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Felixstowe F.1

Страна: Великобритания

Год: 1916

Fay-Wilkinson - biplane - 1909 - Великобритания<– –>Felixstowe - F.2 - F.5 - 1917 - Великобритания


В.Обухович, А.Никифоров Самолеты Первой Мировой войны


В 1913 г. американская компания "Кертисс" основала в Великобритании дочернюю фирму "Уайт энд Томпсон", которая занималась продвижением летающих лодок на английский рынок. Летчиком-испытателем фирмы стал англичанин Джон Порте, тесно сотрудничавший с Кертиссом в подготовке беспосадочного перелета через Атлантику на его летающей лодке, названной "Америка". Начавшаяся война помешала осуществлению этого проекта. Порте поступил на службу в морскую авиацию и был направлен в Америку для закупки летающих лодок Кертисс Н-4. После возвращения в 1915 г. в Англию он был назначен командиром авиационной базы ВМС Великобритании в Феликстоу. Большой опыт морского летчика позволил Порте взяться за разработку летающей лодки собственной конструкции, названной Феликстоу Е1. Впрочем, новым был лишь однореданный корпус лодки. Крыло и оперение Порте взял от гидросамолета Кертисс Н-4. Феликстоу F.1 был оснащен двумя двигателями Испано-Сюиза.
   Документация на F.1 была передана компании "Кертисс", где проект был усовершенствован и запущен в серийное производство с двигателями Кертисс (160 л. с.) под обозначением Н-8 "Большая Америка".
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J.Bruce British Aeroplanes 1914-1918 (Putnam)


