Potters Bar: Probe rules out sabotage

A series of railway points on the tracks around Potters Bar - where seven people died and 76 were injured in May's disaster - were sub-standard, according to a scathing report by the Health and Safety Executive today.

One in five bolts securing the points needed tightening and the design of the adjustable points which broke as the four-carriage train was passing over them may now have to be changed, the interim report into the disaster says.

The report contains a damning catalogue both of the state of the track in the Potters Bar area and of the rail system as a whole.

Maintenance contractors may have had incorrect spanners to ensure that all nuts were tightened on the tracks.

When 1,700 sets of points of similar design were inspected nationwide immediately after the tragedy, three sets - believed to be on the high-speed routes on the West Coast mainline in the Wembley area - were in bad enough condition for them to be immediately withdrawn from service.

The HSE report say that in the wake of the disaster the inspection of points across the entire UK network revealed a "spectrum of standards" although none were found to be approaching the condition of the Potters Bar points which broke.

The report highlights the "differing standard" of the condition of points, of maintenance arrangements and even record-keeping. The Potters Bar points had adjustable "stretcher" bars to hold them in place. Two of these were loose because nuts were missing on both and this put all the strain on a third bar which snapped as the train travelled over them at 100mph.

The points moved, causing the carriage to derail, and it station platforms.

Railtrack has now been given a month to "review" the particular design of these points and identify any immediate modifications needed. These could include changing the locking-nut mechanism to prevent vibrations making the nuts come off.

The worry over the design of the points which failed was first revealed by the Evening Standard last month.

Dr Mike Weightman of the HSE investigation board said Railtrack must look at the possibility of replacing them with a safer design.

The design of the securing nuts must also be investigated "in particular to ensure that nuts remain tight", he said.

The HSE report says that checks after the crash showed "around 20 per cent of the locknuts tested were considered to be not fully tight, though the root cause of this has not been determined".

To carry out the tests the HSE inspectors used tools supplied by Jarvis Rail, the local maintenance contractor. The report says: "Some fastenings could not be tested with the tools available.

"This was a consequence of the difficulty given the design gaps, in getting the adjustable spanners supplied by the contractor on to both the main nut and locknut."

The investigation also rules out that sabotage was to blame for the points breaking as had been suggested by Jarvis Rail. Investigators said: "No technical evidence has yet been established to support speculation that vandalism or deliberate damage caused the derailment" but they are keeping an open mind.

Dr Bob Smallwood, HMRI's head of operations, called on the maintenance contracting companies and Railtrack to be "more vigilant" in the light of what had been discovered.