The work — a mix of structural repairs and track renewals — will run from Monday 26 January to Thursday 5 February, with an extra day of disruption on Sunday 8 February. Services will be diverted, reduced or replaced by buses throughout.
Network Rail says the timing has been chosen to avoid clashing with the England v Wales Six Nations match at Twickenham on Saturday 7 February.
Replacement buses, diverted trains and long detours
Across the two‑week period, passengers face a patchwork of amended services:
From 26–30 January, buses will replace trains between Port Talbot Parkway and Swansea or Llanelli, while trains continue to run between London Paddington and Port Talbot, and between Llanelli and Carmarthen. Transport for Wales will run a limited service via an alternative route that won’t stop at Neath or Swansea.
Over the 31 January–1 February weekend, buses will operate between Cardiff Central or Bridgend and Swansea, with trains still running between Paddington and Cardiff, and between Swansea and Carmarthen.
From 2–5 February, the pattern repeats: buses between Port Talbot and Swansea, diverted TfW services avoiding Neath and Swansea, and reduced long‑distance services.
On Sunday 8 February, buses will again replace trains between Cardiff, Bridgend, Port Talbot and Swansea, depending on the route.
Rail bosses apologise — and warn journeys will take longer
GWR’s Station Manager for South Wales, Kay Davies, said the work was essential but acknowledged the impact on passengers.
“We apologise for the impact this work will have on customers, but this is a really important investment in the long‑term reliability of our railway,” she said.
Davies warned that timetables have been amended, including a reduced service between Cardiff Central and London Paddington, and urged passengers to allow extra time as “bus journeys will take a little longer than the train.”
Transport for Wales Planning & Performance Director, Colin Lea, said the operator was working with Network Rail and GWR to “keep passengers moving” during the upgrades.
He said some services would be diverted with longer journey times, adding: “We’d encourage passengers to plan ahead, check before they travel, and allow extra time for their journeys.”
Network Rail: ‘There’s never a good time to close the railway’
Network Rail Wales and Borders Route Director, Nick Millington, said the work was part of efforts to improve punctuality.
“We recognise there is never a good time to close the railway, but we have planned the renewals to minimise disruption as much as possible,” he said.
Millington thanked passengers for their patience and urged them to check their journeys before travelling.
