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  #1  
Old 01-16-2008
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How to fly an asymmetrical spinnaker (or even spell it correctly)

Should the tack attach to a fitting on the deck, or should it be flown with the foot well above the deckline via a pendant, more akin to how a spinnaker is flown?

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Old 01-16-2008
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I fly the one I have, with a sheave/pulley attached to the anchor post, and a line leading to the cockpit, so I can adjust said tack line as to ht, lower for more upwind, and higher for more direct down wind runs. Some will buy a Seldon gennikar spar, that will get the tack line a bit more forward of the bow. This is probably the best option, but a $600-1000 typical boat unit cost! I believe, do not quote me, but you can u a longer assymetric ie more sq ft with a pole vs mounted on the bow as I have done.

Some boats, it is also not recommended you used the anchor attachment point for the tack line. If you have a weak one, or not well attached, do not use this point. I have pics of my setup at dock if that would help. None at this time sailing.

Marty
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Old 01-16-2008
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Many Asyms come with a tack collar/strap that is meant to go around a headstay (or more likely a furled headsail). A line from this collar to a block at the stem and run aft as per blt2ski is common as well, allowing adjustment of the tack height as you sail.

Generally you will lower the tack height to straighten the luff as your apparent wind angle decreases (ie you sail closer to the breeze)

If you choose to use an anchor roller/stem fitting as the attachment point just ensure it's up to the task (remember that the major load will be in an upward direction as the sail tries to lift)
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Old 01-16-2008
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Faster is correct: The tack collar or strap (I don't even know if there's an "official name", but it's like parrel beads in cloth form) is like a wide, fabric-covered belt with D-rings. It slides up and down the furled headsail as per the windspeed and whatever tension you have on the downhaul, which you would run through a properly sized block below it.

Depending on the point of sail and the windspeed, you can rig a downhaul on a bowsprit or any reasonably secure attachment point forward of the forestay. I personally wouldn't recommend the eye strap you occasionally find on the forward top bar of the pulpit, but I've seen that on some boats.

If you have a constant light wind from a particular direction, tensioning and releasing the tack downhaul on an assym. spinnaker is quite instructive, because you can easily discern the "sweet spots" that produce the most lift and thrust, and you can understand how too much or too little tension will stress the sail or get it out of that sweet spot.
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I knew I would forget something! I do have said "strap" that goes on the tack, that wraps around the forestay too!

As mentioned, I put on an adjustable tack line, while I have not used a set length tack line, as Valiente, you can play with the tack line to get max power out of the sail in different conditions.

I have a North G2 for what it is worth.

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Old 01-16-2008
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I'm not a fan at all of "tack straps" like the ATN Tacker ( http://www.atninc.com/tacker.html ). With a properly rigged tack line you can get a lot of sail rotation to windward by gently easing the tack line, increasing projected area for broad reaches and runs. The Tacker and its ilk prevent the desired rotation.
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I've been thinking of getting an asymetrical.

I was looking at the picture on the linked page that SVAuspicious posted showing the tacker. I wonder if jibing might be a problem. It looks like the downhaul would wrap partially around the furled sail causing chafing on the sail or cover cloth and possibly get tangled.

Is this because it's using a standard symetrical spinaker? Does an asymetrical jibe like a jib/genny? Since I usually sail solo, I would rather not spend a lot of time on the fore deck.
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Old 01-16-2008
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A word of caution about tackers. An inadvertent deployment can kink your furler foil if it's a hard one due to a puff. Don't ask me how I know.
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Quote:
Originally Posted by SVAuspicious View Post
I'm not a fan at all of "tack straps" like the ATN Tacker ( http://www.atninc.com/tacker.html ). With a properly rigged tack line you can get a lot of sail rotation to windward by gently easing the tack line, increasing projected area for broad reaches and runs. The Tacker and its ilk prevent the desired rotation.
I can't say "I'm not a fan", but I understand that it puts in a limitation. That's why it's a good idea to try things in eight knots or so of steady air: Try it with, without, loose on the tack line, tighter, pointing up and falling off. Spinnakers are great at telling you when they are at the edge of ceasing to work by the clever method of making visible the invisible wind.
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Old 01-16-2008
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Quote:
Originally Posted by Hawkwind View Post
I've been thinking of getting an asymetrical.

I was looking at the picture on the linked page that SVAuspicious posted showing the tacker. I wonder if jibing might be a problem. It looks like the downhaul would wrap partially around the furled sail causing chafing on the sail or cover cloth and possibly get tangled.

Is this because it's using a standard symetrical spinaker? Does an asymetrical jibe like a jib/genny? Since I usually sail solo, I would rather not spend a lot of time on the fore deck.
I understood that the product called "The Tacker" was originally conceived to help make a standard symetrical behave like a cruising/asym spinnaker, by pinning one clew down as a tack and eliminating the pole. I'm not sure why someone would use it if they already have a true asym/cruising chute.

Generally, the further forward and to windward you can get the sail, usually the better it will fly. With a sprit, such as on a Melges 24 and most J decimeter boats, you can really get the asym out in front of the boat, which when reaching helps to move it farther to windward out of the mainsail's windshadow. You can effect almost the same result with a conventional spinnaker pole that is secured and rigged to extend beyond the bow of the boat more-or-less at deck level.

Our tack line is a fixed length, and it still works well enough for how we sail our cruising boat (our boat does have a short 2' sprit/anchor platform to which the tack line is shackled outboard). The tack of the sail just floats out there and does its own thing. If we feel we need to tighten or ease the luff, we can adjust halyard tension. But it is certainly best to have an adjustable tack line. As a general guide, the higher you reach the tighter the tack line gets pulled, and the deeper you sail the more it gets eased.

To jibe an asym chute, it is somewhat similar to jibing a big genoa. Turn the boat deeper downwind, so the chute becomes increasingly blanketed by the mainsail. Ease the working sheet to allow the clew to float forward until it is about even with the headstay. At this point begin pulling on the lazy sheet as quickly as you can, to pull the clew across the bow and jibe the chute to the other side. Then jibe the mainsail over and reach up a bit to fill the chute on the opposite tack (if you have good crew you can jibe the mainsail almost simultaneously).

That is how it's done if you are rigged for an "inside jibe". Rigging for an inside jibe is pretty much the standard approach. All this means is that the clew of the asym chute gets pulled across between the headstay and the tack/luff of the chute when jibing. To rig for an inside jibe, you lead one of the spin sheets around the headstay but aft of the chute luff (between tack and sailhead) before tying it off on the clew of the spinnaker.

There is another jibe method called the "outside jibe". It is rarely used, usually only in heavy air. To rig for an outside jibe, one of the spin sheets is lead forward and outboard of the spinnaker luff before coming around the sail, under the foot, and tied off back at the clew. To execute an outside jibe, it is much the same as an inside jibe except that the clew of the sail is permitted to drift further forward of the luff, then the lazy sheet is pulled and the sail snaps over to the other tack, but the clew traces a path out in front of the boat rather than between the luff of the chute and the headstay. One downside to rigging for an outside jibe is that the lazy sheet can fall under the boat because it is not resting on the pulpit or otherwise supported by the tack line.

I've mentioned here before that we get good results by tucking a reef in the mainsail when flying the asym, particularly in light air, or when we're trying to sail very deep downwind. This allows air to spill past the mainsail and fill the chute nicely. The chute is so large that the penalty for losing mainsail area is more than off-set by flying the chute efficiently. Ours is a mast-head rig, and this tactic probably wouldn't work well with a fractional rig unless you also have a mast-head spin halyard.

Man, this is a wordy post. Apologies to anyone who made it this far...
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