Agree, John Bertrand wrote a book that described the design process of the Australian winged keel, the controversy around it, and he stated the keel was chosen to get more sail area within the rule, and the hull was very fast and another keel might have improved it further. That keel was weird, long along the bottom and narrow where it met the hull. Bertrand did a Herculean job overcoming several breakdowns including his bowman breaking his arm while aloft, which were all forgotten when the keel was unveiled. Liberty was a slower boat and Conners was challenged to defend the cup with his superior crew but inferior boat. Years later, Conners won the preliminary Cup races, and then switched to a faster boat. I think it was Young America.
Later, Hunter and Catalina produced many production boats with short winged keels. The Rob Ball winged keel of the 1988 to 1995 vintage has much thicker wings and the PHRF ratings prove better performance. He managed to get the weight very low without increasing the displacement very much. Chuck Resolute 1990 C&C 34R Broad Creek, Magothy River, Md ----- Original Message ----- From: "John Pennie via CnC-List" <cnc-list@cnc-list.com> To: cnc-list@cnc-list.com Cc: "John Pennie" <j...@svpaws.net> Sent: Sunday, May 1, 2016 12:03:43 PM Subject: Re: Stus-List Wing Keel Lift? Your dates are right but I don’t believe there was any magic to the wing keel - other than a way around the 12 meter measurement rule, I believe they referred to them as winglets. The also used a film on top of the keel called “riblets”- really. John On May 1, 2016, at 11:35 AM, robert via CnC-List < cnc-list@cnc-list.com > wrote: 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: <blockquote> (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! </blockquote> _______________________________________________ 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!
