Algerine-class minesweeper

Class overview
HMS Mutine
Name:	Algerine class
Builders:	Belfast, Northern Ireland (50) Canada (60)
Operators:	Royal Navy Royal Canadian Navy Marina Militare South African Navy Belgian Marine Component Royal Ceylon Navy Royal Thai Navy
Preceded by:	Bangor class
Succeeded by:	Ton class
In service:	1942
Completed:	110
Active:	1?
Lost:	6
Retired:	109
General characteristics
Type:	Minesweeper
Displacement:	850–1,030 long tons (864–1,047 t) (standard) 1,125–1,325 long tons (1,143–1,346 t) (deep)
Length:	225 ft (69 m) o/a
Beam:	35 ft 6 in (10.82 m)
Draught:	11–12 ft (3.353–3.658 m)
Installed power:	2 × Admiralty 3-drum boilers 2,400 ihp (1,800 kW) (VTE) or 2,000 shp (1,500 kW) (turbine)
Propulsion:	2 shafts 2 vertical triple-expansion steam engines or 2 steam turbines
Speed:	16.5 knots (30.6 km/h; 19.0 mph)
Range:	5,000 nmi (9,300 km; 5,800 mi) at 10 knots (19 km/h; 12 mph)
Complement:	85
Armament:	1 × QF 4 in (102 mm) Mk V anti-aircraft gun 4 × twin Oerlikon 20 mm cannon Hedgehog (Escorts only)

The Algerine-class minesweeper was a large group of minesweepers built for the Royal Navy (RN) and the Royal Canadian Navy (RCN) during the Second World War. 110 ships of the class were launched between 1942 and 1944.

By 1940 the Royal Navy had realized that the Bangor-class minesweepers were too small to carry the equipment needed to handle magnetic mines. A bigger ship was designed, ironically about the same size as the older Halcyon class that the Royal Navy had rejected earlier as too large and expensive for mass production. The size of the new ship made them suitable for use as ocean-going escort ships and many were used in that role to fill a critical shortage of escorts. In fact most of the ships built for the RCN were solely employed as such and were fitted with more dedicated anti-submarine weapons than the RN ships. To maximise production, alternate designs were made to use either steam turbines or reciprocating steam engines.

The turbine-powered ships displaced 850 long tons (860 t) at standard load and 1,125 long tons (1,143 t) at deep load while the reciprocating group displaced 1,010–1,030 long tons (1,030–1,050 t) at standard load and 1,305–1,325 long tons (1,326–1,346 t) at deep load. The hull's dimensions were the same for both groups and the ship measured 225 feet (68.6 m) long overall with a beam of 35 feet 6 inches (10.8 m). The turbine group had a draught of 11 feet (3.4 m) while the reciprocating ships sat 1 foot 3 inches (0.4 m) deeper in the water. The ships' complement consisted of 85 officers and ratings.

The turbine-powered ships had two Parsons geared steam turbines, each driving one shaft, using steam provided by two Admiralty three-drum boilers. The engines produced a total of 2,000 shaft horsepower (1,500 kW) and gave a maximum speed of 16.5 knots (30.6 km/h; 19.0 mph). The reciprocating ships substituted two 2,400-indicated-horsepower (1,800 kW) vertical triple-expansion steam engines for the turbines and reached the same speed. They carried a maximum of 660 long tons (671 t) of fuel oil that gave them a range of 5,000 nautical miles (9,300 km; 5,800 mi) at 10 knots (19 km/h; 12 mph).

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