The West Spring Gun was a bomb-throwing catapult used by British, Canadian and Australian forces during World War I. It was designed to throw a hand grenade in a high trajectory into enemy trenches. It consisted of a metal frame supporting a throwing arm powered by 24 metal springs. It was invented by Captain Allen West in 1915 and manufactured by the Reason Manufacturing Company of Brighton, which was granted a patent for the device on 19 October of that year. Although called a catapult, it was a hybrid of a ballista and a trebuchet. It required a crew of five - three to compress the springs, one to load the bomb, and one to fire as soon as the fuse was lit or the grenade pin was pulled.