South Western Railway is to resume a full train service between Salisbury and Exeter St Davids from the middle of next month.

For the last two months, the line has been subject to disruption with fewer trains and lower speeds. From Monday, 14th November, South Western Railway (SWR) will restore a regular timetable running at normal line speed.

After last summer’s record-breaking heat and dry weather, which caused the rails to become uneven and unsafe for trains to run at full speed, 40 mph speed restrictions were imposed at a number of locations including near Tisbury, Gillingham, and Axminster.

Since then, engineers have made good progress in restoring the track levels, helped by cooler temperatures and regular rain which has stopped the track bed shrinking. The cause of the speed restrictions is a condition known as Soil Moisture Deficit, which is caused by largely clay-based soils shrinking in hot and dry conditions as trees and other vegetation soaks the water from them. They shrink unevenly, meaning track laid on top loses its level profile.

In the Southern region of Network Rail there are around 6,000 embankments built from clay, and a 4-mile-long section at Tisbury is the longest. That section of the line is only a single track for trains, meaning any delays caused by running at a reduced speed will affect services travelling in the opposite direction, which will compound the delays.

The following month, services on the line will be disrupted again when SWR services between Salisbury and Exeter St Davids are diverted via Westbury between Saturday 10th and Sunday 18th December while track in the Gillingham area is replaced. Rail-replacement buses will serve Tisbury, Gillingham (Dorset), Templecombe, and Sherborne.

During the December closure, improvements will be made to Gillingham and Sherborne stations; drainage will be improved in the Sherborne, Templecombe, and Gillingham areas, track maintenance will be undertaken in the Gillingham and Sherborne areas, and graffiti and litter will be removed from the line at Salisbury.

Mark Killick, Network Rail’s route director for Wessex, said: “We’re still suffering the after-effects of a record-breaking summer on our railway, but I’m pleased we’ll be able to have trains running at full speed again soon, and I’m so grateful for customers for bearing with us.

“We’ve invested tens of millions of pounds on the West of England Line in the last two years by strengthening railway cuttings and renewing track and switches and crossings. As well as December’s track renewals, we’ve got even more planned in 2023 and 2024, demonstrating our commitment to all of the customers who use this line every year.”

Claire Mann, South Western Railway’s managing director, said: “I am sorry to all those customers whose journeys were affected as we waited for weather conditions to improve to enable Network Rail to safely remove the speed restrictions. We’re looking forward to implementing a full timetable and providing the quality services that our customers deserve.”