| R.24/31 (S.18 Knuckleduster) | |
|---|---|
 Short S.18 'Knuckleduster' (K3574), at Felixstowe, 1934 | |
| General information | |
| Type | General purpose flying-boat |
| Manufacturer | Short Brothers |
| Designer | |
| Status | Prototype |
| Primary users | Short Brothers |
| Number built | 1 |
| History | |
| Manufactured | Rochester |
| First flight | 30 November 1933 |
| Retired | 1938 |
The Short R.24/31 (or 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 contract also specified the use of the experimental Rolls-Royce Goshawk engine.[1] The Saunders-Roe London and the Supermarine Stranraer competed successfully for this contract.
Although it never saw military service, the Knuckleduster provided useful information on the steam-cooling of engines and the handling of monoplane flying-boats; much experimental data gathered contributed to the design of the successful Empire and Short Sunderland aircraft.[2]