Everything you need to know about the latest South Wales Metro line closures 

Transport for Wales (TfW) started work on the Rhymney to Caerphilly line on Saturday April 12th 2025 with closures planned for 6 weeks until 23 May. 

Engineering work will continue on the line for the next 8 months, with rail replacement services in operation from Caerphilly to Rhymney station as part of the next phase of development for the South Wales Metro. 

TfW are encouraging all passengers travelling on the Rhymney line to check schedules and closures before they travel.

The closures mark the most recent developments in the £800 million programme to offer some of the South Wales Metro services while works are ongoing and enable electrified Class 756 trains to be introduced to the line.  

Sweeping change

In early 2023, TfW introduced Class 231 trains onto the Rhymney line, marking the first new trains introduced in South-East Wales in decades, while in June 2024, they carried out sweeping timetable change to the South Wales Valley lines, delivering a train every 10 minutes between Caerphilly and Cardiff, and an additional service between Rhymney and Bargoed.

Enhancements will be rolled out gradually until 2027 for a phased approach that minimises disruption to service performance. From Summer 2025, TfW will introduce Class 756s from Caerphilly to Penarth, and from 2026 they’ll  begin to introduce these trains onto the Rhymney line.

Ongoing and future works include the installation of Overhead Line Equipment necessary for electrification along 15km of track, and improvements to railway fencing following cutting back of overgrown vegetation. 

Additionally, tracks and signals along the line will receive comprehensive upgrades, and Rhymney station will be given enhanced station sidings to store new trains, including tri-mode trains powered by a combination of electricity, diesel, and battery. 

TfW also plans to upgrade two footbridges, the Lewis School road bridge and Tir-Phil over bridge to ensure a safe distance between pedestrians and the railway line.

Closures

Changes on the Caerphilly to Rhymney line are expected to continue until December, with services changes including closures:

• Mondays to Thursdays, after 19:00, starting 31 March 2025.
• For 6 weeks from Saturday 12 April to Friday 23 May, and from Saturday 19 July to Sunday 31 August.
• For 2 weeks from Saturday 18 October to Sunday 2 November.
• Across several weekends (Saturdays and Sundays) throughout this period.

Most of these rail closures will take place between Caerphilly and Rhymney, with a normal rail service in operation from Caerphilly into Cardiff and onwards to Penarth, Barry Island and Bridgend. Rail services will run as normal for major events at the Principality Stadium in Cardiff.

Dan Tipper, Chief Infrastructure Officer at TfW said: “We understand that rail closures and engineering work may cause disruption for those who rely on our services and for those living close to the tracks and would like to urge all customers to check before traveling during this period.”

For more information and updates to travel plans, visit the TfW Plan a Journey site here. 

Replacements

TfW has reassured those affected that during periods where the railway line is closed, there will be rail replacement services available, with buses travelling from Rhymney/Bargoed to Caerphilly (stopping at each station in between), and connecting with the train services from Caerphilly to Cardiff.

Mirroring the rail timetable, a rail replacement bus will operate every 15 minutes between Caerphilly and Bargoed, and every 30 minutes between Bargoed and Rhymney.

For lineside neighbours, this means TfW teams will be carrying out major transformation work across the Rhymney line during both the day and night at all points along the Upper-Rhymney line.

TfW have said those they expect to be affected by anti-social noise will be contacted in advance of works taking place, though it will not always be possible to provide the exact dates and times on upcoming work. Last minute changes will be posted to the TfW Facebook page. 

However, it’s expected that new tri-mode trains will be quieter and more environmentally friendly, creating a better environment for lineside neighbours. For passengers, new trains will deliver improved comfort, accessibility and reliability.