Telltales - Part 1

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May 17, 2004
2,111
Other Catalina 30 Tucson, AZ
Mates: I have to do this in sections because the subject is too long for this format. It is probably better that way because there is a poop load of stuff to absorb and we can hit any questions that come up as we go along. POINT OF INFORMATION: All of the following is designed for the beginner to intermediate (my favorite kind of sailors). Experts will probably be bored to death. What are telltales telling you anyway? They are telling you if the flow of air over the sails is attached or not. Why do you care if the air is attached or not? The reason is that if the air is not attached equally to both sides of the sail, the sail will stallas it no longer is efficient. Picture your sails in a wind tunnel with smoke blowing over them. That is the effect your looking for. It is called "attached flow" . The technical name is "stagnation streamline". What we want is the leading edge of the mainsail and jib to be aimed DIRECTLY into the wind. The telltales on both sails will tell us if we have achieved that objective. Telltales will react to the stream of air and tell you whether the flow is smooth or turbulent. You can see this in action by first getting all the telltales on the main and jib streaming back and then ease or trim the mainsheet and jib sheet. Watch what happens. The telltales will react because the sail is no longer pointed directly into the wind. By conducting this simple exercise, it teaches you exactly what adjustment you have to make or what trimming instructions you have to give to the trimmer to get the telltales streaming again. As you can see so far, this is not brain surgery. So, if your sailing along and everything is going nicely and the wind changes direction and start hitting the windward side of the sail, what will happen? The flow of air will become separated or not attached and the windward telltale starts jumping all over the place. Same thing happens if the wind hits the leeward side. Suppose the telltales on both side start jumping all over the place? What is that telling you? It is telling you that the flow is to turbelent on both sides and an adjustment must be made quickly or soon one side telltale will hang limp. What that means is the sail has just stalled and your going to be slowing down. So what exactly are we looking for? We want the jib telltales to both be streaming, especially the middle ones. We want the mainsail to be streaming, especially the top ones and the ones in the middle of the sail. Any questions so far? Next we'll talk about how you tell whether your sailing to high and pinching or too low and footing.
 
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Paul M

Telltales positions and where

I plan on following your post to a T, and I already have a question. How many telltale should I have on my main and head sail, and where should they be placed? I have a Mac 26X with a stock main and jib.
 
May 17, 2004
2,111
Other Catalina 30 Tucson, AZ
Paul M: You need 3 on the leech of the main. Place them next to the batten pockets. If you want to be trick, place two more (one on each side like the jib) at about the center/middle of the mainsail. The most important one to watch is the top one because you use it as your twist indicator. On the jib, you need 3 also - most of the telltale packages come with some sort of direction but if there are none, just divide the jib in 3rd's and attach the telltales in the middle of each 3rd. Place one on each side. They are placed about 2' back from the front of the sail. What we are trying to do is detect the wind flow as it hits the front of the sail. Remember the smoke in the wind tunnel example. While your at it, place one on the port and starboard shroud about 6' to 8' off the deck. They will help you get in the groove. In other words, suppose you notice your telltales are jumping all over the place. At that point glance at your shroud telltales and I'l bet your out of the groove. Actually, I know you are. The most important telltale to watch is the middle one. Every time I identify the most important one to watch I get emails from sailors telling me they feel thus and so is important. Ok, they are all important. That's why they are there but THE MOST IMPORTANT ones are the main top anf jib middle. Also place a telltale on the backstay about 6' to 8' up from the deck and use it for downwind sailing. It saves your neck muscles from having to strain your neck looking up at the mast head fly. Paul, a couple of years ago I raced in the Newport to Ensenada race, which is coming up shortly. Our group was won by a Mac 26. It was no contest as no one could keep up with him. There was a big hub bub about the boat but his win stood the challenge.
 
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Kevin

Can I Simplify?

