Bluebird K7 was a turbo jet-engined hydroplane with which Britain's Donald Campbell set seven world water speed records during the 1950s and 1960s. Campbell lost his life inK7 on January 4, 1967 whilst making a bid to raise the speed record to over 300 miles per hour (480 km/h) on Coniston Water.
Donald Campbell began his record-breaking career in 1949. Hitherto, he had been using his father Sir Malcolm Campbell's propellor-driven hydroplane Bluebird K4 for his attempts, but in 1951 it was destroyed by structural failure, when its gearbox sheared its mountings, and punched through the floor of the hull.
Following rival racer John Cobb's death in Crusader in 1952, Campbell began development of his own all metal jet-powered Bluebird K7 to challenge the record held by the American hydroplane Slo-Mo-Shun IV. Designed by Ken and Lew Norris, the K7 was an aluminium, three-point hydroplane with a Metropolitan-Vickers Beryl axial-flow turbojet engine, producing 3500 pound-force (16 kN) of thrust. Like Slo-Mo-Shun, but unlike Cobb's tricycle Crusader, the three points were arranged in "pickle-fork" layout, prompting Bluebird's early comparison to a blue lobster. It was very advanced, and remained the only successful jet-boat until well into the 1960s.
The name "K7" was derived from its Lloyd's unlimited rating registration. It was carried on a prominent circular badge on its sponsons, underneath an infinity symbol.
Campbell set seven world water speed records in K7 between 1955 and 1964. The first of these occurred at Ullswater on 23 July 1955, where he set a record of 202.15 mph (324 km/h). Campbell achieved a steady series of subsequent speed-record increases with the boat during the rest of the decade, beginning with a mark of 216 mph (348 km/h) in 1955 on Lake Mead. Subsequently, four new marks were registered on Coniston Water, where Campbell and Bluebird became an annual fixture in the later half of the fifties, enjoying significant sponsorship from theMobil oil company and then subsequently BP. There was also an unsuccessful attempt in 1957 at Canandaigua in New York state in the summer of 1957, which failed due to lack of suitable water conditions. Bluebird K7 became a popular attraction, and well as her annual Coniston appearances, K7 was displayed extensively in the UK, USA, Canada and Europe, and then subsequently in Australia during Campbell's prolonged attempt on the land speed record (LSR) in 1963 - 64.
In order to extract more speed, and endow the boat with greater stability, in both pitch and yaw, K7 was subtly modified in the second half of the 1950s with the installation of smoother streamlining, a blown cockpit canopy and, from 1958 onwards, a small wedge shaped tail fin, modified sponson fairings, that reduced aerodynamic lift, and a fixed hydrodynamic fin, fixed to thetransom to aid hydrodynamic stability, and exert a marginal downforce on the nose. Thus she reached 225 mph (362 km/h) in 1956, where an unprecedented peak speed of 286.78 mph (461.53 km/h) was achieved on one run, 239 mph (385 km/h) in 1957, 248 mph (399 km/h) in 1958 and 260 mph (420 km/h) in 1959.
Campbell then turned to the LSR, and after surviving a high speed crash in his Bluebird CN7 turbine powered car, he spent a frustrating two years in the Australian desert, battling adverse conditions. Finally, after Campbell exceeded the LSR on Lake Eyre in 1964, at 403.10 mph (648.73 km/h) in Bluebird CN7, Campbell snared his seventh water speed record on 31 December 1964 at Dumbleyung Lake, Western Australia, when he reached 276.33 mph (444.71 km/h), with two runs at 283.3 mph (455.9 km/h) and 269.3 mph (433.4 km/h) completed with only hours to spare on New Year's Eve 1964.
This made Campbell and K7 the world's most prolific breakers of the Water Speed Record. Campbell became the only person to break both the Land Speed Record and the Water Speed Record in the same year.