i have sent for a book that includes a method of trimming the jib fairlead using telltales on the leeech(?))(aft end) of the jib. anyone know about this method?
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Jib leech telltales
I've never heard of that method but I'll probably learn something new. I was going to wait before I commented (no sense in putting foot in mouth if you don't have to!!) but jib telltales are so basic a concept I thought I would give it a go. Here's why jib telltales are located on the luff or leading edge of the jib and not the leech. In oder for the jib to perform at 100% the leading edge MUST be aimed PERFECTLY into the wind. What you are looking for from your jib telltales is what is called "attached flow". You want this attached flow to be equal on both sides of the sail (that is why there is a telltale on both sides of the jib) and the only way that can happen is if the leading edge is pointed directly into the wind. If the jib is not pointed perfectly into the wind then one or both of the telltales will react and you must make the appropriate adjustment. The above is one of the reasons I suggest a mate attach 2 telltales (one on each side)of the mainsail to read the attached flow on the main. On the main sail I'm interested in the "exhaust" as it comes off the back of the main but on the jib I really don't care much about the exhaust. I want to know how the wind is hitting the leading edge. Secondarily, I might be interested in jib leech telltales but not as a primary source of info.
I've never heard of that method but I'll probably learn something new. I was going to wait before I commented (no sense in putting foot in mouth if you don't have to!!) but jib telltales are so basic a concept I thought I would give it a go. Here's why jib telltales are located on the luff or leading edge of the jib and not the leech. In oder for the jib to perform at 100% the leading edge MUST be aimed PERFECTLY into the wind. What you are looking for from your jib telltales is what is called "attached flow". You want this attached flow to be equal on both sides of the sail (that is why there is a telltale on both sides of the jib) and the only way that can happen is if the leading edge is pointed directly into the wind. If the jib is not pointed perfectly into the wind then one or both of the telltales will react and you must make the appropriate adjustment. The above is one of the reasons I suggest a mate attach 2 telltales (one on each side)of the mainsail to read the attached flow on the main. On the main sail I'm interested in the "exhaust" as it comes off the back of the main but on the jib I really don't care much about the exhaust. I want to know how the wind is hitting the leading edge. Secondarily, I might be interested in jib leech telltales but not as a primary source of info.
alan, my terminology may be faulty - notice the plethora of question marks. i am referring to the loose aft end of the jib; not the part fuled to the forestay. clearer? is that the leech or the luff of the jib?
ok, alan, what are luff telltales, and not everyone knows how to use them; i have no idea. please tell all.
Try google
I did on telltales and got this: http://www.wb-sails.fi/news/95_11_Tellingtales/Tellingtales.html
I did on telltales and got this: http://www.wb-sails.fi/news/95_11_Tellingtales/Tellingtales.html
How to use tell-tales
Basic concept: 1) a piece of cloth will "fly with the wind" 2) the apparent wind up high comes from a less forward angle and its speed is greater than the wind down near the deck To get the luft tale-tells to all "stream backward" you have to be able to see all six of them. While this may sound dumb lots of roller feruling sails have opaque sunbrella fabric right where you would place a tale-tail. Fixing this means modifying your sail's UV covers and most will not want to do that so you are going to have to suffice with luft tale-tells that are not in the optimum position. Once on a tack, adjust the sheet tension to get the center set of tale-tells to both stream straight back. Then adjust the sheet lead car to get both the top and bottom tale-tells to stream straight back. Once trimmed properly you can move to getting the mainsail trimmed. To keep the jib trimmed you can either adjust the sheet tension (if boat direction is more important) or change the boat direction (if speed is more important). Adjusting the jib sheet lead car is done as follows; look at the top and bottom tale-tails. If the top "inside" and bottom "outside" tale-tails are not streaming back then the sail has too much twist in it and you should move the car forward. If the top "outside" and bottom "inside" tale-tails are not streaming back then the sail has too little twist and you should move the car aft to increase the twist. Then re-trim the center tale-tails and repeat trimming the car. To keep them trimmed by using the helm do the following: if the "inside" tale-tails stop streaming back you are "pinching" and you need to turn away from the wind a bit, if the "outside" tale-tails stop streaming back you have "fallen off the wind" and need to turn into it. To keep them trimmed by using the sheet do the following: if the "inside" tale-tails stop streaming back tighten the sheet and if the "outside" tale-tails stop streaming back loosen the sheet. For the record using tale-tails on the main luft is dumb because of the turbulence the mast causes. They will never be streaming back and so can't be used to trim the mainsail.
