P.Bowers Curtiss Aircraft 1907-1947 (Putnam)
Model T (Wanamaker Triplane, Model 3)
At the time of its construction in 1915-16, the Curtiss Model T flyingboat, which was instigated by Rodman Wanamaker of America fame, was the largest seaplane in the world. It was also the first four-engined aeroplane built in the United States. An unusual feature was the arrangement of the engines-four 250 hp Curtiss V-4 tractors in a straight line, a feature used successfully up to that time only by the Russian Sikorskys and the single German Siemens-Forsman. Because of marginal directional control under one-engine-out conditions, designers usually grouped engines as close to the aeroplane centreline as possible to minimize the turning couple of an unsymmetrical power condition. A favourite procedure was to pair two side engines in tandem installations in a single nacelle, which Curtiss did on the C-2 in 1919.
The America-type control cabin was equipped for two pilots and an engineer. The control forces were so great that an early form of power boost was provided. Small windmills installed on the wings were connected to the aileron cables by electrically-operated clutches. The power of the windmill was imparted to the cable to aid the pilot. Similar devices were used for the tail controls.
The T was designed to requirements of the British Admiralty, which ordered 20 examples, RNAS serial numbers 3073/3092. While the first T was assembled inside the Buffalo plant, it was not flown in the US because the V-4 engine was not developed in time. The aeroplane was shipped to Britain without engines and 240 hp French Renaults were installed there.
The big triplane was not put into service and the remaining 19 on order were cancelled. The basic design concept was retained, however; the Curtiss Model T was the direct predecessor of the five-engined Felixstowe Fury triplane that Cmdr Porte designed for the Admiralty.
Model T Triplane
Patrol Bomber flying-boat. Crew included two pilots, one engineer, and gunners. Four 240 hp Renault.
Span 134 ft (40,84 m) (top). 100 ft (30,48 m) (centre). 78 ft 3 in (23,85 m)(lower); length 58 ft 10 in (17,93 m); height 31 ft 4 in (9,55 m); wing area 2,812 sq ft (261,23 sq m).
Empty weight 15,645 lb (7,096 kg); gross weight 22,000 lb (9,979 kg).
Maximum speed 100 mph (160,93 km/h); climb to 4,000 ft (1,219 m) 10 min; endurance 7 hr.
O.Thetford British Naval Aircraft since 1912 (Putnam)
Twenty of these enormous triplane flying-boats were ordered from the USA for the equipment of the RNAS in 1915. They were intended to carry a crew of six and to be heavily armed for anti-Zeppelin patrols over the North Sea. They were allotted the serial numbers 3073 to 3092, but in the event only one (No.3073) reached the RNAS in 1916. Power was provided by four 250 hp Rolls-Royce Mk.I engines. Loaded weight, 22,000 lb. Maximum speed, 100 mph. Span, 134 ft. Length, 58 ft 10 in.
Flight, January 13, 1916.
A FIGHTING FLYING BOAT.
NOT only is there a great deal of time and thought being given to the production of large fighting aeroplanes in this country, but in America the problem is being strongly attacked. Thus the Curtiss Company are building a huge triplane flying boat of which the following particulars have been given by the Scientific American:-
"This machine, which can properly be called the first battleship aeroplane, is a direct development of the 'America,' a twin-engine flying boat which was to cross the Atlantic in the summer of 1914, when the outbreak of the war stopped the attempt.
"The Curtiss 'battleship-aeroplane' is a triple-screw triplane flying boat, which will weigh, fully equipped, 21,450 lbs.
"The hull is of cedar planking, sheathed with copper on the under side, and riveted to stout ash ribs: it is 68 ft. long, and has a beam of 20 ft. The hydro-planing surface of the hull is furnished with a V-shaped bottom, which ends in a straight stem forward, while its rear, cut off sharply, gives the 'step,' on which the boat must ride in order to get off the sea. From the step on the hull it has straight side lines, and tapers gently towards the stern, to end with a water-rudder.
"The hull is divided into twelve water-tight compartments, one-third of which are supposed to keep the machine floating, should the hull be pierced and several compartments be flooded.
"The inner arrangement of the boat consists (1) of a conning tower containing the controls and the navigating instruments, and (2) of a cabin, fitted as quarters for a crew of eight, and containing the fuel tanks, ammunition and stores.