Felixstowe F.1

  JOHN CYRIL PORTE was a Lieutenant in the Royal Navy when, in 1909, he began to experiment with a glider on Portsdown Hill, near Portsmouth. Two years later he was invalided out of the Service with tuberculosis. His disability did nothing to diminish his enthusiasm for flying; rather it seemed to increase it, and by 1912 he was appointed technical director and designer of the British Deperdussin Company. He had learned to fly on a Deperdussin monoplane at Rheims, and his Aviator’s Certificate, dated July 28th, 1911, was No. 548 of the Aero Club de France.
  From then until the Deperdussin company’s flying school at Hendon was forced to close down in August, 1913, Porte became well-known as an excellent pilot. Later that year he became associated with Captain Ernest C. Bass, who, on behalf of White & Thompson, Ltd., acquired the British rights for the products of the Curtiss Aeroplane Company of Hammondsport, New York, U.S.A. In October, 1913, Glenn Curtiss personally delivered one of his latest flying boats to Bass at Brighton: the machine was housed in a canvas hangar which had been erected by Magnus Volk. At Brighton, the Curtiss flying boat was flown by J. D. Cooper, and his passengers included E. C. Gordon England and John Porte.
  Porte was so impressed by the flying boat and its potentialities that he resigned his position as test pilot of the White & Thompson Co., Ltd., in 1914 and went to join Curtiss at Hammondsport. Curtiss had been commissioned by Rodman Wanamaker to design a flying boat capable of flying across the Atlantic, with the intention of competing for the prize of £10,000 which had been offered by the Daily Mail in 1913 for the first trans-Atlantic flight.
  The flying boat was named America and was the precursor of the Curtiss H.4 type which was used by the R.N.A.S. during the war. The original America had a wing span of 72 feet, and was powered by two 90 h.p. Curtiss engines; there was tankage for 300 gallons of petrol and 25 gallons of oil. An enclosed cabin was provided for the crew of two. Porte was to have been one of those two, but just when America was completed the war began in Europe. He returned to England at once and rejoined the Navy: he was at once made a Squadron Commander in the R.N.A.S. At his instigation the Admiralty bought two flying boats of the America type which, when delivered, were given the official serial numbers 950 and 951. These boats were delivered by November, 1914, and were sent to Felixstowe for trials. The results were regarded as promising and a few more Curtiss flying boats were ordered; after further trials an order was placed in March, 1915, for fifty machines of similar design but with more powerful engines. These aircraft were delivered in the second half of 1915 and were officially designated Curtiss H.4.
  In September of that year, Squadron Commander Porte was given the command of the R.N.A.S. Station at Felixstowe. By that time he had flown the America boats operationally and was aware of their shortcomings. He had therefore set about the task of modifying and improving them in an endeavour to produce a truly seaworthy and usable flying boat. In this work he was ably assisted by his Chief Technical Officer, Lieutenant J. D. Rennie.
  The first experiments had been carried out early in 1915, using No. 950, one of the original America boats purchased by the Admiralty. This had a 30-foot hull, which was modified by the addition of wide longitudinal fins which ran from near the bows to the single step, which was under the C.G. The original lifting tail was given negative camber to improve longitudinal stability.
  This hull was not too satisfactory in rough weather, and a second was constructed for the Curtiss flying boat No. 1230. This hull had longer, narrower fins which ran farther aft, for the step was under the rear spar of the lower mainplane; the tail portion of the hull was rounded and had a concave curve on its underside. This caused excessive suction, and take-off with this hull was very difficult. Overall length of No. 1230’s hull was 32 feet 7 1/2 inches, but a different method of construction enabled it to be made 300 lb lighter than that of No. 950. Its lightness was obtained at the expense of strength, however, and it failed after several landings.
