Network Rail was today fined £70,000 and ordered to pay costs of £25,000 after its failure to properly maintain a level crossing led to the derailment of a 90mph train.

The train hit a heavy rubber panel at Croxton level crossing near Thetford in Norfolk and travelled for 460 metres before coming to a halt fouling the line next to it, Norwich Crown Court heard.

Now Network Rail says it will install a ‘single-slab’ concrete crossing deck at Croxton crossing by April 2010.

Network Rail Infrastructure Limited pleaded guilty under the Health and Safety at Work Act 1974 to failing to ensure the safety of passengers, train crew and road users by inadequately maintaining the level crossing.

It was also found guilty of breaching the Level Crossing Regulations 1997 as it failed to maintain the surface of the carriageway of the level crossing in a good condition.

The prosecution brought by the Office of Rail Regulation (ORR) followed an incident on 12 September 2006 at the crossing.

The court heard that just before 6am a heavy rubber panel in the crossing surface was dislodged by a lorry and then hit by at least two other vehicles.

One car was lifted and spun out of control after it hit the ‘ramp’ created by the panel.

Then, shortly afterwards, a passenger train travelling at almost 90 mph was derailed by the panel.

There was no train coming the other way and no serious injuries to the car drivers, train passengers or crew.

An investigation by the Office of Rail Regulation’s railway safety directorate found that the dislodged panel, and others at the crossing, were not properly supported by sleepers.

Network Rail missed a number of opportunities to re-space the sleepers despite being told about loose panels at the crossing on at least seven occasions in the previous five months. There was also insufficient training for staff.

Allan Spence, ORR deputy chief inspector of railways, said: “This was a very serious incident which, but for good luck, could have been catastrophic.

“The repeated failings of Network Rail’s level crossing maintenance system at Croxton put road users and people on trains at great risk - and that is simply unacceptable.

“The derailment highlights the importance of effective infrastructure maintenance, so that equipment is installed to appropriate standards and that maintenance checks identify and fix deterioration before it becomes dangerous.

“It also demonstrates the need for more effective training of the workers who install and maintain key assets. Effective management by Network Rail of their maintenance regime would have identified that maintenance and inspection records for this crossing were missing, unsigned, and in at least one instance, signed by a person who did not complete the work.

“ORR will continue to press Network Rail to improve its asset management, and so address the significant failings illustrated here, as one of the seven strategic themes in our recently published strategy.”

A Network Rail spokesman said: “Network Rail takes full responsibility for what happened at Croxton on 12 September 2006. As ever, safety is a top priority for us and our record is good.

“We have acted promptly and practically following the incident, as the judge in this case acknowledged in determining the sentence.

“He took into account Network Rail’s immediate response to the incident, our prompt admission of responsibility and the plans which we have in place to improve the crossing by the end of the current financial year.”