Cardiff Bay Line Transformation FAQ

We’re building a new two-platform station in the north of Butetown, as part of the biggest upgrade to public transport in the area for a generation.

The existing Cardiff Bay station will also get a second platform as well as new signage, customer information screens and other enhancements.

Installation of a new track will allow faster and more frequent services using brand new tram-trains and will allow us to introduce a new timetable.

As we continue to make upgrades to the Core Valley Lines as part of the wider delivery for the South Wales Metro, there’ll be occasions where rail services will be unavailable on the Cardiff Bay line. Whenever we need to close the railway line for engineering work, we’ll put on replacement buses or make arrangements for ticket acceptance on local services, so please check before you travel for full details at tfw.wales/service-changes

We’ve also been busy installing the overhead line equipment (OLE) that will power the smoother and faster tram-trains. The OLE is being installed between the new Butetown station and Cardiff Bay station, but the new trains will run on battery between Cardiff Queen Street and the new Butetown station.

We’ve achieved some significant milestones and carried out essential works on Cardiff Bay line so that we can progress the delivery of the transformation. Work to date has included:

• Progress at the site of the new Butetown station with one of the platforms being installed, as well as the ramps at the second platform being constructed.
• Progress installing the additional second track which will improve frequency on the line, as well as piling and foundation works for the overhead line equipment to power the new tram trains.
• Progress on the building of the second platform at Cardiff Bay station and the extension of the existing platform. 
• Vegetation management
• Significant service diversions
• Ground investigation
• Surveys and route clearance
• Closure of Cart Road Underpass to carry out safety critical engineering works

If you live or work near the Bay line, our work on Metro may affect you.

This may include…

• Nighttime working
• Noise from piling works
• Road closures
• Changes to rail timetables and the need for us to run rail replacement bus services, please check before you travel at tfw.wales/service-changes
• Line possessions as part of upgrades to the Core Valley Lines, please check before you travel at tfw.wales/service-changes

Further details of road closures will be updated within the FAQs.

Please check your journey before you travel by train by visiting tfw.wales/service-changes

You can find out more information about Cardiff Bus services here. Please check with Cardiff Bus for the most up-to-date information on their services.

Compounds provide temporary, adequate space and allow our people to work safely beside the railway, store and transport materials up and down the track and provide access to undertake the required construction and engineering work.

Equipment and welfare facilities at our compounds comply with the relevant health and safety guidelines. The three compounds located on the trackside of Lloyd George Avenue store equipment and provide a temporary office, canteen, drying rooms and toilets for staff.

The compounds were installed in Janaury 2023 and work started on the track in early 2023. The compounds will remain in place until the new timetable is in effect.

Workers will typically be on site 24/7. There’ll be no parking available for workers within the compound, staff will therefore arrive on site in a crew van to minimise any on-street parking.

We’re using overhead line equipment (OLE) to run our electrically powered tram-trains, which are smoother, faster, quieter and more environmentally friendly than the diesel trains which currently service the valleys.

OLE should be treated with extreme caution. It carries 25,000 volts of electricity, which is enough to easily cause fatalities. It’s also incredibly important to bear in mind that carrying items like fishing rods, umbrellas, helium balloons, having people sat on your shoulders and even using selfie sticks near the line is dangerous. OLE is always switched on, no matter what time of the day it is, and we’re legally obliged to take steps to put measures in place to prevent people from electrocuting themselves. If you use the railway correctly, there’s no danger from overhead lines. But trespassing on the railway boundary - which is illegal - puts you at risk.

OLE consists of steel metal structures, built to last, which are approximately between 7 and 10 metres tall - slightly higher than the tram-trains - and approximately 50 metres apart. They’ll make our railway lines look quite different to how they appear now.

Depending on ground conditions, an average pile can take between 20 to 60 minutes. Some piling is completed in one job, so the noise shouldn’t last too long, but some piling needs more visits to complete.

OLE is being installed between the new Butetown station and Cardiff Bay station, but the train will run on battery between Cardiff Queen Street and new Butetown station.

You can read more about our piling work at tfw.wales/piling.

As part South Wales Metro, Transport for Wales is electrifying over 170km track across all the Core Valleys Lines (Treherbert, Aberdare, Merthyr, Rhymney, Coryton, Bay and City lines). The installation of OLE will power our new Class 398 Stadler City-link tram-trains to enter service.

We’ve tried to minimise the impact of the installation of the OLE posts at the design stage. However, with approximately 2,500 structures needed for the project and with thousands of homes facing or backing on to our railways, it’s not possible to completely avoid some of them needing to be installed near properties. Moving even one post just a few metres is incredibly difficult – it can quite easily have knock-on effects up and down the line. Unfortunately, we’re not able to consider individual requests to relocate the OLE posts.

