Curtiss Wanamaker Triplane

The Curtiss Model T, or Curtiss Wanamaker Triplane, and retro-actively Curtiss Model 3, was a large experimental four-engined triplane patrol flying boat of the First World War. When built, it was the first four-engined aircraft built in the United States, but only a single example was built, orders for a further 19 from the British Royal Naval Air Service (RNAS) being cancelled.

Design and development
In 1915, the American businessman Rodman Wanamaker, who, prior to the outbreak of the First World War, had commissioned the Curtiss Aeroplane and Motor Company to build a large flying boat, the Curtiss America to win the £10,000 prize put forward by the British newspaper, the Daily Mail for the first aircraft to cross the Atlantic, commissioned Curtiss to build a new, larger flying boat, which became known as the Wanamaker Triplane, or Curtiss Model T in Curtiss's then-current designation scheme (It was later retroactively re-designated Model 3 when Curtiss changed its designation system).

Early press reports showed a large triplane, 68 ft (17.9 metre) and with equal-span six-bay wings of 133 foot (40.5 metre) span. The aircraft, to be capable of carrying heavy armament, was estimated all-up weight of 21,450 pounds (9,750 kilogrammes) and was to be powered by six 140 hp 104 kW) engines driving three propellers, two of which were to be of tractor configuration and the third a pusher.

The British Royal Naval Air Service (RNAS) placed an order for 20 of the new triplanes with the first one being completed at Curtiss's factory at Buffalo, New York in 1916, the first four-engined aircraft to be built in the United States and one of the largest aircraft in the world. While of similar size and weight to the aircraft discussed in the press, the Model T had unequal span wings, with the upper wing having a span of 134 feet, while it was planned to be powered by four tractor 250 hp (187 kW) Curtiss V-4 engines installed, unusually for the time, individually on the middle wing. The two pilots and flight engineer were provided with an enclosed cabin, similar to that in the Curtiss America, while to reduce control loads, small windmills could be connected to the aileron cables by electrically operated clutches to act a form of power assisted controls.

The planned Curtiss V-4 engines were not available when the prototype was completed, so it was not flown in the United States, but was taken to England by ship and re-assembled at the Seaplane Experimental Station at Felixstowe, being fitted with four French 240 hp (180 kW) Renault engines. Although later re-fitted with four 250 hp Rolls-Royce Eagles, it was unsuccessful, with the order for the remaining twenty being cancelled. It did, however, provide the inspiration for John Porte of the Seaplane Experimental Station to build a massive five-engined flying boat of similar layout, the Felixstowe Fury.