Flying Canting Keel-Extraordinary Innovation!

Making a keel boat fly

I think the canted ballast idea is a dead end for a foiling monohull. Too much to go wrong and way too expensive. The idea of swinging the ballast way to one side and hoping you will be able to get it back to where you started seems to be begging for trouble. Undoubtedly it is the lightest solution. But it is a solution not likely to work as promised.

A simpler, more reliable system would be to have two sets of foils, one on each side. Each would be canted up on its outboard side. The keel would remain fixed. The foils and their legs would be hollow and able to free flood or drain, preventing them from putting buoyancy too low or carrying weight too high. As the boat heels from the press of the sails, the lee foils fly the boat. The windward ones would clear the water (for the most part).

If the boat capsized, the fixed keel, in concert with the hollow foils and legs (and maybe a little help from the crew) would right the boat.

Variations on this theme could be tried. Such as using the lee legs and foils as supplemental floatation (increasing the Righting Arm) by temporarily 'blowing' them full of air (like in a submarine).

This would still be inordinately expensive and may not even be faster than a more standard (90 deg.) canting keel boat without foils. Most of these vessels are designed to plane. When you factor in the foil area needed to lift, say, a ten thousand pound boat, you may actually end up with more drag than the planing causes.

But still. It would be a grandiose sight watching the hull of a keel boat leave the water for a significant amount of time. Kind of like watching an elephant fly.

 

I'm sure someone has mentioned this at some point and maybe its against the race rules or something but wouldn't it be better to have a lifting foil on the downhill side rather than a weight on the uphill side so to speak. the foil would reduce the amount of surface area in the water by lifting the main hull whereas the ballast would drive the hull deeper so you'd end up with almost the same amount of friction in the end even with the canting keel. Ok maybe the rules don't allow for a lifting foil but still it seems like our resident foil guy would agree

 

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Boston, Hugh Wellbourne, from the UK, devised a sliding(athwartship) foil just below the waterline that lifts the boat just as you describe. He calls it DSS(Dynamic Stability System)- still under development.
Vlad Murnikov has a project underway(Speed Dream) to design the fastest sailboat period and he is considering using the DSS system.
The problem I see is keeping the foil far enough below the surface to not create too much drag.
http://www.boatdesign.net/forums/sailboats/speed-dream-35-prototype-36205.html

 

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1) Canting Keel: Canting ballast is being used successfully on most large ocean race monohulls. It is probably not a dead end on a keelboat foiler any more than on any other race boat. For a foiler application the keel would have to cant at least 90 degrees each side(like the Reichel-Pugh "Q" or the Whitehouse/Richards project). And the boat would require fast sliding on-deck water ballast as well.
2) Fixed keel ballast-no canting keel: However, a small amount of ballast(440lb on a 30 footer) can be placed at the juncture of the main foil and vertical fin strictly to aid self-righting from a capsize or pitchpole and with additional waterballast(as in the first example) the boat would foil well and be 100% self-righting. It is a matter of careful design and engineering.
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For a foiling keel boat to actually work, takeoff early and be fast it will probably need to limit the lifting hydrofoils to just two.
The advantage of a bi-foiler is less drag and the ability to use "Veal Heel" to increase RM(righting moment) up to 40%, essentially for free, by heeling the boat to weather when on foils. This only works on a bi-foiler and it moves the CG of the hull(and everything else) to weather. In addition, the rig generates a small amount of lift and the foils unload the daggerboard reducing the chance of ventillation as well as reducing some forms of drag inherent to a t-foil being sailed level on a sailboat.

edit: 10:42 5/31-1 & 2 added for clarity/ previous quote added for same reason-and to prevent misrepresentation of previous comments

 

Fascinating and very different take on solving the problems - and best of all much simpler and less things to go wrong. I can't see how cycling a canting keel through 180 degrees of rotation under a hull when tacking or gybing is a better solution. And the whole point of water ballast is that it can move by pumping it rather than Doug's concept of sliding a tank around on the deck.

Nice to see lateral out-of-the-box thinking on the very real problems of attempting to help elephants get airborne.

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CutOnce

 

180 deg. canting ballast vs. 90 deg. canting baallast.

