The Short S.47 Triple Tractor was one of a series of experimental twin-engined aircraft built by

Short Brothers Short Brothers plc, usually referred to as Shorts or Short, is an aerospace company based in Belfast, Northern Ireland. Shorts was founded in 1908 in London, and was the first company in the world to make production aeroplanes. It was particu ...

in 1912. It acquired its name because the two engines drove three

tractor A tractor is an engineering vehicle specifically designed to deliver a high tractive effort (or torque) at slow speeds, for the purposes of hauling a trailer or machinery such as that used in agriculture, mining or construction. Most common ...

propellers.

Design and development

The Triple Tractor followed the Tandem Twin and Triple Twin in the series of twin-engined aircraft built by Short Brothers, the intention behind fitting two engines being to produce an aircraft capable of sustaining flight in the event of one engine failing. It was powered by a pair of Gnome Double Omega engines mounted in tandem in the extended nose of the aircraft, the front engine driving a single propeller and the other driving a pair of tractor propellers mounted at mid-gap between the wings, using chains. In order to reduce the torque effect of the rotary engines they were arranged to revolve in opposite directions. The airframe of the Triple Twin was similar to the contemporary S.36, S.41 and S.45 tractor biplanes built by Shorts, being an unequal-span two-seater two-bay biplane, with the square-section

fuselage The fuselage (; from the French ''fuselé'' "spindle-shaped") is an aircraft's main body section. It holds crew, passengers, or cargo. In single-engine aircraft, it will usually contain an engine as well, although in some amphibious aircraft t ...

mounted in the gap between the upper and lower wings. The tail surfaces consisted of a rectangular rudder mounted on the sternpost of the fuselage, with a rectangular horizontal stabiliser and split

elevator An elevator or lift is a wire rope, cable-assisted, hydraulic cylinder-assisted, or roller-track assisted machine that vertically transports people or freight between floors, levels, or deck (building), decks of a building, watercraft, ...

mounted in front of it on top of the fuselage. The crew of two were seated side by side behind the trailing edge of the wings.

Service history

The aircraft was first flown by

Frank McClean Frank McClean FRS, FRAS (13 November 1837 – 8 November 1904) was a British astronomer and pioneer of objective prism spectrography. Life His father was the engineer J. R. McClean, FRS. Graduating from Trinity College, Cambridge, in 1859, Fra ...

on 24 July 1912, and after a formal acceptance flight carried out by Lt. C. L'Estrange-Malone, the aircraft was bought by the

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, Tr ...

, being given the serial number T.4 at the Eastchurch Naval School. The aircraft performed well, the only problem being the amount of heat generated, earning it the nickname "The Field Kitchen".

Specifications

References

Notes

Bibliography

*Barnes, C.H. ''Shorts Aircraft Since 1900'' London: Putnam, 1967 {{Short Brothers aircraft 1910s British experimental aircraft Triple Tractor Aircraft first flown in 1912 Biplanes Twin piston-engined tractor aircraft