British Rail Class 172

British Rail Class 172 Turbostar
West Midlands Trains Class 172/3s at Birmingham Moor Street
West Midlands Railway Class 172 saloon
In service	10 July 2010 – present
Manufacturer	Bombardier Transportation
Built at	Derby Litchurch Lane Works
Family name	Turbostar
Replaced	Class 150 Class 153
Constructed	2010–2011
Number built	39
Successor	Class 196 (West Midlands Trains) Class 378 (London Overground)
Formation	2 cars per 172/0, /1, /2 unit: DMOS-DMOSLW 3 cars per 172/3 unit: DMOS-MOS-DMOSLW
Fleet numbers	172/0: 172001–172008 172/1: 172101–172104 172/2: 172211–172222 172/3: 172331–172345
Capacity	172/0: 124 seats 172/1: 140 seats + 5 tip-up 172/2: 120 seats + 19 tip-up 172/3: 192 seats + 27 tip-up
Owners	Angel Trains (172/0 and /1) Porterbrook (172/2 and /3)
Operator	West Midlands Trains
Depot	Tyseley
Lines served	Snow Hill Lines Coventry–Leamington Line Coventry–Nuneaton Line
Specifications
Car body construction	Welded aluminium with steel ends
Car length	DM. vehs.: 23.62 m (77 ft 6 in) MOS vehs.: 23.00 m (75 ft 6 in)
Width	2.69 m (8 ft 10 in)
Height	3.77 m (12 ft 4 in)
Doors	Double-leaf sliding plug (2 per side per car)
Maximum speed	172/0 units: 75 mph (121 km/h) Others: 100 mph (160 km/h)
Weight	(see § Vehicle weights)
Axle load	Route Availability 1
Prime movers	2 or 3 × MTU 6H 1800 R83 (one per car)
Engine type	Inline-6 four-stroke turbo-diesel
Displacement	12.8 L (782 cu in) per engine
Power output	360 kW (480 hp) per engine
Transmission	ZF Ecomat HP 902 R (6-speed mechanical)
UIC classification	2-car: 2′B′+B′2′ 3-car: 2′B′+2′B′+B′2′
Bogies	Bombardier B5006
Braking systems	Electro-pneumatic (disc) (Westinghouse 3-step)
Safety systems	AWS BR ATP (172/1 only) TPWS
Coupling system	BSI
Multiple working	Within class, and with Classes 14x, 15x, and 170
Track gauge	1,435 mm (4 ft 8+1⁄2 in) standard gauge

The British Rail Class 172 is a British diesel multiple unit (DMU) passenger train from the Turbostar family, built by Bombardier Transportation's Derby Litchurch Lane Works for use on inner-suburban passenger services. The entire class is currently operated by West Midlands Trains.

The Class 172 is part of the Turbostar range, similar to the Class 168, Class 170 and Class 171.