John Cobb- Crusader/Railton Special

[ace_chris]

I suggested to the crew a few times that we build a replica Crusader as a follow on project it alas, no takers.

Surely it’s got to be cn7? Or finishing quicksilver

[Renegadenemo]

Surely it’s got to be cn7? Or finishing quicksilver

We looked at the CN7 thing a long time ago but the trouble there is that it's owned by the Science Museum or some such and displayed at Beaulieu and whereas the NMM crew are all for seeing thngs live and breathe again the museologists mired even the preliminary talks in committees then wet their collective knickers when I said we must, of course, bring the machine to running order, albeit at zero cost or effort to anyone but ourselves. At that point I walked away.

Now, Quicksilver, on the other hand, is very interesting... Having had the pleasure of a couple of years of dialogue with Ken Norris I believed that what he set out to do with his original, four-point design was a real winner. Many years later I inherited a mass of data and drawings that only served to further convince me. It used the same sponsons as K7 (the only part of the boat, Ken told me, that was never modified) and a simple layout that relied on engine thrust from the Spey to bully it onto the surface. After that it was a solid design. Now that I would like to build and prove that Ken had it right a second time.

[quicksilver-wsr]

Be my guest, but don't call it Quicksilver.

And any drawings you have will be my property, as Ken didn't do any drawings at all. Not one. That was the whole problem. There were calcs aplenty from Ken, and a fair few sketches along the way - plus endless meetings: well over 150 meetings, in fact, with Ken present and in charge, at locations such as Bournemouth/Hurn, Farnborough, Southampton, Cambridge and Haslar - but drawings there were none, not one single drawing ... not even a drawing for a windtunnel model ... during the entire 12 years that Ken was directing the design effort.

Hence the split, which was my regretful only option at that time.

I would have thought by now that the point had been well made that I sidestepped Ken in the whole process because he was incapable of committing to any hard lines on drawings and left it entirely to others to try to interpret what he was looking for. Each time that was done, it resulted in Ken saying, "That's not really what I wanted" - without ever really laying down what it was that he did want.

The drawings for the reverse four-pointer were done entirely by other people, this work paid for by me. They were the best-guess for what most closely approximated to what Ken indicated he wanted, and that way we all rubbed along very well, until I finally felt the situation had become utterly untenable. We added a lot of detail to a concept, basically, during and after the time Ken was involved, but you can only do that for so long when the concept itself is at question.

There were many good things about the reverse four-point layout. It didn't deserve the, "I'm booking a funeral" remarks from Ken Warby - the ultimate public insult to Ken Norris, given what had happened to Donald and Ken's very understandable sensitivity to that - but those comments should be judged from whence they came.

A word for Chris - whoever you are. If anyone has the gumption to go after the World Water Speed Record in a credible way, they had better have their own clear ideas about a design, not steal someone else's. Any design is the product of a lot of work behind the scenes - the stuff no-one sees but takes all the time and effort and resources. Anyone can build a reverse four-pointer. But it can't be our design, because it's not theirs to mess with.

As far as the reverse four-pointer goes, we moved on in the end, of course, because other designers who got involved had their own ideas as to the optimal layout. And that's what we're building - a boat very similar in many respects to K7, which was yet another idea from Ken as to which way we should go.

I think I've gone on record here a long time ago saying that was the last straw for me: when Ken said, after 12 years of research work - and I quote - "If the boat doesn't work with the sponsons at the back, we'll saw them off and put them at the front."

All of that said, if I had to start the whole process again, I'd do it with Ken.

Nigel

[ace_chris]

There’s no one better qualified than you and your team Bill to make it happen!

[Black Knight]

& you know what to do if you have a spare tin of the ol’ Dulux

[quicksilver-wsr]

Ken wanted to call our boat Bluebird and insisted that it was his right, granted in Donald's will, to restore that name where he saw fit. This was something he wouldn't let go and it was one of many frustrating 'battles' I had to wage with him - employing my best diplomacy skills, so as not to upset the applecart - to ensure that he stuck to the name I'd given it, which of course was Quicksilver.

I viewed the name Bluebird as a Campbell family name, and still do. Never mind any legal issues as an aside - on a moral level, it would be totally wrong to exploit a name that was built on the efforts of others.

Besides that, I felt that a project worth its salt should be prepared to make its own name from scratch - and stick with it. Which is why I successfully resisted the calls from some within my team to change our boat's name when the design we have now was conceived. "Break with the past," and all that. I didn't agree.

The colour and the name go together, in my book, and so blue was out too. I won the point in the end, but Ken copped out for a long time by calling our boat KX, which rather narked me.

Turning to the model boat in the photos ...

