Talking About Adventure In Small Boats
teak
Member
I need your thoughts,
I know tall and narrow is fast and points will.
I want to shorten my mast alot. so two masts or a realy long boom. to get the sail area,
that is the question?
a single mast would have a jib, and the boom could be 12 to 15 ft.
My two masts I have now are 18.5 ft, when I add a carbon fiber sock they will be strong enough to be free standing,
My boat is 21 ft,hull 36" wide amas 13' wide
I would love to try a pair of high aspect lugsails like these:
This would allow your masts to at least be a couple feet shorter than equivalent masthead sails. It does not appear that the guy who made this drawing ever made the boat, so I have no idea how the performance would be, but I think they look great. I'm quite confident you could get your desired 150 sq ft with two 18.5ft masts using this type of sail.
lugnut
Member
I agree with Ridgerunner except sometimes my balanced lugs seem to better on the "bad" tack, especially in stronger winds. Tough to beat a balanced lug reaching and running, all other things being equal. All ya gotta do is figure what kind of winds we're going to have in March.
Lugnut
ZeroTheHero
Member
a cat ketch is never going to point as well to windward as a sloop or similar. The aft sail is in the turbulance of the forward sail. However reaching and running they are very efficient. Also tall and skinny are only a plus if you can get the high aspect shape to the sail. It's the shape plus sail area that gives power, one or the other is no good. With the sort of rig pictured can you control the shape enough? Bring the draft forward with a flat exit? How bendy are the masts? You need the sail and mast to work together. Our Nomad is sloop rigged and has and undersized mast section so it is very bendy. When we first got the boat I could never get enough shape out of the sail, it was always too deep at the luff. The mast was too straight, I hadn't tuned it properly. When we got our new sails this was a primary concern, and while there is still more to learn we are getting much better upwind performance out of the rig. The boat was designed to have a very flexible, light spar so that tuning would be important. Also as far as a good tack vs. bad there isn't going to be heaps of difference. Maybe a knot at most. That's a guess. Sure it adds up but I think ease of use trumps all out efficiency. The gear head in me thinks you could design a way to move the booms to the windward side for max shape. Sure the process would be slow but you might make it up quickly. Of course you could also spend time and energy gaining little and risk problems to boot. Why the desire to have shorter masts? Lower center of effort? Or ease under bridges on the inside? Weight aloft? Free standing tells me they are likely tubular and stepped in a tube at deck level. Probably light. Is the boat currently rigged another way? I would go with waht you know and go for the k.i.s.s . method. Keep it simple, stupid! (that's me, stupid)
One lesson about mast and sail needing to work together. When we had the new sails made we had the main increased by almost 30%. It's almost a square head with lots of roach, like America's Cup boats. The conventional thinking with our boat was to keep the lowers slack in light air so the lower portion of the mast could sag to leeward, bringing the head to windward. This increases drive in lighter air and there for is faster. However with more area aloft the head gets pushed away so with the lowers loose our mast bends to leeward slightly, esentially depowering itself. Great in heavy air, not great in light. So we have to tune the opposite. Lowers tight in light to keep the mast in column and the head powered. We let off the lowers in higher winds.
In the most basic terms, sailboats don't go windward well at all. Deep keel boats with high aspect sails go windward better than other sailboats but only by comparison. When you are in a narrow channel with the wind against you, you need a motor, oars, paddles or a tow from a motor boat. For motorless cruising, you'll be better off with a boat that you can self power upwind in channels quickly. Also a boat that allows you to get the rig all the way down pretty easily is important.
The year Randy won the NCC, everyone was amazed by how fast his boat sails, but you should have seen how fast he was paddling up the canal!
I really like the lug rigs so I'm very biased in that regard.
teak
Member
thanks for lots of good information, it is all about compromise. I like the lug rig idea, there would be two masts,4 more spars, and about 150 sq ft if I used battens for roach. second idea that i like is a sloop, one mast to take down,50 sq ft jib,roller furling, and main with 12' boom low at mast,high aft,no battens, 92 sq ft, 142 sq with less rig, I think it should point ok, sloop rigs point well but with a taller mast.
Jerry,
I just sent you an email with the sailplan of our Core Sound 17 with fat head sails and wishbone booms on unstayed carbon rigs. No question that the sloop rig will be better to windward and if you have roller furling jib and a wishbone boom on the mainsail you will end up with the low tack and high clew you want...when supported by double top lift bridle forward and single aft the wishboom is supported when reefing and dropping the sail and we have lines under the booms to catch the sails. We have the reef lines rigged on the booms jiffy reefing style and it works great. As others have stated the split rig is at its best reaching and running. Us old guys don't like going to windward although last year I went 30 miles upwind in the Sunfish to Blackburn Point then ran out of gas.
