GERMAN RAILWAY engineers confirmed this week they were changing the wheels on Inter City Express trains to the type now blamed for the high speed derailment on the East Coast main line in Sandy, Bedfordshire, last week.
The move comes just two weeks after the Eschede rail disaster in northern Germany which cast serious doubt on the integrity of the ICE trains' steel tyre wheels (NCE 11 June).
But investigators from the Health & Safety Executive and Great North Eastern Railway claimed this week that a cracked mono-block wheel - the type now being fitted to German trains - was the most likely cause of the English derailment last Tuesday. Rail safety experts believe that only good fortune prevented the accident from being as serious as at Eschede.
A spokesman for German Railways said on Tuesday that the company was changing all the wheels on its fleet of 49 first generation ICE trains to the mono-block design in the wake of the Eschede crash. The tragedy - Germany's worst since the war - left 98 dead after a steel tyre broke on a carriage wheel, causing the train to derail at a set of points and plough into a concrete overbridge.
By comparison the Bedfordshire accident was minor. Only nine people were slightly injured when the last carriage of the nine-coach 17.30 service from King's Cross to Edinburgh came off the rails at around 200km/h.
But rail safety experts claimed that had one of the front carriages come off the rails instead of the last, the scale of the accident would have been much worse. The carriage is believed to have derailed at a set of points before passing through Sandy station and under a single span concrete overbridge.
Independent rail expert Peter Rayner said: 'If the first one had come off at the points and gone wide, the rest would have impacted into it in much the same way as Eschede.'
Rayner, who conducted the inquiry into the Colwich rail crash which killed two people in 1986 said it was only good fortune that the train had not hit either the station platform or the bridge.
However, a spokesman for Railtrack said the company would not be re- examining the positioning of points and clearances at the side of the track.
'We have very firmly established safety cases which are agreed with the HSE and as far as we are concerned those safety cases remain robust,' he said. The track had been ultra-sound tested earlier in the month and visually inspected the day before, and there was no hint that it was to blame for the derailment.
No modifications have been made to the track in Germany as yet. But a spokesman for German Railways said: 'When we know exactly the cause of the Eschede crash, then perhaps we will change the layout of the track and design of the bridges. At the moment our priority is to get all 49 ICE trains back into service.'
In the UK, HSE investigators believe that stress cracks had developed in the wheel of the GNER train from a hole drilled to accommodate a heavy bolt used to balance the wheel for smooth running - the standard way to balance such wheels. This hole caused a quarter of the wheel to fracture off.
A spokesman for GNER said that all the drilled wheels on the fleet of 31 InterCity 225 electric trains had since been checked for cracks by magnetic particle testing. The frequency of checks has also been increased from 90 day intervals to 10 day intervals.