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Paul L
 
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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



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JAXAshby
 
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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











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JAXAshby
 
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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








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Robert Larder
 
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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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