Network Rail provides behind-the-scenes look at recent Severn Tunnel track upgrades as vital link between South Wales and England reopens

Here’s how engineers installed 3.2km of new track, 5,200 new sleepers and 13000 tonnes of ballast -over a ten-day period – in one of the most challenging environments on our railway.

The railway between Monmouthshire and South Gloucestershire has reopened this morning (Monday 19 June) following a ten-day closure to improve reliability of the line through the Severn Tunnel.

Teams worked a collective 17,000 hours, night and day, to replace the worn and corroded track, which will make journeys more reliable and reduce the need for emergency repairs.

During the project, Network Rail and train operators kept passengers moving by using a diversionary route through Gloucester, with buses replacing trains between Bristol Parkway and Cardiff Central.

Originally built around 150-years-ago, the Severn Tunnel is one of the most challenging environments Network Rail maintains, due to the harsh salt-water conditions, which make for a corrosive environment. This means the track, that usually lasts 25 years, needs to be replaced every ten. The new sleepers will be coated in tin to extend their life.

Here’s a look at what track replacement looks like inside the Severn Tunnel

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Mark Dix, project manager at Network Rail Wales & Borders, said: “The Severn Tunnel is a vital rail link for passengers and freight between Wales and England – around 32,000 trains travel through the tunnel each year.

“Although working in the 150-year-old-tunnel presents some unique challenges, such as water and corrosion, we are determined to continuously maintain the railway to keep trains running.

“As always, I would like to thank passengers and operators for their patience while we safely carried out this essential work.”

The main bulk of the renewal has been complete with one more closure on Sunday 25 June.

Here is how services between South Wales and England will be impacted on Sunday 25 June:

• Trains between London and South Wales will use a different route between Swindon and Newport, and will not call at Bristol Parkway
• Trains between Cardiff Central and Portsmouth Harbour will run between Bristol Parkway and Portsmouth Harbour instead
• Trains between Cardiff Central and Taunton/Penzance will run between Bristol Temple Meads and Taunton/Penzance
• No trains will stop at Patchway or Pilning
• Replacement buses are planned between Bristol Parkway Newport. Passengers who wish to avoid using a rail replacement bus can use their tickets to travel to Gloucester or Cheltenham Spa using CrossCountry or Transport for Wales services