The Fremantle was designed to
Air Ministry specification 44/22 calling for a single long-range
reconnaissance aircraft. One of several contracts aimed at keeping British design teams together in difficult economic times, it was hoped to produce an aircraft that might achieve the first around-the-world flight. It was a large (almost 70 ft/21 m span) two-bay
unstaggered biplane. The
fuselage was rectangular and deep, with a two-windowed section for the cabin, built of
mahogany planking over a wooden frame in small-boat fashion to avoid the need for internal bracing. The fuselage was deep enough to allow the crew to stand in the cabin, which contained provisions, storage, bunks and navigator's table. The navigator also had a position for
celestial observation at the rear of the cabin. The pilot's open cockpit was at the trailing edge of the wing, in front of the cabin. In front of the pilot was the engine firewall and the metal-covered engine bay housing a 650 hp (490 kW)
Rolls-Royce Condor III water-cooled motor. This drove a fixed-pitch wooden
propeller via a spur
reduction gear which conveniently raised the propeller shaft high on the nose. This arrangement had at least two advantages: for a given propeller diameter, the height of the fuselage above the water was reduced, shortening the length and weight of the float struts; the underside of the nose could be swept up to the base of the
radiator for better aerodynamics. The two mahogany-planked floats were short, so that at rest the Fremantle sat on the water like a
tailwheel-type landplane with the assistance of a tail float fixed to the fuselage underside. The
tailplane was mounted at the top of the fuselage with bracing underneath and the
rudder hinge post carried a water-rudder for directional control at low speeds on the surface. Since the main floats were not widely spaced, there were two more floats attached to the underside of the lower wing immediately below the outer pairs of
interplane struts to provide lateral stability. Fuel was stored in tanks in the floats but there was another large and very conspicuous tank mounted centrally above the upper wing. This gravity-fed the engine and was replenished by pumping (hand- or wind-powered) fuel from the float tanks. ==Operational history==