Lightnin"
teak
Member
lightnin, Thanks, I am still thinking sloop rig and your advice about a wishbone boom sounds great, Now I think I will find a mast that is 21 ft tall, even though stayed, I will still go to the floor like a free sytanding mast, that way it will stay put while I unhock the stays, then lift strait up.
lots of help on the water tribe forum. thanks
teak wrote:
I have already made a drawing that looks like this, that is the way I am leaning.
I was going to post the drawing but I do not know how, I was going to upload it to shutterfly whith a link but .pdf does not seem to upload.
the picture you show is a proa.
Yes, a proa. This kind of rig lets the boat shunt (rather than tack) without changing sail center-of-effort so much in relation to hull center-of-lateral-resistance.
As someone said above, the thing with a shorter rig of two masts, is that the mizzen sail operates less efficiently in the wash of the mainsail, but there are other benefits to the rig that would make up for that assuming the majority of one's life is not spent going to windward. Yes, a fast outrigger can make good use of the rig because making many close reaches at high speed could get you to the target as fast a slower, higher pointing/footing boat, and with more fun. Hypothetically. But sometimes you need that "as close to 45 degrees as I can get" to miss something or to get up a narrow place -- ah, so many variables! But take heart -- I was telling my skipper, John, this summer that our reefed balanced lug, hseeted to centerline (thus lots of twist) would not let us tack us a long narrow canal against a stiff wind during the Texas 200, but he proved me wrong. I would not have believed it had I not been there. I think a ketch, well tuned, would have done as well, and if you were not racing a sloop up the canal, would feel OK about it.
Regarding comments on sail shape at the head of a sail, definitely. I'm struggling with this now. I have a squaretop-ish rig with a diagona lpole-batten so stiff that the top 4 feet of the sail will never be anything other than flat until I find a way to grind the glass pole thin toward the LE, or find a heavier batten that can both square-out the top but also allow curve. How do you square-top-sail people manage that?
However, a good sail-maker can get some good shape near the head of a standing lug. I have heard though that the high-apsect standing lugs are not all goodness and delight due to a long unsupported luff that needs high tension to make stand -- not what lug rigs were reall made for. Hopefully the mast will be stiff and the downhaul powerful, at least 3:1? -- Wade
ZeroTheHero
Member
Thistripisnecessarty, DON"T GRIND THAT BATTEN!!!! That batten is not there for shape, it's there for support. Square top mains, or nearly square top mains are not just about sail area, they are about efficiency. If you grind that batten to gain shape it will likely fail, leaving you with a sail that is not useable till you get a new batten in there. The very top of your sail will be flat, but it has a little shape and twists off to leward as wind picks up. The leach of your sail, and in fact much of it's area are far more efficient thanks to the head. The whole tuning of the sail is different than a conventional shape and is better for it. In a traditional sail the head is so tiny it doesn't contribute anything and doesn't help with shape. Also the foot is often over sheeted and offers little in power as well. A square top adds power throught the mid section while also controlling twist. When you sheet in or add vang the square top is pulled down more than in. The force on that batten is down. By attempting to pull that batten down it brings the leach more to centerline, and more in line with the boom. The affect is that the whole sail is more in line with itslef, less twist. They used to say twist was good, but square heads prove that otherwise. With a few full battens and a square head the sail is more like a hard wing than a traditional sail. Which is more efficient. That top 4 feet you think you are loosing was never helping before. It's what it is doing to the rest of the sail that counts.
Zero hit the nail right on the head, sails yous to have about 18% twist bilt in most are at about 4% now, leaving it to tuning the vang to controle the twist as described.
on kayak sails with no ajustment I pot about 12% twist, it makes them more forgiving with the fack we have no underwater presence and if a bulet of wind hits thay spill the exces power more readily.
my kayak sails are a cross between squer tops and sprit sailswith all the set made into the sail, to keep the simplisity ther but yousing a more up to date sail shape.
