16' Keel boat-high performance

I am concerned about the canting mechanisms in Tactics pic being so close to the sailors family jewels (if it were a guy) could have implications in future.

 

Dead right John, another reason not to use a canter !
Tactic

 

What about canting rig only, kind of similar to canting the keel but safer and probably simpler and cheaper to arrange than a canting keel.

 

Dont canting keels increase performance more so than a canting rig?

 

16

The canting rig would sure be simpler but the potential gain is much less. You might be able to cant the rig 30° but thats doubtfull and that means the boat is heeled 30° with the rig vertical.
With a canting keel you should be able to get 55° or maybe 60° with the rig vertical and the hull level.
The canting strut in Tactic's drawing doesn't need to be there. He shows an inverted T bulb/strut inersection when you could use an L shaped intersection that would move the strut much further forward. That would be possible using a CBTF type system since the strut develops no lateral resistance. In fact, in that case the strut could even be angled a bit if it didn't interfere with other things too much.
Even then the problem remains to keep the crews legs & feet out of the way.
And I think using CBTF on this small a boat would be too expensive more than likely.
If you go to a lateral resistance solution like wings then the strut changes to a working fin and would have to move back to the position shown in Tactic's sketch.
There are solutions to make either version work but the real problem is having to retract the keel fin/strut.
This is probably too wild for the market and would probably be too difficult to sail but I've thought of something like an 8-10' hollow wing shape running athwhartship and supported by "trapeze "wires going to the mast that could carry a 150-200 pounds and be either electric or hand cranked.If it was too much to handle you could tame it a little by having a small amount of ballast on a daggerboard. You could tie the mast into the athwhartship weight movement up to maybe 15 or 20° max. The wing would be mounted so that as the weight moves outboard and the hull heels it stays level and the inside seat could be tied to the wing in such a way that going downwind you slide aft-wing and all. The system works on a model...

 

High performance 16' self righting singlehander

I still think a boat along these lines has potential. The combination of self righting , retractable keel, sit inside(no hiking) and real serious high performance is lacking completely in small boats. The racing in the 2.4 Meter class is good from what I read but the boat is slow as are the other singlehanded sit-inside keelboats.
I wonder why something like this hasn't been done?

 

I bet a laser would beat it. At that size, the person crewing it makes up a substantial portion on the total displacement. If that person can't use his weight to flatten the boat, more ballast would be needed. The result would be a boat that weights 3 times as much as a laser. Since the person is sitting on the centreline, and there is a canting keel, this could also be dangerous (autotack, sails fill, and boat goes over with the keel on the wrong side). Have you seen a canter sailing with the keel on the wrong side? chances are the person would get dumped. This is why singlehanded sit-inside keelboats are underpowered and slow. For safety (especially if it's a special olympics boat). The single person would also have way too much going on with steering, sheeting, and canting keel.
because they have the keel these would also be difficult to transport (no car topping), and would be a commercial failure. No one wants a small, slow, underpowered keelboat. (If it's small, it should be a sportboat)

 

Movable Ballast 16' or so

At first I was 100% behind using a canting keel. It could be moved electrically or by hand; a trunk could make it retractable and the kFOIL or fixed wings could eliminate having a daggerboard for lateral resistance. But after working on it for a while it became apparent that achieving a 50+° cant angle at this boat length would be difficult with a retracting system.A Bongo-like boat with the keel canted and the crew on the rail might still be a blast to sail with either manual or electric canting keel-and would sure as hell beat a Laser. But it violates the "sit inside" concept....
So I think I'm leaning toward an on-deck movable ballast system with no keel or litely ballasted daggerboard (75lb or so) if sailed by a disabled person. The weight(140lb+ and inside a wing with buoyancy podsthat might also move) would be moved electrically or by hand(or foot) and would allow numbers at least as good as a two person boat with a trapeze.This kind of a system is much easier to move than a canting keel and the weight can be moved significantly further to weather. Capsize would be recoverable esp. with the ballasted daggerboard and would be greatly aided by having buoyancy pods like the larger Bethwaite and Langman boats described in another thread. And the crew sits inside and low down.....
See this thread:
http://www.boatdesign.net/forums/showthread.php?t=8799

 

I think this is a great idea Doug. I just commented on the mini-12s in another thread, before seeing this one. I know of many older folks who would enjoy a boat like this, excellent sailors in their 70s and 80s for whom sailing a Sabot is both too uncomfortable and too boring. For these folks, such a boat would have to be easy to get in and out of, almost capsize-proof or easy to self-rescue, and easy to rig and launch. The mini-12 was almost there but not quite.

