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12-11-2015, 01:32 PM
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#1
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Veteran Member
City: Portsmouth NH / Cartagena Colombia
Vessel Name: Las Caleñas
Vessel Model: Bristol 42
Join Date: Aug 2014
Posts: 34
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Head Sail
I have read the endless discussion for stay sails but has anyone every used a HEAD sail. My boat and rig was designed for it, but the sail is missing. Before I run and have one made I am wonder what kind of lift can be expected (obviously this depends on wind and sea state.).
a) can I expect a lift in speed, what is realistic 1kt, 1/2kt ?
b) any experience with decreased roll?
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12-11-2015, 03:43 PM
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#2
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Guru
City: Flattop Islands
Vessel Name: Blackfish
Vessel Model: custom
Join Date: Dec 2012
Posts: 724
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12-11-2015, 03:57 PM
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#3
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Guru
City: Victoria TX
Vessel Name: Bijou
Vessel Model: 2008 Island Packet PY/SP
Join Date: Nov 2012
Posts: 5,290
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That's a cool boat!
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12-11-2015, 04:53 PM
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#4
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Guru
City: Bethlehem, PA
Vessel Name: Lady Kay V
Vessel Model: 1978 Hatteras 53MY
Join Date: Oct 2015
Posts: 1,098
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OK, as a recovering sailor...... a head sail is forward of the mast. Usually a jib. Be it a staysail, 100 (working jib)/110/135/150 (genoa)and so on. (100 percent is the distance from the tack, that's where the bottom forward corner attaches to the boat.... anything over 100% is the percentage of the foot, that's the bottom side of the triangle, extends past the mast) Then there's bloopers, spinnakers and other variations of downwind sails. (As in sailing on a broad reach or running, which is....but I digress.....)
Why yes I do have some experience, with a slew of sailboats over the last 50 years, but more to the point, recently a 37 foot motor sailor where we collected just these kind of data.
So here's the answer to your question. If you get a LARGE jib up there..... say 300+ square feet and it's blowing on the beam or abaft.... at, oh, 15 or so knots..... you will add 1-2 knots. In reality what you will do is pull back the throttle, because you don't want to waste any added energy pushing hull speed. So.... WAG 7 knots at 1450 rpm would become 7 knots at 1050.......Burn would be less. If your a twin, you may want to consider shutting one down. (Caution, depending on your tranny this may require a shaft brake)
So a sail may help for economy..... it's not going to turn it into a Cigarette.
There are plenty of used sail lofts. Even if you can't find the exact size, get something bigger for not too much, and have them cut it down.
Sailors change sails like power boaters change props..(chasing the same dream.... more for less)... and the cost is about the same. Always used sails around.
I hoped I answered your question. If you want to yack, pm me your number.
(And no, you will never see any benefit forward of a beam reach...(Wind coming in 90º to the centerline of the boat)
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12-11-2015, 06:22 PM
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#5
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Master and Commander
City: Vallejo CA
Vessel Name: Carquinez Coot
Vessel Model: penultimate Seahorse Marine Coot hull #6
Join Date: Sep 2010
Posts: 12,559
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My headsail is significantly larger than the "mainsail." Nevertheless, I use the mainsail more frequently than the headsail because it's easier to handle and is usefull in more wind directions.
__________________
Kar-KEEN-ez Koot
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12-11-2015, 06:52 PM
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#6
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Guru
City: Flattop Islands
Vessel Name: Blackfish
Vessel Model: custom
Join Date: Dec 2012
Posts: 724
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A cut down used sail might sorta work, but it will never be very good. The rig on a powerboat (short, with horizontal headstay) is a very different shape than today's typical high-aspect sailing yacht with vertical headstay. The sails are a very different shape, and cutting one in half will not work that great. It's fine to cut the foot off a sail, more or less square, but cutting the whole middle out of it is not recommended. But talk with a sailmaker about it.....
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12-11-2015, 06:57 PM
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#7
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Guru
City: Bethlehem, PA
Vessel Name: Lady Kay V
Vessel Model: 1978 Hatteras 53MY
Join Date: Oct 2015
Posts: 1,098
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A horizontal headstay? You have a diagram to go with that?
A larger headsail cut down (properly) will do fine on a trawler on a beam reach. Barn door lift only. No laminal flow. No way to make this a finesse thing.
I understand what you're saying, sort of, but it's waaaay simpler.
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12-11-2015, 07:42 PM
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#8
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Master and Commander
City: Vallejo CA
Vessel Name: Carquinez Coot
Vessel Model: penultimate Seahorse Marine Coot hull #6
Join Date: Sep 2010
Posts: 12,559
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While underway and under hull-speed, the sails can add half a knot in ten-knot winds from abeam.
__________________
Kar-KEEN-ez Koot
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12-11-2015, 08:38 PM
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#9
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Guru
City: Marathon, Florida
Vessel Name: Walkabout
Vessel Model: 1989 Sea Ray 380 Aft Cabin
Join Date: Jan 2012
Posts: 521
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Quote:
Originally Posted by Tad Roberts
How effective the sail is will depend on; 1) the sailmaker, 2) rigging tension, and 3) sheeting angles. Adding sail area will certainly help across or downwind, but don't expect that boat to sail upwind at all. With only 82 sq ft (34 main & 48 jib) the 4000 pound Timbercoast will sail (no engine) at 2.5 knots in 10 knots of wind, 3 knots in 12 knots of wind, and 4 knots in 15 knots of wind. She will also sail upwind at 60 degrees to true wind angle. I attribute this as much to deeper than average draft (and a big rudder) as to anything else.