  A third hull, 32 feet 4 inches long, was made for the Curtiss H.4 No. 3545. The tail portion was two feet longer than that of No. 1230, and the hull resembled No. 950 in a general way. The forebody was slightly longer and the longitudinal fins were wider, whilst the underside of the tail portion was flat.
  The fourth experimental hull was fitted to the Curtiss H.4 No. 3569, and was 32 feet 2 inches long. It was fundamentally similar to No. 3545, but had a much more pronounced vee bottom. The available power (presumably a nominal 200 h.p.) was insufficient to lift the flying boat off the water, so a step was added five feet aft of the C.G.; the machine then took off at a loaded weight of 4,200 lb. Landing was easy and comfortable, thanks to the vee bottom, but the position of the step so far behind the C.G. demanded considerable physical exertion by the pilot at take-off. To relieve the pilot, the step was moved three feet forward.
  The fifth hull differed from all its predecessors, both in construction and appearance. It was a completely new design and was in every sense the prototype of all the succeeding “F” boats. The machine to which it was fitted was No. 3580. The hull was named Porte I, and subsequently the aircraft was designated F. 1. The basic structure of the hull differed little from that of contemporary landplanes, for it was a cross-braced wooden box girder, to which a vee planing bottom and longitudinal fins had been added. This hull was 36 feet 2 inches from stem to stern, and originally had a single step below the rear spar; the bows were more fully flared than those of earlier hulls. The aircraft was powered by two 150 h.p. Hispano- Suiza engines.
  Tail drag made take-off difficult, so a second step was added 7 feet 6 inches from the stern; and finally a third step was fitted between the first two. This hull proved itself superior in every way to its predecessors: the improved bow design prevented the shipping of water, and take-off and landing performance was excellent. The cockpit was open, whereas all the preceding experimental hulls had had enclosed cabins.
  The F. 1 had the wings and tail unit of a normal Curtiss H.4 flying boat, but the Hispano-Suiza engines were a special installation, for the standard R.N.A.S. machines had two 100 h.p. Anzani radial engines.


SPECIFICATION
  Manufacturers: Seaplane Experimental Station, Felixstowe.
  Power: Two 150 h.p. Hispano-Suiza.
  Dimensions: Span: upper 72 ft, lower 46 ft. Length of hull only: 36 ft 2 in. Chord: 7 ft. Gap: 7 ft 6 in.
  Serial Number: 3580.


G.Duval British Flying-Boats and Amphibians 1909-1952 (Putnam)


Porte/Felixstowe F.1 (1915)

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   Early in 1915, Porte was stationed at Felixstowe, and flew the H.4 operationally, being therefore well qualified to understand its shortcomings. In the spring of 1915, he began a series of experiments, officially approved, with the aim of producing a seaworthy and operationally useful flying-boat. This involved re-designing and fitting of completely new hulls to four H.4s, Nos. 950, 1230, 3545, and 3569, culminating in the modification of H.4 No. 3580 with a new hull incorporating all the structural and hydrodynamic features developed to high efficiency in the preceding experiments. This hull, built at Felixstowe, was named the Porte 1, the complete machine being designated F.1, the first of the line of Felixstowe ‘F’ boats. The wings and tail unit of the F.1 were standard H.4 components, but its chief interest lay in the hull construction, which differed little from the fuselages of most contemporary landplanes. Of strong cross-braced box girder configuration, it was fitted with an external vee-shaped planing bottom and long side fins. Overall, the hull was 36 feet 2 inches in length, with a maximum beam of 8 feet, and unlike its predecessors, possessed open cockpits. Originally the hull had only one step, but performance requirements were not met, so a second and finally a third step were added. The machine was powered by two 150 h.p. Hispano-Suiza engines driving tractor propellers.


