New Era for South Wales Metro as First Class 398 Tram-Train Carries Passengers

Transport for Wales has reached a major milestone in the transformation of rail services across South Wales, with the first of its new Class 398 tram-trains now carrying fare-paying passengers.

The landmark journey took place on 23 June when unit 398028 operated a morning service between Pontypridd and Cardiff Bay, marking the long-awaited introduction of the fleet that will play a central role in the South Wales Metro programme.

The arrival of the Class 398s completes the rollout of Stadler-built trains ordered as part of the extensive modernisation of the Core Valley Lines network. The new vehicles join the operator's growing fleet of Class 231 diesel-electric trains and Class 756 tri-mode units already serving passengers across the region.

The tram-trains have been several years in development, with the first unit arriving in Britain from Stadler's manufacturing facility in Valencia during 2022 before being transferred to the purpose-built depot at Taffs Well the following year.

One of the fleet's most high-profile moments came in November 2025 when King Charles III took the controls of 398028 during the official opening of the Taffs Well depot.

Transport for Wales plans to introduce the new fleet gradually throughout the remainder of 2026. Initially, the vehicles will operate services on the Cardiff Bay branch before expanding onto routes serving Aberdare, Merthyr Tydfil and Treherbert.

Their introduction will also trigger a wider fleet reshuffle across the network. Class 756 trains are expected to move onto Rhymney Line services, while Class 231 units will take on additional duties on main line routes and services to the Vale of Glamorgan.

The operator has ordered 36 Class 398 tram-trains, with ambitions to have the full fleet available by the end of the year.

According to Transport for Wales, the rollout represents another key stage in delivering faster, more reliable and higher-capacity public transport across the Valleys.

The new trains offer significantly improved acceleration and braking performance compared with the ageing diesel fleets they are replacing, helping reduce journey times and improve service reliability. Their enhanced performance is expected to be particularly noticeable on routes with frequent station stops.

The arrival of the Class 398s also signals the beginning of the end for the long-serving Class 150 diesel units that have operated across South Wales for Decades.

Transport for Wales said the new fleet will be introduced progressively as driver training and operational preparations continue, with passengers set to see increasing numbers of the modern tram-trains across the Metro network over the coming months.