I have a questions for all the sail experts out there... As I have stated above, I really like the look of those high aspect, squaretop lug sails. I have also read that lugsails (when highly tentioned with very powerful downhaul) have the benefit of presenting a nice tight luff to the wind, out of the turbulence of the mast. I also understand that split rigs (such as the drawing above) are less efficient upwind than a more standard "main + jib" setup. So,what are your thoughts on this rig:
The jib head would be set low enough to always stay forward of the main yard, and it seems that with appropriate sheet setup, it would be possible to prevent the jib clew from getting hung up on the lower parts of the balanced lug.
Is this crazytalk? Been tried before to resounding failure?
My end goal is a medium performance rig for my XCR sailing canoe. I will be building larger plywood amas than the small inflatables I used during the EC. I would like something that I could use as a class 5 entry that has decent upwind performance, but I would also like to be able to build as many of the bits and parts as possible. The rig as shown has a 16.5 ft mast, which would be relatively easy to construct (birsdmouth + carbon sleeve)
Any other ideas, tips, suggestions, ect... are welcome.
Thanks,
Macatawa
I cut down a fully battened Trac 16 mainsail for Clarity, leaving an almost square top, and a preally efficient shape. With about 102 sq ft of sail, and a mast 5' shorter than stock, I don't think we lost any speed or efficiency when compared to the original partially battened 126 sq ft sail. Marconi rigs aren't as efficient as one might this, otherwise airplane wings would also be pointed at the wingtips, like many sails. True, you get more luff length, which helps slightly going to windward, but the older sail types (gaff, sprit, etc) have turned out to be far more efficient than people thought, many times surpassing modern design. OUrs worked great, even BEFORE I remembered to tension the downhaul!
I like the shape, dont be tempted to get to much fulnes in the main, the downside of a balanced lug is that the mast, spa and boom deform the sail on one tack, this can be eliviated by desiding which is the best tack to set up for on the day, and yousing a wishbone boom.
I have douts about the hedsail working well with the main going to windword, not shore if you will get a good wind slot efect hapening, but I pridict it will point higher than most on a canoe, and the hedsail will realy help with a down wind blast, being mindfull of the geomitry of the head spa I wold consider a genica cut headsailand have it easily roler reefed or abel to get it stowed in a tube like a spinica? and have it made of light cloth so it works well in light wind.
I have a pashon for modifide old stile rigs for small boats , just about all my disigns are based on sprit sails with thear origins from sentyry old working rigs.
Sumone mentiond a fat head sail, havent herd that term in years, since my aprentiship !
ZeroTheHero
Member
I have no experience with Lug sails but I have a few thoughts about it, based on hunch more than anything. I doubt you could get enough downhaul on to keep the luff controlled. Without the luff being unsupported and uncontrolled the head will fall off to leeward easily, rendering much of the head ineffective. Can you simultaniously vang and downhaul a lug? Hard? But don't relay on me, have a sailmaker give you an opinion. At the luff end of my battens I have a heavy duty car with a tensioner screw. It depends on the mast for support to make it work, with no mast I am not sure how to make it work. Good luck.
ZeroTheHero
Member
looking again, as you vang you will also tension the luff as the top of the sail will cantilever so there might be enough tension but with no mast, I can't tell. SailbirdMike, yeah you could use more downhaul, but your mast looks really straight. More prebend would help pull some draft out.
Zero,
With what is essentially a masthead rig, inducing prebend would be very difficult without adding either swept back diamond stays or an intermediate forestay, neither of which I wanted to do. Also, my mast does not rotate like a beach cat. Fortunately, in practice (and with a proper downhaul!!) the draft was just about exactly right for every wind we have encountered.
HoldYourCourse
Member
SailbirdMike,
Thank you for that wonderful example of cutting five feet of mast off and getting the same speed out of your boat. You probably gained a great deal of stability as well. The many sail questions I have tried to answer over the years have been about a new type of watertribe boat and how it relates to the latest formula 20 catamaran rigs. Simply put we have to start with the boat. Will a square top help you point upwind the answer is yes but only if you put some form of dagger board in the water. Will a tall skinny sail make your boat faster like an A-cat. The answer is yes if your hull can go through water at 18+ knots. Not if your boat weighs more than 400lbs with crew.