Attachment 47243
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Tad, that is a really cool boat.
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12-12-2015, 06:07 AM
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#10
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Guru
Join Date: Oct 2007
Posts: 22,553
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Sails are usually made (hoisted) from aft to fwd , and struck (lowered) from fwd to aft
This is so a vessel with a normal sail rudder (big) and keel can sail under full control with the raised sails.
A jib alone would help some downwind , but do little as a steadying device until a high wind speed.
At 17K a sq ft of sail area can create a pound of push downwind .
250 sq ft , 250 lbs of push @ 17K, about equal to a 12-13 hp push from an engine.
About the same as an extra GPH of fuel burn , perhaps + 1K.
If you were willing to throttle back to maintain the same speed , it might be more worthwhile , but Heating oil is about $1.20 today so under $2.00 diesel is on the way.
Look up the variety of propulsion kites that can be flown from the bow ,these can be far more effective .
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12-12-2015, 07:53 AM
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#11
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Guru
City: Bethlehem, PA
Vessel Name: Lady Kay V
Vessel Model: 1978 Hatteras 53MY
Join Date: Oct 2015
Posts: 1,098
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Don't remember what the results from this were, doesn't look like it's use has become widespread.....
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12-12-2015, 11:33 AM
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#12
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Guru
City: Adelaide
Vessel Name: Kokanee
Vessel Model: Cuddles 30 Pilot House Motor Sailer
Join Date: Jul 2012
Posts: 3,218
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I have a 200 sq ft mainsail, and a 100 sq ft jib. Although I usually run both, I occasionally run with the jib alone, and the effect on both speed and roll reduction seems to be relative to the sail area. (mainsail has roughly double the effect of headsail)
I'm not sure what size headsail your forestay could carry. Maybe 150 ft2 ? as it seems limited by the flybridge canvas. I doubt if you'd be overwhelmed by the extra speed, however, I think you would be pleasantly surprised with the roll reduction.
A soft bilge hull shape such as the Bristol 42 will benefit greatly from a steady sail; much more so than a hard chined hull.
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12-12-2015, 05:58 PM
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#13
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Guru
City: Mooloolaba
Vessel Name: Flora
Vessel Model: Timber southern cray boat
Join Date: Oct 2007
Posts: 1,859
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I run up my main sail if I am really after roll reduction but put up both if wanting to gain speed or reduce fuel consumption. Very rarely put up the mizzen except maybe at anchor for a bit of direction.
__________________
"When I die I hope my wife doesn't sell my toys for what I told her I paid for them"
Money: It's made round to go round , not flat to stack.
"Get out and do it"
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12-12-2015, 06:18 PM
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#14
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Senior Member
Join Date: Sep 2015
Posts: 494
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Sail
Quote:
Originally Posted by Jimmy James
I have read the endless discussion for stay sails but has anyone every used a HEAD sail. My boat and rig was designed for it, but the sail is missing. Before I run and have one made I am wonder what kind of lift can be expected (obviously this depends on wind and sea state.).
a) can I expect a lift in speed, what is realistic 1kt, 1/2kt ?
b) any experience with decreased roll?
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GB 32'. Pic from PassageMaker.
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12-12-2015, 06:25 PM
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#15
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Senior Member
Join Date: Sep 2015
Posts: 494
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Sail
GB 32'. Pic from PassageMaker Magazine
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12-12-2015, 06:53 PM
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#16
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Guru
City: Victoria TX
Vessel Name: Bijou
Vessel Model: 2008 Island Packet PY/SP
Join Date: Nov 2012
Posts: 5,290
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Quote:
Originally Posted by Tidahapah
I run up my main sail if I am really after roll reduction but put up both if wanting to gain speed or reduce fuel consumption. Very rarely put up the mizzen except maybe at anchor for a bit of direction.
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Sure like the looks of your boat!
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12-13-2015, 06:49 PM
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#17
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Veteran Member
City: Portsmouth NH / Cartagena Colombia
Vessel Name: Las Caleñas
Vessel Model: Bristol 42
Join Date: Aug 2014
Posts: 34
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I was unable to google this article or boat. What issue was this in. Thanks JJ
Quote:
Originally Posted by omc
GB 32'. Pic from PassageMaker Magazine
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12-13-2015, 06:56 PM
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#18
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Veteran Member
City: Portsmouth NH / Cartagena Colombia
Vessel Name: Las Caleñas
Vessel Model: Bristol 42
Join Date: Aug 2014
Posts: 34
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Lots of really cool boats! Thanks all. I would post a pic of the rig but I can never remember how to post a pic on this site.
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12-13-2015, 07:26 PM
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#19
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Guru
City: Hotel, CA
Join Date: Sep 2011
Posts: 8,323
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Quote:
Originally Posted by Jimmy James
Lots of really cool boats! Thanks all. I would post a pic of the rig but I can never remember how to post a pic on this site.
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http://www.trawlerforum.com/forums/s...-etc-5739.html
Post number 6 of the above linked thread explains the painless process quite susinctly sir.
__________________
Craig
It's easier to fool people than to convince them that they've been fooled - Mark Twain
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12-14-2015, 03:09 AM
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#20
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Senior Member
Join Date: Sep 2015
Posts: 494
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PassageMaker magazine
Quote:
Originally Posted by Jimmy James
I was unable to google this article or boat. What issue was this in. Thanks JJ
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Hi Jimmy James,
I took pictures of this PassageMaker article and made it in PDF. If you give me your email address, I will send you through email.
omirabelch@yahoo.fr
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