Don - I got the book and charts yesterday - great stuff. Can I simplify a bit? Work on the middle telltales untill I am comfortable with their flow, and then progress to working on getting the twist correct? Actually, I think twist of the jib should be easy, but I am a little worried that I overload myself with information if I try to do too much with the main all at once. One thing at a time is easier for my crew of little buddies as well. The J22 has no cunningham - so do I just use the main halyard for those adjustments? Also - is it correct - at least as a beginner's simplification, to say this - - - sheet toward the flapping telltale, or steer away from it? Thanks also for the extra explanation on where to have the telltales, that helped as well. Thanks, Kevin
 
May 17, 2004
2,111
Other Catalina 30 Tucson, AZ
Kevin: On the cunningham - that devise is a simple small boom vang. Actually, you can make one. Here is the reason I prefer it over the jib halyard (I have one on the jib also) or mainsail halyard. My halyards were not led back to the cockpit so I had to go forward to the mast to make any adjustments. Due to the weight of the mainsail on a C30, as soon as I loosened the halyard, I'd lose a couple of feet of sail. With the furling jib, that could turn into a mess as the tube would come out of the drum up top and I really didn't need that experience. Also,it was difficult for me to get the adjustment I wanted. With the cunningham, it is simple to dial in an adjustment and I can watch it happen. All you have to do is try it once and you'll see what I mean. I may not be a big factor on a J22 but as you go to a bigger boat the more important it becomes due to the size of the sail. The easiest way to deal with the jib telltales is this - Tell your sons that if the OUTSIDE telltale flips, to let OUT the sheet until the telltale stops. If the INSIDE telltale flips, the should trim the sheet IN until the telltale stops flipping. it is important for them to know what is happening to the sail that causes them to make that correction, so read on. Here's what is happening from a steering standpoint. If the windward telltale is flipping, your sailing too close to the wind so fall off so either deal with the sheet or fall off. The reverse is true for the leeward telltale. On twist: mainsail twist is very simple to deal with and deal with it you should because twist is a power robber. When the top of the sail opens up, air (power) spills out. In heavy wind, inducing twist is an excellent way to calm the boat. The two controls for twist in the main are the boom vang and the mainsheet. Twist is the jib is a little more difficult in that you have to move the fairlead. After I finish this telltale section, I'll discuss twist in the jib and tell you the steps you go through to determine the correct fairlead adjustment. In your case, you already have it - it is in the book and on your chart!! The great thing about your sailing family, is that your sons will become great little sailors because they are getting the basic. They will grow to love the sport and it will stay with them all through their lives. I learned to sail in RI on Narragansett Bay. Unfortunately, we learned by the seat of our pants and had no idea what we doing but we did manage somehow to get the most out of the boat.
 
K

Kevin

Thanks

Don wrote: “What we want is the leading edge of the mainsail and jib to be aimed DIRECTLY into the wind”. It is amazing in all of the sailing classes that I have taken – no instructor has made that simple statement! A really helpful insight. On the J22, using the halyards to adjust the luff tension is not that big a deal, and our lines are led back, so easy to use. My ‘owned’ boat is a NACRA 5.8 catamaran – I am still working it back into shape for summer and the water is still too cold here for it. The J22 is a season rental, so I won’t be adding hardware to it (just add telltales). Thanks for the tips though, and the more I study the book, the more I think that I am getting it. All I need now is proper wind to experiment with. Our first day out it was too light, and today was a real blow. We sailed with just the main – reefed to make is easier, whitecaps all over the lake, but the small body of water means no real waves, just a bunch of small breakers. The 9 year old did a pretty amazing job at the helm! Gotta take a few days off sail trim, to study for my ASA 105 exam. Also, the weather will be lousy, so no sailing until next week :(. I will take your test under Telltales 4, just to see what I have learned. Cheers! Kevin
 
Dec 25, 2000
6,052
Hunter Passage 42 Shelter Bay, WA
Don, you offer some great trim...

guidelines. Thank you for sharing your insight. A question. When you say to aim the sails directly into the wind, do you mean apparent wind or true wind? A shroud or stay telltale or masthead windex will give you an apparent wind reading once the boat begins to move. Terry
 

Alan

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Jun 2, 2004
4,174
Hunter 35.5 LI, NY
Terry

Your sails don't know what true wind is and they never see it. Telltales, Windex, and sails ONLY deal with apparent wind. When your boat is stationary, the apparent wind is the true wind but then you’re not sailing. All the rest of the time true wind is an imaginary anomaly.
 
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