The stories of this machine are wildly inaccurate. K7-style sponsons were only used because they represented a known starting-point for the windtunnel work. When going into the unknown, which Ken largely was with the reverse four-pointer, it is sometimes a good idea to take one known quantity as a starting-point and then add to that. Contrary to what Bill implies from Ken's remarks, the K7-style sponsons were not a constant factor - they were dropped after a while, in favour of a shape more suitable for a rear-sponsoned layout.

Just because they worked at the front on K7 didn't mean they'd be of the right design if they were at the back, and under the influence (at lower speeds) of the wake from the front of the boat. The sponson design changed a lot. I have boxes full of model sponsons in my garage here, all of different shapes, that were tested in the Southampton windtunnel. Ken could never make his mind up which ones to settle on, irrespective of the vast amounts of data we garnered.

And there were towing-tank models, too - and models that ran under their own power, with radio-control. Most of the sponsons from those tests were thrown away.

Again, with the choice of the Spey engine - I could shoot holes in the story of how that came about, and how Ken had dithered to the point where it took someone else - John Ackroyd - to make the case for a decision to be made, and sought out the Spey because there happened to be a Buccaneer for sale just a few hundred yards from Ken's office. Ken hadn't worked out whether the Spey was a suitable engine when he asked me to fork out £20,000 on the Buccaneer - in fact, nobody had done the calcs. It was a massive gamble, and the calcs were done later.

I'm not going to reveal what they showed.

Fact is, we changed the design to what we have now for very good reasons. But it's nice that Bill has acknowledged that the reverse four-pointer is not as daft a concept as various clever-clogs have made out. The problem is that people are like sheep and one person said the design was no good and so everyone else duly followed.

Nigel

[Renegadenemo]

Contrary to what Bill implies from Ken's remarks, the K7-style sponsons were not a constant factor

Perhaps I didn't put that too well. What Ken said was that the sponons were the only part of K7 never to be modified, which is why he looked at them for the four pointer. A known quantity, as you say.

My interest is now piqued. I must go delve into the mass of material I have on that design and see what's what. I remember going through it in some detail years ago and concluding that it was perfectly viable.
From memory it all came down to pushing the shape up onto the plane with thrust vs hydro drag being the limiting factor with the Spey just winning the day on paper. There was also some curious and (I thought) rather heavy design of the outer skins with inner skins attached that were designed to fit snugly into the gaps in the frame. PDS had a selection of these prototype panels and, whereas the frame was made with great accuracy, the fabricated skin panels were never the snug fit intended due to weld distortion.
I'd do the skins a different way and the rest would fall well within our skill set. Like I say - always fancied proving that Ken had it right all along.

[quicksilver-wsr]

Perhaps I didn't put my point too well, either - so let me put it another way ...

As far as K7 goes, yes, the sponsons weren't ever modified - except made deeper, when the front sponson-arm was lifted. My opening point was that, as far as Quicksilver went, the K7-pattern sponsons were only ever a starting-point, and they had a relatively short time in the picture before Ken started experimenting with other shapes.

The reason being that model tests in the windtunnel and the towing-tank showed that the K7 design of sponson did not work well when the sponsons were at the back.

Now to the choice of the Spey. What concerned me is that your first post on this gave the impression that Ken had a clear idea of a big, powerful engine - the Spey - pushing the boat up onto the plane. The reality, though, is that Ken had no clear idea of what engine he wanted - either big or small. It took others making the decision for him to move the project on, and at the point when the commitment was made and Speys actually obtained, no-one had done the math to prove that a big engine was the way to go.

That is not the way to do it when spending other people's money.

The first thing Ken did when we got the Spey was to add an eight-foot section to the centre of the hull. That's how crude the methodology was, and it was only later that it dawned on me that, although Ken had some brilliant ideas and undisputed knowledge, he was leading a team in an extremely haphazard way.

What finally emerged into the public eye as an apparently 'mature' design was the work of a group of people, including myself, who pushed and shoved it into something that might be workable. But if you are considering building a replica, you will be doing the wrong thing.

Use the calcs, if you wish - they are Ken's, not mine - but start afresh.

Nigel

[Renegadenemo]

If you look at K7 it's no more than brute force and ignorance made to float then bullied into working. I have no doubt that the brute force and ignorance four pointer would have got the job done.

[quicksilver-wsr]

If you look at K7 it's no more than brute force and ignorance made to float then bullied into working. I have no doubt that the brute force and ignorance four pointer would have got the job done.

There's got to be something about the hull(s) that make it want to go up instead of down when power is applied en route to planing, but broadly speaking a big engine is better than a small one.

Malcolm Campbell once said you can't have too much power. He was talking about the cars, but with water being 800 times the density of air, it could equally be said of the boats.

Nigel