"The boat is steered from the conning tower; when riding a rough sea the latter can be hermetically closed against the spray. The fuel tanks contain 700 gallons of gasoline and 80 gallons of oil; this will give the machine (at a speed of 75 miles per hour) a cruising radius of 675 miles. This could be considerably increased by fitting additional tanks, in which case the military load (guns, bombs, &c), would have to be decreased. The superstructure of this battleship aeroplane consists of (1) the supporting planes, (2) the propelling apparatus, and (3) the steering organs.
"There are three superposed supporting planes, each having a span of 133 feet and a chord of 10 feet, with a gap of 10 feet between each plane; the total area of support amounting to about 4,000 square feet. The weight of the hull and of the supporting planes amounts to about 12,000 lbs. As customary on marine aeroplanes, the tip of each lower wing is fitted with a pontoon, which prevents the wing from digging into the water when running on the surface or when at anchor.
"Just like the 'America,' which revolutionised aircraft construction with her twin engines, the latest product of the Curtiss yards marks again a new departure in the arrangement of the propelling apparatus. The latter consists of six 160 h.p. water-cooled V-type engines, which are coupled in twin units of 320 h.p., each unit driving an air-screw about 15 feet long. But while one of these twin units is placed amidship and drives a central pusher screw, the two other units are mounted on the leading edge of the centre plane on either side and above the cabin, and each drives a tractor air-screw.
"An auxiliary engine of 40 h.p. enables the pilot to start these engines from the conning tower by means of an electric starter. This engine is also used for generating the current required by the automatic stabiliser, the drift indicator and the minor apparatus. Finally, for water navigation, the auxiliary engine also drives a water propeller.
"Aside from the truly gigantic dimensions of this machine, the disposition of her power plant marks a notable advance in aircraft construction.
"If in an ordinary aeroplane the engine fails, the airman has to glide down to earth in order to effect repairs. In the twin-screw flying boats of the 'America' class this contingency arises just as well, but as long as one engine is kept running, skillful steering will keep the machine on a much longer glide-path, whereby there is much less risk for the pilot to fall into the hands of the enemy.
"But in the new triple-screw flying boat, engine trouble can be dismissed almost entirely as far as the machine's safety is concerned. In fact, each of the three air-screws being actuated by twin engines, the failure of one or two of the engines will only result in reducing the flying speed; and, owing to the great inertia of the machine, a mechanic can easily climb on a ladder to the defaulting engine and promptly repair it without impairing the lateral stability. And, taking it at its worst, should both of the twin engines, which drive the tractor-screws, break down, the engine unit actuating the pusher-screw (320 h.p.) would still give the boat a very wide gliding ratio, about 15 in 1, in the course of which there still would be time to repair the defaulting engines or else to choose the best possible landing place.
"This feature of the new flying boat makes her particularly desirable for military and naval work, where long range reconnaissances are always fraught with danger on account of the relative unreliability of flight engines.
"The steering organs placed at the boat's stern consist of a balanced rudder of 54 sq. ft. area, with a keel-fin of 46 sq. ft. area. Longitudinal stability is effected by a non-lifting tail, consisting of a tail-fin of 126 sq. ft. area and of an elevator of 96 sq. ft. area. For transverse stability interconnected ailerons are hinged to the supporting planes.
"Little is known so far as to the armament this flying boat will carry. Whereas the pure military load (outside of crew, instruments and fuel) amounts to about 3,000 lbs., it can be safely assumed that at least two 1 1/2-lb aircraft guns, of the type used on the 'America' class, will be mounted on the forecastle, in addition to which there should be a small battery of machine guns for repelling speed scouts. It is possible, however, that the main armament will comprise a much heavier arm, such as a 3- or even a 6-pound gun, and that there will be a trapdoor in the hull through which the said gun could be fired in all directions, owing to a turret mounting.
"The craft will carry a very complete equipment, such as pneumatic life preservers and cushions, fire extinguishers, anchors, ropes, and possibly a collapsible mast for signalling.
"Altogether, there is no exaggeration in saying that the Curtiss triple-screw flying boat opens a new epoch in aircraft construction; and while far from being an aerial battleship such as may be seen in the future, she certainly represents the embryo of such an idea. In the present war she should prove immensely valuable; for in view of her superior armament, cruising radius and sufficient speed, there does not seem to be anything aloft that could meet her on even terms."