The new equipment needs to be in a place where we can access it if needed, including for inspections or maintenance. It also needs to be a suitable distance from public spaces.

Learn more information about OLE here: Overhead line electrification

We’ve been progressing much of the work on the railway lines so that we can electrify them ready for the new tram-trains. Most of our work will be carried out at night as this is when our trains aren’t running and is safest for our workers. Our work can be noisy, but we’ll try to keep disruption to a minimum by using the most appropriate noise reduction measures for the area.

We’ll also need to emit light as part of our work. Light will be used on pathways to ensure the safety of our staff. We’ll emit less light where this is possible through the use of LED technology. We’ll comply with Cardiff Council and the Health and Safety Executive guidance on LUX readings.

Our site teams are committed to being considerate to our neighbours. Please be assured that we’ll try to address any concerns about noise or light that we receive.

We’ll need to cut back vegetation to safely provide the electrical clearances for the public, staff and the infrastructure for OLE, as laid out in legislation. Once our vegetation management work is carried out, we’ll need to return occasionally for routine maintenance of the vegetation, including keeping the trees and bushes under control. This is necessary so that we can continue to provide a reliable and safe service for our passengers. This work is usually carried out at night and can be noisy, but we’ll try to keep disruption to a minimum.

Metro will help to support economic growth across the region by improving the connections across South Wales and beyond. It’ll mean faster, more frequent and better journeys for passengers.

The brand new tram-trains that will service Metro are electric and produce less CO2 than the trains currently in service. The new trains are also quieter for both those onboard the train and those living close to the railway. Better, more reliable public transport will also mean that less people will need to use their cars, easing the strain on the congested roads around Cardiff and surrounding areas.

Our new timetable and tram trains will improve connectivity for local residents by having:

• 3 carriages, instead of 1
• 126 seats, with the capacity for 256 people
• 6 trains per hour
• Double track

TfW will be working to minimise disruption to communities and local businesses as much as possible, however, the nature of some of our work means that some disruption is unavoidable.

We have a right and a duty to maintain and renew our assets and infrastructure and, as a publicly funded organisation, we’re not able to provide compensation, or ‘gesture’ payments owing to disruption caused by our work, and we’re not able to make home improvements.

Transport for Wales isn’t obligated to pay for alternative accommodation during rail works, but we’re committed to keeping noise to a minimum. We’ll write to you in advance of particularly noisy planned works so, if necessary, you can make arrangements.

The new station will be built opposite Maria Street, just north of the Letton Road underpass.

This is to be determined as part of our placemaking. We'll be working with the community and our partners to develop the name.

We’ve constructed a compound near Roath Docks as part of our work to update the railway. This compound allows us to strategically manage our work to deliver your Metro, store materials for future use and provide essential welfare facilities for our colleagues. There will be no physical work taking place at the site. We’reusing the compound to facilitate construction activities for the Cardiff Bay and Butetown stations.

Due to occasional 24/7 work on the line, lighting has been installed at the Welfare Compound, but has been directed away from Adventurer’s Quay residential buildings where possible, and the noise from workers being mitigated by sound baffling systems.

You can find up to date information on upcoming closures on the Cardiff Bay line here.

As part of Cardiff Bay Line Transformation, we closed the current access to Cardiff Bay Station from Lloyd George Avenue and have been redirecting station users to the Bute Street entrance. This has allowed us to progress the concourse preparation works in a safe manner and without any public interface. Following this period, it will be reopened and access to the station via Bute Street will be closed and redirected to the Lloyd George Avenue entrance. We’ll add the dates here once they’re confirmed.

The Welsh Government and TfW are committed to an ambitious programme of Metro improvements known as the Core Valleys Lines (CVL) Transformation. This transformation project has been part-funded by the European Regional Development Fund.

We want you to join us on the journey to transform transport in Butetown and the Bay. As we work to plan and deliver your upgrades, there’ll be opportunities for your community to  collaborate with us.

To bring you onboard, we’ll be setting up workshops and drop-ins in your area, where you can discover more about the Bay transformation project. To learn how you can get involved, please visit tfw.wales/engagement.

Our team is available to answer your questions 24/7, so please call us on 03333 211 202. Alternatively, you may contact us via WhatsApp on 07790 952 507 (0700-2000 on Monday to Friday, 0800-2000 on Saturday, and 1100-2000 on Sunday).

If you're looking for more information or would like the information presented in a different format, please visit tfw.wales/contact-us. You can learn more about our vision for the South Wales Metro by visiting tfw.wales/projects/metro. You can also learn about our work to build the Metro at tfw.wales/projects/metro/building-our-metro.

To learn more about the work we’re doing in your community, please visit our Facebook page: facebook.com/TfWCommunities.