British Rail Class 231
Diesel-electric multiple-unit passenger train
The British Rail Class 231 is a class of eleven diesel-electric multiple units of the FLIRT family, which were built for Transport for Wales by Swiss rolling stock manufacturer Stadler Rail. The first units entered service on 18 January 2023. The entire class is due to be converted into bi-mode multiple units.
01History
The previous Wales & Borders rail franchise operator, KeolisAmey Wales ordered the new trains. Although KeolisAmey was removed as the franchise operator and replaced by an operator of last resort Transport for Wales Rail, owned by the Welsh Government, the scheduled full fleet replacement continued.
The units began testing in Switzerland in July 2021 and in November 2021 the first two units were delivered to Cardiff Canton depot.
02Operators
Transport for Wales
The Class 231 units are currently used for services on the Rhymney line and the Vale of Glamorgan Line. They mostly operate between Rhymney/Bargoed and Barry Island from Mondays to Saturdays, and between Rhymney/Caerphilly and Barry Island on Sundays.
Sometimes they operate on other valleys lines as well such as the Merthyr/Aberdare Lines, the City Line and the Treherbert Line.
It is expected that they will operate the following services from around late 2025 or early 2026:
- Maesteg to/from Ebbw Vale Town via Cardiff
- Newport to/from Ebbw Vale Town
- Cardiff Central to/from Cheltenham Spa.
The official revenue launch of the Class 231 took place on 29 March 2023 at Caerphilly.
03Technical details
Class 231 units have four passenger vehicles, along with a separate "Power Pack" vehicle at the centre of the unit that contains four diesel generator sets. The diesel generators comply with EU Stage V emissions regulations. All vehicles are linked by unpowered Jacobs bogies, while the outermost bogie at each end of each unit carries the traction motors.
From October 2024, TfW were considering fitting pantographs to these units to allow them to operate as "hybrid" or "bi-mode" (like Class 755s), and had mobilised a project team to support the implementation of the conversion with Stadler. These plans were confirmed in June 2026.
04Fleet details
| Subclass | Operator | Qty. | Year built | Passenger cars | Unit nos. |
|---|---|---|---|---|---|
| 231/0 | Transport for Wales Rail | 11 | 2021-2022 | 4 | 231001-231011 |
Illustration
Named units
- Unit 231001 is named Sultan. It was suggested by a local school as part of a competition run by TfW, and is named after a statue at Ystrad Mynach of the pit ponies used in the local coal mines.
- Unit 231005 is named Gavin & Stacey. It was suggested by a local primary school that participated in the Christmas Event at Barry Island which is part of the final episode of Gavin and Stacey.
Sources and credits
This article is adapted from the Wikipedia article “British Rail Class 231”, written by its contributors and licensed under CC BY-SA 4.0. Fathomly has changed the layout, removed citation markers, navigation and maintenance notices, and adjusted punctuation. This adapted version is shared under the same license. For references, see the original article.
Images, from Wikimedia Commons:
- 20240316 TfW 231001 Bargoed (cropped).jpg by Alex Noble (original photo), Anamyd (crop), CC0
Fathomly is not affiliated with or endorsed by the Wikimedia Foundation. Spotted a problem? Tell us.
