Why Did Bluebird K7 Crash?
4 January 1967: the Final Record Attempt
Donald Campbell was effectively a ‘test pilot’, going into uncharted territory, in his attempt to determine how fast it was possible for a boat to travel on water, and whether the ‘water barrier’ existed.
In 1954, the Norris Brothers designed Bluebird K7 for Donald Campbell. The hydroplane was designed to achieve a maximum speed of 250mph, and incorporated various lessons learned from John Cobb’s fatal crash in 1952 on Loch Ness. K7 achieved seven World Water Speed Records between 1955 and 1964.
In 1966, Donald Campbell announce his intention to attempt a new Record in excess of 300mph.
The Norris Brothers agreed to modify the hydroplane, and re-engine the 11-year-old K7 with a Bristol-Siddeley Orpheus turbo-jet, capable of a peak speed of 325mph. Such high speed would inevitably reduce Bluebird K7’s stability margins, so Ken Norris attempted to counter this problem by ensuring that the craft’s centre of gravity was moved forward.
In November 1966, K7 started trials at Coniston, but the boat would not come up on the ‘plane’. This was resolved by adding 170lb of lead weights to the rear of the hydroplane. This resulted in the centre of gravity regressing rearwards, and the stability benefits – mentioned above – were virtually lost.
Bad weather limited test-runs and created appalling conditions for the Bluebird Team working on site.
In the 1950s, it was known that when aircraft [or sea birds] fly close to the surface they experience enhanced aerodynamic lift. The primitive [without digital sensors] wind tunnel methods used to test K7’s design in 1954 could not quantify this phenomenon.
On 27 December 1966, this underestimated problem was compounded when a collision with a duck resulted in severe damage to the leading edge panel of the left front spar. This introduced asymmetric airflow over K7.
The reduced lift and increased drag on the left hand side of K7 caused the right hand side to lift preferentially, and so exacerbated instability.
Film footage of the final runs has now been digitised to extremely high resolution, and frame-by-frame analysis reveals ‘hovering’ episodes.
Travelling at 311mph Donald Campbell gradually closed the throttle on exiting the measured kilometre.
K7’s right sponson leaves the water, the bows pitch up 3 to 4 degrees for seven-tenths of a second before the boat settles back on to the surface.
Running over choppy water – caused by the deployment of the water brake on the first run – K7 enters smooth water and ‘hovering’ occurs at 270-280mph.
Bluebird accelerates rapidly to a peak speed of 328mph. There are several ‘bouncing’ episodes of increasing intensity and, following the third bounce, the boat decelerates dramatically by almost 35mph.
The engine fails.
K7 becomes air-borne. It hovers for 2 seconds, then enters a nose-up pitch before ‘flipping over’ backwards, hitting the water at 183mph.
Donald Campbell dies instantly.
After the accident, the Campbell family requests that the crash site be respected as a grave, for ever. For over 30 years, villagers kept the site a closely guarded secret.
However, major advances in diving equipment and technology rendered the site increasingly vulnerable. Bill Smith lead a professional search for K7. Gina Campbell gave him permission to continue, instructing ‘. . . Find my Dad so I can put him somewhere warm . . .’
On 12 September 2001, Donald Campbell’s funeral was held in Coniston. He is buried in Coniston Cemetery.
The Bluebird Project Ltd’s Volunteers’ Labour of Love
In May 2015, The Ruskin Museum received from James Walshe, Assistant Editor of Practical Classics magazine, [who is writing a detailed feature about the conservation rebuild to full operative order of Bluebird K7, for publication later this year], the following testament about the quality of The Bluebird Project Ltd’s volunteers’ labour of love:
“We’re often asked to reveal the secret of restoring a car and although the need of each vehicle is always quite different, the answer is always the same: Patience.
“No good comes of rushing a restoration. It must be done properly. Fix your brakes in a hurry and you will most likely end up with your bonnet buried in a hedge. Hurry your way through the welding process without the necessary care and attention and your vehicle will in no time at all turn into a useless heap of rust.
“Likewise, it’s important to ensure authenticity and deliver a fully working engine. You wouldn’t unveil a restored grandfather clock without ensuring the pendulum worked, would you?
“It’s heartwarming to know that Bill Smith and the Bluebird team are applying this rule of patience – and attention to detail - to the restoration of K7. It is – after all – one of the most important landmark machines of the 20th century. What it represents is too important for it to be rushed. And when finished, it will be a living, breathing machine. One that Donald would have been proud of. Indeed, it will be something Britain can be proud of.
“The question of timescale is irrelevant at this stage. We know it will be done. It’s being done as we speak. On a recent introduction to Bill, I was struck by his great passion and commitment to the project. In order to complete Bluebird K7, he and the team are regularly working late into the night to revitalise, repair, sculpt and carefully craft a machine developed and piloted by one of the greatest Britons who ever lived. And like all great restorations, that is something most definitely worth waiting for.”