The Rolls-Royce Goshawk was a development of the

Rolls-Royce Kestrel The Rolls-Royce Kestrel (internal type F) is a 21.25 litre (1,295 in³) V-12 aircraft engine from Rolls-Royce. It was their first cast-block engine, and used as the pattern for most of their future piston-engine designs. Used during the interw ...

that used evaporative or steam cooling. In line with Rolls-Royce convention of naming piston engines after

birds of prey Birds of prey or predatory birds, also known as (although not the same as) raptors, are hypercarnivorous bird species that actively predation, hunt and feed on other vertebrates (mainly mammals, reptiles and smaller birds). In addition to speed ...

, it was named after the goshawk. The engine first ran in 1933 and provided 660

horsepower Horsepower (hp) is a unit of measurement of power, or the rate at which work is done, usually in reference to the output of engines or motors. There are many different standards and types of horsepower. Two common definitions used today are t ...

(490 kW). Only a few engines were built as the aircraft designs intended to use it were not adopted by the

Royal Air Force The Royal Air Force (RAF) is the Air force, air and space force of the United Kingdom, British Overseas Territories and Crown Dependencies. It was formed towards the end of the World War I, First World War on 1 April 1918, on the merger of t ...

. The Goshawk was used to power the Short Knuckleduster, the Supermarine Type 224 (a predecessor to the

Supermarine Spitfire The Supermarine Spitfire is a British single-seat fighter aircraft that was used by the Royal Air Force and other Allies of World War II, Allied countries before, during, and after World War II. It was the only British fighter produced conti ...

) and other prototype aircraft.

Design and development

The Goshawk was developed from the Kestrel IV prototype engine, to use evaporative (also known as "steam") cooling. Rather than keep the cooling liquid below its boiling point in the cooling system, the coolant was allowed to boil; the phase change from liquid to vapour takes more heat from the engine, so less weight of coolant is needed. However, the radiator had to be bulkier to accommodate coolant in its gas phase, which increased drag. Twenty engines were built, and flew only in prototypes as a few manufacturers' private ventures and "one-offs". Powers for individual installations are quoted between 650 and . Problems with coolant leaks, coolant pumping and the realisation that large wing-mounted condensing radiators would be vulnerable to combat damage caused the project to be cancelled, although valuable lessons had been learned and were put to good use with development of the later

Merlin The Multi-Element Radio Linked Interferometer Network (MERLIN) is an interferometer array of radio telescopes spread across England. The array is run from Jodrell Bank Observatory in Cheshire by the University of Manchester on behalf of UK Re ...

Variants

;Goshawk I :(1932) Developed from the prototype Kestrel IV. ;Goshawk II :(1935) 600 hp. Lowered propeller reduction gear ratio. ;Goshawk III :(1935) 600hp. Further reduction of gear ratio. ;Goshawk VI :660 hp. High ratio reduction gear. ;Goshawk VII :660 hp. Raised reduction gear ratio. ;Goshawk VIII :660 hp. Special experimental engine. Maximum power output: 837 hp.

Applications

The Goshawk was the power unit specified for the twin engined Short Knuckleduster flying boat (''K3574'') to Specification R24/31 and "preferred" for submissions to Air Ministry specification F7/30 for a fighter aircraft. Goshawks were used by all three officially sponsored prototypes, the Supermarine Type 224 (''K2890''),the Westland F.7/30 (''K2891'') and the Blackburn F3 (''K2892''), which only taxied with the Goshawk fitted and did not fly, in addition to two private venture entrants, the Bristol Type 123 and the Hawker P.V.3. The Goshawk also powered Hawker's privately developed "High Speed Fury Mk 2" (''K3586'') and "Intermediate Fury" 2" (the latter Hawker's own development aircraft and "hack" serial ''G-ABSE'')"Fighting Breed"
Flight 1951 p692 and the Westland Pterodactyl V (''K2770'') and was installed for trials in the Gloster TSR.38 (''S1705''), and the first Gloster Gnatsnapper prototype (''N227'').

Application list

* Blackburn F3 * Bristol Type 123 * Gloster Gnatsnapper * Gloster TSR.38 * Hawker Fury * Hawker P.V.3 * Supermarine Type 224 * Westland Pterodactyl V * Westland F.7/30 (sometimes called the Westland P.V.4)

Specifications (Goshawk I)

References

;Notes ;Bibliography * Gunston, Bill. ''World Encyclopedia of Aero Engines''. Cambridge, England. Patrick Stephens Limited, 1989. * Lumsden, Alec. ''British Piston Engines and their Aircraft''. Marlborough, Wiltshire: Airlife Publishing, 2003. .
"The Two Rs"
''Flight'' 1954 from archive at Flightglobal.com