- Bluebird K4
"Bluebird K4" was a
powerboatcommissioned in 1939 by Malcolm Campbell, to rival the Americans' efforts in the fight for the world water speed record.
The name "K4" was derived from its Lloyd's unlimited rating, and was carried in a prominent circular badge on the forward hull.
K4 was a "three pointer"
hydroplane. Unlike conventional planing powerboats, which have a single keel, with an indent, or "step", cut from the bottom to reduce drag, a "three pointer" 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 planes on the three contact points. The benefit is a reduction in drag. 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.
The Bluebird K4 was built as a repacement to the
Bluebird K3, which had set three other water speed records for Malcolm Campbellbefore the K4 was built. The K4 set one world water speed record on 19 August 1939on Coniston Water, Cumbria, England.
The boat was tried out by
Donald Campbell(Malcolm's son) but deemed too slow, so after a structural failure in 1951it was replaced by the jet-powered K7, in which Donald died during a record attempt in 1967.
A replica of "K4" currently is on show at the
Lakeland Motor Museum, Holker Hall, Grange-over-Sands.
* [http://www.lakelandmotormuseum.co.uk/ Lakeland Motor Museum]
* cite web
title=Malcolm Campbell and Bluebird K4
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