A tractor driver’s failure to use a phone to notify a railway signalman he was crossing a busy Fen line may have caused last month’s derailment near March.

The Rail Accident Investigation Branch (RAIB) said they had been “unable to find any evidence that a request to use the crossing was made by the driver of the tractor involved”.

The derailment was caused when a freight train collided with a tractor on a remote level crossing outside of March.

The crash happened at 9.01am on August 13 when a freight train with 36 container wagons struck a loaded farm trailer at Kisby user worked level crossing.

An RAIB preliminary report said: “The train driver applied the emergency brake around six seconds before the collision occurred, but the train was still travelling at around 58 mph (93 km/h) when it struck the trailer.

“The trailer parted from the tractor that was pulling it and was then dragged along by the train.”

The report says the leading axle of the locomotive and an unladen wagon in the middle of the train also derailed.

The train ran derailed for around 780 metres before it came to a stop.

Both the train and tractor drivers suffered shock and the train driver was treated for minor injuries.

RAIB says the locomotive suffered significant structural damage and the level crossing and track equipment were also extensively damaged.

“Train services were disrupted on both lines for four days,” says their report.

“Kisby user worked crossing is fitted with a telephone and with user-operated powered (POGO) gates.

“These gates are not interlocked with the railway’s signalling system.

“Users are directed by signs at the crossing to use the telephones to obtain permission from the signaller before opening the crossing gates and crossing the railway.

“RAIB has been unable to find any evidence that a request to use the crossing was made by the driver of the tractor involved.”

RAIB says their investigation will seek to identify the sequence of events which led to the accident, including the actions of the tractor driver and other users of the crossing.

It will examine how the crossing was being managed and how the risks associated with its use were being assessed and mitigated by Network Rail.