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Brian Hancock 04-06-2004 08:00 PM

Refining Your Downwind Sails
 
<HTML><TABLE cellSpacing=0 cellPadding=0 align=right border=0><TBODY><TR><TD width=8></TD><TD vAlign=top align=left width=237><IMG height=328 src="http://www.sailnet.com/images/content/authors/hancock/010202_bh_undersail.jpg" width=237><BR><DIV class=captionheader align=left><FONT color=#000000><B>Almost any boat—<STRONG>even speedy multihulls</STRONG>—<STRONG>can gain additional performance by adding a spinnaker to their downwind inventories.</STRONG></B></FONT></DIV></TD></TR><TR><TD colSpan=2 height=8></TD></TR></TBODY></TABLE></FONT></B></I><FONT color=#ff0000></FONT>Perhaps you have already dipped into the delights of downwind sailing using an asymmetrical spinnaker and discovered the fun and satisfaction of sailing with the wind at your back and a colorful sail billowing out ahead of you. However, if you're like most cruisers, your boat is probably fitted with a "conventional" symmetrical spinnaker and, for now, your budget doesn't allow the purchase of an asymmetrical. And like other sailors, you would probably love to use the spinnaker you have, but having to rig up all those lines and blocks and a pole seems pretty complicated, so you've shelved that until another time. Hopefully, after reading this piece, you'll be willing to set the sail and actually enjoy the experience. And fortunately, the same spinnaker sock that makes setting and dousing asymmetrical spinnakers so easy can be used on your "conventional" spinnaker with just a few changes. Before getting into that, let's take a look at the conventional spinnaker and discuss its advantages and drawbacks.<P></P><P>Unlike the asymmetrical, both edges of the sail are the same length and the only way to set the sail efficiently is with a spinnaker pole. You use the pole to rotate the sail to windward as the wind comes aft, keeping the pole perpendicular to the wind direction. The main disadvantages of this sail are obvious. A spinnaker is somewhat complicated to set, and once it is drawing, it requires your undivided attention. Also, getting the sail down can be a daunting task even for the experienced among us. </P><P align=justify></P><P align=justify>In the plus column, however, once set and drawing, spinnakers can be a beautiful sight to see and the added boat performance always makes it worth the effort. For some sailors, learning the lines and rigging a spinnaker pole is simply not worth the effort. For others, especially those sailing in consistent winds like the trade winds, the performance gain is a better-than-even trade for the effort. If you have a big crew of experienced people, it is an easy decision whether to set the sail, but for now let's assume that you are sailing shorthanded and still want to use it.<FONT color=#ff0000></P><P><TABLE cellSpacing=0 cellPadding=0 align=right border=0><TBODY><TR><TD width=8></TD><TD vAlign=top align=left width=294><IMG height=222 src="http://www.sailnet.com/images/content/authors/hancock/110100_BH_tripmechanism.gif" width=294><BR><DIV class=captionheader align=left><FONT color=#000000><B>Using a pole-guy fitted with a trip mechanism as illustrated in this diagram can simplify the way you use your spinnaker.</B></FONT></DIV></TD></TR><TR><TD colSpan=2 height=8></TD></TR></TBODY></TABLE></FONT><P align=justify></P>Setting your spinnaker shorthanded requires preplanning and diligence. You need three additional components to do this properly: pole-guy, a short length of low-stretch line, and a spinnaker sock. A pole-guy is a separate line that runs from the end of your spinnaker pole, through a block on the deck, aft to its own winch. The pole-guy sets and secures the position of the pole independent of the after-guy, which is attached to the clew of the sail. With the pole-guy in place, you can then set up a trip mechanism (see diagram) that will release your spinnaker in a sudden emergency. For the trip mechanism you need a quick-release shackle and a length of low-stretch line. When you set the spinnaker, run the line through the shackle (that is attached to the clew of the spinnaker), looping it around the pole and attaching it back onto itself. With the pole held in a fixed position by the pole-guy, you need only surge the after-guy to trip the spinnaker. The pole remains firm, the line snaps tight and exerts pressure on the shackle, which opens and releases the clew, and down it comes—that is if you are using a sock and have it rigged properly. <P></P><P><TABLE cellSpacing=0 cellPadding=0 align=right border=0><TBODY><TR><TD width=8></TD><TD vAlign=top align=left width=294><IMG height=222 src="http://www.sailnet.com/images/content/authors/hancock/110100_BH_bipolespin.jpg" width=294><BR><DIV class=captionheader align=left><FONT color=#000000><B>The spinnaker sock on the author's boat, ready for action.