Rail passengers are being urged to plan their journeys as a part of the Cumbrian Coast Line will close for essential track upgrades.
Network Rail will replace railway lines and sleepers, track foundation stone and drainage through the 1km long Bransty Tunnel which connects Whitehaven and Corkickle.
A full railway closure will be in place between August 30 and September 22, with rail replacement buses in place.
In recent years the tunnel has been flooding with water containing iron ochre, understood to be from old mine workings, which has resulted in train speed restrictions.
In preparation for the main phase of the renewal, the line will be closed for one weekend from late Friday July 25 to Monday July 28.
Darren Miller, Network Rail’s North West route infrastructure director said: “We thank people in advance for their patience during our extended closure of Bransty Tunnel so we can carry out essential track and drainage renewals to improve future journeys between Whitehaven and Corkickle.
“We always try to plan our improvements to cause the least disruption to passengers, which is why we have scheduled it in late summer to avoid the peak holiday season. Please check National Rail Enquiries so you know exactly what to expect from your journey.”
Craig Harrop, regional director for Northern, said: “We are working hard to minimise disruption while essential engineering works are taking place in Bransty Tunnel in Whitehaven and will be running rail replacement services.
“Customers are asked to check before they travel as journeys may take longer than usual. We will provide more information on our website and in posters and announcements at stations along the route.”
It is believed that the tunnel’s water is contributing to Whitehaven Harbour’s orange water issues.
Network Rail said it had worked closely with the Environment Agency to deliver the project sensitively.
Pete Miles, environment and monitoring manager at the Environment Agency said: “We have been working closely with Network Rail and their consultants as they have developed plans to renew the tracks and ballast in Bransty Tunnel.
“We are satisfied that the control measures being implemented mean no release of iron ochre above that currently being observed should occur and will be inspecting the site during the works to check the impact on the harbour.”
