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#1
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There aren't too many other things you can do to gain that much performance
that easily. Paul "Glenn Ashmore" wrote in message news:OI2Yc.31945$A91.27814@okepread02... JAXAshby wrote: glenn, just where is it you found you "facts" that "a medium displacement boat" has 2,866.66666666 pounds of drag? From the VPP diagrams and backup data on my boat, the VPP for a Beneteau First 47, C.A. Marchaj's "Sail Performance" and working backwards from Dave Gerr's figures. The VPPs were run with standard and Gori folding 3 bladed props and showed from 12 to 15% increased speeds with the folding props up to about 80% of the first reef point. 20 miles a day is a 15% improvement on a base 5.6 knot cruising speed and you are correct that folding props make the most difference in light air. Reducing drag has the advantage over adding sail area in that it does not add to heeling moment. BTW, Gori, Martec, Brunton/Varifold and others make 3 blade folders. Volvo even makes a 4 bladed folder. Now, you can continue to rant and make an ass of yourself as usual but that is all I have to say about it. -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com |
#2
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There aren't too many other things you can do to gain that much performance
that easily. sure there are. you can clean the bottom of your boat. you can thoroughly fair the hull before you bottom paint. you can take 500# of useless junk out of your boat. you can trim the sails. you can buy better sails. you can take down your dodger and/or bimini and/or 3 of your 8 solar panels. you can use a hank on jib instead of a roller furled jib. you can use a vinyl bottom paint. you can do polars on your boat to sail it smarter. you can move your anchor and 275 foot of chain to the center of the boat. you can sail more so you need 300# less fuel onboard. ----------------------- you can install a two blade prop ------------------------- which i damned cheap and damned effective. you can line up your prop with the keel. To name just a few. Paul "Glenn Ashmore" wrote in message news:OI2Yc.31945$A91.27814@okepread02... JAXAshby wrote: glenn, just where is it you found you "facts" that "a medium displacement boat" has 2,866.66666666 pounds of drag? From the VPP diagrams and backup data on my boat, the VPP for a Beneteau First 47, C.A. Marchaj's "Sail Performance" and working backwards from Dave Gerr's figures. The VPPs were run with standard and Gori folding 3 bladed props and showed from 12 to 15% increased speeds with the folding props up to about 80% of the first reef point. 20 miles a day is a 15% improvement on a base 5.6 knot cruising speed and you are correct that folding props make the most difference in light air. Reducing drag has the advantage over adding sail area in that it does not add to heeling moment. BTW, Gori, Martec, Brunton/Varifold and others make 3 blade folders. Volvo even makes a 4 bladed folder. Now, you can continue to rant and make an ass of yourself as usual but that is all I have to say about it. -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com |
#3
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#4
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putting a folding prop on Westsail is like putting Nikes on an obese man.
The person that inquired has a Westsail. This is not a racing boat. He wants to sail faster WITH the dodger and bimini, and with the roller furled jib and with the solar panels and the fuel etc. He isn't racing. Just because these are all things that can make a boat go faster doesn't mean that they are viable options for a cruising sailboat nor that the folding prop isn't also an option that he can use effectively. grandma Rosalie |
#5
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The other way of looking at it is that the Westsail needs all the help it can get ;-)) Bob Larder JAXAshby wrote: putting a folding prop on Westsail is like putting Nikes on an obese man. The person that inquired has a Westsail. This is not a racing boat. He wants to sail faster WITH the dodger and bimini, and with the |
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