Telltales and such

[Eddiebou]

Yesterday, I decided to run a piece of surveyors tape up the main halyard to act as a telltale. I was sailing to windward for about a mile, and it took about 10 tacks to get there. I was surprised at how often the telltale streamed in line with the mainsail. The wind was south and it puffed and stopped, puffed and stopped constantly. Sometimes the telltale just dangled behind the sail.
I failed to make one tack and ended up in irons. The telltale was hanging in line with the luffing sails. I managed to get out with the help of an oar.
On another tack, I felt the wind dying out and decided to jibe. The telltale wrapped around the mast and stayed there. I couldn't get it to come from around the mast, even after a few tacks. It bothered me.
I came home wing and wing, and somehow the telltale straightened itself out.
Anyhow, I googled telltales and got more info than I ever thought possible. But none of the examples showed telltales at the top of the mast. They were all on the sails in various places.
So, What do you say? Is it wrong to run a telltale from the halyard? Would it be better if it were on top of the mast? What about putting one on each mast? Why would you?

[Gerarddm]

Seems to me that the usual tell-tales on the sails and shrouds tell you more info. The sail indicators are the most important especially if, LOL, you have an unstayed mast.

[Wooden Boat Fittings]

I'm pretty sure a series of telltales along the leech would help a dinghy sailor improve his vessel's performance, and that someone will be along soon to tell us so. But a non-speed-freak like me only ever had, or wanted, a masthead pennant to show apparent wind direction at the masthead.

Mike

[Todd Bradshaw]

A masthead fly is always worth having as a general wind indicator, especially on points of sail like running downwind when sail-mounted ones may not be terribly handy. The fact that it's up on top in pretty clear air means that you may get a better idea of what's really going on in terms of the apparent wind that your boatspeed and wind direction are generating. Shroud-mounted telltales can work, but may not give you a reading that is as accurate since their air may be influenced by other things in the vicinity.

Sail telltales are a bit different. They are giving you a direct read-out of what the wind passing over your sails is doing. There are a variety of places where they can be attached. Two or three mainsail leech telltales, spread along the leech at the quarter or 1/3 heights are among the most effective. Above all else, they will tell you when the main is being over-trimmed. It's quite possible to trim the main in too far and have it look nice and full, firm and as if it's performing properly - while in reality, much of its potential power is being lost due to improper airflow over the sail. If the sail has leech telltales and you over-trim it, they will show you. When you see the leech telltales (especially the highest ones) hiding behind the leech, rather than streaming, then you know that the sail is trimmed-too tightly. You ease it out a little bit until they stream behind the leech again and restore proper flow over the sail. In other instances, the lower leech telltales may be streaming, but the top one may be hidden. On traditional boats, which may have fairly large-diameter round masts, sprits, angled yards, etc. creating turbulence, I don't generally put many telltales in the middle of a mainsail. Maybe a pair in the middle of a large unobstructed section (if there is one) but te leech telltales are the ones I use most.

Jib telltales (usually a couple of them, upper and lower, around 10"-12" or so back from the luff and on both sides of the sail) will tell you when the jib is getting good flow over both sides. Telltales streaming on one side and not on the other generally indicate that the sail will need to be trimmed-in or eased out a little bit until both sides are streaming again. When sailing to weather, especially close-hauled and trying to point high, you can use the jib luff telltales to steer the boat. You trim both the mainsail and jib in pretty tightly. You still want the mainsail leech telltales streaming and you don't want the jib in too far, as it will back-wind (blow a dent in) the mainsail. Now you adjust your heading until the jib luff telltales are streaming on both sides of the jib. Re-check your mainsail to be sure it's still streaming at the leech and not being back-winded. Now steer a course that keeps those jib luff telltales streaming. If the inner (windward) jib telltales break (stop streaming and start wandering around) your headed up a little too high and need to bear off a little bit. If the outer (leeward) telltales break, you adjust your heading and point up a bit higher until they stream again. Without messing much at all with the sail trim and simply steering to keep the jib telltales streaming, you will likely be steering a course that's about as high as your boat can go without stalling the sails, and the telltales are about the only way to tell for sure.

On any boomless sail (mainsail or jib) we can also use telltales to adjust the sheet lead and sheeting angle. The sheet will be pulling down on the leech as well as back on the foot of these sails. The sheeting angle will adjust the relationship of these two forces and whether the sheet tension is pulling down evenly, or putting more pressure on the leech, or on the foot. For maximum power, we generally want upper and lower telltales to break at the same time - as we head up into a tack, for example, and the sail starts to luff. This tells us that the entire sail is working, from top to bottom. If one set (upper or lower) breaks well before the other, it means that part of our sail isn't working as hard as the other section and we probably need to adjust our sheeting angle a bit. If it's really windy and we're trying to depower the sail a bit, we might want to adjust the lead to let the top twist off to leeward some and spill wind. This would be a case where we didn't want the telltales to break evenly showing us that the top is luffing first and the bottom of the sail is the part getting most of the wind pressure.

