Train wagons 'jumped' at level crossing in Sutherland
Network Rail were alerted to the derailment of a freight train after a member of the public saw some of its 27 empty wagons "jump".
The train had been travelling from Georgemas in Caithness to Hartlepool on 23 February this year.
Parts of a brake broke and fell on to the tracks at Dalchalm level crossing in Sutherland causing the last wagon to derail, according to a new report.
It re-railed at another level crossing about 340m (0.2mile) down the line.
No-one was hurt in the incident.
A newly-published Rail Accident Investigation Branch (RAIB) report said a man living near the Dalchalm crossing had seen some of the wagons "jump".
When the train had passed he found parts of the broken brake and alerted a signaller at Inverness.
The train driver, who had been unaware of the derailment, stopped between Golspie and Rogart.
After finding the damaged brake he considered it unsafe to continue any further and called for assistance.