Network Rail to complete essential upgrade works in the Severn Tunnel

Network Rail are to renew the tracks in the Severn Tunnel over a ten-day period to ensure more reliable journeys for passengers.

Working inside Severn Tunnel to renew the track

Credit: Network Rail

Trains will be diverted or replaced as Network Rail works around the clock to renew the tracks in the Severn Tunnel. Engineers will replace 3.2km of old track, as well as 5,200 sleepers (track supports) and 14,000 tonnes of ballast (supporting stone) over a ten-day period. 

Salt-water makes for a corrosive environment inside the tunnel and track that would usually last 25 years needs to be replaced every ten. The new sleepers will be coated in tin to extend their life.  In 2022, Network Rail replaced 3km of track on the Monmouthshire side of the tunnel. Now, the track will be replaced on the South Gloucestershire side. 

The new track will ensure more reliable journeys for passengers as well as reducing the need for emergency closures for track repair work. Network Rail engineers will be working 24/7 over the ten days to reduce the length of the disruption. 

“Owing to the environmental conditions within the tunnel, we have an enhanced programme of track renewals, which includes replacing worn sections of track every 10 years, as opposed to every 25 years for less challenging environments,” Mark Dix, Project Manager at Network Rail, said. “This renewal is therefore part of an ongoing maintenance schedule which is more cost effective than multiple weekend closures and vital to ensure the continued safe and reliable running of train services along this busy route.” 

“These upgrades in the Severn Tunnel form part of an ongoing programme of work that will enable us to maintain services for those travelling to or from South Wales,” David Bailey, GWR’s Customer Service Manager for South Wales, said. “We’ve been working with other train companies to provide alternatives to ensure that our customers can still complete their journeys during this engineering work.”