AN investigation has been launched after a heritage locomotive partially derailed during a festival at a Swanage Railway.

The diesel locomotive, a 1968-built ex-British Rail Class 50 No. 50 026 ‘Indomitable’, was partially derailed at Corfe Castle station on Saturday, May 11 during the annual Diesel Gala and Beer Festival.

The Rail Accident Investigation Branch (RAIB) has been made aware and is investigating the cause of the incident.

It took place at around 6.30pm as a passenger train bound for Harman’s Cross and Swanage was running into the station from Norden.

No passengers were injured, and no damage was sustained to the carriages of the train.

Saturday was the second day of the three-day festival, which is in its 17th year, with passengers returned to Swanage after evening train services were suspended.

Specialist contractors re-railed the locomotive, which was completed in the early hours of Sunday, May 12.

‘Indomitable’ has been taken out of service and will be examined for any damage as a result of the incident.

Meanwhile, services on Sunday have been altered, with 11 trains operating on a shortened five and a half miles of line, between Swanage and Norden and not along the four miles of line to the River Frome.

The Jurassic Crompton rail tour from Swanage to Eastleigh and London Waterloo, which arrived on Thursday, May 9, will run as scheduled on Sunday afternoon.

Swanage Railway Company chairman Gavin Johns said: “The Government’s Rail Accident Investigation Branch has been advised of the incident and we liaised with the RAIB regarding the recovery of the diesel locomotive and the RAIB’s investigation into what caused the partial derailment of the diesel locomotive.

“While the RAIB is investigating the incident – and after discussions with the RAIB - our planned train services for Sunday, May 12, have been altered.”