The torpedo solutions that made Taranto possible

Captain Boyd of Illustrious had helped develop the duplex pistol fitted to the 18-inch aerial torpedoes. It could detonate beneath a ship's hull and also retained a contact fuse. A reel and tension cable controlled the torpedo's entry into the water, producing a shallow belly flop instead of a steep nose-first dive. This reduced the danger of striking the harbour bottom before the weapon could begin its run. The advanced firing system and simple entry restraint solved different parts of the same attack problem. Their combination reflected sustained attention to reaching an enemy fleet in harbour, a frustration that had persisted since the First World War. Plans to use Furious and Sopwith Cuckoos against the High Seas Fleet had already existed before that war ended.