open 20 footer

canting keels

55° is a good round number that has come to be synonomous with high performance canting keels vs, say 20,30 or 45°. Nothing too special just a good indicator....

 

So you're deciding the venue? Nope. I was thinking the City Front in Ess Eff.

Don't forget, it is in monohulls, yours on foils, and YOU have to sail it.

 

Try again.

Tell us WHY 55°. You repeat it like a mantra, over, and over, and over...

Are MaxZ 86s canting at that angle? No. How about Volvo 70s? No. Genuine Risk? Come on, tell us where it has become "synonomous" with high performance canting keels.

 

canting keels

As best as I remember the z86's ,and Genuine Risk, the Schock 40 and many others are close to if not precisely 55 degrees....
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I looked in the maxZ86 rule and max cant there is 50 degerees; 55° or close has been used on many boats but the number itself is,as I said before, just an indicator. As time goes by I'll add the boats that are close or at 55°.....
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55 degree canting keels:
1) Many CBTFco boats including the CBTF 52 Cruiser Racer
2)-6 rc canting keel prototypes of my design and three full size small boat preliminary designs of mine-12', 16' and 18'.
3) Schock 40
4) more to come....
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Why 55°? It's not a hard and fast number but you'll find if you layout a few canting keel systems that it is pretty hard to get past this angle in most hulls and with most canting mechanics-based on what I've done and what I've seen others do....It's a good target number for a high performance canting system.

 

Come on, you are the expert who has done so much research. This is your mantra. Which boats use 55°? More importantly, why? Why not 60, or 62?

 

Z86's and Genuine Risk are 52 degrees. I think the reason they dont cant farther is because the rams sort of run out of space and there isnt any more room to cant it farther unless you punch a hole through the hull. out of all the canters, only Skandia has succeeded with this method. Obviously, Lorsail supports canters and foilers, but i dont think either thing is going to assist on a 20 footer. Aussie 18's have been clocked at over 30 knots on occasion, and the only really effective foiler design which has been used on RACING boats is the Moths.

 

speed or?

Well, lets see: the 16' rotomolded Rave multifoiler has been clocked at over 30 on occaision and the Moth guys seriously believe they'll be approaching 30 in the next couple of years,if not sooner. Thats an 11'(12.75' overall) boat with 85 square feet of sail!
But aside from top speed there is the incredible light air speed of the little Moth: 19 knots in 10-12 k wind recorded on a test sail.
So I think a larger well designed two person foiler has enormous potential and it won't have near the SA of an 18-or the cost...

 

If you're going to scale up the skiff, you'll want a crew of four. And what are you guys talking about a mono doesn't need moveable ballast to be fast? Are you not counting the guys out on the wing? They certainly help hold the boat down. Are you saying you can do that without moving crew/ballast or with a leadmine?

 

Doug, re "CHris, none of the boats you mentioned SAIL on their rudder foil!(except the Moth) So, if comparing a Moth foiler to another similar foiler the overall length can be important."

Will you told Paul Bieker that his I-14s (which have a hull design developed for rudder foils) don't sail on their rudder? And basically, what is it about this "sailing on the rudder" that makes a boat that has always been 11' long, which is classed by the rules at 11' long, which is said by the designers, sailors and class to be 11' long, suddenly longer?

There are lots of classes that can't sail without bowsprits etc, it doesn't meant that they are counted as LOA. Why suddenly change the rules on the Moth? It is not the only class that relies on extensions beyond the LOA to sail.

Re "Saying that monofoilers are unproven is absurd!"

If you look at the context you will see that I was clearly referring to them being unproven in fast 20' buoy racers. They ARE unproven in that role. It's simple; are there any? No. Then they are not proven.

Surely you know from experience in 18s, Moths and flying on foilers that the techniques vary widely from a Moth to an 18...... you DO have experience on 18s and Moths and flying on foilers don't you?

"Even with a souped up 18 sailing alone would drag out the learning curve not eliminate it-which was my point."

Not really, there's a vast amount of info; videos, books, articles, sailors, regattas to go and watch; that will teach you how to sail a big skiff. There's no-one who knows how to sail a big skiff foiler.

By the way, I found out Full Pelt went against the non-canting Libera boats in Lake Garda? Beaten in the first race, retired with canting mechanics problems in the main event.

 

speed length

Chris, I've always thought it was absolutely ridiculous to call a boat 11' when it was actually 1.75' longer than that! In the Moth for the purposes of comparisons to other foilers overall length is important. I've said clearly
said that 12.75 is length overall putting it in parentheses next to the hull length-11'(12.75' LOA).
Comparing the way Paul Biekers 14 foil performs to the Moth in terms of what the rudder foil does is completely off base: they act in two different ways! As you can tell by looking at a picture of both boats under sail...

 

I was hoping The Lord of All Canting and Foiling would answer here, using his vast (half-vast?) knowledge.

You are in the ball park, but just a bit off. Of course the lug above the keel pivot can be quite short, so through a large range of motion it can stay inside the boat. As the length of the lug get shorter compared to the length of the fin the forces go up.

To see the real problem lay out the canting mechanism and run check the kinematics. As the ram pushes the lug away from the cylinder the included angle gets smaller and smaller. Check the forces here (another vector problem). Ditto pulling the lug toward the cylinder.

You could get around that by having independent cylinders for each tack (P&S), but then you have no redundency if one fails. If you set the angles of the cylinders to allow redundency you are back to square one.

Less than a year from now he will prove us all wrong and will be sailing a 20 foot foiler. So he claims.

 

has anyone discovered what happens if a foiler runs into a a nasty seaway?

 

foiler in waves

In the recent Moth World Championship held in Australia there were very rough conditions and the foilers did very well with Rohan Veal winning all races against about 41 other boats.
There were problems with some boats sailing through waves and crashing on the otherside; it was tough. But the non- foilers had a rough time as well...
On any foiler waves with height and period combined that cause the boat to bottom out without being able to platform(sail straight and level) or contour(follow the curve of the wave)
can slow the foiler way down. But even in the rough conditions at the Black Rock World Championship that didn't stop the foilers from winning.
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Since two foil monofoilers are in their infancy-the first one sailing in 1999- the potential they have to dominate boats described in the first post of this thread is enormous- and they'll do it with less sail area and less cost than a souped up Aussie 18, Tornado etc.


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"Paul B" I never committed to have a 20 footer of any kind; don't need it.......

 

if like you mentioned sometime earlier on some forum(not sure if it was this one) that foils will soon be suitable for open ocean racers, i dont think that is true. If you stay inshore in relatively flat water the foils will allow you to kill conventional boats, but offshore its highly unlikely foils would be able to survive dropping off large waves.

 

ocean foilers

Time will tell on ocean racing monos: if the mainfoil is retractable and ,maybe, used just downwind in the right conditions I'd bet you'll see it sooner as opposed to later.
There already are ocean going multifoilers and semifoilers and Williwaw ,a trimaran foiler of years gone by, did extensive ocean sailing.
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Even Moths aren't limited to "inshore in relatively flat water".....As I understand it Black Rock was on a big bay open to the Southern Ocean.