Head Sail

[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?

 

[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.

 

[cardude01]

That's a cool boat!

 

[oscar]

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)

 

[markpierce]

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.

 

[Tad Roberts]

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.....

 

[oscar]

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.

 

[markpierce]

While underway and under hull-speed, the sails can add half a knot in ten-knot winds from abeam.

 

[READY2GO]

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.

View attachment 47243

View attachment 47244

View attachment 47245

View attachment 47246

Tad, that is a really cool boat.

 

[FF]

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 .

 

[oscar]

Don't remember what the results from this were, doesn't look like it's use has become widespread.....

 

[AusCan]

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.

 

[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.

 

[User915]

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?

GB 32'. Pic from PassageMaker.

 

[User915]

Sail

GB 32'. Pic from PassageMaker Magazine

 

[cardude01]

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.

Sure like the looks of your boat!

 

[Jimmy James]

I was unable to google this article or boat. What issue was this in. Thanks JJ

GB 32'. Pic from PassageMaker Magazine

 

[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.

 

[CPseudonym]

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.

http://www.trawlerforum.com/forums/s22/set-up-your-account-|-help-tips-etc-5739.html

Post number 6 of the above linked thread explains the painless process quite susinctly sir.

 

[User915]

PassageMaker magazine

I was unable to google this article or boat. What issue was this in. Thanks JJ

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

 

[ranger58sb]

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.

Might be useful; your mast (in your avatar) looks to be so far aft that a head sail would likely foul on your cabin, flybridge, bimini, etc.?

-Chris

 

[User915]

GB with sail

GB 32' underway with sail

 

[ranger58sb]

Not a "head" sail, oui?


-Chris

 

[User915]

Oui, not a head sail. But a friend of mine had that kind of sail on his GB 42' classic, and this sail improved a lot stabilization, then I thought it was interesting.. Sorry about that.

 

[ranger58sb]

Indeed, interesting.


I didn't mean to make my note sound like a criticism. I was just beginning to wonder if I correctly understood what a head sail is, especially since JJ's mast in his avatar is so far aft and I can't make out a forestay in that pic.


-Chris

 

[Jimmy James]

I hope this gives some perspective. Yes, the bimini would be in the way however on long passages I take it down.

 

[markpierce]

My jib has a single sheet (only one line controlling the sail rather than two sheets, on both port and starboard), means I need to "rewind" the jib to tack. Thus, I don't hoist the jib when winds are shifting or I would need to make frequent tacks, or if I'm not unusually energetic.

 

[AusCan]

The PM photo of the GB headsail looks fairly similar to your possible headsail setup JJ. If the winds are flukey, it would certainly foul on the bimini. Close hauling certainly would be a problem. But on a steady beam reach, you'd be able to make use of a fair amount of sail area.
Tacking would be a pain in the butt, unless you had a furler to pull it in during the tack. This may not be much of an issue though, as you'd likely only use it in open water with a steady wind on the beam.

 

[Jimmy James]

The on GB in PM he has a much more vertical stay than I have. See the drawing I posted of a Bristol 42 and is the exact layout of my boat. This sail would only be used on long runs and not in shifty conditions. It would not be of any use or used for any wind fwd of the beam. Since most passages should be made (in a perfect perfect perfect world) on a min of a beam reach and ideally down wind this sail could prove to be invaluable. According to the PM article the GB was able to nearly double his economy and as a bonus added 1 kt to his cruise speed. His goal and actions were to make his GB a sailboat which he did. My goal is to smooth things out and gain a bump in economy. I have the main sail already and the boat is fully rigged (I think over rigged really) I may borrow a small sail and try it out. I think the single line concept is the way to go. First its simple and second it make you go out and walk the line around (which could be dangerous) but also makes you look at your gear. In borrowing a hanked on sail I can add a down haul to bring the sail down, tack/jibe and raise as a test. This should be easy because flybridge will skirt much of the wind very quickly.

 

[User915]

Jimmy James, by the way, the sail on my friend GB 42' classic improved astabilization when at the anchor as well, helping the boat to stay still in the direction from the wind came. Hope you understand what I mean. Olivier.