View source for Engineering:Sopwith 1913 Circuit of Britain floatplane

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{|{{Infobox aircraft begin
 |name=Sopwith 1913 Circuit of Britain Biplane
 |image=File:Sopwith 1913 Circuit of Britain.png
 |caption=
}}{{Infobox aircraft type
 |type=Racing aircraft
 |manufacturer=Sopwith Aviation Company
 |designer=
 |first flight=1913
 |introduced=
 |retired=
 |status=
 |primary user=
 |more users=
 |produced=
 |number built=1
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|}
The '''Sopwith 1913 Circuit of Britain Biplane''' was a British [[Engineering:Floatplane|floatplane]] built by Sopwith to take part in the 1913 ''Daily Mail'' Circuit of Britain Air race.  The only entrant to start, it had to be withdrawn after a landing accident two-thirds of the way through the race.

==Design and development==
The Circuit of Britain biplane was a four-bay [[Engineering:Tractor configuration|tractor]] biplane with a  square-section fuselage with the forward part covered with [[Chemistry:Aluminium|aluminium]] back to the aft cockpit and the remainder covered with fabric. The forward sections of the longerons were made of [[Biology:Fraxinus excelsior|ash]] and the rear sections of [[Biology:Spruce|spruce]].  Lateral control was effected by ailerons on both the upper and lower wings, which were staggered and had  spruce spars spindled to an I section and hollow interplane struts.<ref>[http://www.flightglobal.com/pdfarchive/view/1913/1913%20-%200871.html "The Sopwith Tractor Water-Plane"] ''Flight'' 16 August 1913</ref>  The tail surfaces consisted of unbalanced elevators mounted on the large semi-circular tailplane and an aerodynamically balanced rudder, with no fixed vertical surface. The single step main floats had a framework of ash and spruce covered with two layers of [[Biology:Cedrus|cedar]] and were divided into three watertight compartments.  It was powered by a 100&nbsp;hp (75&nbsp;kW) Green E.6, the radiators of which were placed either side of the fuselage.

==Operational history==
The competition was to start at Southampton on Saturday 16 August, the rules permitting the attempt to take place during any 72-hour period before the end of the month.  Of the four entrants to the race, the Sopwith, piloted by Harry Hawker with Harry Kauper as passenger, was the only aircraft to start.  Samuel Cody had been killed while testing the aircraft he had built for the competition, [[Engineering:Radley-England waterplanes|the aircraft]] entered by James Radley and Gordon England had been damaged during trials and Francis McClean's Short biplane was delayed by engine problems which kept it from competing.<ref>[http://www.flightglobal.com/pdfarchive/view/1913/1913%20-%200933.html Round Britain Waterplane Flight] ''Flight'', 30 August 1913.</ref>
  
Hawker and Kauper started shortly before noon and reached Great Yarmouth on the East Anglian coast at 4.38. where Hawker collapsed shortly after landing.  This was ascribed to sunstroke but may have been due to [[Chemistry:Carbon monoxide#Biological and physiological properties|Carbon monoxide poisoning]].<ref>Blackmore 1993 p. 80.</ref>  (The exhaust pipe of the aircraft was subsequently lengthened, but this may have been to reduce noise).  Under the competition rules there was no flying on the Sunday,  so an attempt was made to resume the flight on the Monday, with Sydney Pickles taking over as pilot, but this was impossible due to deteriorating weather conditions.<ref>[http://www.flightglobal.com/pdfarchive/view/1913/1913%20-%200898.html Round Britain Waterplane Flight] ''Flight'', 23 August 1913.</ref>

A second start was allowed by the race authorities, and the aircraft was returned to Southampton by rail.  The second attempt started on Monday 25 August when Hawker and Kauper took off at 5.30 am. Flying via Ramsgate, Yarmouth and Scarborough, Seaham - where an unscheduled hour stop was made to effect repairs and replace lost radiator water - and ending the day at Beadnell, about {{convert|20|mi|km|abbr=on}} short of the control point at Berwick-on-Tweed, due to one of the radiator hoses having been burnt through.  The next day they left Beadnell at 8.05, stopping at Montrose, Aberdeen and Cromarty  and reaching Oban on the west coast of Scotland at six in the evening,  and took off on the third day at 5.42 am; after a stop at Kiells due to engine problems Larne was reached at 9.30.  At 11 they took off for [[Place:Dublin|Dublin]], but a few miles short of their destination Hawker decided to land in order to make adjustments to the  engine valves.  Unfortunately his foot slipped from the rudder bar and the aircraft sideslipped into the water, breaking Kauper's arm and damaging the aircraft too seriously for the flight to be continued.

Although they had only covered two-thirds of the {{convert|1450|mi|abbr=on}} course, Hawker was awarded a prize of £1,000 and was also awarded the Royal Aeronautical Society's silver medal; Kauper was awarded a bronze medal.<ref>[http://www.flightglobal.com/pdfarchive/view/1913/1913%20-%200954.html Daily Mail £5,000 Prize] ''Flight'', 6 September 1913</ref>

==Specifications==
{{Aircraft specs
|ref= Lewis 1962<ref>Lewis 1962, p.479.</ref>
|prime units?=imp 
|genhide=

|crew=2
|capacity=
|length m=
|length ft=31
|length in=0
|span m=
|span ft=49
|span in=6
|height m=
|height ft=
|height in=
|wing area sqm=
|wing area sqft=500
|empty weight kg=
|empty weight lb=1580
|gross weight kg=
|gross weight lb=2400

|eng1 number=1
|eng1 name=Green E.6 6-cylinder inline water cooled piston engine
|eng1 kw=<!-- prop engines -->
|eng1 hp=100<!-- prop engines -->

|max speed kmh=
|max speed mph=
|cruise speed kmh=<!-- if max speed unknown -->
|cruise speed mph=65
|range km=
|range miles=
|endurance h=<!-- if range unknown -->
|endurance min=<!-- if range unknown -->
|ceiling m=
|ceiling ft=
|glide ratio=<!-- sailplanes -->
|climb rate ms=
|climb rate ftmin=
|sink rate ms=<!-- sailplanes -->
|sink rate ftmin=<!-- sailplanes -->
|perfhide = 
}}

==Other 1913 Circuit of Britain aircraft==
*Cody floatplane
*[[Engineering:Radley-England waterplanes|Radley-England waterplanes]]

==References==

===Notes===
{{Reflist}}

===Bibliography===
*Blackmore, L.K. ''Hawker: A Biography''. Shrewsbury: Airlife, 1993 {{ISBN|1 85310 437X}}
*Lewis, Peter, ''British Aircraft 1809-1914''. London: Putnam, 1962.
<!-- ==External links== -->


[[Category:Racing aircraft]]
[[Category:Floatplanes]]
[[Category:Biplanes]]
[[Category:Single-engined tractor aircraft]]

{{Sourceattribution|Sopwith 1913 Circuit of Britain floatplane}}