One of the world’s oldest railway tunnels is being made more reliable for passengers this autumn.
Network Rail is upgrading tracks through the 180-year-old Summit tunnel between Rochdale and Hebden Bridge.
More than 3km of track across both railway lines will be replaced inside the 2.6km-long tunnel.
It was built between 1838 and 1841 as part of the Manchester and Leeds railway.
The £2M Great North Rail Project investment by Network Rail will take place between 23 and 31 October. For the essential work to take place the railway will be closed for nine days.
Network Rail North West head of performance and customer relationship Karen Hornby described the improvements as "vital".
She added: "The work will mean fewer train delays on the Calder valley line and make tracks inside the Victorian-built structure fit for the 21st century.
“However, replacing track like this means we have no choice but to close the line for old sections to be ripped up and replaced with new. I’d urge anyone planning to travel over the nine-day railway closure to check National Rail Enquiries to they know exactly what to expect from their journeys.”
Northern regional director Chris Jackson emphasised that the work "will provide our customers with an even more reliable railway”.
"We are sorry for any disruption during the improvements and our customers can be assured that both Northern and Network Rail will do everything possible to minimise the impact of the work and deliver alternatives that keep people on the move," he said.
Network Rail is also working with the Environment Agency which will be upgrading a culvert beneath the railway lines as part of a wider flood defence project in the area.
Environment Agency senior flood risk advisor Nick Pearson said: “Working in partnership with Network Rail as part of the proposed £56M Rochdale and Littleborough Flood Risk Management Scheme will make a huge difference to rail passengers, residents and the local economy.
“This project, one of the biggest flood alleviation schemes in the north of England, will play a crucial role in better protecting the community from the risk of flooding and we are pleased to see it progress.”