The locomotive and six wagons derailed
Brakes on a train that derailed in the Highlands had not performed as well as they should have the Rail Accident Investigation Branch (RAIB) has said.
The locomotive was travelling at about 60mph when it overshot a run-out, a short length of track designed to divert trains from Carrbridge station.
Six of the 10 flat bed wagons carrying containers the engine was pulling also derailed in the incident on 4 January.
The RAIB said the brakes and effects of bad weather were being investigated.
In a statement, the branch said: "The driver and a technician who was travelling with the train received minor injuries. Major damage was caused to the railway infrastructure.
"An initial review of the evidence suggests that the braking performance of the train was below that expected of a train of its type.
"The weather at the time was poor, with a layer of snow over the head of the rail, heavy falling snow and extreme freezing temperatures.
"This investigation will take into account any other instances of poor braking performance during extreme winter conditions."