British Rail Class 444

British Rail Class 444 Desiro
A pair of South Western Railway Class 444s near Southampton Airport Parkway in 2021
Refurbished standard-class saloon
In service	21 April 2004 – present
Manufacturer	Siemens Transportation Systems
Assembly	Siemens SGP Verkehrstechnik
Built at	Vienna, Austria
Family name	Desiro
Replaced	Class 411 Class 412 Class 421 Class 423 Class 442
Constructed	2002–2004
Refurbished	2017–2020
Number built	45
Formation	5 cars per unit: DMOS-TOSL-TOSL-(P)TOSLW-DMOC
Fleet numbers	444001–444045
Capacity	As built: 334 seats (35 first-class, 299 standard) As refurbished: 359 seats (32 first-class, 327 standard)
Owner	Angel Trains
Operator	South Western Railway
Depot	Northam
Specifications
Car body construction	Aluminium
Train length	approx. 119 m (390 ft 5 in)
Car length	23.57 m (77 ft 4 in)
Width	2.796 m (9 ft 2.1 in)
Floor height	1.157 m (3 ft 9.6 in)
Wheel diameter	850–786 mm (33.46–30.94 in) (new–worn)
Wheelbase	Bogies: 2.600 m (8 ft 6.4 in)
Maximum speed	100 mph (160 km/h)
Weight	Total: 227 tonnes (223 long tons; 250 short tons)
Traction system	Siemens SIBAS IGBT
Traction motors	8 × Siemens 1TB2016-0GB02 asynchronous three-phase AC
Power output	1,500 kW (2,000 hp) (at wheel)
Tractive effort	Starting: 200 kN (45,000 lbf)
Acceleration	approx. 1 m/s2 (3.3 ft/s2)
Electric systems	750 V DC third rail
Current collection	Contact shoe
UIC classification	Bo′Bo′+2′2′+2′2′+2′2′+Bo′Bo′
Bogies	Siemens SGP SF5000
Minimum turning radius	120 m (393 ft 8 in)
Braking systems	Electro-pneumatic (disc) and regenerative
Safety systems	AWS TPWS
Coupling system	Dellner 12
Multiple working	Within class, and with Class 450
Track gauge	1,435 mm (4 ft 8+1⁄2 in) standard gauge

The British Rail Class 444 Desiro (5-DES) is a third-rail electric multiple-unit passenger train built by Siemens Transportation Systems in Austria between 2002 and 2004. The Class 444 currently operate on express passenger services for South Western Railway.

The class first entered service with South West Trains in 2004.