The Rolls-Royce Vulture was a British aero engine developed shortly before

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

that was designed and built by

Rolls-Royce Limited Rolls-Royce was a British luxury car and later an aero-engine manufacturing business established in 1904 in Manchester by the partnership of Charles Rolls and Henry Royce. Building on Royce's good reputation established with his cranes, they ...

. The Vulture used the unusual " X-24" configuration, whereby four cylinder blocks derived from the

Rolls-Royce Peregrine The Rolls-Royce Peregrine was a , liquid-cooled V-12 aero engine designed and built by the British manufacturer Rolls-Royce in the late 1930s. It was essentially the ultimate development of the company's Kestrel engine, which had seen wides ...

were joined by a common

crankshaft A crankshaft is a mechanical component used in a piston engine to convert the reciprocating motion into rotational motion. The crankshaft is a rotating shaft containing one or more crankpins, that are driven by the pistons via the connecting ...

supported by a single crankcase. The engine was originally designed to produce around but problems with the Vulture design meant that the engines were derated to around 1,450 to 1,550 hp in service by limiting the maximum

rpm Revolutions per minute (abbreviated rpm, RPM, rev/min, r/min, or with the notation min−1) is a unit of rotational speed or rotational frequency for rotating machines. Standards ISO 80000-3:2019 defines a unit of rotation as the dimensionl ...

. Although several new aircraft designs had been planned to use the Vulture, work on the engine's design ended in 1941 as Rolls-Royce concentrated on their more successful

Merlin Merlin ( cy, Myrddin, kw, Marzhin, br, Merzhin) is a mythical figure prominently featured in the legend of King Arthur and best known as a mage, with several other main roles. His usual depiction, based on an amalgamation of historic and le ...

design. Another 24-cylinder engine, the Napier Sabre, proved more successful after a lengthy development period.

Design and development

The

supercharged In an internal combustion engine, a supercharger compresses the intake gas, forcing more air into the engine in order to produce more power for a given displacement. The current categorisation is that a supercharger is a form of forced induct ...

Rolls-Royce Kestrel The Kestrel or type F is a 21 litre (1,300 in³) 700 horsepower (520 kW) class V-12 aircraft engine from Rolls-Royce, their first cast-block engine and the pattern for most of their future piston-engine designs. Used during the interwar ...

and its derivative, the

, were fairly standard designs, with two cylinder banks arranged in a V form and with a

displacement Displacement may refer to: Physical sciences Mathematics and Physics * Displacement (geometry), is the difference between the final and initial position of a point trajectory (for instance, the center of mass of a moving object). The actual path ...

of . The Vulture was, in effect, two Peregrines joined by a new crankcase turning a new crankshaft, producing an

X engine An X engine is a piston engine with four banks of cylinders around a common crankshaft, such that the cylinders form an "X" shape when viewed from front-on. The advantage of an X engine is that it is shorter than a V engine of the same number o ...

configuration with a displacement of . The Vulture used cylinders of the same bore and stroke as the Peregrine, but the cylinder spacing was increased to accommodate a longer crankshaft, necessary for extra

main bearing Main may refer to: Geography * Main River (disambiguation) **Most commonly the Main (river) in Germany * Main, Iran, a village in Fars Province *"Spanish Main", the Caribbean coasts of mainland Spanish territories in the 16th and 17th centuries ...

s and wider

crankpin A crankpin or crank pin, also known as a rod bearing journal, is a mechanical device in an engine which connects the crankshaft to the connecting rod for each cylinder. It has a cylindrical surface, to allow the crankpin to rotate relative to the ...

s. The engine suffered from an abbreviated development period because Rolls-Royce suspended Vulture development in 1940 during the

Battle of Britain The Battle of Britain, also known as the Air Battle for England (german: die Luftschlacht um England), was a military campaign of the Second World War, in which the Royal Air Force (RAF) and the Fleet Air Arm (FAA) of the Royal Navy defende ...

to concentrate on the Merlin, which powered the RAF's two main fighters, the

Hawker Hurricane The Hawker Hurricane is a British single-seat fighter aircraft of the 1930s–40s which was designed and predominantly built by Hawker Aircraft Ltd. for service with the Royal Air Force (RAF). It was overshadowed in the public consciousness by ...

and

Supermarine Spitfire The Supermarine Spitfire is a British single-seat fighter aircraft used by the Royal Air Force and other Allied countries before, during, and after World War II. Many variants of the Spitfire were built, from the Mk 1 to the Rolls-Royce Grif ...

