A 14-wagon timber freight train derailed between Carlisle and Lockerbie on Monday.
All the wagons on the 8.10am service from Mossend to Warrington went off the tracks in the accident, spilling logs onto the trackside. The train driver was uninjured.
Freight operator English, Welsh and Scottish Railway (EWS) said early indications showed there was an axle bearing failure on the first wagon. As a precaution, EWS is checking all other timber wagons of the same type.
It is anticipated that the line will be closed for several days and meanwhile services have been reduced and diversions put in place.