I've sailed mini-12s a few times, and they're a blast. However, part of their appeal is being a slow boat for small waters. The kind of boat you're talking about now is more interesting technically, but a whole new can of worms. I think there's plenty of room for both though!

I've thought of building a small, cartoppable tri like the ones on Kurt Hughes' website, as a fun toy for myself. The only reason I'd want to build one is that I can't just buy it, at least not that I'm aware of.

 

"sit inside" performance boats

Matt, I've always liked Kurt Hughes designs! The very first "sit inside"boat I had the pleasure of sailing was a 14' tri I designed. It was fast and exciting to sail but it could pitchpole.
With the 16(-18) concept I'm trying to come up with something that has the selfrighing capability of a keelboat with the performance of a really fast dinghy.It should be able to be beach sailed and quickly set up.It would be designed for a 220-250 pound crew so it could be "weight equalized" for any crew weight which would open up the range of sailors that could sail this thing in OD competition.
Something that would be a performance step up from a 2.4 Meter and that could be sailed by any sailor regardless of physical ability.
But basically it would capture the speed of my early 14 without the wipeout risk- or maybe it coud be sailed in different configurations like the Bethwaite UD18 that is the new paralympic boat.
Sailing something like this you don't easily forget and I want to do it again!

 

You may have alluded to this previously, and if so I apologize, but it would also be possible with the weighted wing to attach a small pod to each end of the wing so that if you did get caught with the weight on the wrong side it would not capsize. I am not certain, however, whether this could be done iwthin a maneagable size and weight.

 

"Pods"

RC, that's a good point -it would be easy to incorporate molded buoyancy pods into the wing. I think I mentioned this on another thread but there are two ways of doing the wing:
1) Sliding Ballast + Sliding Wing: the lightest way is to have the wing move with the ballast which allows the wing to move considerably further to windward becoming as effective as a fixed wing almost twice as long.This allows the weight of the wing to be part of the rightng moment. There is very little wing+pod to leeward when the sliding wing is at max extension to weather.
2) Fixed(non sliding) Wing+ Sliding Ballast: this is easier to set up ,in some respects, but requires a long wing which is heavier.This set up keeps a buoyancy pod well out to leeward in case of a hand of god gust.
-----------------------------------
With both versions the wing would pivot so that the boat could sail at a twenty degree angle of heel with the wing level. The wing AND crew would slide aft a bit and the boat would use (at least) a rudder t-foil to help prevent pitchpole. For trailering the wing would swing around parallel to the boat's centerline.
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RC, which of those two versions of the wing system do you think would be better?

 

I believe that the sliding wing would probably be best. The non-sliding wing would be simpler, but the added material would add to the cost and might outweigh other savings. The reduced weight overall and lower ballast requirement (because it would not also have to balance out the other half of the wing) would also be critical because this is a reasonably heavy boat to begin with.

 

sliding wing

Thanks RC-I think I agree with that except that at 16-18' this boat has the potential to be as light or lighter than any other TWO person
boat in this range. Depending on the amount of weight used in the daggerboard it could even be substantially lighter.
The Bethwaite UD18 uses variable amounts of keel ballast as a "lead assisted skiff"(LAS); if this boat was ever produced it could have one daggerboard weight for disabled sailors to help insure self righting and another or no board weight for able bodied sailors.
What I like about it is the combination of high performance characteristics in a sit down configuration-like a 2.4 meter except much faster....

 

That is a good point--I am still comparing it to one person boats like a Laser, omitting the fact that this would have the righting moment to throw it into a two person class.