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Squeteague Sailmakers
Full Battens: Are They For You?We are frequently asked about full battens for mainsails--especially about the advantages and disadvantages and the feasibility of converting an existing sail. There is no quick answer to these questions. If you are thinking about making the switch to full battens, there are many points to consider and they must all be examined in the light of your particular situation. FULL BATTENS ARE NOT FOR EVERYONE, and only you can decide if they are the right choice for you. Advantages1. Less Flogging. With full battens the sail doesn't flap like a flag when it is not drawing. This increases the overall life of the sail since flogging is very hard on the cloth. It is also quiete 2. Easier to Furl. The battens make the sail drop onto the boom in a nice neat stack provided you have lazy jacks to hold it.) 3. Improved draft shape. Full battens induce a much smoother sail shape that holds better especially off the wind and in choppy seas. And in heavy air, they keep the draft from moving aft in the sail provided the battens are stiff enough and\or are tensioned enough). 4. Improved profile shape. Aerodynamically, a sail with a large roach at the head (an elliptical profile) is more efficient than the more traditional triangular profile because it creates less induced-drag which increases the lift-to-drag-ratio. In practice this means less heeling, less weather helm and more speed. (For a complete discussion of the aerodynamics see The Art and Science of Sails by Tom Whidden.) Full battens are able to provide the support needed for a large head roach. (The roach is the cloth extending beyond the straight line of the leech.) Disadvantages1. Must have lazyjacks to enjoy the benefits of easier furling, otherwise the full battens fall past the boom and are harder to handle than a sail without full battens. 2. Must have telltales in the luff of the sail because the full battens eliminate luffing making it impossible to check the sail trim by watching the luff. 3. More weight aloft. The additional weight of the battens pockets and extra hardware aloft makes the boat more tender in a breeze. It also makes the sail heavier to hoist. 4. Increased maintenance. The lazyjacks tend to chafe the sail especially at the battens, as do the shrouds when sailing off the wind. This means frequent restitching and patching at the trouble spots. 5. Jamming. Full battens have a strong tendency to hang up when the sail is being raised and lowered. This problem can be largely eliminated with the right luff hardware at the batten ends, but the cost of this hardware ranges from high to astronomical. 6. Batten tension must be adjusted to meet the conditions otherwise you may wind up with worse sail shapes than you would have with a conventional sail. This tensioning can be done in two different ways. The batten pockets can be fitted with tension adjusters (there are several options available), or the leech line can be used to tension all of the battens at once. Tensioning the battens in this way requires exerting quite a bit of force on the leech line, so it is advisable to run the line to the end of the boom and then forward toward the gooseneck where it is more accessible. Ideally, both methods are used by setting the basic tension with the pocket adjusters for the overall conditions you expect for the day and then fine tuning for varying conditions and point of sail with the leech-line to maintain optimal shape. 7. Battens hang-up on backstay. Unless you have running back stays, your backstay position will determine the maximum batten length and hence the amount of roach your sail can carry. Usually this means not much more, if any, than you already have. If your rig will not allow considerable roach to be added to the head of the sail, full battens will not give you the advantages listed in #4. 8. Rating Penalty. Full battens are penalized under many rating rules (including IMS) and are not allowed under IOR. 9. Difficult to handle and store when the sail comes off the boat. 10. Increased initial cost. 15 to 25 percent or even more depending on pocket end treatments. What about retro fitting an existing sail? This can be done. What you need to consider is if the condition of the sail warrants the expense of adding the pockets and hardware needed to accommodate full battens. It is not practical to add more roach to an existing sail, so you would not get the advantages listed in #4. The Asymmetrical Cruising Spinnaker:
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