The Rail Accident Investigation Branch (Raib) has said that it is to investigate the sequence of events that led to a train being derailed by a landslide on a Highland route on 22 January.
The incident occurred at 6.47am when a passenger train travelling between Mallaig and Glasgow Queen Street struck a landslip between Lochailort and Glefinnan.
The leading vehicle of the two-carriage train derailed and tilted to the left but none of the five passengers and two crew were injured.
A statement from Raib said: “The landslip was on a remote section of track between Lochailort and Glenfinnan where the line runs across sloping ground above the shore of Loch Eilt. The accident happened in darkness following a period when significant snow melt occurred at the same time as moderately heavy rainfall.
“The landslip originated above the railway boundary. A proportion of the several hundred tonnes of material that slipped was deposited on the railway. This destroyed a section of a fence installed recently to protect the railway from individual loose boulders rolling down the adjacent slope.”
Raib has said that its investigation will consider the arrangements for protecting the railway from landslip debris at this location; Network Rail’s procedures for managing the combined effect of rain and melting snow; and any underlying management factors.