After Campbell's achievement of the 300 mph
land speed record with
Blue Bird in 1935 he retired from advancing the land speed record. Shortly afterwards he switched his attentions to the
water speed record, at that time dominated by the American
Gar Wood.
Blue Bird K3 was designed by
Fred Cooper and built by
Fred Goatley of
Saunders-Roe. The design was intended to be the smallest possible hull capable of carrying the
Rolls-Royce R racing engine. Campbell had already used this engine in his
Blue Bird car, and they had also been used in pairs in
Segrave and
Kaye Don's
Miss England boats. Of the three individual R engines used by
K3, one had previously run in
Blue Bird and one in
Miss England II. The most compact layout placed the engine behind the driver and relied on a front-mounted
v-drive gearbox to reverse the direction of the drive shaft and increase the shaft revolutions 1:3 to 9,000 rpm. This gearbox, along with much of the mechanical design, was designed by
Reid Railton who had previously designed cars for Campbell. Unlike Gar Wood's multi-engined monsters,
Blue Bird was designed for a single engine, and the smallest possible craft to carry it. She was long with a beam of , compared to 38 feet for
Miss America X. Her estimated top speed on paper was to be 130 mph. It was usual at this time for English hydroplanes to have their engines mounted as far astern as possible (Gar Wood disagreed, and had pointed this out to Segrave). In Cooper's usual style, the hull was wide and low, with a narrow, rounded, central superstructure. The engine was placed right back to the transom and the superstructure was extended rearwards in a fabric-covered overhanging conical nacelle. This rearward weight distribution encouraged planing, but could lead to some peculiar attitudes when setting off at slow speeds, as the whole boat appeared to be sinking by the stern. The displacement was only and the engine alone weighed . Construction was of
plywood, although the attention paid to weight-saving was such that this was laminated to order from varying numbers of
veneers, rather than sawn from factory-made standard sheets. The frames are formed of single-piece unjointed sheets of 7-ply, the hull skins of 5-ply and the deck of 6-ply. Even the engine bearers were made of a central plywood
box girder. Reserve buoyancy in the event of an accident was provided by 36,000
ping pong balls, sewn into pillow cases. == Records ==