The Sopwith Long Range Tractor Triplane (L.R.T.Tr) was a prototype

British British may refer to: Peoples, culture, and language * British people, nationals or natives of the United Kingdom, British Overseas Territories, and Crown Dependencies. ** Britishness, the British identity and common culture * British English, ...

long-range three-seat

triplane A triplane is a fixed-wing aircraft equipped with three vertically stacked wing planes. Tailplanes and canard foreplanes are not normally included in this count, although they occasionally are. Design principles The triplane arrangement may ...

escort fighter of the

First World War 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 ...

. Its unusual layout had a small gunner's nacelle mounted on the upper wing for an all-round field of fire. Only a single example was built, as other, smaller fighters proved more practicable.

Development and design

In early 1916, the British

War Office The War Office was a department of the British Government responsible for the administration of the British Army between 1857 and 1964, when its functions were transferred to the new Ministry of Defence (MoD). This article contains text from ...

drew up a specification for a multi-seat escort fighter to be powered by one of the new

Rolls-Royce Eagle The Rolls-Royce Eagle was the first aircraft engine to be developed by Rolls-Royce Limited. Introduced in 1915 to meet British military requirements during World War I, it was used to power the Handley Page Type O bombers and a number of oth ...

engines, intended to protect formations of bombers from German fighters, with an additional role of destroying enemy

airship An airship or dirigible balloon is a type of aerostat or lighter-than-air aircraft that can navigate through the air under its own power. Aerostats gain their lift from a lifting gas that is less dense than the surrounding air. In early ...

s.Bruce 1957, p. 25. While the specification did not require high speed, a good field of fire for its guns was essential, while the secondary anti-Zeppelin role demanded an endurance of at least seven hours. Orders were placed for prototypes from

Armstrong Whitworth Sir W G Armstrong Whitworth & Co Ltd was a major British manufacturing company of the early years of the 20th century. With headquarters in Elswick, Newcastle upon Tyne, Armstrong Whitworth built armaments, ships, locomotives, automobiles and a ...

(the F.K.6), Sopwith and

Vickers Vickers was a British engineering company that existed from 1828 until 1999. It was formed in Sheffield as a steel foundry by Edward Vickers and his father-in-law, and soon became famous for casting church bells. The company went public in 18 ...

(the F.B.11). All three designs were driven by the need to provide wide fields of fire in the absence of an effective

synchronisation gear A synchronization gear (also known as a gun synchronizer or interrupter gear) was a device enabling a single-engine tractor configuration aircraft to fire its forward-firing armament through the arc of its spinning propeller without bullets strik ...

that would allow safe firing of guns through the propeller disc. The Sopwith proposal was modified from an existing design for a two-seat

, with a nacelle for a gunner added to the upper wing. It had three-bay, narrow chord wings, with the streamlined nacelle housing the upper gunner who was armed with a Lewis gun built around the centre section of the upper wing.

Aileron An aileron (French for "little wing" or "fin") is a hinged flight control surface usually forming part of the trailing edge of each wing of a fixed-wing aircraft. Ailerons are used in pairs to control the aircraft in roll (or movement around ...

s were fitted to all wings, with air brakes fitted to the lower wing. The deep fuselage housed the pilot and a second gunner to guard the aircraft's tail.Mason 1992, p. 78. Balancing wheels were fitted well ahead of the aircraft's mainwheels in order to prevent the aircraft overturning, as the upper gunner would be extremely vulnerable if this occurred. The prototype, which was nicknamed "Egg-Box", flew late in 1916. It was not developed further, with smaller fighters fitted with

such as Sopwith's own 1½ Strutter now available, with all of the proposed three-seat escort fighters abandoned.Lewis 1979, p. 99.

Specifications (L.R.T.Tr.)

Notes

References

*Bruce, J. M. ''British Aeroplanes 1914-18''. London: Putnam, 1957. *Bruce, J. M. ''War Planes of the First World War: Volume Two Fighters''. London: Macdonald, 1968. . *Green, William, and Swanborough, Gordon. ''The Complete Book of Fighters''. New York: Smithmark, 1994. . *Lewis, Peter. ''The British Fighter since 1912''. London: Putnam, Fourth edition, 1979. . *Mason, Francis K. ''The British Fighter since 1912''. Annapolis, Maryland, USA: Naval Institute Press, 1992. . {{Sopwith Aviation Company aircraft Triplanes L.R.T.Tr Aircraft first flown in 1916 1910s British fighter aircraft

Development and design

Specifications (L.R.T.Tr.)

See also

Notes

References