Wales Tests 36 Stadler Class 398 Tram-Trains for Spring 2026 Service

The Welsh Government’s investment in new rolling stock for South Wales is advancing, with the CityLink Class 398 tram-trains now in the final stages of testing. Welsh First Minister Eluned Morgan announced that the new vehicles are scheduled for introduction into service this spring on the Core Valleys Lines network. The deployment follows a testing phase that began in April 2025.

Manufactured by Stadler, the 36 CityLink units were procured as part of an £800 million contract signed in 2019, which also included 35 Flirt trains. The Class 398 is a hybrid vehicle, capable of operating on both electrified lines and non-electrified sections using battery power. This dual-mode capability is essential for the Core Valleys network, which has undergone partial electrification.

The tram-trains are designed to operate on both heavy rail and on-street tram lines. Each three-car unit is 40 meters long with a capacity of over 250 passengers and can achieve speeds of 100 km/h on the main rail network. Interior amenities include modern air conditioning, power sockets, passenger information screens, six multifunctional spaces for bicycles, and two dedicated spaces for wheelchair users.

Supporting the fleet’s introduction is over £1 billion invested in transforming rail infrastructure, including the electrification of more than 170 km of track. A new £100 million depot at Taffs Well was constructed to serve as the control center for the network and the maintenance base for the 36 tram-trains. The depot was officially inaugurated in November 2025.

This Welsh Government-funded project operates alongside broader rail investment in the region. Verification data confirms a separate, long-term £14bn rail investment package for Wales from the UK government. That funding is allocated for different projects, including the construction of seven new stations and line speed improvements, and is distinct from the capital used for the Class 398 procurement and associated Core Valleys upgrades.

Upon successful completion of final testing, the Class 398 units will be phased into passenger service on the Merthyr, Aberdare, and Treherbert lines. These routes include key connections to Cardiff and Cardiff Bay.