The Cosmos Mercury was a fourteen-cylinder twin-row air-cooled radial

aeroengine An aircraft engine, often referred to as an aero engine, is the power component of an aircraft propulsion system. Most aircraft engines are either piston engines or gas turbines, although a few have been rocket powered and in recent years many ...

. Designed by

Roy Fedden Sir Alfred Hubert Roy Fedden MBE, FRAeS (6 June 1885 – 21 November 1973) was an engineer who designed most of Bristol Engine Company's successful piston aircraft engine designs. Early life Fedden was born in the Bristol area to fairly wealthy ...

Cosmos Engineering Cosmos Engineering was a company that manufactured aero-engines in a factory in Fishponds, Bristol during World War I. Sir Roy Fedden, the company's principal designer, developed the 14-cylinder radial Mercury engine during this period. The co ...

, it was built in the United Kingdom in 1917. It produced 347 horsepower (259 kW). It did not enter production; a large order was cancelled due to the

Armistice An armistice is a formal agreement of warring parties to stop fighting. It is not necessarily the end of a war, as it may constitute only a cessation of hostilities while an attempt is made to negotiate a lasting peace. It is derived from the La ...

Design and development

Built at

Bristol Bristol () is a city, ceremonial county and unitary authority in England. Situated on the River Avon, it is bordered by the ceremonial counties of Gloucestershire to the north and Somerset to the south. Bristol is the most populous city in ...

by Brazil-Straker under the direction of Roy Fedden, the Mercury featured an unusual

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 ...

and

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 ...

arrangement that dispensed with the more normal design of a single master rod linking to individual rods for each cylinder. It was said to run well without vibration and set an unofficial time to climb record while fitted to a Bristol 21A Scout F.1, the aircraft achieving 10,000 ft (3,000 m) in 5.4 minutes and 20,000 ft (6,000 m) in 16.25 minutes.Lumsden 2003, p.92. An

Admiralty Admiralty most often refers to: *Admiralty, Hong Kong *Admiralty (United Kingdom), military department in command of the Royal Navy from 1707 to 1964 *The rank of admiral *Admiralty law Admiralty can also refer to: Buildings * Admiralty, Traf ...

order for 200 engines was placed in 1917 but was later cancelled by Lord Weir due to the end of

World War I World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...

, it is also stated that Lord Weir had a preference for the

ABC Dragonfly The ABC Dragonfly was a British radial engine developed towards the end of the First World War. It was expected to deliver excellent performance for the time and was ordered in very large numbers. It proved, however, to be extremely unreliable ...

.Gunston 1989, p.44. The name was re-used by Fedden for the later nine-cylinder

Bristol Mercury The Bristol Mercury is a British nine-cylinder, air-cooled, single-row, piston radial engine. Designed by Roy Fedden of the Bristol Aeroplane Company it was used to power both civil and military aircraft of the 1930s and 1940s. Developed from ...

radial engine.

Applications

Bristol Scout F The Bristol Scout E and F were a British single-seat biplane fighters built in 1916 to use newer and more powerful engines. It was initially powered by the Sunbeam Arab, but the third prototype was used as a testbed for the Cosmos Mercury, ma ...

Specifications (Mercury)

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. .

External links

* Contemporary article on Cosmos Engineering's air-cooled radial engines. Photos of the Mercury are on page 869, and a short technical description is o
page 871

Cosmos Mercury at Aviationarchive.org
{{Cosmos aeroengines 1910s aircraft piston engines Aircraft air-cooled radial piston engines