Bristol-Burney seaplanes
| Industry | Aeronautics |
|---|---|
| Founded | 1911 |
| Headquarters | Filton , United Kingdom |
| Products | Aircraft, including Bristol-Burney seaplanes |
Template:Infobox aircraft The Bristol-Burney seaplanes were two experimental watercraft developed through a partnership between Lieutenant Dennistoun Burney and the British and Colonial Aeroplane Company between 1912 and 1914. Neither aircraft achieved successful flight, but they incorporated an innovative Hydrofoil undercarriage design. Although the project did not yield operational success, it laid the groundwork for Burney’s subsequent creation of the paravane.
Background
Dennistoun Burney, a naval officer, became deeply interested in naval aviation and conceived several technical innovations related to it. Lacking the necessary technical capabilities to advance these ideas himself, he sought collaboration with Bristol. The company showed enthusiasm and, after receiving assurance of backing from the British Admiralty, established a confidential design unit known as the X Department at the end of 1911 to pursue these developments. Frank Barnwell was appointed as lead designer, supported by his assistant, Clifford Tinson. Their initial concept, labelled X.1, was based on modifying a Bristol G.E. 1 biplane. The design intended to keep the aircraft afloat using five streamlined air cushions positioned beneath the wings, while employing the recently developed hydrofoil technique pioneered by Enrico Forlanini for takeoff. This involved three sets of hydrofoils—each comprising a central strut carrying multiple lifting surfaces—collectively called a "hydroped." Besides the air propeller for flight propulsion, water propellers driven via a clutch mechanism were included to assist during takeoff and could be disengaged once airborne.
X.2
The initial concept was quickly set aside, leading Barnwell to propose a two-seat monoplane featuring an inflatable wing composed of eight spanwise rubberised fabric tubes instead of traditional spars.[1] Although some trials were conducted with this configuration, its excessive weight rendered it impractical. Consequently, the design was altered to incorporate a conventional wing structure with three spars and employed wing-warping for lateral control. This wing was mounted atop the fuselage, which had a rounded, boat-like underside constructed from mahogany planking and covered with varnished sailcloth. The fuselage was intended to act similarly to a flying boat hull, allowing the aircraft to remain buoyant until the hydrofoils generated sufficient lift at speed. Two hydropeds extended outward beneath the wing's leading edge, each housing a water propeller driven by an internal shaft within the leg, while a third hydroped supported the rear fuselage. Propulsion came from an 80 hp (60 kW) Canton-Unné water-cooled radial engine powering both air and water propellers through a pair of Hele-Shaw clutches. The cockpit accommodated side-by-side seating with dual controls.[2]
Completed in May 1912, the aircraft was transported by boat to Dale in Pembrokeshire for evaluation by test pilot Howard Pixton.[3] Initial testing demonstrated effective acceleration via the water propellers; however, after a brief run, the aerodynamic fairing on the hydropeds was torn off, prematurely ending the trials. Subsequent static tests uncovered vibration issues within the drive system. While these were being investigated, towing trials were conducted using a torpedo boat. Stability concerns were partly addressed through minor adjustments to the parafoil lifting surfaces and by adding a controllable water elevator and rudder to the rear hydroped, resulting in acceptable towing performance. Nevertheless, when the water propellers operated under power, torque effects caused the aircraft to lean.
In September, it was decided to attempt flight trials by towing; the engine was removed and replaced with 500 lb (230 kg) of ballast. On 21 September, while being towed by a torpedo boat and carrying George Dacre as an instrument observer, the control settings were locked for level flight. The aircraft lifted off at approximately 30 knots (35 mph; 56 km/h) in a nose-up attitude but subsequently stalled, sideslipped, and crashed—fortunately without any injury to Dacre.
X.3
Repairing the X.2 was deemed uneconomical, so work commenced in March 1913 on a second aircraft assigned Bristol serial number 159. This new model was somewhat larger than its predecessor and featured a fuselage sheathed in Consuta plywood. The configuration of the water propellers was revised: they were mounted centrally in tandem with contra-rotating blades to neutralize torque effects. Additionally, wing-warping control was replaced by ailerons. Power was planned to come from a 200 hp (150 kW) Canton-Unné water-cooled radial engine provided on loan by the Admiralty.[4]
Initial taxiing tests were performed using outriggers supporting tip floats instead of wings and powered by an 80 hp (60 kW) Gnome engine. These tests were mostly successful despite a tendency for the nose to pitch downward when engaging the airscrew; this issue was addressed by fitting an auxiliary front-mounted elevator. Subsequently, the Gnome engine was replaced with the Canton-Unné unit and wings were installed. However, before flight testing could commence, the aircraft became stranded on a sandbank requiring extensive repairs. At this stage Bristol requested increased support from the Admiralty but was denied; consequently, development ceased. The X.3 returned to Filton and was ultimately dismantled in 1920.[5] Burney later applied insights gained from both X.2 and X.3 designs toward developing the paravane at HMS Vernon during 1915.[6]
Specifications (X.3)
Notes
Bibliography
- Barnes, C.H. Bristol Aircraft Since 1910 London: Putnam, 1988 (3rd ed.) ISBN 0-85177-823-2
- Lewis, P British aircraft 1809-1914 London: Putnam 1962
- Pixton, Stella Howard Pixton Test Pilot & Pioneer Aviator Barnsley, UK: Pen & Sword Aviation, 2014 ISBN 978-1-47383-670-9