On 25 November 1911, at Windermere, Waterbird made the first successful flight in the world to use a ‘stepped’ float, only achieved by embodying Edward Wakefield‘s two years of persistent experiments. The pilot was Herbert Stanley Adams. This telegram confirms the initial flights.
The two steps of the float may be appreciated on the photo below taken at Hill of Oaks – circled in red.
The central float, and auxiliary wing-tip floats, were built by Borwick & Sons, of Bowness-on-Windermere. The central float survived and, together with other parts, has been held at the RAF Museum since 27 July 1971.
Gertrude Bacon, who flew as a passenger in Waterhen and the Deperdussin at Windermere during 1912, explained the step in her book All About Flying: ‘The lower surface of the float, instead of being all of one piece, changes or ‘steps’ abruptly to another level. Some floats have one step, some more’.
The step-hydroplane bottom has been since used on virtually every floatplane and flying boat.
THE HISTORY IS HERE
‘It was a clergyman, the Rev. Charles Meade Ramus, who first suggested the hydroplane, in 1872, and he drew the attention of the Lords of the Admiralty to his experiments and their results for war ships, but the scheme as a whole was abandoned. The design was essentially a flat bottomed boat with a step half way along the bottom.’ – Flight magazine, 22 February 1913. This magazine item was about the International Aero Exhibition at Olympia, London, at which the hydro-aeroplane made its first British public appearance, including the British-built Deperdussin war hydro-aeroplane. The work by Ramus became generally known when it was republished in the Motor Boat magazine in 1908.
UK patent No. 17,360 filed on 2 August 1906 by Albert Edward Knight is the first patent on record relating to stepped hydroplanes [for boats], as confirmed in a Motor Boat magazine article of 10 December 1908. The article included that Knight had been unaware of the efforts by Ramus.
Henri Fabre made the first flight from water near Marseilles on 28 March 1910. However, not only was his aeroplane not of a practical design, but also the floats were not stepped but arranged with the flat part underneath and a curved upper surface, so as to generate lifting force when moving on water or in air.
In a move away from the flat bottom of initial floats, Gnosspelius developed the wave-cutting, spray-deflecting, V-shaped float; which is used on almost every float today. On 12 February 1914, he obtained UK Patent No. 10,801 for a V-shaped construction.
Glenn Curtiss made the first practical flight from water at San Diego Bay, California on 26 January 1911, using not only a centre float which was 6 feet wide and 5 feet long but also a smaller float forward to provide stability. By 1 February, the size had changed to 12 feet long and 2 feet wide, being the same dimensions as Waterbird’s float. However, the Curtiss float had been designed to ride through waves of the sea, shaped so that it would tend to rise on the surface and was flat-bottomed, not stepped.
On 11 December 1911, through agents Arthur Edwards & Co., Wakefield filed UK Patents No. 27,770 and No. 27,771 relating to the means for float attachment, including rubber bungees to provide shock absorption when taking off and alighting, and a stepped float, which were respectively granted on 12 September 1912 and 18 March 1913. The object of the invention was ‘to provide an aeroplane with means for enabling it to alight, float and travel along the surface of water and to rise again therefrom’. Wakefield had thus combined features of construction in a novel way.
Further, on 13 November 1913, Wakefield obtained UK Patent No. 18,051 for a float of a seaplane to support its own weight or the greater part of such weight during flight.
THE STAGES OF WATERBIRD’S FLOAT, AS SHOWN IN THE VIDEO CLIP, WERE:
built in May 1911, with the additions of a single step in September, a second step towards the stern in November, and a tapering stern – a bustle – later.
THE REPORT BY LIEUTENANT (LATER AIR CHIEF MARSHAL SIR) ARTHUR LONGMORE, WHO TEST-FLEW WATERBIRD FOR THE ADMIRALTY ON 20 JANUARY 1912
The hydroplane float is 12 feet long by 2 feet wide by 1 foot deep, the sides are of ¼” mahogany, the bottom of 22 gauge aluminium and the top covering of Willesden canvas. Wooden lattice girder frames are fitted internally 8″ apart to stiffen up the float and a centre longitudinal of wood runs centrally from bow to stern inside. Wood beading is used at the corners inside to ensure watertightness. No watertight compartments are at present fitted but Mr. Wakefield says he can fit seven with about 10lbs extra weight. The weight of the float is about 96 lbs, but a new one now under construction should weigh only 70, this latter has a duralumin bottom on which the sea has no bad effect. Two steps occur in the bottom of the hydroplane, one at half way of 4″ and the other 8″ from the stern of 3 ½”. The float is attached to the machine by a rubber spring 3 point suspension, the struts being of steel tubing.’
ON 14 MARCH 1912, WAKEFIELD ENTERED INTO AN AGREEMENT WITH THE ADMIRALTY for floats and undercarriages, or royalties, and to convert Admiralty Deperdussin M1 (a monoplane) into a hydro-aeroplane, which conversion he achieved within four weeks from delivery.
EXAMPLES OF AIRCRAFT WHICH USED STEPS
Supermarine S.6B racing seaplane, Boeing 314 Clipper flying boat, Consolidated Catalina flying boat, Slingsby Falcon glider flown from Windermere in 1943 by Cooper Pattinson and Wavell Wakefield and Tiger Moth at Windermere in 1979.
In early Short Sunderland flying boats the hull step was an abrupt one, but in the Mark III it was a curve upwards from the forward hull line. The Mark III was the definitive Sunderland variant with 461 built, which included 35 at White Cross Bay, Windermere between 1942 and 1944.
EXAMPLES OF BOATS WHICH USED A STEPPED HULL
White Lady II. Built by The British Power Boat Company Limited in 1930, reached 55 mph at Windermere. The designer Hubert Scott-Paine had built the first flying boat to reach 100 mph in 1916, and the racing seaplane which won the Schneider Trophy in 1922. The decks and cowls were covered with aeroplane fabric for lightness. She flooded off Rawlinson Nab during a race on 20 June 1937, until salvage and restoration 45 years later.
Miss England II. Built by Saunders-Roe Limited in 1930, achieved 98.76 mph at Windermere on 13 June 1930. Alliott Verdon-Roe sold his shareholding in A.V. Roe & Co which had built Waterbird, leading to a controlling interest in Saunders-Roe Limited and the production of marine and aviation craft.
REPLICA CENTRAL FLOAT
The replica float combines the innovative design features of the original, including an aluminium floor, with modern techniques and methods of analysis. The result is increased structural integrity.
A construction of lightweight timber and aluminium, the float is longitudinally-framed. That is, the structural members predominantly run forward to aft with only the 4 dividing bulkheads acting as transverse structure – this layout was chosen to best counteract the loads on the float.
It has five watertight compartments fitted and also a significantly increased buoyancy of 119% in excess of the buoyancy required to support the maximum weight of the complete aeroplane of 1170 Lbs – the regulatory requirement is a minimum of 80%.