The minesweeper corvettes of the Algerine class, launched between 1942 and 1944, were used as well for escort missions and some of them
were armed as antisubmarine corvettes. These minesweepers were intended for high seas operations, unlike those of coastal or portuary type.
The illustration shows one of these ships dedicated only to minesweeping operations; note the two paravanes astern.
During the First World War minesweeping operations involved two ships side to side towing the sweeping rigs. This method required
to advance slowly in a straight line to perform the operation, which often forced the ships to cross unswept waters and rendered them
very vulnerable to enemy fire. In 1918 the British introduced the device known as paravan or
oropesa. This one, acting as a second ship, would allow a single ship to sweep the mines. But since the paravan
is an inert object, the minesweeper would have more freedom of movement; she could move faster or follow an irregular course to better
stay out of the mined area, and the paravan would always follow her.
Algerine class: 110 units, including Alarm, Algerine, Loyalty, Regulus, Squirrel and Vestal
Type: Minesweeper corvette
Length: 68.58 meters
Beam: 10.84 meters
Draught: 3.05 meters
Displacement (full load): 1335 tonnes
Propulsion: 2 x shaft, 2 x triple-expansion steam engine/steam turbine, 2 x boiler Admiralty, 2000-2400 horsepower
Speed: 16.5 knots (30.6 kilometers/hour)
Range: 5000 nautical miles (9260 kilometers) at 10 knots
Armament): 1 x 102-millimeter 45-caliber cannon, 4 x 20-millimeter cannon,
Hedgehog antisubmarine launcher (only in escort/antisubmarine ships)