A fleet of £200m publicly funded tram-trains for the South Wales Metro remains mostly unused more than three years after the first was delivered, with Transport for Wales (TfW) now saying full service might not arrive until the end of 2027. Data obtained by the BBC reveals fewer than half of the 36-strong fleet have passed the statutory safety testing required to operate on the UK rail network.
The 36 Stadler Class 398 Citylink units are the "final piece" of the £2bn South Wales Metro project, Wales's single biggest infrastructure project since devolution. First promised to be fully operational by 2022, the first train arrived from the Swiss manufacturer in March 2023. Six units are currently in passenger testing across the valleys network, but have been temporarily removed from service due to what TfW describes as "teething issues" and "early reliability challenges" caused by software problems.
TfW chief executive James Price said he does not accept there is a problem with the tram-trains, saying the biggest issue is a fleet-wide software issue. “The good thing when automation is fully working, any improvements we make with the trains can be delivered through software rather than hard engineering,” he said, adding that he wants trains that work “100% well, 100% of the time” before putting them into large-scale passenger service. Price said he recently met Stadler's chief executive in Germany to try to speed up the rollout.
Railway engineer and broadcaster Gareth Dennis questioned the project's complexity, saying the tram-trains may be too complicated. “It is the case that this is the first deployment that has pulled all this stuff together - being a tram, a train, having a battery and discontinuous electrification,” he said. “But that isn't necessarily a very good idea and that's why it's not common.”
The delay has drawn political criticism, with Reform shadow transport minister Jason O'Connell asking why most of the fleet is “just sitting in a depot gathering dust”. He said taxpayers deserved to know what had gone wrong, how delays had turned into years and that costs were spiralling out of control.
Stadler said it is working closely with TfW to address “minor issues”, describing the refinements as “normal” during fleet introduction. The Welsh government said TfW had already delivered “transformative improvements” and remains on target to complete the full rollout of the tram-trains by the end of 2027.
Analysis
Why This Matters
- More than £200 million of public funds is tied up in a fleet of trains that has largely sat unused for over three years, with no firm date for when they will carry passengers.
- Commuters on the Aberdare, Merthyr Tydfil and Treherbert lines are still waiting for the doubling of services from two to four trains an hour, a pledge initially made for 2022 and now pushed to the end of 2027.
- The delays risk undermining confidence in major public transport infrastructure projects in Wales and raise questions about value for money at a time of tight public finances.
Background
The South Wales Metro is a project to modernise the old Taff Vale Railway network connecting the valleys north of Cardiff. The 36 Stadler Class 398 Citylink tram-trains are designed to run on both traditional tracks and urban streets, bridging gaps in the electrified network using on-board batteries. Ordered in 2018, the first arrived in March 2023, but software issues and testing delays have kept almost half the fleet from being certified for use. Transport for Wales, which took over the Wales and Borders franchise during the pandemic, has faced repeated delays, which it attributes partly to Covid and the war in Ukraine.
Key Perspectives
- Transport for Wales chief executive James Price: Argues the delay is caused by a software problem, not a hardware failure, and that he is prioritising reliability over speed, expecting full service by the end of 2027.
- Reform shadow transport minister Jason O'Connell: Criticises the trains as "just sitting in a depot gathering dust" and demands an explanation for the delay and escalating costs.
- Rail engineer and broadcaster Gareth Dennis: Warns the tram-trains are too complicated, being the world's first deployment combining tram, train, battery and discontinuous electrification.
- Stadler: Says it is working closely with TfW to resolve "minor issues" through software updates, which it calls a normal part of introducing a new fleet.
- The Welsh government: Stands by TfW, saying it has already delivered "transformative improvements" and is on track for full rollout by the end of 2027.
What to Watch
- Whether TfW meets its end-of-2027 commitment to run four trains an hour on the three core valley lines.
- Whether the fleet-wide software issues can be resolved in time to allow the remaining 20 trains to pass their statutory tests.
- Whether the Senedd or UK government launches a formal investigation or imposes conditions on the project's funding.
Checked
12 claims in this story checked against 1 source: 11 supported.
Show each claim
- SupportedThe tram-trains remain largely unused more than three years after the first was delivered.BBC News: “A new fleet of publicly funded trains that cost more than £200m still remain mostly unused more than three years after the first one was delivered.”
- SupportedTfW chief executive James Price says the tram-trains might not be in full service until the end of 2027.BBC News: “Transport for Wales' boss has said it might not be until the end of 2027 when their tram-trains will be in full service.”
- SupportedThe fleet has 36 publicly funded trains and cost more than £200m.BBC News: “A new fleet of publicly funded trains that cost more than £200m”
- SupportedThe trains were initially promised to be fully up and running by 2022.BBC News: “They were initially promised to be fully up and running by 2022”
- SupportedLess than half of the 36-train fleet has passed statutory testing.BBC News: “less than half of the 36 fleet - what TfW call the "final piece" in their £2bn South Wales Metro project - have passed rigorous statutory testing.”
- SupportedSix three-carriage units, worth about £8m each, are in passenger testing.BBC News: “Six tram-trains, worth about £8m each which can run both on urban streets and rail, are currently in passenger testing across the valleys network.”
- Partly supportedThe six trains have been temporarily removed from service for software-related issues.BBC News: “they have been temporarily removed from service on occasions for what TfW described as "teething issues" and "early reliability challenges" because of "software" problems.”
- SupportedPrice said the “biggest issue is a software issue” and the whole fleet is controlled by one software package.BBC News: “the biggest issue is a software issue. That's because the whole fleet is controlled by one big software package”
- SupportedPrice said that, once automation is fully working, improvements could be delivered through software rather than hard engineering.BBC News: “The good thing when automation is fully working, any improvements we make with the trains can be delivered through software rather than hard engineering.”
- SupportedPrice recently met Stadler's chief executive in Germany to try to speed up the rollout.BBC News: “Price said he met Stadler's chief executive recently in Germany for talks in a bid to speed up the tram-train rollout.”
- SupportedThe line electrification infrastructure was finished in March, with delay attributed to Covid hold-ups and Ukraine-war supply-chain impacts.BBC News: “TfW said part of the delay is because the line electrification infrastructure was only finished in March because of hold ups caused by Covid and supply chain impact caused by the Ukraine war.”
- SupportedThe Welsh government said TfW remains on target to complete the full rollout by the end of 2027.BBC News: “"Whilst some issues have delayed the introduction of the new tram trains TfW remains on target to complete the full rollout by the end of next year," it added.”