Country of origin:

United Kingdom

Description:

Single-seat fighting scout

Power Plant:

One 97 kw (130 hp) Clerget 9B nine-cylinder rotary piston engine

Specifications:

Armament:

One or two synchronised 7.69 mm (0.303 in) Vickers fixed machine guns firing forward

History:

In order to design an aircraft that was superior to any produced in Germany, the design team at Sopwith in early 1916 designed a triplane, this machine having three narrow chord wings but the wing area giving plenty of lift.  Ailerons were fitted to all wings in order to achieve good performance, and single broad-chord interplane and centre-section struts were installed, thus reducing the number of bracing wires required.  The fuselage was of wooden box girder construction, and the tailplane, elevator, rudder and fin were similar to those of the Sopwith Pup.  The new wing layout gave the pilot a wide field of vision, the central wing being at the pilot’s eye level. This aircraft introduced new standards of performance and manoeuvrability to RNAS service, albeit for a brief period.

The Triplane was designed by Sopwith’s chief engineer, Herbert Smith, the aircraft being built at Kingston-upon-Thames. Initial power plant was the 82 kw (110 hp) Clerget 9Z nine-cylinder rotary engine, and standard armament was a 7.69 mm (0.303 in) Vickers machine gun synchronised to fire through the propeller. The prototype (N500) was completed on 28 May 1916 and, after initial testing by Australian pilot Harry Hawker, it was sent to France in June that year and underwent service trials with A Squadron of the RNAS at Furnes.  Orders were placed by the Admiralty for 266 from a number of manufacturers, including Sopwith and Clayton & Shuttleworth. Production aircraft were fitted with the 97 kw (130 hp) Clerget 9B engine and a few were fitted with twin machine guns.

In April 1917 No 1 (Naval) Squadron entered service and immediately showed the superiority of the Triplane over the Albatros D.III.  Nos 8 and 10 Squadrons were soon equipped, and on 6 June 1917 thirteen Triplanes from No 10 Squadron attacked 15 enemy aircraft and shot down five for no loss. Under the command of Canadian Flt Sub Lt Raymond Collishaw [CB, DSO and Bar, OBE, DSC, DFC], this unit destroyed 87 enemy aircraft between May and July 1917.  In 27 days in June 1917, Collishaw, shot down 16 enemy aircraft.  However, technology caught up with the Triplane and by late August 1917 casualties in the Triplane units were rising and re-equipment with the Sopwith Camel was proceeding, last operational flights with the Triplane taking place during the Battle of Ypres.

A total of 150 Triplanes was built and its success influenced aircraft design in Germany, with a number of manufacturers in Germany and Austro-Hungary producing triplanes. One Sopwith Triplane (N5431) was operated in Macedonia and was on the strength of No 2 Wing RNAS but was wrecked in a landing accident when flown by Lt John Alcock and had to be rebuilt.  Another (N5486) was delivered to Russia where it operated on Skis.

Although ordered for both the Royal Naval Air Service and the Royal Flying Corps, the Triplane in fact only saw operational service with the Royal Navy, an agreement being reached between the services in February 1917 for the RNAS to take all Triplanes produced and for the Spad S.VIIs destined for the Navy to be delivered to the RFC.

The type was flown by well known Australian aces of World War I, these including N500, the prototype Triplane, flown by Roderic Dallas DSO, DSC and Bar in June 1916 and in combat trials. Dallas claimed two victories in the aircraft, one on 1 July and another on 30 September that year.

Lieutenant Robert Little, DSO and Bar, DSC and Bar, whilst with No 8 Squadron RNAS flew one (N5493) with the name Blymp on the forward fuselage, this being the nick-name of his son; and Richard Minifie, DSC and two Bars, flew one (N5454) with No 1 Squadron RNAS from August to October 1917, claiming one aircraft captured, six destroyed, and three forced down out of control.

At the same time as developing the Triplane, Sopwith developed an aircraft known as the Sopwith Hispano-Suiza Triplane.  Designed around an eight-cylinder liquid-cooled engine, it was produced with two variants of the engine, a 112 kw (150 hp) direct drive and a 149 kw (200 hp) geared unit.  This aircraft was larger than the Clerget powered aircraft and had no real commonality with it. Two prototypes were built but no further development was undertaken.

At least one original example survives, and a few replicas have been constructed.  In the United States plans are available to build a full-scale replica of the triplane and these are marketed by St Croix Aircraft of Lake Oswego, Oregon. In the United Kingdom G-BWRA is painted in the markings of the Triplane prototype (N500) and powered by a 123 kw (165 hp) Warner Super Scarab radial engine; G-BOCK Dixie II is powered by a 97 kw (130 hp) Clerget rotary engine and is airworthy with the Shuttleworth Trust at Old Warden; N5912, one of three built by Oakley & Co of Ilford, Essex in 1917, survives at the RAF Museum at Hendon; and a replica of N5492 is on display at the Canadian Aviation Museum.

An airworthy replica was imported to the collection of World War I aircraft at Omaka, NZ in 2006.  This aircraft was partially built at Coning, Iowa by Mr Chad Wille.It was obtained by the 14-18 Aviation Trust and shipped to New Zealand for completion. It has occasionally been flown, being based at Hood Aerodrome at Masterton on the north island.  A replica of a Sopwith LC-1T Triplane (G-PENY – serial 5492) is airworthy in the United Kingdom.  An 85% replica has been built by Renni Forbes in Queensland, fitted with a Rotec R-3600 radial engine, and is on display at the TAVAS museum at Caboolture.