Mousetrap

Mousetrap (ASW Marks 20 and 22) was an anti-submarine rocket used mainly during World War II by the United States Navy and Coast Guard. Its development began in 1941 as a replacement for Hedgehog, a British-made projector, which was the first forward-throwing ASW weapon. Those, however, were spigot-launched, placing considerable strain on the launching vessel's deck, whereas Mousetrap was rocket-propelled. As a result, Mousetrap's four or eight rails for rockets saved weight and were easier to install. The rockets weighed each, with a Torpex warhead and contact pistol, exactly like Hedgehog. By the end of the war, over 100 Mousetrap Mark 22s were mounted in U.S. Navy ships, including three each on 12 destroyers, and submarine chasers (usually two sets of rails). Statistics Round weight: Warhead: Range: about Firing speed: one round every 3 seconds (maximum) No. of rails: Mark 20: 4 Mark 22: 8