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Validation_Box: third
From: Mack McKinney
Date: 21 Dec 2007
Time: 12:30:08 -0500
Remote Name: 24.173.230.42
I'm probably the least qualified to post a response, but instinctively my knee jerked on this one. It occurs to me that suction, which from our perspective is the force of the atmosphere unsuccessfully attempting to intrude on a vacuum (sealed in this case by water,) as a significant resistant force can only be considered on a body in motion and with a vector 180 degrees opposite the direction of movement. Obviously the only time a boat is static is when it's on the hard, but the resistance of suction might be a factor if for some reason you were trying to lift the boat directly up by its keel and from a fairly level and calm body of water. The event of turning turtle is the result of significant wave action, where the surface of the water is probably never going to be allowed to adhere to the deck enough to keep the atmosphere out, especially given that the wave action would need to create a sustained surface that could form a hermetic seal 30' x 11' over the length of time that all other forces in combination with "suction resistance" could possibly counter the righting forces. In other words, this seems to me to be a theoretical factor if you built your boat without any bulwark scuppers and could find a way to turn turtle with your full sail resisting lateral movement against the water, the wave action calm enough to not want to push the boat back right, the wind calm enough or from a direction that would not push on the inverted keel, the wooden mast not seeking bouyancy, etc. In other words, I don't think we need to consider the force of suction when judging hull and deck form. I am also uncomfortable with the notion of the beam of the Sovereign exceeding a "recommendation." This question implies that Tom was aware of some absolute (as in, higher authority) precept or dictate that would legislate XXX as the "upper limit" and chose to violate it. Logic would indicate that when a successful and seasoned designer departs from, say, "boat show" norms, he or she would have put some thought (read, "stability curve calculations, righting moments, ballast/whatever ratios, etc. as well as philosophical purpose and desired outcome) into his or her justification for doing so, and therefore balance the "radical/innovative design" with the designer's judgment of expected returns in all concievable situations. Said another way, I'm sure that Tom asked the question of whether the additional volume gained below decks will compromise safety in terms of righting ability, sailing characteristics, and resistance to winding up in the situation as you imagined it. To sum things up, I think it is a very good idea to question things, pick ideas up and turn them over so you can see them from all angles, and I encourage you to continue to do so. I, too, have had some challenges wrapping my mind around a few things that Tom does (for example, I still have an entirely emotional resistance to the junk rig simply because I prefer the aesthetics of a gaff rig, even though the junk makes so much more sense,) and I believe that was the tenor of your initial question. I think that the beam/length ratio needs to be considered within the context of the entire boat and therefore it's other parameters (ballast, form, sail area, etc.) I personally think that the biggest issue one faces with a beam of 10'10" is whether you can fit the boat between the pilings at your marina. If you look at some of the "tradtional" forms developed in the latter part of the 1800's you will find some surprising beams as well. As for me, I trust Tom's design judgment much, much farther than many more popular desginers.