Mousetrap (weapon)

Mousetrap (anti-Submarine Projector, Marks 20 and 22) was an anti-submarine rocket launcher used mainly during World War II by the United States Navy[1] and Coast Guard.

[2] Its development began in 1941 as a replacement for Hedgehog anti-submarine mortar.

Those were spigot-launched, which placed considerable strain on the launching vessel's deck, whereas Mousetrap was rocket-propelled.

As a result, Mousetrap's four or eight rails for 7.2-inch (183 mm) rockets saved weight and were easier to install.

[citation needed] By the end of the war, over 100 Mark 22 Mousetraps were mounted in U.S. Navy ships, including three each on 12 destroyers,[1] and submarine chasers (usually two sets of rails).