Anyway, that may be more than you want to know about telltales, but they can be quite handy at figuring out what's really going on as you're sailing. The combination of a masthead indicator for seeing the general direction, and sail telltales for a more specific idea of the actual flow over the sails seems to be a pretty good combination.

[David G]

My whole life I've been in and around boats. Powerboats, and small rowboats. It wasn't until about 8 years ago that I started teaching myself to sail. I added the telltales and a pennant to the top of my balanced lug's yard after the first year... and find them to be an excellent source of information on what's going on, and what working/not working.

[James McMullen]

I have telltales all up and down both the leech and the luff of Rowan's fores'l. You can tell an awful lot more about the flow and whether you're keeping it attached all the way across your sail when you've got plenty of things to look at to let you know what that invisible air is up to The masthead pennant on the mizzen mast isn't particularly useful at all, except to give a general sense of where the wind is coming from--and to display my personal worm-drive burgee, of course.

Especially when you're sailing fast enough to change the apparent wind--by adding the vector of your forward progress to the actual wind--the only thing in the world that matters is how the airflow is striking the sail. Which way the wind is blowing other than relative to your sail is kinda irrelevant to some degree. And tiny changes in sheeting angle or twist or camber by tweaking with things like outhaul tension or downhaul tension can make marked improvements in your sail's power--but only if you can see what's going on.

The best (and cheapest) sail telltales you can make yourself in a jiffy with bits of the magnetic tape from inside a busted cassette. Just thread a length on a sail needle and stick it through.

I don't really have any good pictures uploaded to illustrate what I'm talking about, but you can definitely see them in action in that big Barkley Sound video I posted.

[Todd Bradshaw]

I found a good over-trim photo. This is my wife sailing the Mini Twelve and she has the main trimmed in too far. The red arrows at the mainsail leech point to the leech telltales, which are navy blue strips of spinnaker nylon and about 1/2" wide by 5" or so long. The wind, judging by the masthead fly, is coming from about 10:00 and heading toward about 4:00. Notice that the upper and lower leech telltales are both swung around to the leeward side and hiding behind the leech. She needs to ease the mainsheet until they stream.

[Eddiebou]

Thanks alot, Guys, for the input.

[Gerarddm]

Those sails look pretty sophisticated for such a small boat.

Nice hull shape, very Intrepid.​

[Todd Bradshaw]

Yep, it was a pretty sophisticated little boat and those are the type of sails that I was building about 20 years ago.



I've been in faster sailboats, but I don't think I've ever been in one that was more efficient or fun to sail. When it started becoming obvious that I would need to invest big bucks in a computer system and plotter/cutter to keep building sails like that, and actually spend most of my time making boring white sails at low prices to stay in business, I switched to traditionally-styled small boat sails. They could be built with a minimum of equipment and space by anybody who was willing to put in the extra work and knew how to do it. Even that boat got a set of them, for days when I was in a more traditional mood.

[rbgarr]

Eddib,

I suspect that a telltale flying from the halyard just at the top of the mainsail may be in a spot where the wind is pretty turbulent, interfered with by the mast and the swirling vortices off the top of the sail, and thus it got wrapped and unwrapped from time to time. Todd's first photo shows a flag/wind indicator mounted above the masthead in a less disturbed wind position. It gives a better reading up there on all points of sail.

[John B]

I'm so used to having a windex and dislike sailing without one. I went to a lot of trouble to transfer the same unit with the same 30 degree angle from our old bermudan rig to the gaff rig when I made that, to get a feel for how efficient the new rig was to windward.
A funny thing happened in about feb when I had the pleasure of a race on board the lovely Townson design Talent. John had scored an old exotic cloth racing genoa which still had pretty good shape but was breaking down. As we went around the course full length strings would delaminate and ended up hanging off the leech , so we had these 10 or 15 ft threads hanging out behind it at various heights like telltales off a main except ultra long. It was quite mesmerising watching the flow beside the mainsail through the direction of these long strings of carbon or kevlar.. whatever it was.

[Bluegill]

There is only one way to know if you have your sails trimmed corectly, and that is by the use of telltails.

[Ian McColgin]

While Bluegill has a point that telltails can boost your learning curve for what the sail and boat want, the way to tell if your sails are trimmed correctly is to feel the boat. There are plenty of sailors who trim by the millimeter within the zone where the telltail shows good and they win. And there are plenty of sailors who are able to maintain boatspeed sailing at night. One of the most sensitive helmsmen I know is blind and when he calls for the jib to be trimmed an inch, he means it.

Edited to add - There are times and sails where the tell tails are just plain wrong. This is most notable with traditional catboats that are faster when sailed by the lee rather than gybed over and can be faster on a dead run if trimmed in, letting the sail think it's by the lee. Any leach telltails will be blowing backwards and the boat will move out like a witch. This does not work with taller aspect sails.

[John B]

My main tell tales are all gone, as they do over time, and I seem to manage. Mostly I trim off the luff.and the windex and the back of my neck.

And depending on the type of boat you sail, as Ian says , they can be wrong. Most moderns want to be bang on or under trimmed and sailed flat, but often boats with long ends like to be on the threshold of overtrimmed so as to produce a longer waterline.

[davebrown]

I'm in terrible, terrible trouble.