Rolls-Royce Goshawk


The Rolls-Royce Goshawk was a development of the Rolls-Royce Kestrel that used evaporative or steam cooling. In line with Rolls-Royce convention of naming piston engines after birds of prey, it was named after the goshawk.
The engine first ran in 1933 and provided 660 horsepower. Only a few engines were built as the aircraft designs intended to use it were not adopted by the Royal Air Force. The Goshawk was used to power the Short Knuckleduster, the Supermarine Type 224 and other prototype aircraft.

Design and development

The Goshawk was developed from the Kestrel IV prototype engine, to use evaporative 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 coolant is needed. However, the radiator now had to dissipate more heat to reverse the phase change to condense the vapour back to liquid; this condenser had to be much larger than in a liquid water-cooled engine, which caused 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.

Variants

;Goshawk I
;Goshawk II
;Goshawk III
;Goshawk VI
;Goshawk VII
;Goshawk VIII

Applications

The Goshawk was the power unit specified for the twin engined Short Knuckleduster flying boat 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,the Westland F.7/30 and the Blackburn F3, 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" and "Intermediate Fury" 2" and the Westland Pterodactyl V and was installed for trials in the Gloster TSR.38, and the first Gloster Gnatsnapper prototype.

Application list