Basic concept: 1) a piece of cloth will "fly with the wind" 2) the apparent wind up high comes from a less forward angle and its speed is greater than the wind down near the deck To get the luft tale-tells to all "stream backward" you have to be able to see all six of them. While this may sound dumb lots of roller feruling sails have opaque sunbrella fabric right where you would place a tale-tail. Fixing this means modifying your sail's UV covers and most will not want to do that so you are going to have to suffice with luft tale-tells that are not in the optimum position. Once on a tack, adjust the sheet tension to get the center set of tale-tells to both stream straight back. Then adjust the sheet lead car to get both the top and bottom tale-tells to stream straight back. Once trimmed properly you can move to getting the mainsail trimmed. To keep the jib trimmed you can either adjust the sheet tension (if boat direction is more important) or change the boat direction (if speed is more important). Adjusting the jib sheet lead car is done as follows; look at the top and bottom tale-tails. If the top "inside" and bottom "outside" tale-tails are not streaming back then the sail has too much twist in it and you should move the car forward. If the top "outside" and bottom "inside" tale-tails are not streaming back then the sail has too little twist and you should move the car aft to increase the twist. Then re-trim the center tale-tails and repeat trimming the car. To keep them trimmed by using the helm do the following: if the "inside" tale-tails stop streaming back you are "pinching" and you need to turn away from the wind a bit, if the "outside" tale-tails stop streaming back you have "fallen off the wind" and need to turn into it. To keep them trimmed by using the sheet do the following: if the "inside" tale-tails stop streaming back tighten the sheet and if the "outside" tale-tails stop streaming back loosen the sheet. For the record using tale-tails on the main luft is dumb because of the turbulence the mast causes. They will never be streaming back and so can't be used to trim the mainsail.
Yes, by all means use jib luff telltails but
in their abscence as a general rule position the faileads so the angle of the sheet points to the middle of the luff. At least that is how I was taught.
in their abscence as a general rule position the faileads so the angle of the sheet points to the middle of the luff. At least that is how I was taught.
Luff Telltales
The telltales for the main are not placed on the luff. Their correct placement is about in the middle center of the mainsail and you read them the same way you read the jib telltals. Stu: I like that telltale site you published. I used it in the past but had forgotten about it until you brought it up. Bill R: I like your explanation on reading the jib telltales. I'm sitting here moving my fngers like telltales but I think you've hit on an easy system. For beginners to intermediate - the bottom line is moving the car forward decreases twist and moving it aft increases twist but how do you read it (see below) and how do you physically move the cars. You can see how easy fairlead adjustment would be with a set up like the Garhauer adjustable fairlead system. It would not be that easy with the pin type setup. With the Garhauer system and Bill's method you can dial in perfect jb trim. Using Bill's system: Top inside/bottom outside flip = car forward. Top outside/bottom inside flip = car aft.
The telltales for the main are not placed on the luff. Their correct placement is about in the middle center of the mainsail and you read them the same way you read the jib telltals. Stu: I like that telltale site you published. I used it in the past but had forgotten about it until you brought it up. Bill R: I like your explanation on reading the jib telltales. I'm sitting here moving my fngers like telltales but I think you've hit on an easy system. For beginners to intermediate - the bottom line is moving the car forward decreases twist and moving it aft increases twist but how do you read it (see below) and how do you physically move the cars. You can see how easy fairlead adjustment would be with a set up like the Garhauer adjustable fairlead system. It would not be that easy with the pin type setup. With the Garhauer system and Bill's method you can dial in perfect jb trim. Using Bill's system: Top inside/bottom outside flip = car forward. Top outside/bottom inside flip = car aft.
sorry, guys - a tempest in a teapot. the book arrived and does not say a word about jib leech telltales; once again a wrong tale by a fellow sailor.
