Wing keel vs fin. I think, today's winged keels are the best, most practical, and efficient way to shorten draft, but sailing performance will be better w a deep, narrow fin. The wing gets the weight low, and maintains lift and righting moment. When the boat is heeled, the wings work like an endplate and improve lift and reduce leeway. However, most experts state that a deep fin will work more efficiently, point higher and be slightly faster. This is easily proven by comparing the PHRF ratings that give give credit to winged keels over fin, yet when checking this model the difference in PHRF is only 3 secs.
Summary: The difference in draft of 17" is probably more important than the difference in performance of 3 sec/mile. Chuck Resolute 1990 C&C 34R Broad Creek, Magothy River, Md ----- Original Message ----- From: "robert via CnC-List" <cnc-list@cnc-list.com> To: cnc-list@cnc-list.com Cc: "robert" <robertabb...@eastlink.ca> Sent: Sunday, May 1, 2016 11:35:19 AM Subject: Stus-List Wing Keel Lift? The America's Cup left the NYYC in 1983 but I believe Dennis Conner won it back in Perth, Aus, in 1987. So, correct, it did not return to New York City but I am confident the Americans won it back with an even different keel......I have a book somewhere on the keel he used in Perth......it's like a fin keel with an extension that goes back.....there a name for it.....they kept it under raps until after the races. I'll look it up later. Conner's tested it in Hawaii before bringing it to Perth......it worked. Rob Abbott AZURA C&C 32 -84 Halifax, N.S. On 2016-04-30 4:27 PM, Jerome Tauber via CnC-List wrote: (Sorry - first posted this as reply to wrong posting). Keel lift is a horizontal, not vertical force. Keels are hydrodynamic foils - when they are moved through water they cause both lift and drag forces to develop. Lift is the positive lateral force that allows a boat to move to windward - drag is the negative, resisting force. A good sailboat keel design has a high lift-to-drag ratio. Wing keels were developed by the Australians to win the 1983 America's Cup (first U.S. loss) by getting around the keel depth rules. When the boat heels, the wings increase the draft of the keel creating additional lift. This being said, I'm sure the angle at which the wing cuts into the water does have an effect but that is not what is meant by keel lift. The America's Cup left NY in 1983 never to return but this May there will be some preliminary cup races in NY Harbor with boats that truly do lift out of the water. Jerry -----Original Message----- From: Lorne Serpa via CnC-List <cnc-list@cnc-list.com> To: cnc-list <cnc-list@cnc-list.com> Cc: Lorne Serpa <lorne.se...@gmail.com> Sent: Sat, Apr 30, 2016 2:47 pm Subject: Stus-List Wing Keel Lift? So, working on buying my 1st sailboat greater than 15'. It's a 1988 30MkII. It has a wing keel. I read somewhere that a wing keel generates some lift. So.... Does a wing keel create lift? Should I have more heavy stuff at the back of the boat for increased angle of attack on the keel? Or.. don't be silly.. its a 8,000lb boat going 5 knots. It does nothing. Lorne _______________________________________________ This list is supported by the generous donations of our members. If you like what we do, please help us pay for our costs by donating. All Contributions are greatly appreciated! _______________________________________________ This list is supported by the generous donations of our members. If you like what we do, please help us pay for our costs by donating. All Contributions are greatly appreciated! _______________________________________________ This list is supported by the generous donations of our members. If you like what we do, please help us pay for our costs by donating. All Contributions are greatly appreciated!
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