Donald Campbell's restored Bluebird in museum home row

[Engine 711]

Having seen how violent and effective the water brake is by resurrecting it and actually using it at speed I'd say there's little doubt that had Donald been able to fire it down as his 4th Jan event developed it would have slammed the nose back down, likely destroyed the main spar fairings and blasted a ton of water into the sponson tops whilst pulling his eyeballs from their sockets with the deceleration forces and the front end would have stayed firmly buried in the water until way below any speed where the boat would have blown over. Pretty much all I know about the theory of the water brake I learned over lunch with Lew Norris and much of what he told me he never had answers to because it was never really tried, the rest we learned by making it all work again from a pile of scrap parts that lay rotting on the bottom of a lake for 34 years so to see everything Lew envisaged proved correct is a real thrill and very satisfying.

Thank you. Here's another view, based on the analysis in Neil Sheppards's book. They question how effective the Water Brake actually was, when DMC deployed it towards the end of Run 1 4Jan67. It didn't seem to do much initially - perhaps because the Boat was hovering (or bouncing) and the transom was too high out of the water, for the WB to really dig in....? So deploying on Run 2 might have done little to help. All just conjecture....

But, as you say - the Water Brake does live again - and works pretty well, when operated at low(er) speeds. I think Lew N would be pleased, with your work..

A further related thought, for you & the team. Accounts from '67 mention engine flameouts - DMC having to relight towards the end of Run 1 - successfully. Also an apparent Flame Out during Run 2, just before the problems. Noting that Flame Outs also happened at Loch Fad, is there any understanding of why this happened, yet...? Seems surprising to me - my hunch being there is something fundamentally not right in the configuration of K7's Fuel System - as redesigned for the Orpheus. Again, just guessing here, based on reading books....

IM

[Engine 711]

It seems to be quite easy to come off the throttle pedal such that it takes HP cock off with it - that caught us a few times and might be an error on our part, or may be something Donald had to live with too.

Interesting. Hmmm. That could explain it.

From my last proper job, working on engines that fly, I learned there was an automated function to relight an engine (called Auto Relight...), if the Pilot was daft enough to switch the fuel off - which was triggered by putting the fuel back on. This feature was added after someone Flamed Out an engine, by accidentally flipping the Master Switch - it was on a Boeing aircraft, I recall - so 747 or 777. It was/is time limited - if done quickly it works. If not, the Pilot needs to let the Engine run down & do a proper restart. Oops...

Not suggesting this for K7 though....

IM

[KW Mitchell]

On the water brake issue, Neil's posting of the rare TTTv footage (DCBTFRA FB page, Jan. 16th 2017) and my subsequent comments regarding the soundtrack, might prove illuminating...

[Engine 711]

On the water brake issue, Neil's posting of the rare TTTv footage (DCBTFRA FB page, Jan. 16th 2017) and my subsequent comments regarding the soundtrack, might prove illuminating...

This - ?

Quote -
''This video is also remarkable in that it's soundtrack is the only one which contains the unique sound signature of the water brake being deployed. At approx. - 0.16s on the (countdown) time marker, listen to the 'waff-waff....waff-waff....' sound being emanated as the brake is deployed and oscillates in and out of the water. Now, two very important issues when analysing this - and any - video/sound recording. Firstly, as mentioned by Neil, the delay due to the velocity of sound. The brake was deployed some 3.5km or so from the camera point, therefore the sound is delayed by nearly 12s. Thus, on the video the point at which the brake is deployed is approx. - 0.28s on the time marker (note the change in spray pattern at this point). This underscores the point about allowing for delays due to the velocity of sound and most interpretations of video/cine' data have not allowed for this. Secondly, (and another bit of physics which I apologise for to the non-technically minded!) the frequency of the 'waff-waffing' noise is some 3 - 3.5Hz. This appears strange because the boat's primary oscillation is at around 5Hz. The reason for the discrepancy is the Doppler effect i.e. the effect we hear when a train passes and the frequency of its whistle changes. Now doing the math's, and knowing that Bluebird was at ~ 200mph when the brake was deployed the frequency recorded at the camera point is 3.5Hz. QED!''

IM

[Renegadenemo]

On the water brake issue, Neil's posting of the rare TTTv footage (DCBTFRA FB page, Jan. 16th 2017) and my subsequent comments regarding the soundtrack, might prove illuminating...

