Bluebird K7 is a turbo jet engined hydroplane with which Donald Campbell set seven water speed records. Campbell lost his life in K7 on January 4, 1967 whilst making an attempt to raise the speed record to over 300 miles per hour (480 km/h) on Coniston Water.

Design

Donald Campbell began his record breaking career in 1949 and had hitherto been using his father Sir Malcolm Campbell's propellor-driven hydroplane Bluebird K4 for his attempts, until it was destroyed by a structural failure. Following John Cobb's death in Crusader, and inspired by both events, Donald began development of his own jet-powered Bluebird K7 to take the record from the American prop-rider hydroplane Slo-Mo-Shun. Designed by Ken and Lew Norris, the K7 was an aluminium, 3-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.

The name "K7" was derived from its Lloyd's unlimited rating registration, and was carried in a prominent circular symbol on its sponsons comprising the infinity symbol and the script 'K7'.

Records

Campbell set seven world water speed records in K7 between 1955 and 1964. The first was at Ullswater on 23 July 1955, where he set a record of 202.15 mph (324 km/h). Campbell made a series of speed increases in the 50's. 216 mph (348 km/h) later in 1955 on Lake Mead, and then 4 records on Coniston Water. K7 was modified with cleaned up streamlining, a blown cockpit canopy and from 1958, modified sponson fairing's. She achieved 225 mph (362 km/h) in 1956, 239 mph (385 km/h) in 1957, 248 mph (399 km/h) in 1958, 260 mph (420 km/h) in 1959. Finally after Campbell broke the LSR on Lake Eyre in 1964, Campbell took his 7th record in K7 on 31 December 1964 at Dumbleyung Lake, Western Australia when he reached 276.33 mph (444.71 km/h); making Campbell and K7 the world's most prolific breaker of water speed records. He was also the only man to break the Land Speed Record and Water Speed Record in the same year.

Final attempt and Campbell's death

In June 1966, Campbell decided to once more try for a water speed record with K7; The target 300 mph (480 km/h).

K7 was fitted with a lighter and more powerful Bristol Siddeley Orpheus engine, taken from a Folland Gnat jet aircraft, and lent to the project by the MOD, which developed 4,500 pound-force (20 kN) of thrust. The new K7 had a vertical stabiliser (also from a Gnat Campbell had purchased ) and a new hydraulic water brake designed to slow the boat down on the five mile Coniston course.The boat returned to Coniston for trials in November 1966. These did not go well; the weather was appalling and K7 destroyed her engine when the air intakes collapsed under the demands of the more powerful engine and debris was drawn into the engine compressor blades. The engine was replaced, Campbell using the unit from the crash-damaged and scrap Gnat aircraft purchased to obtain the spare engine. The original engine remained outside the team's lakeside workshop for the rest of the project, shrouded in a tarpaulin.

By the end of November, after further modifications to alter K7's weight distribution, some high-speed runs were made, but these were well below the existing record. Problems with the fuel system meant that the engine could not develop maximum power. By the middle of December, Campbell had made a number of timed attempts, but the highest speed achieved was 264 mph, and therefore still below the existing record. Eventually, by the end of December, further modifications to K7's fuel system, by fitting a booster pump, fixed the fuel starvation problem and Campbell awaited better weather to mount an attempt.

On 4 January 1967, Campbell mounted an attempt and was killed when K7 flipped over and broke up at a speed in excess of 300 mph (480 km/h). Bluebird had completed a perfect north-south run at an average of 297.6 mph (478.9 km/h), and Campbell used a new water brake to slow K7 from her peak speed of 315 mph (507 km/h). Instead of refuelling and waiting for the wash of this run to subside, as had been pre-arranged, Campbell decided to make the return run immediately. The second run was even faster; as K7 passed the start of the measured kilometre, she was travelling at over 320 mph (510 km/h). However her stability had begun to break down as she travelled over the rough water, and the boat started tramping from sponson to sponson. 150 yards from the end of the measured mile, K7 lifted from the surface and took off at a 45-degree angle. She somersaulted and plunged back into the lake, nose first. The boat then cartwheeled across the water before coming to rest. The impact broke K7 forward of the air intakes (where Donald was sitting) and the main hull sank shortly afterwards. Campbell had been killed instantly. Mr Whoppit, Campbell's teddy bear mascot, was found among the floating debris and the pilot's helmet was recovered. Royal Navy divers made efforts to find and recover the body but, although the wreck of K7 was found, they called off the search without locating his body.

Campbell's last words on his final run were, via radio intercom:

The cause of the crash has been variously attributed to Campbell not waiting to refuel after doing a first run of 297.6 mph (478.9 km/h) and hence the boat being lighter; the wash caused by his first run and made much worse by the use of the water brake; and potentially a cut-out of the jet engine caused by fuel starvation. (The configuration of K7 at high speed meant that the thrust of the jet engine provided a downward pressure at the bows of the boat. K7 was operating at her absolute limit in terms of a nose up pitching angle of 6'. A sudden loss of power caused by an interruption to fuel flow would mean that this downthrust was lost and K7's bows would have risen above the 6' safe limit) Some evidence for this last possibility may be seen in film recordings of the crash - as the nose of the boat climbs and the jet exhaust points at the water surface no disturbance or spray can be seen at all.

Recovery

The wreckage of Campbell's craft was recovered by the Bluebird Project between October 2000 when the first sections were raised and May 2001 when Campbell's body was recovered. The largest section representing approximately two thirds of the main hull was raised on 8 March 2001. The wreck had been located by a team led by diver Bill Smith.

Controversy over the recovery

Campbell's body was recovered from the lake on 28 May 2001 and he was interred in Coniston cemetery on 12 September 2001.

Campbell's sister Jean Wales had been against the recovery of the boat and her brother's body out of respect for his stated wish that, in the event of something going wrong, "Skipper and boat stay together". This quote is usually attributed to Donald Campbell when in the final days of 1964 he was waiting for weather to attempt a record but an attempt seemed so unlikely that colleagues were pressing him to leave. He refused and broke the record on the last day of 1964. Jean Wales did not attend his burial or ever visit his grave though she did remain in daily contact with the salvage crew as the boat was being salvaged.

Forensic examination of the wreckage and the causes of the accident

Because the water brake was found to be extended when the wreck was recovered it was generally assumed that Campbell had activated it to slow down before the boat had left the water on his final run. On dismantling the boat, however, a hydraulic accumlator from the donor Gnat aircraft was discovered still connected to the system, so stored hydraulic pressure may well have deployed the brake after the accident.

The boat still contained fuel in the engine fuel lines and a quantity was collected and analysed using gas-chromatography as part of the official investigation of the accident commissioned by Barrow Coroner. However, insufficient was present to completely discount the fuel starvation theory. The engine could have cut-out as a result of intermittent fuel starvation caused by the untried fuel system or failure of the electrical supply to the low-pressure fuel boost pumps. Full details of K7's stripdown, assumptions and findings are in the public domain in the diary pages of the Bluebird Project website.

Restoration and future running

As of 2008, K7 is being fully restored, to a very high standard of working condition in North Shields, Tyne and Wear, using a very high proportion of her original fabric, but with a new engine of the same type albeit incorporating many original components.

As of May 2009 permission has been given for a one off set of proving trials of Bluebird on Coniston Water, where she will be tested to a safe speed for demonstration purposes only. Whether and when she is finally tested will be up to the British government. The restoration of Bluebird is heading towards completion in 2011. K7 will find her permanent resting place at the Ruskin Museum in Coniston, where she will be on display to the general public in her own wing, which was completed in 2009.

Specifications