RAILTRACK THIS week admitted that it was researching new technology to replace ultrasonic testing as its current equipment is unable to fully identify the gauge corner crack (GCC) problems now known to have led to last October's Hatfield crash.
Speaking to NCE in the wake of a new interim Health & Safety Executive report on the crash, Railtrack confirmed that research had begun into more effective non-destructive testing to more accurately detect GCC.
However a spokesman was unable to give further details of this research other than to say that Railtrack sought a system 'to enhance checking capability'. He said that the work was out to tender but could not confirm when the new technology would be available.
The HSE report highlighted that ultrasonic testing equipment used previously at Hatfield and across the rail network, had not been designed to detect GCC. But it points out that the systems now in use are the only way to test large lengths of rail.
HSE investigation board technical advisor Chris Willby said 'the system was not optimised' to look for GCC. The result is that only cracks within a certain angular range will be reliably detected, with shallow cracks and those close to the gauge corner missed.
It is known that the ultrasonic tests carried out at Hatfield in June proved inconclusive. This is thought to be due to surface spalling on the rail. The HSE report notes that the spalling included 'dark' oxidised areas, indicating they had been present for some time.
The HSE report backs findings published last October by US consultant Transportation Technology Center Inc (TTCI), which was commissioned by the Rail Regulator to investigate broken rails. 'Lack of automated ultrasonic inspections may hinder detection of defects before they become breaks, ' it said.
A separate report into GCC, produced this week by Arup and TTCI gave full backing to the rerailing programme launched by Railtrack after Hatfield. But it recommends that lubrication and rail grinding are increased.
It also calls for more research into the track/wheel interface.
Railtrack and the train operating companies this week responded with establishment of a group to investigate this critical area.