South Wales Metro’s £200m tram-trains remain barely used after three years

Most trains still await approval

The first Class 398 Citylink tram-train arrived at a Transport for Wales depot on 21 March 2023. The fleet was ordered from Swiss manufacturer Stadler in 2018 as part of the £2bn South Wales Metro project.

Sixteen of the 36 three-carriage units have passed statutory tests for running on the UK rail network. The remaining 20 have yet to complete the checks required by the rail regulator. Testing on some vehicles began in 2024 and, according to data obtained through a Freedom of Information request, has taken from six weeks to two years.

Some vehicles have been stored at TfW’s new £100m depot near Cardiff for as long as three-and-a-half years. King Charles and former Prime Minister Keir Starmer have travelled on a tram-train, but few passengers have.

Software and reliability challenges

TfW has temporarily withdrawn tram-trains from service at times because of what it called “teething issues” and “early reliability challenges”, including software problems. A representative said the fleet is controlled by one large software package and that automating more of the train is intended to make operation cheaper, quicker and more reliable.

TfW said it chose customer testing rather than a high-profile launch because the trains might need to be taken out of service. The company said it wanted to reach 95% on-time reliability on the valleys network before introducing the vehicles for passengers in large numbers.

Stadler said it was working closely with TfW to resolve what it described as “minor issues”. A railway expert said the trains’ complexity could make testing more demanding because many systems must work reliably.

Service increases pushed back

The Metro is intended to turn an old Victorian railway into a more frequent rapid-transit network. TfW calls the tram-trains central to delivering faster, more frequent journeys and the final piece of its £2bn project.

Passengers have been told that services between Cardiff and Aberdare, Merthyr Tydfil and Treherbert will rise from two to four trains an hour by the end of 2027. They had initially been told the increase would happen by 2022. TfW said part of the delay stemmed from electrification infrastructure being completed only in March, after hold-ups linked to Covid and supply-chain impacts from the Ukraine war.