Network Rail engineers will carry out around £5m of delay-busting upgrades between Axminster and Pinhoe from Monday 19 to Friday 23 September.
The five-day closure will give workers uninterrupted access to the railway to carry out landslip prevention work at Honiton Tunnel, one of the most at-risk sites in the south of England.
Mark Killick, Network Rail’s Wessex route director, said: “The West of England line is a key part of the railway on Southern region so it’s vital we continue to invest to give our customers the reliable service they deserve.
“While we have tiny electronic sensors in the ground at Honiton Tunnel to monitor any movement so we can keep our passengers safe, it’s incredibly important that we carry out these works to stabilise the earth so we can prevent future landslips and lengthy disruption.
“By doing the work over five days means we can avoid a series of back-to-back weekend closures which would be even more disruptive, plus we can take advantage of the extended access to complete other upgrades and vital track maintenance.”
As well as installing two retaining walls, 32 metres and 16 metres in length, sheet piles (metal posts with concrete planks in the middle for added support) will protect the line from lengthy closures caused by landslips. Engineers will also carry out vital track maintenance to give customers a more reliable train service.
On top of that we are improving existing drainage systems and installing a new one. So together with strengthening the cutting, the improved drainage will make the line more resilient to extreme weather and heavy rainfall.
East Devon District Council will also use the railway closure to complete a huge project to protect 65 homes in Feniton from flooding.
Peter Williams, South Western Railway’s commercial director, said: “The upgrades that Network Rail is carrying out will significantly boost the reliability and resilience of a vital part of our network.
“Customers intending to travel from Monday until Friday should check before they travel and make use of the alternative transport options which have been provided.
“We recognise the decision to close the line for an entire working week will have a significant impact on those who use the line, but this will avoid a more protracted series of closures instead.
“We would like to thank those affected customers for their patience and understanding as this important modernisation work is carried out.”
The closure is part of a series of major upgrades planned for the West of England line, totalling millions of pounds of investment (details of further closures in notes to editors), which will make journeys more reliable for customers for years to come.
Similar earthworks will be carried out along the route in December and there is another extended line closure next year too.