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On Fri, 20 Aug 2004 21:18:49 -0400, "Ron"
vaguely proposed a theory .......and in reply I say!: remove ns from my header address to reply via email All of my advice is free, and worth what you paid for it. I do not know your boat, your sail, your experience or intentions. I also have no idea of the wind, water etc conditions you will be working with. IMO, rudderless sailing of any craft is an art. You have been effectively using your paddle as a rudder. The rudders of _most_ sailing craft will have some "weather helm" (you need to pull the tiller toward the wind, so as to make the boat head away from the wind), and this is considered a safety factor. Let the rudder go (get bashed on the head by the boom?) and the boat simply heads up and stops. But the helm should not be excessive. That is to say it should be feelable, but not painful or uncomfortable to use. Obviously, the further the rudder is away from the centre of actions of the craft, the less effort will be required of the rudder to guide the boat against forces. The (back most commonly) end of the boat is best, but this is not always so. There are boats that use the leeboard/centreboard position, mast step position or rake, and sail attitude to balance the boat. As I said, it's an art. The _principles_ are simple. Put very basically, leeboard aft, boat downwind. Sail _effort_ aft, boat upwind. Move either, or the leeboard forward of the Centre of Effort of the sail, and you alter everything...depending on the boat's own "keel" effect (not much in a flat bottomed, round-chined canoe). But again, be aware that: (a) the helm can alter drastically as you alter your sail's relationship to the wind and to the craft - have you done any other sailing in a predesigned craft? * if not, at least study the basic principles of sailing. * One of the commonest reasons for pulling upwind is to have the main sail sheeted home way too tight, especially in boats with no jib. This moves the CofE back, and heads the boat up. But naturally, having the sail out one side of the boat will always pull it one way....back to the rudder, or a lot of fiddling with leeboard position. (b) a "perfectly balanced" boat could keep sailing if you fell overboard. Having said that, in a canoe even you own weight will have a possible drastic efect on the actions of the craft. Moving weight fore or aft, or side to side, could completely alter the dynamics of the boat. I would _experiment _ with giving the boat _slight_ weather helm, then look at a rudder, or accept using the paddle as one. It is rare to have a boat set up to sail _down_wind by itself. If you are sailing high, and something happens, the boat would fall away, and in the process go through the maximum power band, then simply sail away down wind, sail full of air. In many light boats (cats and _maybe_ canoes), _deliberately_ sailing downwind under duress is a good idea, because (the theory goes) you can accelerate fast enough to relieve pressure on the craft. If you are moving fast, and head upwind, you can increase the apparent wind. But having headed downwind, you can then be on the "Nantucket Sleighride" G. It's a 161/2 foot Appleby aluminum flat bottom canoe with a 3/4 keel. I have been setting the sail about 5' from the front and the leeboard about 2' behind. I need to use a paddle strongly on the lee side to go straight even down wind. If I don't use the paddle i turn into the wind. I have to admit I had it loaded with five kids and the wind was not steady the last time we sailed. But even by myself I have had trouble into the wind. I clamp on the mast step and leeboard (10" by 3/4" plywood with about 3' in the lake.) The sail is about 44 square feet. "Stephen Baker" wrote in message ... Ron, Maybe some hints as to what your canoe does would help. Is it a question of balance? Will it simply not move to windward at all? Give us a hint. ;-) Steve Stephen C. Baker - Yacht Designer http://members.aol.com/SailDesign/pr...cbweb/home.htm ************************************************** *** Marriage. Where two people decide to get together so that neither of them can do what they want to because of the other one. |
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