SPECIFICATION

   Power Plant:
   F.1 - Two 150 h.p. Hispano-Suiza
   H.4 - Two 90 h.p. Curtiss, or two 100 h.p. Anzani
   Span: F.1 and H.4 - 72 feet
   Length:
   F.1 - 39 feet 2 inches
   H.4 - 35 feet
   Weight Loaded:
   H.4 - 4,983 pounds
   Total Area: F.1 and H.4 - 842 square feet
   Max. Speed:
   F.1 - 85 m.p.h.
   H.4 - 75 m.p.h.
   Endurance: Not available
   Armament: F.1 and H.4 - One or two Lewis guns, light bombs only


C.Owers The Fighting America Flying Boats of WWI Vol.1 (A Centennial Perspective on Great War Airplanes 22)


2. Development of the Felixstowe Flying Boats

   The Felixstowe flying boats were developed at the RNAS Seaplane Experimental Station, Felixstowe by John Cyril Porte from the Curtiss flying boats into the superb F.2A boats that carried the anti-submarine war into the North Sea. Despite their many shortcomings, the Felixstowe boats were practical machines that served successfully in the war and for a goodly time afterwards in the UK and the USA. There arose two schools of thought on the construction of flying boats in the UK, one that supported the Porte method of construction and the other that supported the ideas of Linton Hope. A series of lectures with question and answer sessions given to the Royal Aeronautical Society by exponents of both methods of construction have left a rich vein of historical material, with a deep undercurrent of a desire to discredit John Porte, that has formed the basis for this chapter.
   As noted in Chapter 1, Porte had been invited to the USA to be the pilot of the Curtiss-Wannamaker America flying boat that was to fly the Atlantic in response to the Daily Mail’s offer of a prize for the first crossing by an aircraft. With the outbreak of war, the flight was postponed and Porte returned to England where he volunteered for the RNAS. He was appointed Squadron Commander at Hendon.
   Directly I got back I saw Commander Suter (sic) the head of the Air Department.
   I saw him the next morning after I arrived and I also informed him that there were these two flying boats which we had built in America to fly the Atlantic which were available and could be bought by the Admiralty if they desired to buy them....
   The boats were delivered to Felixstowe and Porte, who was at the time in charge of Hendon, was to test the first one. Commander Seuter came down and after a flight with Porte reported to the First Sea Lord, Winston Churchill, that he considered them excellent and Churchill then ordered that 12 be contracted for at once.
   In order to understand the experiments and development of the Felixstowe F boats, it is first necessary to understand the difference between a landplanes and a flying boat’s requirements. The following has been taken from the lecture given by Major J.D. Rennie, who had been the Chief Technical Officer while Porte was in command of RNAS Station Felixstowe, to the Royal Aeronautical Society and published in their Journal in 1923.
   The usual biplane configuration of a flying boat differs from that of a large aeroplane in that the span of the upper wing is considerably longer than the lower. This is not intended primarily to obtain greater aerodynamic efficiency owing to the absence of biplane interference on the extensions, but to reduce the wing area in proximity to the surface of the water, thus minimising the risk of damage to the lower wing in a rough sea. For the same reason ailerons are not fitted to the lower plane. To allow for adequate lateral control the ailerons should be positioned as far outboard as possible.
   The position of the wing tip floats should be as close to the hull as possible so that less shock is transmitted to the wing structure on takeoff, landing and rolling, one wing down. The result of these considerations is the wing arrangement described above.
   “It is said of the “F” boats that the use of stabilisers (antiskid fins) on the top plane is a very inefficient aid to lateral stability. They were never really intended as such,” the top plane extensions requiring bracing to withstand downloads that are applied at high speed flight or inertial load during a bad landing. The rectangular cross-braced kingposts were considered to be better than the triangular type, and by fairing it in, it also acted as a stabiliser.
   “In the F boats, which had twin tractor airscrews, about three-quarters of the tailplane was in the slipstream and seemed fairly satisfactory, but on trial the boat was decidedly tail heavy, as were all of the F boats. This was partly due to the fact that when carrying full military load the CG was further back than was originally intended. With pusher propellers the conditions are simpler but they are very liable for damage from parts that may work loose, or even tools that have been left through carelessness.
   “With regard to fin and rudders, these are of relatively large area due to the long forebody of the flying boat. The rudder area of the F boats was barely sufficient for control with one engine out.
   “As with the aeroplane, controllability at low speeds is of importance, but probably less so as generally the extent of a landing ground is not so restricted. Also once alighted the boat pulls up quickly due to the large hull resistance. Thus it is possible to glide at a comparatively high speed until close to the water before flattening out and alighting.”
   The modifications carried out on and the new type hulls evolved at Felixstowe were arrived at from full size experimentation as model hull testing was not available at the time with the exception of the Fury triplane. From 1915 experiments with full sized machines were carried out to correlate the results of tank tests at the National Physical Laboratory’s William Froude tank. These were not successful due to the problems of collecting data. Visits were made to seaplane stations for the purpose of studying the behaviour of the machines in disturbed water when getting off and alighting. The following visits took place:
   July 1916 at Felixstowe when the “America” flying boat and Short seaplanes were flown. The machine was described as the 4,000 lb America type with propellers rotating in the same direction.
