Flying Canting Keel-Extraordinary Innovation!

[Gary Baigent]

yachtie2k4, with 60 million new images published weekly on Facebook, perhaps you're slightly over reacting ... a word in your ear: the day of the precious photographer has gone ... and a bloody good thing too. By the way, I take photographs .... like the other untold millions out there.

[yachtie2k4]

hey gary, i don't mind other people using my pics, i just don't want the ******* **** **** doug lord using it, he is a **** and he seriously needs to be banned from the internet!

[sharpii2]

Originally Posted by Doug Lord

Potential combination of technologies:

While CBTF has proven many times over that it is the fastest system for a canting keel their original keel cant angle was 55 degrees. With the flying canting keel that angle is upped to 90-110 degrees or more. Yet the advantages of the twin foils remain.
If we look at the second CBTF patent it shows a keel that is NOT a strut but a lifting foil designed to create downforce with the keel at max angle -but still in the water-further reducing the ballast requirement. To my knowledge this version has not been built.
Now, as time has gone by a new technology has emerged to increase stability
DSS- a sliding foil(see the Quant 28 thread) Quant 28-foil assist keelboat / DSS
So what if we take the flying canting keel, the twin foils from CBTF and Hugh Welbourns DSS and combine them all in one boat!*
Advantages:

-- The CBTF-like twin foils allow "collective" steering eliminating leeway drag from the hull as well as reducing drag further by placement of the foils on the hull.
-
-- The flying canting keel 100% eliminates drag from the keel and bulb.
a. would be ideal to be able to quickly adjust the horizontal keel in and out-probably easier on a system like this where DSS develops significant RM.
-
-- The DSS foil can increase RM significantly allowing even greater reduction
in the ballast carried by the keel bulb. This is probably superior to the second CBTFco patent when coupled with the flying canting keel.....
-
-- When used in combination with high dihedral racks with designed in buoyancy the self-righting characteristics may be improved.
-
-- Any others?
* UPDATE 7/2/11 : There will be an additional technology that can be potentially "blended" with the above and that is on-deck movable waterballast in a dynamic pressure, pumped or sliding tank system. Such a system was considered years ago by Julian Bethwaite and by Sean Langman in conceptual systems for ocean going speedsters.(see pix below) This is an exciting era in sailboat design and development and when the economy really turns around wild, new and exciting projects will spring up all over the place. Hope I get to see it!

=============
Disadvantages:

-- not as fast as a full flying keelboat foiler,
-
-- ballast could be reduced so much that the self-righting characteristics that are ideal in a keelboat are compromised. Analysis of the effect of racks with buoyancy would be important.
-
-- Relying on buoyancy in racks may not be acceptable in ocean racing rules.
-
--Any others?


click on image:

This thing is looking more and more like a double outrigger. I suspect it would be faster sans the water ballast, the pods converted to floats, but keeping the canting ballast. A great deal of weight (the water ballast) would be converted to minimal whetted surface drag. Most of the time, the lee float could be kept out of the water by use of the canting ballast and the crew moving to the windward float.

In a knock down, the lee float goes in the water, but does not have enough buoyancy to lever the main hull out. It would be able to recover from a knock down of up to 90 degrees in that condition, providing the lee float does not get totally waterlogged. The enormous drag of the cross beams going under would dampen the capsize moment long enough, perhaps, for the initial force causing the capsize to diminish.

It would certainly be more seaworthy than a more conventional trimaran and far more user friendly than this proposal, which, though technically a mono hull, really looks like a trimaran.

The next step would be to eliminate the canting ballast (a half ton or more of useless weight) and put a pair of foils on each float. The aft foils would have rudders attached.

It should then be much faster but less safe. Once supported by the foils, it could flip just like a more conventional trimaran. It would still be safer than the vessel drawn.

Very rarely does added weight equal more speed. And even then, it's to a very limited extent.

[Doug Lord]

Originally Posted by sharpii2

It would still be safer than the vessel drawn.The Whitehouse rendering?

Very rarely does added weight equal more speed. And even then, it's to a very limited extent.

===========
1) just out of curiosity which vessel drawn?
-
2) I guess that depends: on every dinghy the boat would not sail at all w/o the added (crew) weight-in other words added weight is absolutely essential for performance-not to mention high performance. The same can be true of almost any performance monohull sailboat regardless of size.

[sharpii2]

Originally Posted by Doug Lord

===========
1) just out of curiosity which vessel drawn?
-
2) I guess that depends: on every dinghy the boat would not sail at all w/o the added (crew) weight-in other words added weight is absolutely essential for performance-not to mention high performance. The same can be true of almost any performance monohull sailboat regardless of size.

1.) The one on your 10:00 pm, 07-02-11 post.

