Bangor class minesweeper

HMS Bangor (J00) during the Second World War
Class overview
Builders:	Multiple builders
Operators:	Royal Navy  Royal Canadian Navy  Royal Indian Navy  Imperial Japanese Navy
Preceded by:	Halcyon class
Succeeded by:	Algerine class
In commission:	7 November 1940 –
Completed:	Bangor 14 Blyth 19 Ardrossan 26
General characteristics Bangor (Diesel)
Displacement:	605 tons (RN) 592 tons (RCN)
Length:	162 ft (49.4 m)
Beam:	28 ft (8.5 m)
Draught:	8.25 ft (2.51 m)
Propulsion:	2 shafts, 9-cylinder diesel, 2,000 bhp (1,500 kW)
Speed:	16 knots (30 km/h)
Complement:	60
Armament:	(RN specs): 1 × QF 12-pounder 3 in (76.2 mm) gun 1 × quadruple 0.5 in (12.7 mm) Vickers machine gun Mark III (RCN specs): 1 × QF 4 in (101.6 mm) gun 1 × 2-pounder Mark VIII 2 × twin 0.303 in (8 mm) machine guns
General characteristics Blyth (Reciprocating)
Displacement:	673 tons
Length:	171.5 ft (52.3 m)
Beam:	28.5 ft (8.7 m)
Draught:	8.25 ft (2.5 m)
Propulsion:	2 Admiralty 3-drum water tube boilers, 2 shafts, vertical triple-expansion reciprocating engines, 2,400 ihp (1,790 kW)
Speed:	16 knots (30 km/h)
Complement:	60 (RN) 70 (RCN) 87 (RIN)
Armament:	(RN specs): 1 × QF 12-pounder 3 in (76.2 mm) gun 1 × quadruple 0.5 in (12.7 mm) Vickers machine gun / single QF 2-pounder Mark VIII (RCN specs): 1 × QF 4 in (101.6 mm) gun 1 × QF 2-pounder Mark VIII 2 × twin 0.303 in (7.70 mm) machine guns (RIN specs): 1 × QF 12-pounder 3 in (76.2 mm) gun 3 × single Oerlikon 20 mm guns
General characteristics Ardrossan (Turbine)
Displacement:	656 tons
Length:	174 ft (53.0 m)
Beam:	28.5 ft (8.7 m)
Draught:	8.25 ft (2.5 m)
Propulsion:	2 Admiralty 3-drum water tube boilers, 2 shafts coupled to steam turbines, 2,000 shp (1,500 kW)
Speed:	16 knots (30 km/h)
Complement:	60 (RN) 87 (RIN)
Armament:	(RN specs): 1 × QF 12-pounder 3 in (76.2 mm) gun 1 × quadruple 0.5 in (12.7 mm) Vickers machine gun / single QF 2-pounder Mark VIII (RIN specs): 1 × QF 12-pounder 3 in (76.2 mm) gun 3 × single Oerlikon 20 mm guns

The Bangor-class minesweepers were a class of warships operated by the Royal Navy (RN), Royal Canadian Navy (RCN), Imperial Japanese Navy (IJN), and Royal Indian Navy (RIN) during the Second World War.

The class derives its name from the lead ship, HMS Bangor (J00), which was launched on 19 February 1940 and commissioned on 7 November of that year. Royal Navy ships were named after coastal towns of the United Kingdom.

Their lack of size gave them poor sea handling abilities, reportedly worse even than the Flower class corvettes. The diesel-engined versions were considered to have poorer handling characteristics than the slow-speed reciprocating-engined variants. Their shallow draft made them unstable and their short hulls tended to bury the bow when operating in a head sea.

The Bangor-class vessels were also considered overcrowded, cramming six officers and over 90 ratings into a vessel originally intended for a total of 40.

Despite claims to the contrary, the Australian Bathurst-class corvette was a wholly Australian design, and not based on the Bangor class.

The original intent of the Bangor-class minesweeper design was to provide a coastal equivalent of the Halcyon-class minesweeper; however the realities brought to light by the start of the war caused a modification of the design before construction had started.

The need for quick construction coupled with the limitations of engineering resources resulted in several variations existing based on the availability of propulsion machinery. The ships all had twin screws, but the machinery was a mix of steam turbine, slow-speed steam reciprocating, high-speed steam reciprocating and diesel. The diesel powered examples were about 20 feet (6 m) shorter than the rest as they had no need for boiler rooms. Displacement varied with propulsion machinery from 590 to 672 tons. The reciprocating engine powered Bangors were also known as the Blyth class and the steam turbine powered versions as the Ardrossan class.