Water Speed Record - Boat Design Changes

Boat Design Changes

Wood's last record would be one of the final records for a conventional, single-keel boat. In June 1937 Malcolm Campbell, the world-famous land speed record breaker, drove Blue Bird K3 to a new record of 203.31 km/h (126.33 mph) at Lake Maggiore. Compared to the massive Miss America X, K3 was a much more compact craft. It was 5 metres shorter and had one engine to X's four. Despite his success, Campbell was unsatisfied by the relatively small increase in speed. He commissioned a new Blue Bird to be built. K4 was a ‘three pointer’ hydroplane. Unlike conventional powerboats, which have a single keel, with an indent, or ‘step’, cut from the bottom to reduce drag, a hydroplane has a concave base with two floats fitted to the front, and a third point at the rear of the hull. When the boat increases in speed, most of the hull lifts out of the water and runs on the three contact points. The positive effect is a reduction in drag and an increase in power-to-weight ratio - the boat is lighter as it doesn’t need many engines to push it along. The downside is that the three-pointer is much less stable than the single keel boat. If the hydroplane's angle of attack is upset at speed, the craft can somersault into the air, or nose-dive into the water.