   Reputed getting of speed 38 knots, speed in flight 48 knots. The machine rose and settled three times. The pilot held the tail down on the water and bow up until 30 knots was reached then decreased the angle so that the tail came off, after which the flying speed was quickly reached. To lift the tail earlier than 30 knots would mean throwing up a lot of water at the fore end and it could not be lifted earlier than 18 knots. The machine took a little time to reach the speed of 30 knots, but when the tail was lifted accelerated rapidly. This agrees with tank results which show that the drag of the tail adds very largely to the resistance. The landing was gentle on each occasion, once on the tail tip and twice on the step. The machine was run up once, for a few seconds, at a speed slightly over 30 knots tail out, without control. The air balance was fairly good and the machine moved but very slowly from its longitudinal trim.
   September 1916 at Calshot where the F.B.A. flying boat was flown.
   August 1916 to Southampton to view the A.D. flying boat.
   October 1916 at Felixstowe saw some data obtained on a Porte boat.
   A “Porte” boat with chine running continuous from stem to stem, front step a little abaft the centre of gravity and two other steps at the rear and under the chine. On practically smooth water and with no wind, both with the elevator full up and down, failed to unstick the tail. With no observer, less petrol, and a little wind, this machine got off, but it was too far away for its behaviour to be noted.
   “The great drawback in all these cases was the absence of any reliable scientific data and the contradictory character of the opinions expressed by those concerned in the running of the machines. It was in no case possible to get reliable speeds or inclinations of the machine. The visits served, however, to show the general character of “porpoising” and to some extent the means adopted by pilots in evading this phenomenon.” It was hoped that by using models in the Tank it would be possible to save a certain amount of experimental work at the stations with greater ease and considerable savings. Until the results of tank testing and full sized boats could be established the only way to determine the best type of hull was by full scale experimentation and this was how Porte approached the problem.
   At rest the total weight of a flying boat is supported by hull buoyancy, and lateral stability by means of the wing tip floats. Owing to the high centre of thrust and low water and air resistance up to speeds of say 10 knots, the throttle is opened slowly, and elevators held up to prevent trimming by the bow. As speed increases, elevators are put into neutral when the hull should trim back of its own accord. From this speed the load that is supported by the buoyancy is gradually transferred to the hydrodynamic water forces acting on the planing surface, the fore body rising first, followed by the tail, which may be assisted by putting the elevators down slightly until the boat is planning cleanly. Water resistance will increase steadily, however if the hull is designed correctly, it will continue to drop owing to the improved working to the step and to the increasing percentage of the load taken by the wings. The speed at which the water resistance reaches a maximum is generally known as the “hump” speed. Generally a boat that gets over the hump has power for flight. From this speed or generally a little above, a sharp pull up on the elevators will make a clean break away from the water, the boat becoming entirely airborne. The elevators are then depressed before trimming to gain height.
   The hull should be designed so that it is able to be trimmed back to such an attitude that the angle of incidence of the wings is that corresponding to the lowest safe speed, usually a few knots above stalling speed, without excessive elevator movements and increase in hull resistance. Serious accidents due to taking off in a stalled condition are rare as flying boats are generally well above the lowest flying speed providing sea conditions are suitable.
   Up to about the “hump” speed lateral stability is obtained by use of the wing tip floats and such aileron control as is available. After the “hump” speed the boat trims naturally onto an even keel due to the stable hydrodynamic forced acting on the planning surface. As speed increases the aileron control becomes more effective.
   Thus a flying boat hull must
   (a) Avoid diving at low speeds.
   (b) Have seaworthiness.
   (c) Have hydroplaning efficiency and landing with minimum shock.
   (d) Have stability at high speeds on the water.
   (e) Have the ability to trim fore and aft to enable take offs and alightings.
   As noted in Chapter 1 the Admiralty bought the two Curtiss America flying boats that had been built for the proposed pre-war trans-Atlantic flight. These boats were delivered to Felixstowe in October 1914 where they underwent trials. The boats proved promising and, as previously recorded, Churchill, First Sea Lord, ordered a dozen as the Curtiss H.4 with more powerful engines.
   Porte has recorded that he wanted to build the boats in the UK and so an order for eight (1228-1235) was given to the Aircraft Manufacturing Company. These were designated as H-4 America flying boats. Four were ordered at the same time from the Curtiss Aeroplane & Motor Co Inc (1236-1239). As noted further on it appears that Curtiss provided the AMC with details of the design. The four Curtiss boats arrived long before the ones to be made in England were completed. These latter boats were built under Porte’s supervision at Hendon. The hulls were built by Saunders at Cowes. Later orders followed with 50 H-4 boats being supplied by Curtiss under Contract No. C.P.01533/15.
   Porte had flown the H.4 and knew of their limitations and began the task of modifying the boats to get one that would be usable in the North Sea. “At the end of January 1915 I was appointed to take charge of Felixstowe Air Station and in May of that Year I left Hendon altogether and took over Felixstowe completely and have remained there practically continuously” since then. When he went to Felixstowe there were then only “50 men and three small sheds; there are now 1,000 men and an enormous number of sheds... I have built the whole thing up”