, and as a consequence the reliability of the Vulture when it entered service was very poor. Apart from delivering significantly less than the designed power, the Vulture suffered from frequent failures of the

connecting rod A connecting rod, also called a 'con rod', is the part of a piston engine which connects the piston to the crankshaft. Together with the crank, the connecting rod converts the reciprocating motion of the piston into the rotation of the cranksh ...

big end Big or BIG may refer to: * Big, of great size or degree Film and television * ''Big'' (film), a 1988 fantasy-comedy film starring Tom Hanks * '' Big!'', a Discovery Channel television show * ''Richard Hammond's Big'', a television show present ...

bearings, which was found to be caused by a breakdown in lubrication, and also from heat dissipation problems. Rolls-Royce were initially confident that they could solve the problems, but the company's much smaller Merlin was already nearing the same power level as the Vulture's original specification, in part because of its accelerated development in 1940, and so production of the Vulture was discontinued after only 538 had been built.Lumsden 2003, p.200.

Applications

The Vulture had been intended to power the

Hawker Tornado The Hawker Tornado was a British single-seat fighter aircraft design of the Second World War for the Royal Air Force as a replacement for the Hawker Hurricane. The planned production of Tornados was cancelled after the engine it was designed to ...

interceptor but with the cancellation of Vulture development, Hawker abandoned the Tornado and concentrated on the

Hawker Typhoon The Hawker Typhoon is a British single-seat fighter-bomber, produced by Hawker Aircraft. It was intended to be a medium-high altitude interceptor, as a replacement for the Hawker Hurricane, but several design problems were encountered and i ...

, which was powered by the Napier Sabre. The cancellation caused the abandonment of the Vulture-engined version of the

Vickers Warwick The Vickers Warwick was a multi-purpose twin-engined British aircraft developed and operated during the Second World War. In line with the naming convention followed by other RAF heavy bombers of the era, it was named after a British city or ...

bomber. The only aircraft type designed for the Vulture to go into production was the twin-engined

Avro Manchester The Avro 679 Manchester was a British twin-engine heavy bomber developed and manufactured by the Avro aircraft company in the United Kingdom. While not being built in great numbers, it was the forerunner of the famed and vastly more successful ...

. When the engine reliability problems became clear, the Avro team persuaded the

Air Ministry The Air Ministry was a department of the Government of the United Kingdom with the responsibility of managing the affairs of the Royal Air Force, that existed from 1918 to 1964. It was under the political authority of the Secretary of State ...

that switching to a four-Merlin version of the Manchester, which had been in development as a contingency, was preferable to retooling Avro factories to make the

Handley Page Halifax The Handley Page Halifax is a British Royal Air Force (RAF) four-engined heavy bomber of the Second World War. It was developed by Handley Page to the same specification as the contemporary twin-engine Avro Manchester. The Halifax has its or ...

. The resulting aircraft was initially called the Manchester Mark III and then subsequently renamed

Avro Lancaster The Avro Lancaster is a British Second World War heavy bomber. It was designed and manufactured by Avro as a contemporary of the Handley Page Halifax, both bombers having been developed to the same specification, as well as the Short Stirlin ...

, going on to great success as the RAF's leading heavy bomber.

Application list

Hawker Tornado (with Rolls-Royce Vulture engine)

* Blackburn B-20 *

Hawker Henley The Hawker Henley was a British two-seat target tug derived from the Hawker Hurricane that was operated by the Royal Air Force during the Second World War. Design and development In 1934 Air Ministry Specification P.4/34 was issued which calle ...

Specifications (Vulture V)

References

Notes

Bibliography

* Gunston, Bill. ''Rolls-Royce Aero Engines''. Cambridge, England. Patrick Stephens, 1989. * Gunston, Bill. ''World Encyclopedia of Aero Engines: From the Pioneers to the Present Day''. 5th edition, Stroud, UK: Sutton, 2006. * Kirby, Robert. ''Avro Manchester: The Legend Behind the Lancaster''. Earl Shilton, Leicester, UK: Midland publishing Limited, 1995. * Lumsden, Alec. ''British Piston Aero-Engines and their Aircraft''. Marlborough, Wiltshire: Airlife Publishing, 2003. . * Rubbra, A.A. ''Rolls-Royce Piston Aero Engines - a Designer Remembers: Historical Series no 16'': Rolls-Royce Heritage Trust, 1990. . * White, Graham. ''Allied Aircraft Piston Engines of World War II: History and Development of Frontline Aircraft Piston Engines Produced by Great Britain and the United States During World War II''. Warrendale, Pennsylvania: SAE International, 1995. {{RRaeroengines

Vulture A vulture is a bird of prey that scavenges on carrion. There are 23 extant species of vulture (including Condors). Old World vultures include 16 living species native to Europe, Africa, and Asia; New World vultures are restricted to North and ...

1930s aircraft piston engines X engines