Good discussion
Mortyd: No problem. Look at the good discussion that came out of it. A mate should be able to adjust his fairleads pretty well now from following this thread. Just to recap on fairlead adjustment. When tacking the boat, just before the jib sheet is cut, the trimer on that side should read the break of the sail from top to bottom and relay that info to the trimmer on the other side. He then sets the fairlead either forward, backwards or leaves it alone. Afer sheeting in, the fairlead should be pretty close to exact. The trimmer then fine tunes using the method Bill Roosa presented. Then the main trimmer trims the mainsail. The end results, if you follow this method, is that sailors around you will be very envious of your sail trim and will seek you out for advise as to how you manage to have such good looking sails. You might think I'm kidding but try it and see what happens.
Mortyd: No problem. Look at the good discussion that came out of it. A mate should be able to adjust his fairleads pretty well now from following this thread. Just to recap on fairlead adjustment. When tacking the boat, just before the jib sheet is cut, the trimer on that side should read the break of the sail from top to bottom and relay that info to the trimmer on the other side. He then sets the fairlead either forward, backwards or leaves it alone. Afer sheeting in, the fairlead should be pretty close to exact. The trimmer then fine tunes using the method Bill Roosa presented. Then the main trimmer trims the mainsail. The end results, if you follow this method, is that sailors around you will be very envious of your sail trim and will seek you out for advise as to how you manage to have such good looking sails. You might think I'm kidding but try it and see what happens.
lest I you think I'm smart
I stole the whole concept from Chapman's Piloting. Just a great book for the beginner and a good reference for the old salt.
I stole the whole concept from Chapman's Piloting. Just a great book for the beginner and a good reference for the old salt.
Jib sheet lead car adjusting
While a setup like you have on the main traveler would be great not all of us have the resources or deck space to install one. I have found that you can release the tension on the car by going forward and pushing down on the jib sheet forward of the car. 6" is enough as all you are trying to do is get the sheet to run straight through the car with little upward or athwart ships pressure. I also found that there are really only 3 places I ever put the car so there are not as many variables as one might think. Note to legend 37.6 owners. The bolts that hold the track down are not all installed equally. The ones that you can't find a nut to inside are not really attached to anything. They are just there for eyewash. The bulkhead aft of the nav station and the reinforcing rib aft of the entertainment center are where you find them. And yes this is where that pesky leak that drips on the nav station is coming from
While a setup like you have on the main traveler would be great not all of us have the resources or deck space to install one. I have found that you can release the tension on the car by going forward and pushing down on the jib sheet forward of the car. 6" is enough as all you are trying to do is get the sheet to run straight through the car with little upward or athwart ships pressure. I also found that there are really only 3 places I ever put the car so there are not as many variables as one might think. Note to legend 37.6 owners. The bolts that hold the track down are not all installed equally. The ones that you can't find a nut to inside are not really attached to anything. They are just there for eyewash. The bulkhead aft of the nav station and the reinforcing rib aft of the entertainment center are where you find them. And yes this is where that pesky leak that drips on the nav station is coming from
jib leech tell-tales
Several years ago a North Sails rep who had been an olympic competitor told us a go-fast trick was to attach a leech tell-tale about 2/3 of the way up the foresail. He said anything farther down won't tell you much, but at that location you can get a pretty good read on what the air is doing in the upper half of the sail.
Several years ago a North Sails rep who had been an olympic competitor told us a go-fast trick was to attach a leech tell-tale about 2/3 of the way up the foresail. He said anything farther down won't tell you much, but at that location you can get a pretty good read on what the air is doing in the upper half of the sail.
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