Felixstowe’s Experiments

   When the first of the Curtiss flying boats arrived in the UK, “Commander Porte was specifically instructed by the Director of the Air Department Admiralty to experiment with and improve the said boats.”
   “When the first experiments were taken in hand no engines of high power were available. Consequently, seaplane designers were faced with the problem of “Getting off’ as the chief difficulty. For this reason the early experiments were made with the main object of developing hydroplaning efficiency and the question of simplicity of structure and shockless landing were neglected.”
   The first hull tested was a modified Curtiss America flying boat serial 950, one of the original America boats purchased by the Admiralty. This hull weighed light 3,100 lbs and, on certain occasions, 4,500 lbs was taken off the water. The original hull was 30 feet long, and was modified by the addition of a wide longitudinal projecting fin forward, ending at the single step that was under the CG of the machine. The fore and aft angle between the underside of the tail and planning surface of the ship was 10°. The available engines gave about 160-hp.
   At high speeds all single step hulls balance on the step and trim depends on the angle of the tail portion, which in order to avoid water drag, should be kept up while accelerating the boat. The original tail plane was lifting and hence excellent from this point of view, and as much load as could be flown with could be taken off the water. In order to improve stability in flight the tailplane was made negative. In smooth water there did not seem to be any appreciable loss in hydroplaning efficiency, but in rough weather, owing to the lack of buoyancy forward, this hull was very wet. The nose of the hull tended to dig in and water was thrown up over the engines to such an extent as to cause the engines to misfire, thus indirectly making it difficult to get off.
   A new hull was built for the Aircraft Manufacturing Company by S.E. Saunders Ltd in which the fins were narrower and carried further aft as the step was under the rear spar. The straight lines of the previous form were replaced by curves, the planning bottom being slightly hollow. The underside of the tail was rounded and construction was lighter. This machine was given the serial 1230. This hull proved inferior to that of 950, largely due to the rounded tail section that was not only a less efficient hydroplaning surface but increased suction making it very difficult to lift out of the water in calm weather. This hull was 32 ft in in length. While there was a savings of 300 lbs in weight over previous hulls due to its different construction, it was considerably weaker and “did not outlast many landings.” The Saunders hulls were covered in the patented Consuta stranded copper wire sewn plywood and heavily varnished.
   The next hull was made for Curtiss H.4 serial 3545 and was similar to 950 but the tail portion was 2 feet longer, and the fins were wider. The fore and aft angle was reduced from 10° to 7°. “Consequently the machine had to be held at a finer angle of incidence when planning to avoid drag due to (the) submersion of the tail, which caused the getting off speed to be higher.” In smooth water the hull gave a better planning efficiency than the original hull. While the total weight of 4,500 lbs was taken off the water by this hull, the same load as for the original hull, this hull was 300 lbs heavier than the original one.
   “The main conclusion arrived at from these experiments were that, from the point of view of planning efficiency and low getting off speed, a large fore and aft angle was essential and a flat bottomed tail portion was advantageous. But it was also evident that much remained to be done in the direction of lighter construction and of general seaworthiness.” From the experiments with these hulls it was learnt that from the point of view of the ability to hydroplane and low take off speed, the tail portion should be flat bottomed to reduce suction, and the fore and aft angle should be large to obtain the necessary trim.
   Next it was decided to tackle the problem of easy landing conditions, and increased strength of the hull without sacrificing planning efficiency. “This series ended with the production of ‘Porte I’, which machine showed marked improvement in these particulars.”
   In the early days all landing breakages of flying boat hulls occurred at the step, a structural weak point, indeed a Small America had broken in half at the step. The need to reconsider the best form of hull was evident. The next experiment was to find if a step was necessary at all. A complete new steeper V bottom was built on 3545 having no step but with a steeper fore and aft angle of nearly 20° and with the tail very much swept up with the keel line following a smooth curve. The fins that extended for % of the length were extended back to meet the hull instead of ending off square under the wings as before. The result was to decrease head resistance by making the whole hull more streamline and also to make a stronger hull. This machine was given the serial 3569 and was known as the Transitional boat, as it was the link between the America boats, all those boats that had their fins cut off short at the step, and the Felixstowe group with their long fins and steep V bottom. This hull was 32 ft 2 in long. With the available engines (presumably of nominal 200-hp) there was not enough power to take off. A step was added 5 feet behind the CG and the hull was then capable of getting off but with only 4,200 lbs total load as against 4,500 lbs with the earlier hulls. Although “Getting Off” was not as good as the America boats, landing was exceptionally easy owing to the large fore and aft angle. The deeper V resulted in little or no landing shock with a normal or nearly stalled landing. “This latter method of landing is a very severe test because, immediately the tail portion touches the water, the heavy water drag pulls the machine down very suddenly.” Owing to the step being so far aft of the CG, the hull ran at a small angle and required a large moment to trim the machine back for takeoff. To relieve the pilot of this load the step was shifted 3 feet forward.
   The next experiment was the building of “Porte I” an entirely new single step hull built at Felixstowe to carry the same Curtiss superstructure as before. The bows were kept fuller and given a flare or concave entry. Porte used an entirely different form of construction for the next hull with longerons and spacers with wire bracing as used in the construction of landplanes, rather than the boat builder methods used for the Curtiss hulls. The America hulls depended on their tubular shape and stiffness of their skins for strength. They had reinforcement from the keel and, in the larger boats, from bulkheads, and some centre line wiring in the tail, but the rounded form and continuous planking was essential to the structure. Porte’s method gave the requisite strength for a low weight. Originally a single step, located below the rear spar, was fitted. The hull was 36 feet overall in length, three feet longer in the nose and two feet in the tail than the third type of hull.12 The fore and aft angle was 18° and the tailplane was raised 7 inches more than that of the fourth hull, and the line of the keel was kept higher. Fins were carried well at of the step and swept back into the hull. The V-bottom was similar to 3569 and the bows were fuller with a distinct flair on the first three feet.
   With this hull the tail portion was liable to catch the water and drag held the speed down to below take off speed. To overcome this, a second step was added 7 1/2 feet from the stern. This modification meant that it was now possible to takeoff but with less load than the earlier hulls. A third step was added intermediate between the main and aft steps. This allowed the load to be brought back to very nearly that of the earlier hulls. This hull was far superior to any hull previously tested at Felixstowe. Owing to the improved form of bow, the cockpits were perfectly dry. Landing shocks were reduced to a minimum, and behaviour generally in alighting and getting off was excellent. Seaworthiness was far superior to the preceding hulls. This hull was named Porte I and the aircraft was subsequently designated the F.1.
   3580 had a long and varied career and at the Felixstowe Seaplane School by December 1917, and was flown for many hours by students who did their worse to her. When dismantled for overhaul no serious defects were found other than corrosion of various metal fittings. It survived until January 1919.
   In 1918 she was re-engined with two 150-hp Hispano-Suiza engines and subject to further testing. With no step she just staggered into the air in a stalled condition showing that such a thing was possible with a low enough loading. With a single step she was not as efficient as with two steps, thus seeming to confirm the results of the Transitional Boat.
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C.Owers The Fighting America Flying Boats of WWI Vol.2 (A Centennial Perspective on Great War Airplanes 23)


