AN OFFICIAL inquiry is under way into how two busy Bradford commuter trains were allowed to travel at nearly full speed over unstable track after a flash flood swept away supporting gravel.

The independent Railway Accident Investigation Branch (RAIB) says one train driver spotted the hazard and despite trying to stop crossed the unsupported track at 45mph, leaving him “shaken by the event.”

Aire Valley Rail Users’ Group, which represents the interests of passengers, labelled it a serious incident.

The RAIB is also probing why Network Rail, which manages the track, only informed it of the June 7 incident 17 days after the event.

That Tuesday afternoon, torrential rain had sent flash floods across the line close to Baildon Station and then between 5.45pm and 5.58pm two four-coach electric trains passed over a section where part of the supporting embankment had been washed away.

The RAIB statement says: “This had left one of the rails unsupported over a length of between three and four metres. The driver of the second train saw the washout, but was unable to stop the train before passing over it at a speed of around 45 mph.

“The train did not derail, but the driver was shaken by the event. He stopped the train and made an emergency call to the signaller.”

A member of the public had earlier reported some damage and another train driver had reported flooding. Network Rail had then stopped train movements and sent staff to inspect the track at the reported flooding location.

The inspection carried out at that stage found floodwater had receded significantly, but did not identify the washout beneath the track 340 metres further along the line towards Bradford.

And at 5.29pm the line was reopened for use at its maximum speed of 50 mph.

At 5.45pm, the 5.16pm train from Bradford Forster Square to Ilkley service passed over the damaged section of track. Its driver did not report any fault, but a second call from a member of public was then received by the local police stating they had witnessed a train passing over the damaged track.

The message was passed to Network Rail, but before the line was blocked to traffic, a second train, the 5.20pm Ilkley to Bradford Forster Square service, had passed over it despite that driver’s attempts to stop.

An RAIB spokesman said: “Our investigation will identify the sequence of events that led to the two passenger trains being allowed to pass over the damaged section of track. It will also consider how the reports of the track damage and the flooding were communicated within Network Rail. The cause of delay in notifying us will be part of our investigation.

“The member of the public did the right thing to raise the alarm. We are not looking for further witnesses as we have the information needed to conduct our investigation which may typically take between six and 12 months.”

Engineers rebuilt the track within three days using 60 tonnes of ballast to fully support the line.

A Network Rail spokesman said yesterday: “We are working with the RAIB into the investigation at Baildon.” Local railway stations are run by Northern Rail and a spokesman said they would also be working closely with the RAIB.

Tim Calow, chairman of Aire Valley Rail Users’ Group said: “This is serious. If the worst had happened and the train had come off the track it would have been a very bumpy stop indeed. However it’s unlikely there would have been fatalities. One reason for that is it’s lucky that this is a single track without any trains coming in the opposite direction.

"Obviously the RAIB will have to look closely at whether there was some sort of confusion over where the issue with the swept away gravel was and whether there any avoidable mistakes were made.

"They will also have to look at what communications took place. These would have been four-coach electric trains which can carry 360 passengers and would have been relatively full at that time of day.

Ward Councillor Debbie Davies, (Con, Baildon), said: “It’s really quite shocking to learn that it left the train driver shaken. That seems to say quite a lot and show that this could have been a major incident. I’m glad that it’s being investigated so thoroughly.”

MORE TOP STORIES