Cardiff Bay Line Transformation FAQ

  • What work are you carrying out?
    • We’ll be 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, with a new timetable set to be in place from 2025.

      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, so please do check before you travel at

      We’ll also be installing the overhead line equipment (OLE) that will power the smoother, faster and greener tram-trains. The OLE will be 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.

  • How long will improvement works take?
    • We’ll be upgrading Cardiff Bay station and building a brand new station in the north of Butetown. Improvements to the Bay line commenced in early 2023 and is expected to complete around 2025.

  • What work’s been done so far?
    • You may have seen some of our workers already on site. TfW has carried out surveys and testing during autumn 2022, in readiness for the start of improvement works.

      To allow for a large amount of work on the Bay line, we closed the line throughout April and some of May and June. Work to date has included:

      • Vegetation management
      • Haul road construction
      • Ground investigation
      • Surveys and route clearance
      • Closure of Cart Road Underpass to carry out safety critical engineering works
  • Will the work cause disruption?
    • If you live or work near the Bay line, our work on Metro may affect you.

      This may include…

      • Night time working 
      • Noise from piling works 
      • Road closures 
      • Changes to rail timetables and the need for us to run rail replacement bus services 
      • Line possessions as part of upgrades to the Core Valley Lines

      Further details of road closures will be updated within the FAQ’s.

  • Can I still travel by bus or train in Cardiff Bay during the works?
  • What are compounds and why are they being installed on Lloyd George Avenue?
    • 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.

  • When will workers be on site? 
    • 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.

  • Are there safety considerations?
    • 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 Transport for Wales is 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 will be 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. We expect the OLE to be installed during the day and night, from autumn 2023.

      We’ll also be installing two east to west crossings across the track for pedestrians, which will be located at the new Butetown station and between Cardiff Bay station and Letton Road underpass. The tram trains will be travelling at a maximum speed of 20 to 30 mph. TfW will be hosting safety workshops with local schools and youth groups on OLE and safely using pedestrian crossings.

      You can read more about our piling work at

  • Will overhead line equipment be installed near my property?
    • 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.

      To learn more information about OLE: Overhead line electrification

  • What noise and light can I expect?
    • We have a lot of work planned on the railway lines to 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.

  • Why do you need to cut back trees?
    • 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.

  • What benefits are there for Butetown and the Bay?
    • 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
  • Am I entitled to compensation?
    • 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.

  • What will happen to the wall located between Lloyd George Avenue and Bute Street?
    • This project is being reviewed by Cardiff Council as part of the wider regeneration for Cardiff Bay. The wall may need strengthening prior to Cardiff Council’s improvement work.

  • Why is a new station being built in Butetown when there’s already a station in Cardiff Bay? 
    • A review in early 2021 concluded that having a train station positioned further north of Loudoun Square would provide better access for the wider Butetown community and would allow for an east to west crossing at Loudoun Square, while keeping the Cardiff Bay station would provide better access to local amenities.

      These plans are to fit with the wider collaborative vision including a new station on Pierhead Street and the option of potential future transport routes which we're currently exploring.

  • Where will the new station in Butetown be located?
    • The new station will be built opposite Maria Street, just north of the Letton Road underpass.

  • What will the new Butetown station be named?
    • This is to be determined as part of our placemaking. We'll be working with the community and our partners to develop the name.

  • What will we be doing at Roath Dock compound?
    • We’ve constructed a compound near Roath Docks as part of our work to update the railway. This compound will allow 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’ll be using 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 erected 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.

      The compound will be in place between now and spring 2025.

  • Will the Cardiff Bay Line be closed?
    • Further information about future line closures will be added here in due course.

  • Will access to Cardiff Bay station be affected during the works?
    • As part of Cardiff Bay Enhancement Works there is a requirement to close the current access to Cardiff Bay Station from Lloyd George Avenue and redirect the station users to the Bute Street entrance. This will allow the concourse preparation works to be undertaken in a safe manner and without any public interface. This closure is expected to be in place for approximately 12 weeks. Following this period, it will be reopened and access to the station via Bute St will be closed and redirected to the Lloyd George Avenue entrance.

  • How are these works being funded?
    • 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.

  • How can I give my feedback?
    • 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

  • Where can I find more information?
    • 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 You can learn more about our vision for the South Wales Metro by visiting You can also learn about our work to build the Metro at

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