6. The America Flying Boats in Detail

Felixstowe F.1

   The Felixstowe F.1 was the name given to John Porte’s experimental flying boat that had an experimental Porte designed hull and H-4 aerostructure. The hull was built on aircraft lines with cross braced girder of simple longerons and spacers to which was attached the bottom of the hull. Power was provided by two 150-hp Hispano-Suiza engines.
   Unfortunately on test the following result occurred. “On practically smooth water and with no wind, both with the elevator full up and down, the flying boat failed to unstick the tail.”

Specifications
   Length hull 36 ft 2 in. Wing Span: Upper 72 ft. Lower 46 ft. Chord 7 ft; Gap 7 ft 6 in. Engines: Two 150-hp Hispano-Suiza.

J.Bruce - British Aeroplanes 1914-1918 /Putnam/
The “Incidence Boat”, No. 3546.
C.Owers - The Fighting America Flying Boats of WWI Vol.1 /Centennial Perspective/ (22)
The "Incidence Boat", H-4 3546 with experimental hull. It is fitted with rotary engines in this photograph. Initially fitted with two 100-hp Clerget engines, it was re-engined with 100-hp Gnome Monosoupape engines. It was finally given two Anzani radials. It served from July 1915 to April 1917. Its part in the Felixstowe story is still unknown.
C.Owers - The Fighting America Flying Boats of WWI Vol.1 /Centennial Perspective/ (22)
The "Incidence Boat" 3546. What input, if any, Porte had into this hull is unknown.
J.Bruce - British Aeroplanes 1914-1918 /Putnam/
One of Squadron Commander Porte’s experimental hulls: the aircraft had the wings of a Curtiss H.4 and two Clerget engines; it was known as “The Incidence Boat”.
C.Owers - The Fighting America Flying Boats of WWI Vol.1 /Centennial Perspective/ (22)
The hull of 8651, the first Curtiss H-12 to arrive at Felixstowe. The hull bottom is concave and the canopy is different to later H-12 boats. Note the "Incidence Boat" in the background.
C.Owers - The Fighting America Flying Boats of WWI Vol.1 /Centennial Perspective/ (22)
3569 was fitted with a steep V-bottom with fins that carried on almost to the tail without a step. It proved incapable of getting off the water and a step was added as shown on Plan No.5. This enabled the machine to takeoff and exceptionally smooth landings were accomplished due to the deep V-bottom. It was recorded as being tested by Porte and Flt Lt R.J.J. Hope-Vere on 30 May 1916. It lasted until being deleted on 25 April 1917.
C.Owers - The Fighting America Flying Boats of WWI Vol.1 /Centennial Perspective/ (22)
Porte hull on 3569. Note what appears to be a camera window on the port side bottom of the hull.
C.Owers - The Fighting America Flying Boats of WWI Vol.1 /Centennial Perspective/ (22)
3569 was fitted with a steep V-bottom with fins that carried on almost to the tail without a step. It proved incapable of getting off the water and a step was added as shown on Plan No.5. This enabled the machine to takeoff and exceptionally smooth landings were accomplished due to the deep V-bottom. It was recorded as being tested by Porte and Flt Lt R.J.J. Hope-Vere on 30 May 1916. It lasted until being deleted on 25 April 1917.
C.Owers - The Fighting America Flying Boats of WWI Vol.1 /Centennial Perspective/ (22)
Curtiss H-4 3570 still has its Curtiss engines installed. This experimental hull had a relative deep afterbody and reduced fin area. Compare with that of 3579. Note the curved shape to the cockpit that has windows in the roof. Compare with 3570. These photographs were included in the section on 3545 in Sueter's report. Unfortunately no photographs of 3545 have been located to date.
C.Owers - The Fighting America Flying Boats of WWI Vol.1 /Centennial Perspective/ (22)
Curtiss H-4 3570 still has its Curtiss engines installed. This experimental hull had a relative deep afterbody and reduced fin area. Compare with that of 3579. Note the curved shape to the cockpit that has windows in the roof. Compare with 3570. These photographs were included in the section on 3545 in Sueter's report. Unfortunately no photographs of 3545 have been located to date.
