We’re upgrading the Rhymney line as part of the next phase of the South Wales Metro.
Beginning in March, we’ll be undertaking an intensive 8-month programme of engineering work on the upper Rhymney line, from Caerphilly to Rhymney station.
To deliver this intensive 8-month programme of work safely, there will be periods where the railway line will be closed and rail replacement services in operation to keep passengers moving.
We encourage all passengers travelling on the Rhymney line to check before they travel.
Map of the upper Rhymney line, shown in red above.
Work completed so far
In early 2023, we introduced our Class 231 trains onto the Rhymney line, marking the first brand-new trains introduced in South-East Wales in decades.
In June 2024, we carried out the biggest timetable change to the South Wales Valley lines in a generation.
This enabling us to introduce some of the benefits of Metro sooner. This delivered a train every 10 minutes between Caerphilly and Cardiff, and an additional service between Rhymney and Bargoed.
Work you can expect
From April to December 2025, significant work will be undertaken on the upper Rhymney line, which runs from Caerphilly to Rhymney.
Transformation work on this section will include:
- Electrification: Installing Overhead Line Equipment (OLE) to electrify the line.
- Enhanced Infrastructure: Upgrading railway fencing and cutting back overgrown vegetation.
- Tracks and Signalling upgrades: Comprehensive upgrades across the line, including track lowers to enable electrification.
- Station Improvements: Upgrades at Rhymney station, including enhanced station sidings where the new trains will be stored.
This work will allow us to introduce brand-new tri-mode trains onto the Rhymney line, powered by electricity from the OLE, battery and diesel.
For our lineside neighbours, this will mean quieter and more environmentally friendly trains. For passengers, these trains will deliver improved comfort, accessibility and reliability.
Service changes on the Rhymney line
To carry out significant work across this section, there will be periods of railway closures, allowing our teams to work around the clock to transform and upgrade the railway line.
From March to October 2025, the railway line from Caerphilly to Rhymney will be closed:
- 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.
Rail closures
A full list of all the planned rail closures on the upper Rhymney line (from Rhymney to Caerphilly) can be found below. Please note that these closures can change at short notice, so we encourage all passengers to check before they travel.
Closures by month:
April
May
June
July
August
September
October
Keeping passengers moving
During periods where the railway line is closed, we’ll replace each planned train with a rail replacement service. These buses will travel from Rhymney/ Bargoed to Caerphilly (stopping at each station in between) and will connect with the train services from Caerphilly to Cardiff.
Mirroring the rail timetable, we’ll operate a bus every 15 minutes between Caerphilly and Bargoed, and every 30 minutes between Bargoed and Rhymney.
Rail replacement services
Rhymney to Caerphilly | Open as PDF
Rail replacement bus stops
Rhymney to Caerphilly
Caerphilly to Cardiff
What this means for our lineside neighbours
Our teams will be carrying out major transformation work across the Rhymney line. To allow this work to be completed within 8 months, our teams will need to work during both the day and night from Caerphilly to Rhymney.
This means there’ll be periods where engineering work is undertaken at night, causing disruption to those who live close to the railway.
We’ll do our best to contact our neighbours in advance of noisy engineering works planned to take place at night.
Due to last minute changes to programmes, it’s not always possible to provide the exact dates and times of upcoming work.
We encourage our lineside neighbours to keep up to date with our Facebook and website pages, where we’ll post last-minute changes to planned work.
