South Wales electrification

Work to electrify the South Wales Mainline – an important rail route linking major towns and cities – is well underway.

Electrification of the railway means quicker and more reliable journeys for passengers and better connectivity for businesses. Electric trains are faster, quieter, longer and greener than current diesel trains. They are also cheaper to run because of lower fuel and maintenance costs.

The South Wales Mainline runs from the Severn Tunnel in Monmouthshire, through Newport, Cardiff, Bridgend, Port Talbot, Neath and Swansea.

Severn Tunnel upgrade

We’ve carried out significant work on the Severn Tunnel to prepare it for when the South Wales Mainline is electrified.

Newport station

To electrify the South Wales Mainline, we’ve been carrying out essential work on the platforms at Newport station throughout 2016, and this will continue into early 2017.

Platforms will remain open, but bridges on the railway nearby will also need to be rebuilt to accommodate the overhead lines that power electric trains, and this will require the temporary closures of roads and footpaths.

Ongoing work includes:

  • preparing the platforms and canopies for masts and overhead electric wires
  • removing the redundant footbridge over Christmas 2016
  • Bridge Street is due to reopen in December 2016
  • upcoming work to the Newport Tunnels, west of the station, in 2017
  • jacking and raising Tunnel Terrace footbridge in 2017 once Bridge Street has reopened
  • working on the two closed bridges in Marshfield (Hawse Lane and Heol Las) until 2018, when they are due to reopen
  • tiling work through Newport and along the South Wales Mainline until 2018.

See the bridge works we’re carrying out around Newport (PDF)

Please check National Rail Enquiries before you travel, for changes to night-time and early-morning train services.


As part of our plan to electrify the South Wales Mainline, a number of bridges in Monmouthshire will need to be rebuilt as they are too low to accommodate the overhead lines that power the trains. We began work at the eastern end of the South Wales Mainline, in Monmouthshire, in spring 2015.

See the bridge works we’re carrying out in Monmouthshire (PDF)