H.M.S. Pelorus was one of the large "Algerine" class of minesweepers ordered for the navy in the middle of the Second World War. With one exception, the entire batch with reciprocating engines was built by Lobnitz Ltd. at Renfrew where Pelorus herself was launched on 18th June 1943. Displacing 850 tons (935 fully loaded), she measured 225 feet in length with a 35½ foot beam and her 2,000ihp. engines gave her a top speed of 16½ knots. Lightly but effectively armed, she and her sisters proved invaluable additions to the fleet and gave excellent service with remarkably few wartime losses. Surviving the War, Pelorus was sold to the South African Navy in 1947 and renamed Pietermaritzburg. Converted into a midshipmen's training ship in 1961-2, at which time she was re-armed, she was withdrawn from service and hulked in 1976.