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Advance Notice of June 2023’s Severn Tunnel Rail Improvement Work

24 April 2023


We want to give you advance notice of Network Rail improvement work taking place this summer in the Severn Tunnel between South Wales and England.

On Friday 9 June, Monday 12 to Sunday 18 June, and Sunday 25 June, Great Western Railway services between South Wales and London Paddington will run on a diversionary route between Swindon and Newport, not stopping at Bristol Parkway, and adding around an hour to journey times.

We recommend that customers wishing to travel between South Wales and Bristol travel via Gloucester/Cheltenham Spa using Transport for Wales Rail and CrossCountry services. We do plan to have a replacement bus service in place between Bristol Parkway and Newport however the national shortage of bus drivers means that we may have a smaller number of replacements services than we would hope.

On Saturday 10 and Sunday 11 June, the diversionary route between South Wales and Swindon is also closed, and buses will replace trains between Bristol Parkway and Cardiff Central. No trains will stop at Newport, Patchway, Pilning or Severn Tunnel Junction.

Great Western Railway train services between Cardiff and Swansea, Carmarthen and Pembroke Dock will continue to operate, and we continue to operate our additional Carmarthen services and our summer Pembroke Dock service as planned.

Online journey planners have been updated and we’ll also update customers aware through at station and on board announcements, station posters, and traditional and social media. More information can also be found at