C.Owers - The Fighting America Flying Boats of WWI Vol.1 /Centennial Perspective/ (22)
Probably 3579 with a standard hull showing the Curtiss shallow V-form with a slight concave planning bottom.
C.Owers - The Fighting America Flying Boats of WWI Vol.1 /Centennial Perspective/ (22)
Curtiss H-4 3579 with Porte type hull. Compare the flat appearance of the cockpit with that of 3570. Note the torpedoes lying in the background.
C.Owers - The Fighting America Flying Boats of WWI Vol.1 /Centennial Perspective/ (22)
Aircraft Manufacturing Co (AMC) version of the H-4 1231 was fitted with an experimental hull built by Saunders to Porte's design. The rounded aft section would be similar to that of 1230. Suction prevented the boat's ability to take off and was blamed on the shape of the hull.
Another experimental hull, built by Saunders, and flown at Felixstowe. Aircraft No. 1231, with flight organs of Curtiss H.4, and two Anzani radial engines of 100 h.p. each. fifty machines of similar design but with more powerful engines. These aircraft were delivered in the second half of 1915 and were officially designated Curtiss H.4.
C.Owers - The Fighting America Flying Boats of WWI Vol.1 /Centennial Perspective/ (22)
Saunder's built hull on 1231. The actual input that Porte had into the design of the AMC batch's hulls is unknown, however it must have been considerable given the different hull shapes tried out. They were built under his supervision.
C.Owers - The Fighting America Flying Boats of WWI Vol.1 /Centennial Perspective/ (22)
Porte Baby prototype 9800 outside the camouflaged hangars at Felixstowe with another boat with an experimental hull in the background. Note the small cockade on the underside of the Baby's upper wing.
C.Owers - The Fighting America Flying Boats of WWI Vol.1 /Centennial Perspective/ (22)
Rearview of the Porte I showing the V-bottom and how the tail of the fuselage like rear hull rose quickly above the water line.
C.Owers - The Fighting America Flying Boats of WWI Vol.2 /Centennial Perspective/ (23)
3580 had a new hull built to Porte's method of construction. Initially it has two Anzani radial engines but is shown with two 150-hp Hispano-Suiza engines.This machine became the Porte I, later renamed Felixstowe F.1. It was at the Felixstowe Seaplane School by 29 December 1917, not being written off until early 1919. Note the pitot tube extending from the bow.
C.Owers - The Fighting America Flying Boats of WWI Vol.1 /Centennial Perspective/ (22)
The Porte I hull. When combined with the flight surfaces of 3580 and with two 150-hp Hispano Suiza engines providing power, became the Felixstowe F.1. Note the straight V-form of the hull bottom.
C.Owers - The Fighting America Flying Boats of WWI Vol.1 /Centennial Perspective/ (22)
C.Owers - The Fighting America Flying Boats of WWI Vol.2 /Centennial Perspective/ (23)
With an original caption stating this is also the F.1, this Felixstowe boat has a revised rudder and forward gun ring.
C.Owers - The Fighting America Flying Boats of WWI Vol.1 /Centennial Perspective/ (22)
Experimental Flying Boat No.950
C.Owers - The Fighting America Flying Boats of WWI Vol.1 /Centennial Perspective/ (22)
Experimental Flying Boat No.1230
C.Owers - The Fighting America Flying Boats of WWI Vol.1 /Centennial Perspective/ (22)
Experimental Flying Boat No.3545
C.Owers - The Fighting America Flying Boats of WWI Vol.1 /Centennial Perspective/ (22)
Experimental Flying Boat No.3569
C.Owers - The Fighting America Flying Boats of WWI Vol.1 /Centennial Perspective/ (22)
Experimental Flying Boat Hull (Porte I)
G.Duval - British Flying-Boats and Amphibians 1909-1952 /Putnam/
Felixstowe F.1
C.Owers - The Fighting America Flying Boats of WWI Vol.1 /Centennial Perspective/ (22)
Felixstowe F.1 / Porte I
C.Owers - The Fighting America Flying Boats of WWI Vol.1 /Centennial Perspective/ (22)
Felixstowe F.1 / Porte I
C.Owers - The Fighting America Flying Boats of WWI Vol.1 /Centennial Perspective/ (22)
Felixstowe F.1 / Porte I