Donald Campbell - Bluebird K7 Crash

[athonite]

Just wondered if anyone out there with an expertise in Aerodynamics.

I was recently in Connistion in the Lake District with my son, the location of the above accident and we had a conversation about the Bluebird crash and since looked at video footage. My son's question was surely sooner or later a boat at high speed is just going to become airbourne. I tend to aggree

Since 1940 there has been a 85% fatality rate in water speed records.

What we wondered based on the knowledge of aerodynamics at the time which was highly developed, concorde was in the final stages of development, were any aerodynamic engineers involved or was there any wind tunnel tests?

Here is the is an extract of the events:

On 4 January 1967, Campbell was killed when Bluebird K7 flipped and disintegrated at a speed in excess of 300 mph (480 km/h).[5] (http://www.pprune.org/#cite_note-4) Bluebird had completed a first 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 refueling 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, it was travelling at over 320 mph (510 km/h). However the craft's stability had begun to break down as it travelled over the rough water, and the boat started tramping from sponson (http://www.pprune.org/wiki/Sponson) to sponson. 150 yards (140 m) from the end of the measured mile, Bluebird lifted from the surface and took off at a 45-degree angle. It somersaulted and plunged back into the lake, nose first. The boat then cartwheeled across the water before coming to rest. The impact broke Bluebird forward of the air intakes where Campbell was sitting, killing him instantly; the main hull sank shortly afterwards.
Campbell's last words on his final run were, via radio intercom:
Pitching a bit down here...Probably from my own wash...Straightening up now on track...Rather close to Peel Island...Tramping like mad...er... Full power...Tramping like hell here... I can't see much... and the water's very bad indeed...I can't get over the top... I'm getting a lot of bloody row in here... I can't see anything... I've got the bows up...I've Gone.... oh![6] (http://www.pprune.org/#cite_note-BBC.2C_last_words_from_Bluebird-5)
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, most likely, a combination of the boat having exceeded its maximum safe speed and a cut-out of the jet engine, caused by either fuel starvation or an electrical failure. 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. Mr Whoppit (http://www.pprune.org/wiki/Mr_Whoppit), Campbell's teddy bear mascot, was found among the floating debris. Royal Navy divers made strenuous efforts to find and recover Campbell's body but, although the wreck of K7 was soon found, they called off the search without locating his body

[Alber Ratman]

There were wind tunnel and model tests done during the orignial design of Bluebird in 1953-54. The first tests of the boat in Ullswater however showed flaws in the design that required the repositioning of the front spar supporting the sponsons. Further modifications were carried out in refairing the upper sponsons (around 58 I believe), the first tail fin (around the same time) and the prespex bubble canopy. Wherever these were wind tested, I don't know. The final modification included the high tail, the Orpheus engine replacing the Breyl and the water brake. Where they wind tested? Possibly but Campbell was skint at this time. The K7 had a design speed of 250 MPH when it was built. Personally, My opinion is that the combination of wake from the first run and no down thrust from the fuel staved engine allowed the pitching moment of the boat to exceed the alpha that the nose could reach without taking off.. The boat was on its absolute limit even if campbell had refuelled and allowed his wake to die down.. He would have been bankrupted anyway afterwards as the tax man was after him..

[lsrdatabase]

Hi all,

Just registered, and read this post on Donald. I have been a Campbell enthusiast since the early 1950's, and maintain a large archive of anything Campbell/Richard Noble/Land Speed records.
After reading the post, I would just like to say, the 'Blown' canapy was introduced after K7 returned from Lake Mead in 55' and in situte by Coniston in 56.

[Alber Ratman]

Thanks for correcting me on the date of the blown canopy. I would be fairly correct on most of the other facts (I hope). The facsinating story of the restoration of K7 is to be found on Bill Smiths website " The BlueBird Project (http://www.bluebirdproject.com/bbp/)" I for one will make the effort to go an see its first run when completed..

Modification was mostly trial and error towards the end. The 66 modifications affected the weight distribution of the boat, that caused problems with getting the boat to plane and engine water ingestion. The initial trial fix was sand bags lashed to the stern and the subsquent permanent fix of bolting lead blocks internally.

Did see the Quicksilver frame at East Midlands 8 years ago.. Did question some of the design philosophy of building a frame that nothing could be bolted onto.. not surprised its never really got any further.

[PPRuNe Pop]

This is NOT aviation and has no place here. Sorry!