close to Liverpool Street station.''
Trains were forced to use alternative routes around the damaged points and two of the six lines serving Liverpool Street remained closed until repairs were completed early on the following morning.
The RAIB said the nature of the track and the tight curve should have led Network Rail (NR) to consider ``mitigation measures to deal with the associated enhanced derailment risk''.
But adding that ``an inappropriate inspection regime'' had been adopted at Liverpool Street, the RAIB said: ``The investigation found that no consideration had been given to these enhanced risks because the maintenance management staff did not have the knowledge necessary to appreciate the need for, and to undertake, this activity. ''
The report went on: ``This lack of knowledge had not been appreciated by more senior staff. The NR procedures for establishing a track inspection and maintenance regime for non-standard track did not require the regime to be independently checked.''
The RAIB made three safety recommendations.