British Rail Class 231

British Rail Class 231
*FLIRT*
British Rail Class 231; FLIRT
	Class 231 unit at Lisvane and Thornhill in 2023
	Interior
In service	18 January 2023 – present
Manufacturer	Stadler Rail
Assembly	Stadler Bussnang AG
Built at	Szolnok, Hungary; (bodyshells); Bussnang, Switzerland; (final assembly);
Family name	FLIRT
Replaced	Class 170; Class 769; Class 153; Class 150;
Constructed	2021–2022
Number built	11
Number in service	11
Formation	4 cars per unit:; DMS-TS-PP-TSW-DMS
Fleet numbers	231001–231011
Capacity	170 seats, plus 36 tip-up & 180 standees
Owners	SMBC Leasing
Operators	Transport for Wales Rail
Depots	Canton (Cardiff)
Specifications
Car body construction	Aluminium
Train length	80.7 m (264 ft 9 in)
Width	Passenger vehicles:; 2.720 m (8 ft 11.1 in); Power Pack:; 2.822 m (9 ft 3.1 in);
Height	3.915 m (12 ft 10.1 in)
Floor height	960 mm (3 ft 2 in)
Doors	Double-leaf sliding plug, each 1.300 m (4 ft 3.2 in) wide; (total 6 per side)
Wheel diameter	Powered: 870 mm (34 in); Unpowered: 760 mm (30 in);
Wheelbase	Bogies: 2.700 m (8 ft 10.3 in)
Maximum speed	90 mph (145 km/h)
Weight	154.3 tonnes (151.9 long tons; 170.1 short tons) (4-car set)
Traction system	IGBT
Prime mover(s)	4 × Deutz 16-litre V8 turbo-diesel
Power output	1,500 kW (2,000 hp) at wheel
Tractive effort	Starting: 160 kN (36,000 lbf)
Acceleration	0.9 m/s2 (2.0 mph/s)
UIC classification	Bo′2′2′2′2′Bo′
Safety system(s)	AWS; TPWS; (plus provision for ETCS);
Multiple working	Within class (max. 3 units)
Track gauge	4 ft 8+1⁄2 in (1,435 mm) standard gauge
Notes/references
	Sourced from unless otherwise noted.

The British Rail Class 231 is a class of eleven diesel-electric multiple units of the FLIRT family, which have been built for Transport for Wales by Swiss rolling stock manufacturer Stadler Rail. The first units entered service on 18 January 2023.