Technical

On 25 November 1911, at Windermere, Waterbird became the first hydro-aeroplane to successfully take off from and alight on water outside of France and the USA.

It was the world’s first successful flight to use a ‘stepped’ float.

Waterbird was an Avro Curtiss-type, built to the order of Edward Wakefield by A.V. Roe & Company (‘Avro‘) as a landplane at Brownsfield Mills, Manchester. The Avro plan shows the wings to be of equal span. Upon transfer to Brooklands on 25 May 1911 for testing, alterations included extension of the upper wing, the ailerons were disconnected and smaller straight trailing edge ailerons were added. So, the original ailerons with semi-circular trailing edges became the inner ailerons, and serve as part of the wing once enough forward speed has been achieved so as to raise them.

DIFFERENCES BETWEEN THE REPLICA WATERBIRD AND THE ORIGINAL:-

The original had a 7-cylinder 50hp Gnome rotary engine: the replica has a new 7-cylinder 110hp Rotec radial engine.

The replica’s propeller is bespoke, created by computer-controlled machinery. Engine to propeller speed is reduced by a ratio of 3:2.

On the original, the outer ailerons were pulled down by the control stick into the airflow: on the replica, there is a closed circuit – each moves in the opposite direction to the other. (The stick also controls the canard; the inner ailerons are not controlled.)

The replica has been the subject of a design analysis to calculate the best angle to set the horizontal tail.

The original’s wing spars were made of spruce: on the replica, they are made of Douglas fir, which is stronger.

Copper nails and ruffs were used on the original’s spar webs: on the replica, they are screwed and glued.

The replica has the benefit of modern dope and fabric sewn in place: in contrast to the use of tacks on the original.

For the airframe, the replica has:-

modern glues, with glue applied where it was not originally used;

certified bracing wires (it is diamond braced, with flying, landing and incidence wires);

certified turnbuckles (1 on each bracing wire), and

load-testing of specimens of bamboo, in comparison to aluminium, used for the outriggers.

The replica’s main float was built with state-of-the-art techniques, creating increased integrity and buoyancy.

Computer modelling has enabled gathering of data and verification of the overall replica aeroplane’s design, leading to some bracing wires being replaced with steel tubes, additional tubes installed and parts manufactured by computer-controlled machine.

Photos of the replica build (Note the aluminium outriggers prior to the change to bamboo) and surviving parts are here.

PATENT APPLICATIONS BY EDWARD WAKEFIELD

On 11 December 1911, through agents Arthur Edwards & Co., Wakefield filed Patents  No. 27,770 and No. 27,771 relating to the means for attachment and a stepped float, which were respectively granted on 12 September 1912 and 18 March 1913. The objects of the inventions were to ‘prevent jar [by way of rubber bungees to provide shock absorption] when rising from and alighting upon the water, and to provide an attachment of such a character that when the hydroplane is upon the water the aeroplane is suspended therefrom’; and 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.

Wakefield also provided inflatable balancers at each wing tip, known locally as ‘Wakefield Sausages‘. – Britain’s Seaplane Pioneers by M H Goodall, Air Pictorial December 1987.

Also, on 13 November 1913, Wakefield obtained Patent No.18,051 for the float of a seaplane to support its own weight or the greater part of such weight during flight.

WAKEFIELD WROTE AN ARTICLE ON THE PRINCIPLES OF FLYING FROM WATER, WHICH WAS PUBLISHED IN THE AEROPLANE MAGAZINE, 10 APRIL 1913

Click here to view the full article.

PATENT APPLICATION BY OSCAR GNOSSPELIUS

In a move away from the flat bottom of initial floats, designers developed the wave-cutting, spray-deflecting, V-shaped stepped float bottom which is used on every float today. On 12 February 1914, Gnosspelius obtained Patent No.10,801 for a V shaped construction.

PATENT APPLICATIONS BY ALLIOTT VERDON ROE

The first control column in the world – ‘stick’, for which Roe obtained Patent No. 26,099 on 14 November 1907. Like the Wright Flyer, which first flew eight years beforehand, and the Roe I Biplane of three years earlier, Waterbird is a biplane with pitch control by way of a forward-mounted, pivoting canard, albeit the Wright Flyer had a bicanard. The single control column differed from the design which had a lever for each hand, and from the control wheel used by Glenn Curtiss. The connection from Waterbird’s control column to the canard is by way of a Farman-type bamboo pole, and to the outer ailerons of the replica by a circuit of wires, pulleys and horns.

The turnbuckle, for which Roe obtained Patent No.17,740 on 30 March 1916. Turnbuckles were initially known as strainers and marketed by Avro through their Aviator’s Storehouse, whose products included bamboo, fabrics, propellers, shock absorbers and wood, and ultimately by the Aircraft Supplies Company Limited as sole selling agents. Supplies of Admiralty, A.G.S. and Binet types of turnbuckles were not equal to demand, and Avro increased output as much as possible such that it made an annual £40,000 profit on turnbuckles alone for a number of years in and subsequent to World War One. The replica Waterbird has an estimated 250 turnbuckles.

The Aeroplane magazine, 28 February 1917.

The Aeroplane magazine, 14 March 1917.