A preliminary investigation into an incident which saw a runaway train carriage smash through a level crossing onto a public road, has been completed.

On December 10, shortly before 4pm, the centre carriage of a three-car class 144 Pacer unit belonging to the Mid-Norfolk Railway "detached from a winch rope during unloading from a heavy haulage road trailer directly onto the railway."

The carriage "ran away and collided" with the gates of the level crossing on Norwich Road in Dereham, breaking through the barriers and coming to a stop on the road.

No one was injured and no other vehicles were damaged in the incident, but the event did cause delays for motorists after the carriage was left blocking the crossing.

Eastern Daily Press: The carriage blocking the Norwich Road crossing in Dereham.The carriage blocking the Norwich Road crossing in Dereham. (Image: Supplied)

Following the incident, the Railway Accident Investigation Branch has notified the Mid-Norfolk Railway that its preliminary investigation into the events of December 10 has been completed and it will be issuing a safety digest in the coming weeks.

The RAIB, is an official body which independently investigates accidents and incidents which occur on the UK mainline networks in order to improve railway safety.

Once the RAIB is notified of an incident it will conduct a preliminary examination into the circumstances surrounding the event to see if a full investigation is needed. When the RAIB feels the safety learning from an event has been identified by a previous investigation or relates to compliance with existing rules, it will publish a safety digest, rather than carry out a full investigation.

The issuing of the safety digest brings the RAIB's involvement with the incident to a close.

Charlie Robinson, chairman of the Mid-Norfolk Railway Preservation Trust, the owners and operators of the Mid-Norfolk Railway, said: "On behalf of the Trust and the railway's members I would like to thank all of our staff who have worked to resolve this issue both at the time and subsequently.

"As a railway, we are fortunate to have a number of very experienced railway people as well as members with the right skill sets who dealt with this incident in a calm and professional manner.
"I can assure the membership and our travelling public that as a railway we will be actioning the recommendations of the RAIB, but are also looking at our own procedures in a critical way to ensure such an incident cannot happen again."