Ah - the world's self-appointed greatest authority on the K7 accident. Please forgive my lack of illumination...

[sheppane]

On the water brake issue, Neil's posting of the rare TTTv footage (DCBTFRA FB page, Jan. 16th 2017) and my subsequent comments regarding the soundtrack, might prove illuminating...

Ah - the world's self-appointed greatest authority on the K7 accident. Please forgive my lack of illumination...

Come on, thats a bit unfair Bill. You're better than that. Its a subject of interest to us all. A lot of work has been put in, and being presented here is just another strand in helping us better understand what went on all those years ago. There is no contemporary evidence of how well the water brake worked, and at what speed and it what conditions it worked optimally, so this helps add to the potential understanding. I'm absolutely convinced that the running at Bute will also offer up further clues. Like it or not, the public out there are interested, and although we can't turn the clock back, we can do a better job of producing an explanation of how all the various factors combined than was able to be done in 1967. Like rebuilding the boat, its down to putting the hours in.

[KW Mitchell]

On the water brake issue, Neil's posting of the rare TTTv footage (DCBTFRA FB page, Jan. 16th 2017) and my subsequent comments regarding the soundtrack, might prove illuminating...

Ah - the world's self-appointed greatest authority on the K7 accident. Please forgive my lack of illumination...

To see my contribution to this topic summarily and impolitely dismissed, is very disappointing.

I have never - and would never as those who know me would confirm - claim to be '- the world's self-appointed greatest authority...', an assertion which is so very far from the truth and, quite frankly, offensive.

My sole aim over the last ten years or so has been to try and better understand what happened to my boyhood hero and his craft all those years ago. My contribution to DCBTFRA - in close collaboration with those who worked with, and for, Campbell in that last campaign - has been solely to that end. It is not flawless - and I would be the first to admit that - but it is a genuine attempt to get at the physical and scientific root as to why and how things happened as they did and those referred to above endorsed the findings and conclusions of my work.

I have marvelled at what has been achieved by the BBp team over the long and often tortuous years to present to us a working restoration of unquestionable quality. To witness at first hand on Bute the culmination of all that effort, hard work and sheer doggedness was a privilege I will hold to my dying day.

It would be nice if my own humble efforts in trying to understand Bluebird's very complex behaviour when it skirts that boundary between water and air were - if not agreed with - at least respected.

[Renegadenemo]

I am asked to look over and comment on several in-depth analyses of the accident every year. In fact I received another only last week. A brilliant CFD study by a fourth year student at Leeds Uni. Some are very good, others not so good but all are full of effort and intent. The ones I like the best are the ones in plain-speak and not full of pointless 'gaffer-dazzlers' and the ones I really respect the most are those that accept the fact that they may be completely wrong because so many variables were at play and insufficient data remains. Something that we are now beginning to rectify by actually running the craft.

[Engine 711]

To see my contribution to this topic summarily and impolitely dismissed, is very disappointing.

I have never - and would never as those who know me would confirm - claim to be '- the world's self-appointed greatest authority...', an assertion which is so very far from the truth and, quite frankly, offensive.

My sole aim over the last ten years or so has been to try and better understand what happened to my boyhood hero and his craft all those years ago. My contribution to DCBTFRA - in close collaboration with those who worked with, and for, Campbell in that last campaign - has been solely to that end. It is not flawless - and I would be the first to admit that - but it is a genuine attempt to get at the physical and scientific root as to why and how things happened as they did and those referred to above endorsed the findings and conclusions of my work.

I have marvelled at what has been achieved by the BBp team over the long and often tortuous years to present to us a working restoration of unquestionable quality. To witness at first hand on Bute the culmination of all that effort, hard work and sheer doggedness was a privilege I will hold to my dying day.

It would be nice if my own humble efforts in trying to understand Bluebird's very complex behaviour when it skirts that boundary between water and air were - if not agreed with - at least respected.

I hope I am not alone, in appreciating your contributions.

There is unlikely to ever be a definitive explanation of the events on 4th Jan'67. But you attempt is - in my view - a good one. Others will have their own views.

IanM

[KW Mitchell]

Kind comments, Ian. Thankyou.
Keith