TfW closes Cardiff Bay line for seven days to lay new track for six-trains-an-hour Metro service

Transport for Wales has closed the Cardiff Bay line between Cardiff Queen Street and Cardiff Bay for seven days from Saturday 24 October so engineers can lay new track for more frequent South Wales Metro services.

No trains will run on the line until Friday 30 October, TfW said in a notice published on 23 October. The track installation is intended to support future timetable changes and increased service frequency on the Bay line, which TfW's project pages say is targeted to reach six trains an hour between Cardiff Bay and Cardiff Queen Street once the transformation is complete.

Dan Tipper, Chief Infrastructure Officer at Transport for Wales, said: "The Bay Line transformation will see the biggest upgrade to public transport in the Butetown and Cardiff Bay area for a generation and is an important part of the South Wales Metro."

He added: "These track works, including the laying of new track, are a key milestone in that transformation and will help pave the way for future service frequency improvements on the line."

The works

TfW said the Bay line transformation forms part of the wider Core Valley Lines (CVL) transformation for the Metro and has been part-funded by the European Regional Development Fund through the Welsh Government. The notice gives no cost for the track works.

According to TfW's project FAQ, the Bay line scheme includes a new two-platform station in the north of Butetown, opposite Maria Street and just north of the Letton Road underpass, and a second platform at the existing Cardiff Bay station. Overhead line equipment is being installed between the new Butetown station and Cardiff Bay, and TfW says the new track will allow faster and more frequent services.

During the closure, ticket acceptance is in place with Cardiff Bus. TfW is also running additional rail replacement buses in the mornings and evenings between Cardiff Bay and Cardiff Central or Cardiff Queen Street, and has advised passengers to check its website because times may vary.

Background

The closure comes in the final stretch of a programme that TfW describes as a six-year transformation of the Core Valley Lines, which began in 2020. In March 2026 the operator announced that overhead line equipment on the final 800 metre section between Cardiff Queen Street and Cardiff Bay had been completed and tested, finishing electrification of the 170km CVL network, on which 281.5 miles of overhead wires have been installed.

At the same time TfW said it would introduce the first of its 36 fully electric Class 398 tram-trains that spring, initially between Pontypridd and Cardiff Bay. In June 2026 it said the first tram-trains would enter service on Pontypridd to Cardiff Bay routes over the summer, replacing the older Class 150 trains on those services, with Metro changes bringing journey times to around 50 minutes and a train every 15 minutes, delivered in phases.

The Welsh Government, in a February 2026 statement, described the 36 trains as running on the Merthyr, Aberdare and Treherbert lines to Cardiff and Cardiff Bay, and as part of its £800m investment in new trains across the Wales and Borders network. Ken Skates, Cabinet Secretary for Transport and North Wales, has separately put Welsh Government investment in the CVL transformation at more than £1bn.

The Bay line was also among six lines, alongside the Rhymney, Coryton, Treherbert, Aberdare and Merthyr lines, covered by TfW's summer 2026 Metro engineering works, which ran from 25 July to 15 August.

The timetable has moved since work started. When TfW confirmed the Butetown station plans in summer 2022 and began work in January 2023, it said the Bay line works would allow a new timetable to be introduced from 2024. This week's notice and the project FAQ describe the frequency increase as a future outcome, without giving a new date.

What happens next

TfW said rail services will resume as normal on Saturday 31 October.

The Bay line also features in TfW's plans for Cardiff Crossrail. TfW's project page says the first phase will be a tramway between Cardiff Central station and Cardiff Bay, joining the existing Bay line, with GRAHAM identified as principal contractor. Site clearance and enabling works were scheduled to start in June 2026, with the main construction phase following in July 2026.