</B></FONT></DIV></TD></TR><TR><TD colSpan=2 height=8></TD></TR></TBODY></TABLE></P><P>As I mentioned in my earlier article about asymmetrical spinnakers, I recommend the spinnaker sock made by ATN. One of the problems that you run into when setting a conventional spinnaker is that, unlike the asymmetrical, the tack of the sail isn't within easy reach. On a conventional, symmetrical spinnaker, the tack is all the way out at the end of the spinnaker pole, making it difficult to raise the sock. Generally, you need to square the pole back before setting the sail and this presents even more of a challenge. There is, however, a simple trick that works. In order for your spinnaker to set properly, you need to have your pole squared and your sheet set before the spinnaker fills with air. Set it too early and the spinnaker will oscillate like the pendulum on a runaway grandfather clock. Here is how you do it. Set the sail in a sock with the clew attached to the after-guy and the quick-release shackle in place. Pre-trim your sheet so that when the sail opens it will set properly. (As with any unfamiliar maneuver, you should practice this on a day when the wind is light, and you should mark the sheets and guys with reference points so that you can be sure the sail will be trimmed properly when it fills.) Then, with the set and douse lines (from the sock) run through a double cheek block that is pulled out to the end of the spinnaker pole by way of a third line that is run through a fairlead, you're ready to hoist. You need to have the control lines for the sock led through a block that is located directly under the sock for all of this to work. Once the pole is in place with the pole-guy set, the clew of the spinnaker pulled aft, and the sheet positioned correctly, you can then raise the sock and set the sail. <P></P><P><TABLE cellSpacing=0 cellPadding=0 align=right border=0><TBODY><TR><TD width=8></TD><TD vAlign=top align=left width=224><IMG height=308 src="http://www.sailnet.com/images/content/authors/hancock/110100_BH_spinsock.gif" width=224><BR><DIV class=captionheader align=left><FONT color=#000000><B>With control lines led to the deck, setting and dousing with a spinnaker sock is simple for a shorthanded crew.</B></FONT></DIV></TD></TR><TR><TD colSpan=2 height=8></TD></TR></TBODY></TABLE></P><P>Fortunately, dousing with a sock is relatively easy. You simply trip the spinnaker by way of your quick-release shackle, release the line that holds the control lines for the sock, and let the spinnaker float into the lee of the main. At this point, it is easy to pull the sock down over the sail. I realize that all this probably sounds complicated, but if you follow me closely and do a few trial runs on a calm day, you'll find that it is a good system which works well and allows you to use your spinnaker more effectively. The only modification that you might need to make is to ensure the control lines on your sock are long enough to be led through the block at the end of the pole all the way to the deck and back.</P><P>If you do not like spinnakers and are determined not to have one on board, yet you still want downwind performance, you might consider a bi-pole spinnaker. It is a simple sail designed for the cruiser who spends time in the trades or anywhere else where the wind is consistently from behind. The bi-pole spinnaker is essentially two wing-on-wing headsails joined at the luff and set either on your forestay, or on a roller-furling system just in front, or just behind it. You set the sail with your spinnaker halyard, tweak the windward side out with your spinnaker pole or whisker pole, and sheet the other side through a block on the rail. A well-proportioned bi-pole spinnaker should not have less sail area than an asymmetrical spinnaker; however, it has the advantage of being secured so that it doesn't oscillate, and is easier to set and douse. These sails are made of nylon and are light and easy to stow. On my boat, the sail hanks onto the forestay, and the spinnaker halyard is led aft so that it can be reached from the cockpit. When I set the sail, I often deep-reef or douse the main so that there can be no chance of an accidental gybe. If a sudden squall passes overhead, I dump the halyard and secure the sail on deck. When the squall passes, it's easy to hoist the halyard again. All the lines are in place and within seconds the bi-pole spinnaker is set and drawing. <P><TABLE cellSpacing=0 cellPadding=0 align=right border=0><TBODY><TR><TD width=8></TD><TD vAlign=top align=left width=294><IMG height=222 src="http://www.sailnet.com/images/content/authors/hancock/110100_BH_wingbrian.jpg" width=294><BR><DIV class=captionheader align=left><FONT color=#000000><B>The bi-pole spinnaker as deployed aboard the author's boat.</B></FONT></DIV></TD></TR><TR><TD colSpan=2 height=8></TD></TR></TBODY></TABLE>If you are one of those sailors who still has hanks on your sails, the bi-pole spinnaker will set with hanks run down the middle of the sail. You only need a few of them, widely spaced, to secure the sail to the forestay and stop any oscillation. If you have roller-furling headsails, and your forestay is thereby inaccessible to hanks, you can set the bi-pole spinnaker on its own roller-furling unit just in front, or just behind the forestay. The two wing-on-wing headsails are joined in the middle with a low-stretch line like Spectra® or Vectran®. With the halyard hoisted tightly against the line, it stops any oscillation, and you can set and douse the sail with a quick pull on the furling line. You can also lead the line aft to the cockpit so that the sail can be set and doused without having to go onto the foredeck. In all it provides a practical alternative to a spinnaker without much loss of performance. <P align=justify></P><P>So there you have it—four sails for downwind sailing. A well-equipped vessel and an energetic crew could probably make use of them all, but you might decide you only need one. As always, think about the kind of sailing you plan to do and then decide which sail or sails, best suit your needs. Most importantly, give these methods a try. Using these downwind systems is easier than it looks and will definitely add to your sailing enjoyment. </P></HTML>


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