2.) That's why I say 'very rarely'. If you look at most dinghies where the crew hikes out, you'll notice that the crew weight makes up a major portion of the boat's weight as well as it's 'cargo'. Using ballast to do the same thing works, but seems a waste when other methods of lengthening the righting arm are available, especially ones that add little weight (such as the Quant-28).

The foiling moth is a typical example. The crew hike out, but the crew is the cargo. It would be on the boat anyway. Adding more weight to replace a larger crew, just makes the boat heavier and, arguably, more dangerous. With the ballast moved that far outside the edge of the deck into pods that look suspiciously like amas, I wouldn't blame any rules committee for flagging it as a multihull, even though neither of the pods is ever supposed to touch the water.

I think you know enough about the math of this situation to know that a larger monohull trying to be a scaled up foiling 'moth' may be remotely workable, but is far less practical and reliable than other other solutions. And is probably slower and more expensive as well.

[Doug Lord]

Originally Posted by sharpii2

1.) The one on your 10:00 pm, 07-02-11 post.
2.) That's why I say 'very rarely'. If you look at most dinghies where the crew hikes out, you'll notice that the crew weight makes up a major portion of the boat's weight as well as it's 'cargo'. Using ballast to do the same thing works, but seems a waste when other methods of lengthening the righting arm are available, especially ones that add little weight (such as the Quant-28).

The foiling moth is a typical example. The crew hike out, but the crew is the cargo. It would be on the boat anyway. Adding more weight to replace a larger crew, just makes the boat heavier and, arguably, more dangerous. With the ballast moved that far outside the edge of the deck into pods that look suspiciously like amas, I wouldn't blame any rules committee for flagging it as a multihull, even though neither of the pods is ever supposed to touch the water.

I think you know enough about the math of this situation to know that a larger monohull trying to be a scaled up foiling 'moth' may be remotely workable, but is far less practical and reliable than other other solutions. And is probably slower and more expensive as well.

===============
Oh- those are two different "hybrid" solutions-one from Sean Langman with a canting keel and the other by Julian Bethwaite(suggested by Coutts and Cayard) with sliding on deck lead or water ballast.
--
I'm 100% convinced that a properly designed keelboat foiler using on-deck movable ballast(and a fixed keel for self-righting) will be the fastest possible type of ocean racing monohull. Especially when you consider that 40% of its RM will come from the use of a sailing technique-veal heel- rather than ballast in and of itself.
Another poster looked at my 60' Moth and did a bit of a study of it predicting it would be at least as fast as the same length ORMA trimaran with 60% of its weight supported by a single foil(the bad news was, at the time, he didn't think it could be built).
I'm convinced that new techniques, new thinking and new materials will lead to a continuing revolution in monohull design. And the days of multihulls being the fastest type of sailboat are numbered-as proven by the Moth on everything(sailboats not sailboards or kiteboards) under 20'.

[sharpii2]

Originally Posted by Doug Lord

===============
Oh- those are two different "hybrid" solutions-one from Sean Langman with a canting keel and the other by Julian Bethwaite(suggested by Coutts and Cayard) with sliding on deck lead or water ballast.
--
I'm 100% convinced that a properly designed keelboat foiler using on-deck movable ballast(and a fixed keel for self-righting) will be the fastest possible type of ocean racing monohull. Especially when you consider that 40% of its RM will come from the use of a sailing technique-veal heel- rather than ballast in and of itself.
Another poster looked at my 60' Moth and did a bit of a study of it predicting it would be at least as fast as the same length ORMA trimaran with 60% of its weight supported by a single foil(the bad news was, at the time, he didn't think it could be built).
I'm convinced that new techniques, new thinking and new materials will lead to a continuing revolution in monohull design. And the days of multihulls being the fastest type of sailboat are numbered-as proven by the Moth on everything(sailboats not sailboards or kiteboards) under 20'.

Well. I guess time will tell.

It is interesting to note that a number of monohulls sail as fast as multis used to sail. But much of the same technologies, mostly materials science, that made the mono's faster, made the multis even faster still.

I have no reason to believe this will not happen with lifting foil technology as well.

Right now, I have no idea how fast the largest, fastest multis can go. I have long since lost track. And mainly for lack of interest. Speed for its own sake, is in my view, not much of a virtue. Especially when it comes at the costs of over virtues such as low cost, reliability, decent carrying capacity, and, above all, safety.

As I always like to say: If you want to go fast over the water, get an airplane.

[CT 249]

Originally Posted by sharpii2

In a knock down, the lee float goes in the water, but does not have enough buoyancy to lever the main hull out. It would be able to recover from a knock down of up to 90 degrees in that condition, providing the lee float does not get totally waterlogged.

With respect, isn't that pretty much the same theory as the long-discredited "submersible float trimaran" one?

I seem to remember Lock Crowther, initially a fan of submersible float theory IIRC, later noted that one significant issue was that designing a float that could stay intact under the pressure of being shoved (say) 30 feet underwater. Basically, I don't think anyone was ever able to design a boat that worked out like the theory said, even in smaller sizes where float implosion under water pressure was less of an issue.

