Mainsheet question

[JMAC]

Closing in on my mooring today in light winds I realized that I appeared to be trying to nose into the wind too much with the sails hauled in tight. I slacked off a bit and got moving better but had to tack back to get the mooring...no big deal about that, but what I would like to know - is there a visual check to know when you've got the sheets hauled in too tight for the situation at hand? Trick o' the trade thing?

[Thorne]

Other than using yarn or tape telltales, nothing that I know of. Always tempting to pinch the sails when sailing in light air, but many rigs respond quickly with more speed when let out a bit. In my extremely limited experience with small gaff rigs and spritsails, they really don't like being hauled in too tightly...

[SchoonerRat]

There is a strong temptation to try and tighten your sails in order to point higher. This is really the wrong thing to do in light air. You flatten the sail and move its draft into a shape that is depowered and far better for heavy air. Pointing too high will further reduce your speed. Your boat will be pointing at where you want to end up, but you'll be going sideways as fast as you're going forward. Experiment, and get a feel for the proper trim and the best angle of the boat to the wind.

[Ian McColgin]

Almost all small boat sailors pinch up way too much. You don't say what sort of boat, so I'll assume a normal little sail boat rather than anything super hot and not a traditional boat with a spritsail or such.

Start by sailing with the wind four points off the bow. (There's eight points to the quadrent, four is 45 degrees. Points are more easily estimated as each point subtends an angle across the horizon about equal to the width of your fist held out at arm length.) At slow sail boat speeds the difference between apparant wind and the objective wind not counting your movement is pretty marginal. So if you're really sailing 4 points off, you'll tack through eight points, leaving a nice right angle track with your wake. Sail there adjusting the sail OUT till it just tries to luff. If you have a jib, adjust that first.

So sail making eight point tacks for a bit. Get a sense of your speed. If you look closely you'll note where the bow wave leaves the boat and where the next (hopefully stern) wave is. The further these are apart, the faster you're going. At four knots, the wave seperation is just under nine feet. At five, fourteen feet. At three about 5 feet. Easy to estimate speed from that.

Once you've got that eye, try trimming the sails a little and pinching up. The quetion is how much slower you're going, versus how much less distance
you need to cover. You can make good the same total to weather if you pinch five degrees higher if you loose less than about 8% of your speed. If you pinch up a whole point (11.25 degrees) you can loose about 18.5 % speed and still break even.

How much you can pinch up with a net gain, or how much you might bear off to go faster for a net gain over the longer distance, changes a bit with conditions. Some folk can just plain feel it. Not being one of those myself, I recommend a lot of practice and close observation. Maybe even make a polar diagram showing what speed the boat makes at different angles. All that will help you make the call as to how tightly to sail.

Always remembering the simple minded rule of sail trim - for and angle of boat to the wind, have the sail out as far as you can, just about thinking about luffing.

There are many details to sail trim as you get more sophisticated but if you just don't over-trim you'll be ahead of 90% of the jokers around.

G'luck

[Canoeyawl]

"When in doubt, let it out"

[Todd Bradshaw]

....and stick an upper and lower telltale on the leech. When the upper one, in particular, doesn't show, ease the sail until it does.

[LongIslandBoy]

"When in doubt, let it out"

+1, sir!

[JMAC]

What is the make-it-yourself telltale method for the leech? Sail tape and yarn?...and at what heights?

[Figment]

Yarn has been used forever, but in my opinion it's too easily glued to the sail by a bit of dampness. Ribbon seems less prone to this for whatever reason.

Locations.... eh, 1/3 and 2/3 of the way down the leach. If the sail has battens, these are good points as well.

[bluedog225]

Wow Ian...good info. Thanks.

[JimConlin]

I've used 1/4" strips of spinnaker cloth and audio tape for telltales.

[Todd Bradshaw]

Yes, yarn is traditional, but it does tend to get stuck at times, and often on the stitching near it. I use yarn for correctness on traditional sails and live with it. I run it through the leech hem with a big needle and tie stopper knots on both sides of the leech. On other sails I use 1/4"-1/2" wide strips of hot-cut spinnaker nylon. To attach them, I use a disk about 1.5"-2" diameter of peel-and-stick Dacron insignia fabric with a small slit at its center. The disk is folded over the leech edge with the tip of the nylon strip running through the slit and tacked to one side of the sail by the disk. No holes, effective and easy to replace. One third and two thirds is fine, though I usually avoid batten pockets as they often generate their own turbulence. Depending on the layout and aspect ratio, I may use three, roughly at the quarter-height positions. Jibs get uppers and lowers on both sides of the sail, placed slightly aft of the luff. They're excellent steering telltales. Jibs don't generally get leech telltales. That big dent you're pushing in the mainsail is usually a pretty good sign that the jib is over-trimmed.

Yarn:


and nylon

[Peerie Maa]

If I don't misremeber from waaay back when I was being taught to sail. I think that you sheet in the main until the leech just stops trembling.

[Ian McColgin]

Nope. Even when a sail is overbagged and twisted by letting the boom lift too far, the leech only flutters if it's stretched, not fair with the rest of the sail. To "correct" this many sails have a leech line (sailmaker's second best friend, after the batten pocket). Leech flutter may tell you a lot about the sail's condition but in itself has nothing to do with finding correct trim.

Let it out to just almost thinking about contemplating luffing. Or let it out till it does luff and tweek it in gently till the luff is barely gone.


That's for trim. But how high should you point? Out to about a beam reach, you always go faster as you bear off. The reason for doing lots of careful observation is to judge the relationship of speed through the water at a give angle where you're still not pointing right at your goal and the velocity made good to that goal.

Draw three icosolese triangles with the same base, one 30-120-30, one 45-90-45 and one 60-60-60. These represent the extremes and the nominal norm for beating. Clearly if you can only sail 60 degrees off the wind, it takes two miles of sailing to get one mile to weather. If you're slick enough to sail 30 degrees into the wind (right!!) you go less than a mile and a half through the water to make that mile good to weather. There are times when the 60-60-60 is the best you can really do if it takes power to ease through serious waves under reefed sail in a storm.

[Jay Greer]

An adjustable main sheet horse is valuable for allowing a main to be trimmed to the correct angle in light airs without flattening the sail or streaching the leech.
Jay

[Todd Bradshaw]

That's one of the nice things about multihulls. It's really easy to fit most of them with a really wide traveler. Add some Barberhaulers for the jib sheets and you've got it made....as soon as you get used to the fact that they don't heel much, which at first doesn't feel like sailing.

[JimConlin]

That's one of the nice things about multihulls. It's really easy to fit most of them with a really wide traveler. Add some Barberhaulers for the jib sheets and you've got it made....as soon as you get used to the fact that they don't heel much, which at first doesn't feel like sailing.

True, but the jewelry can get spendy fast.
On Damfino, there's more money in the mainsheet system than in 500+ feet of sail.

[John B]

Jmac, I don't know if you sail onto your mooring with your jib still up but if its main only the rules change a little and you run your sail either down the traveller a bit more or eased( by comparison to your normal on the wind sheeting). The boat'll tell you.

[Hwyl]

For beginner kids I tell them never to pull the boom in over the corner of the transom, a vast generalisation, but one that works