12/8/2023 0 Comments Sail telltales flutter meaningThe second set is more sensitive(being closer to the luff) and so is used in light conditions, the lower set (being further from the luff) is less sensitive and is used in heavy conditions. The number two set is slightly higher than the firsthand only six inches away from the luff. Some people put two lower pairs on the jib. ![]() Once again come in from the luff about twelve inches. The top pair about one third down from the top, and the lower pair about one third from the bottom. In a few more years this might be another change to small boat sailing coming from the racing world. You will not see too many small boats with leech telltales, but many larger yachts have them. Attach them to the batten pockets at battens 2 & 3 (or 4) from the top. Place another pair halfway down the sail from the tang, or about the mid-position of the jib.Īnother place for telltales is streaming from the leech. Place a pair just above the forestay tang so it has clear airflow unaffected by the jib. On the mainsail the best sites for telltales is about twelve inches back from the mast. As well as sail telltales, many sailors have some form of telltale on their side stays, masthead, and fore-stay separator. ![]() Although every telltale will tell you something, you can only take effective notice of a certain amount of information at a time. ![]() The task of the telltale is to tell you what is happening with the airflow against the sail surface, and to allow you to make these compromises between wind and sail as advantageous to you as possible.ĭo not put too many telltales on your sails. The wind can push the power producing surface of the sail inwards, causing, you guessed it, loss of power and speed. This layer of "slow" air can be several inches thick, and it can separate the real wind from the sail, again robbing you of power and speed. When the moving air hits the sail it slows down because of the friction. Or it might separate from the aft area of the sail and form a whirlwind on the lee side, also robbing the sail of power. The angle of attack might mean that the wind just can't bend around to the back of the sail quickly enough, and so it leaves a swirling bubble of air on the lee surface which robs the sail of power. The thin sail means that the wind has to follow a curved inner surface and can develop a thick layer of still or slow air in there. The mast means that there is a pocket of turbulence for the first few inches of the sail. In all these things the air flow will make its own compromises. The sail is highly flexible and the wind prefers to push it into a less powerful shape. The angle of the sail to the wind sometimes makes the wind separate from the sail, or makes it build up against it.Ĥ. The sail is very thin, and the wind prefers a thicker section like an airplane wing without a concave lower surface.ģ. There is a mast in the way that is not the wind's preferred shape.Ģ. When the wind flows over the sail it has to make some compromises.ġ. The wind you feel across your back when sailing is not the wind the sail feels. However, the air flown a sail can become complicated, and when it does the telltale will complain to you. That sounds simple, and simple is how the telltale likes it. Telltales show the actual wind across the sail surface. Books and magazines I have from about twenty years ago show not a telltale in sight and they include some big name innovators such as Frank Bethwaite and Bob Miller (later known as Ben Lexcen). However, somewhere in the last twenty years tufts have turned into telltales, and they have crept onto nearly everybody's sails and into most sailing books. Some sailors put what they called "tufts" on their sails, but they were an obscure minority. Your local library probably has many books in its sailing section with no mention of telltales, and they will also be absent from the boats in the photographs. One of the surprising things about telltales is that they are so recent. They should be the first thing to tell when you are slowing down. If those other boats are passing you by, take a look at your telltales. They might like rolling around in the breeze on really lazy days, but mostly they prefer streaming out with the wind running across their back. Telltales do more than just enjoy rolling around in the breeze. If you have comments about this or sailing articles on, click on the “comments” link at the end of each story. This article, originally published in the On The Wire Ezine for Catamaran Sailors in January 1997, is still great information for all sailors. ![]() How do you know if you are sailing your catamaran efficiently? One thing that can help catamaran sailors “listen” to their boat is the proper use of telltales.
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