By the way, I agree with the rest of your recent posts.

[sharpii2]

Originally Posted by CT 249

With respect, isn't that pretty much the same theory as the long-discredited "submersible float trimaran" one?

I seem to remember Lock Crowther, initially a fan of submersible float theory IIRC, later noted that one significant issue was that designing a float that could stay intact under the pressure of being shoved (say) 30 feet underwater. Basically, I don't think anyone was ever able to design a boat that worked out like the theory said, even in smaller sizes where float implosion under water pressure was less of an issue.

By the way, I agree with the rest of your recent posts.

Thanks, CT.

Actually, I don't think its all that difficult.

The floats have to structurally resemble what the Indonesians used on their double outriggers, bamboo.

This requires many web frames and is not all that conducive to light weight.

Another approach is to use plastic foam floatation and let the floats flood from the over pressures. A third approach, my favorite, is to use airbags. The airbags combined with some ballast may make the double outrigger capable of self rescue by its crew in the event of a capsize. But that would be in relatively calm conditions with a fit and alert crew, with the boat and rig entirely intact. A most likely fantasy dreamed up by boat nerds, such as myself.

Of course, all this adds weight and subtracts from the buoyancy of the already buoyancy challenged floats. There is no way such a set up would be competitive with a full buoyancy float trimaran. Perhaps this is what Lock was getting at.

Adding hydrofoils to these floats may be a complete game changer, along with the bringer of more engineering headaches.

This is why I always contend that really fast boats generally suck. They are Johnny one notes and are generally short lived.

[CT 249]

Yeah, I think Lock was referring to craft that would be competitive.

I love fast boats and some of them can lost well, but I agree that they can be very much one-note wonders and that more accessible boats are more important in many ways.

[Gary Baigent]

Ah, CT, the fast boats that you have enjoyed have all come from "very much one note" designs - maybe thought of, and written off at the time by conservatives, to be short lived - but in reality the beginning of life for an acceptable to masses fast boat.
By the way, I've race watched and race sailed on a few Crowther low buoyancy float designs in Auckland, in some savage NZ conditions too, and, with their relatively low sail area, have never seen, or experienced, a lee float bury knockdown, that so much emphasis is placed upon such designs by so called experts. Fashion can be a ridiculous load of BS sometime.

[Gary Baigent]

Oh, correction; I saw Krisis go over in a hard williwaw when she was spinnaker reaching ... but that wasn't the fault of float buoyancy but because the turkeys on board had cleated the spi sheet and Krisis rounded up, took the full load of wind forse on her beam and kite and gently rolled over, crew falling off a la X40's.

[Gary Baigent]

And if Krisis had 200% buoyancy floats, the result would have been the same, only quicker.

[CT 249]

Originally Posted by Gary Baigent

Ah, CT, the fast boats that you have enjoyed have all come from "very much one note" designs - maybe thought of, and written off at the time by conservatives, to be short lived - but in reality the beginning of life for an acceptable to masses fast boat.
By the way, I've race watched and race sailed on a few Crowther low buoyancy float designs in Auckland, in some savage NZ conditions too, and, with their relatively low sail area, have never seen, or experienced, a lee float bury knockdown, that so much emphasis is placed upon such designs by so called experts. Fashion can be a ridiculous load of BS sometime.

Sure, I enjoy fast "one note" craft, and nothing in my post suggested otherwise.

However, in many ways (allowing easy entry to the sport, maintaining critical mass, being more enjoyable for most people to own) slower boats are more important, which is all I said.

I don't know of many conservatives who have written off any of the fast craft I've sailed as short-lived; there was probably the odd guy here and there of course. Some did say that light IOR boats wouldn't last, but then again many of the early lightweights haven't actually lasted that well. However, some fast craft and plenty of slow boats have incorrectly been written off in various ways by those who like to think they are leading-edge.

One of those "so called experts" who decided to move away from submersible floats was, of course, Lock himself. I was simply recalling what he said.

[Gary Baigent]

"This is why I always contend that really fast boats generally suck. They are Johnny one notes and are generally short lived."
" ...very much one-note wonders and that more accessible boats are more important in many ways."
The first quote is Sharp112 and the second is yours CT - and I read some disparaging commentary in them.
Sure, Lock changed direction but for a long period, with numbers of Krakens and 24 foot Buccaneers built, he advocated the lower buoyancy floats ... and they worked fine, only crew error built negative reactions. I guess you could aim the same criticism at Dick Newick too, yet his boats with low buoyancy floats have sailed many thousands of racing miles. Point is, they weren't driven as hard with their lower sail areas.
Speaking of the lightweight monohulls from the IOR period: there is a strong revival of Quarter and Half ton designs right now, 35 years after they first appeared; in my book that is definitely longevity of design.