Michael wrote; >The person we need here is John Winters; he's said that stability >is one of his favorite topics. He's also explained broaching in a >way that is easy for me to understand. AWWW Shucks. Like so many things in boat design volume can have a positive or a negative effect just as stability can cause problems as well as solve them. In a better world boats would be designed as system with every part or factor balanced to produce a given result. The better world having not yet arrived we do the best we can with what we have. The problem we face is that a person having a bad experience with a type of boat might assume that a particular factor (high or low volume for example) is a "bad" thing when the problem may have been how the volume was distributed. A simple example; Imagine a boat with X volume but having "U" shaped sections with vertical sides It will probably pound and be slow. Now imagine the same volume boat with "V'd" sections that have a concave side. It will probably pearl and plunge deeply into waves. Clearly how the boat gets shaped affects the way the boat performs. Now imagine a full ended high volume boat with "V'd" sections tapering up to a chine. It might not pound at all and may have enough lift when immersed deeply to prevent pearling. Now imagine a fine ended boat with spray rails or a flaring topsides. It might do the same thing. Simply put, one can achieve the same thing in many ways. The issue of control also lends itself to a multitude of solutions. One can approach control as something that one does with the paddle I.E. a short rockered boat. One can also approach it as a long boat with excellent directional stability that will not allow the boat to waver from the desired course. Both approaches work for specific goals. All this applies to stability. Some features (high initial stability coupled with low displacement) can be dangerous in some conditions but it can also be advantageous in others. The great sponson war erupted because people claimed that sponsons were all good or all bad. In truth they had good features and bad features and so long as one did not assume they made everyone safe all the time you might get some benefit form them. Boats with low initial stability have value in those conditions and circumstances where that proves useful but the blanket statement that the characteristics is always best simply doesn't hold water. Not much help other than to emphasise that what one wants may not have anything to do with what one gets. Cheers, John Winters Redwing Designs Specialists in Human Powered Watercraft http://home.ican.net/~735769/ . *************************************************************************** PaddleWise Paddling Mailing List Submissions: paddlewise_at_lists.intelenet.net Subscriptions: paddlewise-request_at_lists.intelenet.net Website: http://www.gasp-seakayak.net/paddlewise/ ***************************************************************************Received on Wed Feb 24 1999 - 05:45:37 PST
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