I agree with you, Doug.

Canting ballast is now a proven technology. Within limits, even I will defend it.

With a 90 deg. canting ballast, if the boat capsizes it is likely to happen with the ballast canted all the way to one side. Since the ballast is light in proportion to the weight of the boat, say 20 to 25% having it canted to one side while inverted is to some advantage. It prevents the boat from floating level when inverted. It will have quite a list to which ever side the ballast is canted toward. This will increase the likelihood that the boat will right itself, over that of a fixed ballast boat of the same ballast depth and ballast weight.

Mind you. Once it comes upright it will be stuck at an around 40 deg. list (with deeply reefed sails it may be able to be sailed even in this condition). But it can be worked on with some rather crude jury rigging techniques. The hydraulic rams can be relaxed, allowing the ballast to hang more or less straight down. Then some sort of shoring can be used to hold it there. The boat would then be a fixed ballast vessel for the rest of the voyage.

Now try that with a 180 deg. canting ballast. With it canted all the way to one side and the boat capsized, the boat will now have about an 110 deg. list (from upright). Now, assuming the canting mechanism is disabled, but can be relaxed, the hull has no form stability left to right itself. It will prefer to stay at its approx. 110 deg. list. Forever.

Bashed about in big waves in this condition, there is a good chance it will first lose its rig, then be impaled by it.

This is why I stand by my outrage.

A 180 deg. canting ballast is not an 'extraordinary innovation'. It is merely a ridiculous over extension of a somewhat venerable past one. In short, it is dumb, dumb, and dumber.

My advice to you, Doug, is to think more like an engineer and less like a lawyer. Think about what can go wrong with your dream machine, rather than just thinking about what can go right.

Doing that will more likely further your cause.

 

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Sharpii, any boat I would use a 180 degree canting keel on would not look like either the Reichel-Pugh "Q" or the Whitehouse/Richards flying canting keel
boats because I would only use such a keel on a keelboat foiler if I didn't go with #2 in my previous post. When I first came up with the idea of a 110 degree each side(220 degree canting keel) about 5 years ago(and published it here-see 60' Moth link in the 2nd post of this thread) I envisioned a boat that would also use sliding on-deck water ballast and be very wide. Sliding water ballast in a tank is MUCH faster than pumping it and any amount can be moved incrementally.
The ballast in the canting keel + the buoyancy outboard would make it very difficult to capsize in the first place and it would be self-righting in the manner of an Open 60-ie, the crew would be able to right the boat from a pitch pole or capsize(resulting in a turtle) by moving the keel and dumping the water ballast.
Since then I've done some experiments and calculations that lead me to believe that a "normal" or flying canting keel may not be necessary-but sliding on-deck waterballast would be. If the boat turtled with a fixed keel(ballast at the juncture of the mainfoil and vertical fin) wave action might allow the boat to right with no crew action, or the vertical fin/hydrofoil/ballast could be canted 20 degrees or so to begin the righting process. Plenty of experimenting to do to find the best combination.
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At this point ,the keelboat foiler is not a boat for the masses and it may never be. It is an experimental boat whose whole purpose is to increase the speed of a monohull ocean(and/or coastal) racing sailboat. It is an exploration of technology that could possibly lead to a boat as fast or faster than a multihull of the same length with the added benefit of being rightable. Properly designed,built and engineered the foils would enhance the seaworthiness and seakindliness of the boat. I and a number of other people think this is possible but not without a lot of work, danger, money, guts, determination, invention and faith. "Outrage" at this kind of R&D is an unfortunate over-reaction but will have little effect on those doing the work. The end result could be a significant contribution to the science of yacht design for which the developers will be remembered in a positive vein forever. Or not.
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As far as the Reichel-Pugh 180 degree canting system goes I don't know enough about their design to intelligently criticize it-the failure could be just a minor glitch easily rectified or a major unforeseen design, building or engineering disaster. Knowing Reichel-Pugh ,and to a lesser degree McConaghy, it is probably a minor glitch.
Questions about how a boat equipped with such a system(with a "normal" beam) would behave in a vast number of conditions can't be answered without a whole lot more info on how the system works and what went wrong this time. I wish them good luck and I hope the system can be refined to be reliable in the conditions it was designed to be able to race in.
And I beg to differ: both the flying canting keel systems represent "extraordinary innovation" of the highest order as would a foiling keelboat when it is developed.

