Short Knuckleduster

The Short R.24/31, also called the Short S.18 and nicknamed the Knuckleduster, was a British twin-engined, high-wing cantilever gull winged monoplane flying boat designed and built by Short to Air Ministry specification R.24/31 for a general purpose open sea patrol flying boat. The specification also called for the experimental Rolls-Royce Goshawk engine. While Saunders-Roe and Supermarine chose traditional biplane designs, Shorts produced a more modern all-metal monoplane. Its first flight took place on 30 November 1933. Although it never saw military service, it gave useful information on steam cooling of engines and the handling of monoplane flying boats, and its data contributed to the design of the Empire and the Sunderland.