Newquay branch line has reopened after emergency repairs were carried out.
Engineers have worked around the clock in challenging conditions to rebuild a retaining wall on an embankment near Pontsmill viaduct.
The wall had fallen into the river below the railway line during Storm Bert and displaced a significant amount of ballast, which are the stones that hold the track in place.
A number of piles were driven into the river to support the railway and new ballast has been laid.
The repairs were not related to the engineering work that has also taken place to help create Mid Cornwall Metro.
Chris Fuoco, Network Rail’s director for Devon and Cornwall, said: “We thank passengers for their patience while we completed the urgent repairs on the line between Par and Newquay.
“We worked as quickly as possible to repair the railway and ensure your journeys remain safe.”