Teak,
IMHO, Lets start out with your new boat, 21feet long 36" wide, 13 feet wide with ammas. Find the center of gravity of the hull then go up. Design the center of effort of the rig directly above the Center of gravity. I am going to assume dagger or centerboards. If this is done many of your handling issues, weather or lee helm will go away. Next try to determine actual speed. A Hobie 21 can go 20mph but also is under 550lbs with double trapezed with 280 ft of sail on a 25ft mast on a 100 degree reach. IMHO calculate on 9mph boat speed going upwind, all the other points of the boat will take care of themselves. (You can tell I am a Isotope Skipper). I do not understand why you want freestanding masts on a 13ft wide ammas. This can become a weight to effort issue,why have 13ft of leverage on your rig if you are only going with a 12 ft mast. I would go with a tall 20 to 22 ft mast with a 175 ft main and 70 ft jib. With would be a very long boom 7-9 ft. Don't worry about square top as much as a good belly in the main. Make sure your sailmaker calculates for 9mph hull and wind speed not 20mph. Hope this helps.
If you are looking for good amas I know where there are some old Isotopes for cheap.
Your Teak E Torch was a wonderful boat What is going to happen to it?
Holdyourcourse
Almost forgot there is a smaller version of the Isotope called a Cheshire Cat. Excellent balanced high volume hulls with large storage Ports. Can be ordered as a hull or hunted down old hulls.
HoldYourCourse, the shorter mast makes Clarity incredibly stable for such a small tri with relatively low-flotation amas. During the 2011 EC, we went as far as 5 miles offshore, seeing really heavy seas (we now know the view the tidy-bowl man had just after the lever was pushed!) and we never questioned her stability, nor did we ever need the second reef in the main.
We could, however, have used a better leak sealer... !
Thanks for advice on the top batten of my square-toppish sail. The problem then is that the twist is excessive, and I need to put a traveler bar in front of me (the boom ends a couple of feet in front of where I sit) across my 22 inch wide hull -- an inconvenience when I have to "go forward" to do something, but I could build it so that I can quickly detach one side and and rotate it aside to open up the cockpit. I am guessing that about 4 feet of traveler swing will be emough to haul down and get out some twist?
My video around 1:56 shows a view of the twist in this sail. Is it my imagination? Is the twist excessive? Video at http://www.youtube.com/watch?v=k2hvRJj128o -- Wade
teak
Member
HoldYourCourse, You are right about free standing mast, I am set on this design, I am using stays,jib,spiniker,your spiniker. The mast will be freestanding and 21 ft above waterline. and I am using stays and it will be roller furling main around mast. a swivel plate on top of mast. boom is 12 ft long, with some roach the main should be about 110 sq ft. the jib is 50. overall weight without gear and people should be 225 to 250 pounds. I think that should be enough power to go past 10 kts.
you said , With would be a very long boom 7-9 ft. Don't worry about square top as much as a good belly in the main. Make sure your sailmaker calculates for 9mph hull and wind speed not 20mph.
I will take this advise.thanks.
teak
Member
what will I do with the catamaran?
I will probably give it away, At first I thought I would use so many parts from it that it would not be good to sale it. I will use the seats and mirage drives from it and maybe a few blocks, hull and tramp,sails, mast still there to get rid off.
HoldYourCourse
Member
ThisTripIsNecessary wrote:
Thanks for advice on the top batten of my square-toppish sail. The problem then is that the twist is excessive, and I need to put a traveler bar in front of me (the boom ends a couple of feet in front of where I sit) across my 22 inch wide hull -- an inconvenience when I have to "go forward" to do something, but I could build it so that I can quickly detach one side and and rotate it aside to open up the cockpit. I am guessing that about 4 feet of traveler swing will be emough to haul down and get out some twist?
My video around 1:56 shows a view of the twist in this sail. Is it my imagination? Is the twist excessive? Video at http://www.youtube.com/watch?v=k2hvRJj128o -- Wade
ThisTripIsnecessary,
Don't change the sail, it looks great!! The only changes maybe tightening the two top battens. Your boom position is something to look at possibly knot off the traveler to center the boom closer to the center of the boat. By centering the boom more "effort,force,wind" should fill out the upper part of the sail. While sailing along trying to get a good angle up wind keep in mind the weather helm, the force on your rudder If this increases drasticaly to the new boom position keep carfuly track of your speed and carefuly bare away. The angle that fills your sail and doesn't choke your hull is the perfect angle. A wind vane and a GPS could help you.
Grind away on the top two battens I do it all the time.
Going down wind this is a great sail. Just let your outhaul out 6 inches and let out your boom an additional foot. Angle off your downwind about 30 to 40 degrees. Again a wind vane and a GPS could help you.
I love these new boats. All undiscovered potential....
Holdyourcourse.
Thanks HYC. More stuff to ponder. Yeah, that tackle could be attached more gracefully. If no ice forms on the launch ramp, hope to get out and play with that plus outhaul. -- Wade
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