British Rail Class 756

The British Rail Class 756 FLIRT^[7] is a class of tri-mode multiple units built for Transport for Wales Rail by Swiss rolling stock manufacturer Stadler Rail. They are closely related to the Class 755 bi-mode units delivered by Stadler to Greater Anglia between 2018 and 2020, which can be powered either by overhead electric lines or on-board diesel generators. The Class 756 units also carry batteries as an additional source of traction power.^[8]

British Rail Class 756 FLIRT
Class 756 unit at Aberdare in November 2024
Interior of a Class 756 unit
In service	15 November 2024-Present[1]
Manufacturer	Stadler Rail
Assembly	Stadler Bussnang AG
Built at	Bussnang, Switzerland[2]
Family name	FLIRT
Replaced	Class 150 Class 153 Class 769
Constructed	2021–2023[3]
Number built	24[1] (7 × 756/0, 17 × 756/1)
Formation	3-car units:[a] DMS-PP-PTSW-DMS 4-car units:[a] DMS-PTS-PP-PTSW-DMS
Fleet numbers	756/0: 756001–756007 756/1: 756101–756117[3]
Capacity	3-car: 118 seats, plus 24 tip-up & 148 standees 4-car: 158 seats, plus 32 tip-up & 204 standees
Owners	SMBC Leasing[4]
Operators	Transport for Wales Rail
Depots	Canton (Cardiff)
Specifications
Car body construction	Aluminium
Train length	3-car: 65.0 m (213 ft 3 in) 4-car: 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)[5]
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 5 per side per 3-car, 7 per side per 4-car)
Wheel diameter	Powered: 870 mm (34 in) Unpowered: 760 mm (30 in)
Wheelbase	Bogies: 2.700 m (8 ft 10.3 in)
Maximum speed	75 mph (121 km/h)
Traction system	IGBT
Power output	On AC power: 2,600 kW (3,500 hp) On battery power: 1,300 kW (1,700 hp) On diesel power: 480 kW (640 hp)
Tractive effort	Maximum starting: 200 kN (45,000 lbf)
Acceleration	Maximum starting: 1.1 m/s2 (2.5 mph/s)
Electric system(s)	25 kV 50 Hz AC overhead
Current collector(s)	Pantograph
UIC classification	3-car: Bo′2′2′2′Bo′ 4-car: Bo′2′2′2′2′Bo′
Safety system(s)	AWS TPWS (plus provision for ETCS)
Multiple working	Within class (max. 2 units)
Track gauge	4 ft 8+1⁄2 in (1,435 mm) standard gauge
Notes/references
Sourced from [6] unless otherwise noted.

A total of 24 units were built, split between 7 three-car units and 17 four-car units.^[1]

History

The Wales & Borders rail franchise, awarded to KeolisAmey Wales with effect from 14 October 2018, included a commitment requiring that the operator oversee a full fleet replacement during the franchise period.^[9] As part of this process, KeolisAmey placed an order with Stadler in February 2019 for the 24 FLIRT tri-mode units that came to be designated Class 756. The tri-mode capabilities are intended to facilitate operations over lines that have only been partially electrified. Production of the fleet was underway by mid-2021.^[2]

The Class 756 officially entered service on 18 November 2024, and for consecutive days,^[10] after initially entering service on one previous day of 15 November 2024.^[1]

Operators

Transport for Wales

Transport for Wales Rail Class 756 units currently operate services between Cardiff-Merthyr Tydfil, Cardiff-Aberdare and Cardiff-Treherbert.^[1]

It is expected that the Class 756 units will move across to the Rhymney Line from late 2025 as the Class 398 tram-trains enter service.^[11]

Technical details

Class 756 units have three or four passenger vehicles, along with a separate "Power Pack" vehicle near the centre of the unit that contains a diesel generator set and three battery modules.^[12] The diesel generator produces 480 kW (640 hp), while the batteries are capable of supplying up to 1,300 kW (1,700 hp).^[6] All vehicles are linked by unpowered Jacobs bogies, while the outermost bogie at each end of each unit carries the traction motors.^[6]

The batteries use Lithium-titanium-oxide chemistry, with the capacity of 447 kWh for 3-car units and 559 kWh for 4-car units.^[13]

Fleet details

Subclass	Operator	Qty.	Year built	Passenger cars	Unit nos.[3]
756/0	Transport for Wales Rail	7	2021–2023	3	756001–756007
756/1		17		4	756101–756117

Illustration

Illustration of a four-car Class 756 unit (based on concept art)

See also

• British Rail Class 231 - A diesel multiple unit variant of the Stadler FLIRT UK platform also built for Transport for Wales Rail.
• British Rail Class 745 - An electric multiple unit variant of the Stadler FLIRT UK platform built for Greater Anglia.
• British Rail Class 755 - A bi-mode multiple unit variant of the Stadler FLIRT UK platform built for Greater Anglia.

Notes

1. The Power Pack is technically a fourth or fifth vehicle in these units, but as it contains no passenger accommodation it is excluded from the count of passenger cars.