Fairmile B motor launch

The Canadian Fairmile B motor launch ML-Q056 in 1941
Class overview
Name	Fairmile B motor launch
Preceded by	Fairmile A motor launch
Succeeded by	Fairmile C motor gun boat
Completed	c. 650
General characteristics
Displacement	85 tons
Length	112 ft (34 m)
Beam	18 ft 3 in (5.56 m) except Canadian built at 17 ft (5.2 m) or 17 ft 10 in (5.44 m)
Draught	4 ft 10 in (1.47 m)
Propulsion	Two 650 bhp (480 kW) Hall-Scott Defender petrol engines
Speed	20 knots (37 km/h; 23 mph)
Range	1,500 mi (1,300 nmi; 2,400 km) at 12 kn (22 km/h; 14 mph)
Complement	16 (later increased)
Sensors and processing systems	ASDIC
Armament	(for 1940 Sub Chaser) 1 × QF 3-pounder Hotchkiss 1 × twin 0.303 in machine guns 12 depth charges later(some vessels): 1 × QF 3-pounder Hotchkiss 2 × twin 0.303 in machine guns 1 × Oerlikon 20 mm cannon 1 × Bofors 40 mm gun
Armour	Wheelhouse plated

The Fairmile B motor launch (often abbreviated to 'ML') was a very numerous class of motor launch produced in kit form by British boatbuilder Fairmile Marine, and then assembled and fitted out by numerous boatyards during the Second World War to meet the Royal Navy's coastal operation requirements.