Rough sketch of my 60' Monofoiler by N Flutter done some years ago; original concept posted on this forum 5 years ago. Illustrates 110 degree each side(220 total) canting keel and rack type buoyancy pods:

 

Speed Dream Flying Canting keel

For more info: http://www.boatdesign.net/forums/sailboats/speed-dream-35-prototype-36205.html#post466487
150 degree canting keel....

click on image:

 

FF (fuckin' FAIL)

yes Doug here is the 180^ RP42 canter in action in it's 4th light weather inshore race

of course the keel is in it's ultimate position, pointing DOWN

when will you realise there is a difference between practical and theorizing at your desk

sailing is a practical pastime

 

+1.

This is a great example of consciously deciding to NOT make mandatory systems failsafe. Something happened (fire? as smoke was observed) and the system did not fail safely - it failed catastrophically. Adding a backup system capable of supplying reserve hydraulic pressure (to force the keel to a locked, central position) was probably considered and dropped due to added weight. Once the decision was made to operate this boat without a failsafe system for centering the bulb, it only became a matter of time before this happened.

I'm not indicating this is a decision without precedence - the US F-117 Stealth aircraft is by design unstable - it can only fly with an active and functioning computer to deal with the stability. There is no option to fly a F-117 without a functional fly-by-wire computer - it can not fly straight and level without constant correction at computer speed.

As an offshore captain of a racing boat, you accept responsibility of the lives of the people on your boat, I certainly would not want to be in the middle of the Bass Straight on this boat if the engine seized. Nobody has ever had an engine fail on a sailboat, have they?

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CutOnce

 

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That is a preposterous statement most especially without knowing anything about what happened.

 

Wrong. It is perfectly correct. The boat is on it's side. QED.

Something failed, and the systems did not return the keel to center. How more clear does it need to be? The failure could be operator error, engine failure, hydraulic failure ... it doesn't matter. SOMETHING failed and the boat is capsized. It DID NOT fail safely, ergo my absolutely correct post.

The photographer on site indicated smoke from the boat, smoke usually means fire or chemical reaction. Given the application and requirements, most likely an engine was running to supply power to hydraulics. By Occam's Razor the most likely cause was related to the smoke, which means the keel could not move by hydraulics.

If there was a working fail safe system in place we would not be having this discussion.

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CutOnce

 

CutOnce,

So wherre are you getting your information on this? Do you know when in the recovery process this picture was taken? Do you know that someone didn't release the failsafe? Do you even know what went wrong to cause this?

The reality is you are making a lot of assumptions about a boat and situation that you have no dirrect or even reported knowledge about. I have seen boats over like this time and time again, the fact that they failed somewhere is certainly likely, but without more information it is all speculation.

 

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That is just completely wrong, uninformed and unfairly speculative-if you read and understood the incident with Wild Oats you'd realize that the simplest thing could cause a problem perceived by the uniformed masses as a great failure. A problem that when viewed on the outside from an uninformed perspective fuels outrageous comments like the ones that said that the Reichel-Pugh designed Wild Oats was just another in a long line of canting keel failures. The truth of the matter was a far cry from the lynch mob mentality spewed by many then- and is likely to be now.

 

The situation with Wild Oats has exactly nothing to do with this one. You are the person making the association, and prolonging the comments. No one else brought it up.

This situation is clearly an example of leading edge development becoming bleeding edge. I did not make any comments about this being a great failure - you seem to keep bringing it up though.

You seem to be quite sensitive to any possible commentary about canting keel boats. I think this boat (Q) has implemented a far better canting mechanism that works on a unround bottom - the canting section obviously adapts to changing hull radii, and appears very fair - far better than the "round" example.

Do I respect the risk and money taken to put this boat on the water - absolutely. Do I think it "ready for prime time"? Not yet. Do I think it extraordinary? Jury is not in yet - it will take proven performance, safety and reliability to make me think so.

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CutOnce