Recent inspections at Parton found huge waves and gales caused cracks to appear in a railway bridge after storms Ciara, Dennis and Jorge.
Repair work has already started but further investigations found the damage to the bridge and sea wall is worse than at first thought.
To make the railway safe and reliable the bridge carrying the tracks is being completely replaced over the coming months.
Chris Jackson, Regional Director at Northern, said: “The extreme weather earlier this year was prolonged and we are still feeling the effects of the damage caused.
“The repairs being carried out at Parton are vital if rail services are to return and I’d like to thank our customers for their patience and understanding.
“Of course, services in the area are also being limited by measures to restrict the spread of coronavirus, but the rail industry is doing all it can to keep key workers on the move during this difficult time.”
Phil James, Route Director for Network Rail’s north west route, said: “The severe storms earlier this year battered Cumbria’s railway and we’re still working hard to repair the damage.
"Our engineers are replacing the bridge at Parton to make this exposed section of railway much more reliable in the future.
"I’m sorry for the inconvenience this will cause for passengers using the Cumbrian Coast line.”
To keep passengers moving bus replacement services will be in operation for passengers between Workington and Whitehaven until the summer.
Trains will continue to run on the rest of the Cumbrian Coast line between Carlisle and Barrow-in-Furness.
With only essential travel being recommended during the coronavirus pandemic, a reduced timetable is operating on the rail network.
Passengers are advised to check how this may impact on their journeys over the coming months at www.nationalrail.co.uk.