Countdown to final stage of refurbishment of iconic Barmouth viaduct

It's all part of preparation for the final stage of Network Rail’s multi-million-pound refurbishment of the Barmouth viaduct, with work on the metallic elements taking place from Saturday (September 2) for 13-weeks.  

New span with Barmouth viaduct behind. (Image: Network Rail)

Buses will replace trains between Machynlleth and Pwllheli between Saturday 2 September and Friday 1 December as engineers begin the final stage of Barmouth Viaduct’s restoration, which will boost resilience and reliability for passengers on the beautiful Cambrian Coast railway line for generations to come. 

The work will involve replacing and restoring the metallic elements of the Grade II* listed structure on a like-for-like basis, maintaining the historic aesthetic of the 154-year-old railway bridge, whilst demonstrating innovative 21st century engineering. 

This includes removing the two old metallic spans, which weigh 160-tonnes, each. Due to the complexities and challenges of this task, a mock manoeuvre was recently carried out to streamline the process ahead of the real move, this Autumn.  

The practice operation took place on a purpose-built mock railway track, just outside Barmouth, and involved a team of 15 engineers testing the cantilever and jack system, which will be used to lift the span onto the viaduct. 

With one newly fabricated span weighing the same as an average adult blue whale, teams had to utilise more than 16 jacks - ranging from 20 to 100 tonnes capacity - as well as six rail trailers to carry out the technical move.  

Now that the trial is complete, Network Rail and Alun Griffiths have begun preparing for the final move, where two metallic spans will be lifted onto the viaduct and transported via rail, to its new home, on the northern end of the bridge. This unique and intricate process will be done over two days with the finer details being completed during 13-week closure. When in position, the old span will be taken apart, piece by piece, onto a pontoon in the Mawddach Estuary.  

In addition to replacing the metallic span, Network Rail will replace 130-metres of new track near the old Barmouth Toll House, on the northern edge of the viaduct and carry out further track upgrade work at Dovey Junction.  

In order for this work to be safely carried out, the railway over the viaduct will be closed on the following dates:   

• Saturday 2 September to Friday 24 November – This 13-week closure of the line has been confirmed. During this period, engineers will be working to refurbish the metal sections of the bridge.   
• Saturday 25 November to Saturday 2/Sunday 3 December – Network Rail teams are planning to renew the tracks near to Barmouth Toll House, on the northern end of the viaduct, during this period.  

Transport for Wales will operate a combination of bus replacements and train services along the Cambrian Coast line. Passengers are advised to check before they travel at tfw.wales for more information.  

The footpath over the viaduct will also be closed from Thursday, August 31, to Friday, November 24. This is so teams are able to have full access while they safely carry out the essential restoration.   

New span for Barmouth viaduct. (Image: Network Rail)

The restoration of the Grade II* structure began back in 2020, with the work purposely split across several years to reduce the impact on rail services, the community and local economy. The £30m investment has already seen teams replace the timber beams, as well as additional timber strengthening work.  

Nick Millington, route director for Network Rail Wales & Borders, said: “We’re delighted to begin the final, and most visually exciting, stage of our multi-million-pound restoration of Barmouth Viaduct, with our focus now on restoring the metallic elements on a like-for-like basis. 

“A huge part of this phase of work has been planning the replacement of the 160-tonne metal spans, a feat of engineering that has involved months of preparation to develop a unique delivery and installation system. We have also worked closely with our partners at Natural Resources Wales to ensure we’re doing everything we can to protect the delicate ecology of the Mawddach Estuary. 

“As the railway and footpath across the viaduct will need to be closed for the duration of our work to ensure everyone’s safety, I would like to thank everyone for their patience as we carry out this vital work, which will protect this important and iconic rail link for years to come.” 

Colin Lea, Planning and Performance Director at Transport for Wales, said: “This investment in one of the most iconic railway bridges in the world by our partners Network Rail will secure the future of the Cambrian coast line for decades to come. 

“This vital improvement work to replace the metallic spans does mean train services will need to be replaced with road transport until early December, and customers should check journey times before they travel.”