Trains on the West Coast Main Line are running normally again after services were stopped on Sunday when engineering trains were derailed.
Passenger services on the West Coast Mainline, heading out of London and Scotland, were delayed by up to 90 minutes, as trains were diverted or replaced by buses.
Six wagons, carrying materials being used to upgrade the line, came off the rails in Cumbria leading to the termination of trains in Carlisle and Lancashire.
A driver of one of two engineering trains required hospital treatment after suffering minor injuries during the incident.
A Network Rail spokeswoman said the wagons were derailed at Shap, south of Penrith, at about 2230 BST on Saturday.
She said inspectors from Her Majesty's Rail Inspectorate (HMRI) were called in to investigate and concluded their inquiries on Sunday morning.
A diversion was set up for some trains to be re-routed via Settle and Carlisle, while others coming from Scotland terminated in Carlisle.
A Virgin Trains spokesman said passengers had experienced delays of up to 90 minutes.