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 Britain's railway. 

The railway between Monmouthshire and South Gloucestershire reopened this morning (Monday 19 June) following a 10-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 the Forest of Dean, with buses replacing trains between Bristol Parkway and Cardiff Central. 

Opened in 1886, 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 10. The new sleepers will be coated in tin to extend their life.   

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 but there will be one more closure on Sunday, June.  

Here's what will happen to keep travellers moving between South Wales and southern England.

Replacement buses are planned between Bristol Parkway and 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