Mainsail Trim - Top Telltail

[VT Fitz]

I have read several sailing books, so I think I have a good theoretical knowledge of the issues involved. In addition, I've consulted the archives here but still have a question as it pertains to the 23.5.My basic rule of thumb in sail trim is the old adage, "When in doubt, let it out." My issue is getting that darn top telltail to stream back, especially on winds below about 7 kts. It doesn't seem to want to join the party. I keep letting out the main sheet until it streams, but by that time I'll get some "bubbling" by the mast -- i.e. the battens bend the wrong way for 12"-18" off the luff, which seems to me antithetical to good sail shape -- and/or fluttering along the luff. I also don't see any improvement in boat speed, maybe even a bit less. I seem to recall reading somewhere that it's the top telltails which are the most important in creating drive, so you want to see them streaming back.(Also, while sailing Labor Day weekend, we got dusted by an old salt out with his wife & grandson. I don't recall the make -- an O'Day, perhaps a Catalina. His boat was a bit larger than ours, but not much, with a masthead rig. We were on slightly different courses as we neared to about 25 yds from each other, both on port tack, and he altered to match our course since we were windward. While in our windshadow, we were about even. But then he cleared the shadow & just left us in his wake until he gained enough headway to cross our bow. As he zoomed ahead, I noticed how beautifully all his mainsail tails were streaming back, all the way up the line. I KNEW I just wasn't doing something right in my trim!)As I thought it through while sailing this past weekend, I reasoned I needed more twist to get a deeper shape & let the top of the sail move further forward while the rest of the sail stayed put. I let off all the vang tension, but it still didn't seem to induce enough twist or at least the streaming in the top tail I was hoping to see. Finally I tensioned the topping lift in an effort to create more twist. It seemed to help & I think I picked up a tenth or two of speed. However, this last aspect is what I'm wondering about the most because I don't recall anyone ever mentioning that they utilize the topping lift in creating shape.I know I'm obsessing over it. I'm not racing. Notwithstanding, I am an efficiency nut & want to know I'm maximizing performance. Moreover, while cruising, say, 25 NM in a day, each tenth gets you in almost 10 min earlier. The difference between 4 kts & 4.5 kts is over 40 min.Can anyone lend any experience, strength or hope on this question? Am I on the right track in identifying the need for more twist? Does anyone use a topping lift or boom kicker to create more shape in light air? Perhaps I need to loosen the outhaul more, though I'm not sure how that would help the twist at the top.Thanks,Kevin

 

[Rick Macdonald]

Twist

Kevin (hello again!)You should post this in the Sail Trim forum. See the link below. Buy Don's book if you don't have it. (Tell him I said so!) ;-) I'm only in the middle of the pack of experience over there. I can tell you know a lot of what I've written here, but I included it all in case it is a help to others.The boomvang is the thing that controls twist, but can do very little when you are close-hauled because the mainsheet is so hard. The mainsheet also affect twist. You didn't say what point of sail you were on.Twist doesn't give a "deeper shape". The outhaul allows that. All the sail trim controls interact in various ways, affecting angle of attack, twist, draft depth and draft position. The topping lift gave you twist as a by-product of raising the boom and slackening the leech. The sail twisted because the apparent wind direction is different at the top of the mast compared to down by the boom, such that the force of the wind naturally twisted the sail to that shape. The reason the apparent wind direction is different is because the true wind is slower nearer the water due to friction between the wind and water. The varying true wind speeds combine vectors with the "wind" caused by the forward motion of the boat to give different apparent wind angles up and down the mast. We use twist to match the angle of attack of the sail with the wind direction as it varies up the mast. As Don says, "The boom is close-hauled but the top of the sail is on a beam reach!".Put another way, the top telltail is indicating that the sail is stalled at the top due to the angle of attack being too great because the apparent wind up there is coming from further aft. So, you add twist.The winds on my lake are never steady for more than a few seconds so I'm rarely successful with any speed tests. For example, I adjust a sail trim control, and the boat slows down. Damn, I put it back where it was and the boat slows down even more.One of many things I learned from Don and his book (besides everything I wrote here) is to put telltails in the middle of the main (between the mast and the leech). One on each side, red and green, just like on the jib (one slightly higher than the other, but I forget which). I put two sets vertically, between the batten pockets so they don't get stuck on the threads. You certainly want these streaming nicely. I think most people will say maximum power occurs not exactly when the telltails are streaming back, but when you increase the angle of attack just a bit more so the telltails just flick every few seconds. Oh, the topic of using the topping lift as a sail control does come up. The idea I've heard is in very very light air, use it to raise the boom a bit, and put the crew to leeward in the hopes of getting some sail shape and some air. Harden the outhaul some to reduce the draft depth or else the wind won't be strong enough to fill and shape it.Rick

 

[VT Fitz]

Ah, the Sail Trim Forum!

Thanks for your considered reply, Rick.I didn't even realize there *was* a sail trim forum! Thanks for the link. I'll also check out Don's book.As I reduced the problem to writing, I realized I hadn't really fiddled with the outhaul in experimenting. That may have created the deeper shape effectively rather than the way I tried it. I certainly wouldn't catagorize the winds as very, very light, so the lift was not the right approach.The more I learn about sailing in general & the H23.5 in particular, the more I realize I don't know as much as I think I do.

 

[Wanderer138]

More on sail trim manuals

Before getting too deep into ANY sail trim manual, you should be aware that most of them are written for masthead rigs, i.e. rigs with the forestay attached to the masthead. Manuals that discuss fractional rigs, i.e., with the forestay attached at some point below the masthead (some "fraction" of the mast height) are often written by and for racers and tend be more complex than the typical sail trim novice needs. The worst news is that the backstayless B&R rig on the newer Hunters (including the H23.5) is a less common variant of the fractional rig, so there isn't a lot of information out there.That being said, I think Don Guilette's sail trim guide is an excellent place for anyone to start. Since your H23.5 has a fractional rig, I'd suggest the North U Manual of Sail Trim (published by North Sails) next. Hunter Marine should have a guide for B&R rig tuning. After that, it's up to you. Try altering things in a systematic manner (take notes if you have to) and see what works. Good luck.PeterH23 "Raven"

 

[VT Fitz]

North U Manual

Thanks for the input, Peter.I actually have a copy of the North U Manual knocking around the office. A former Sea Scout Master, former boat rigger, and current winter full-time ski teaching colleague gave it to me last winter. It's pretty dense.I'm going to pick up Don's book.In the meantime, trial-by-error -- emphasis on error -- will be my best teacher. Unfortunately, we're probably pretty much done for this season.Thanks again for replying.

 

[Connie Berchem]

Twist

Your on the right track when you used your topping lift to add twist up top. In light air the boom on the 23.5 will close the leech of the mailsail. Having been a Hunter dealer and a Doyle Sailmaker, I alway's suggested the use of a boom kicker, to lift the boom open the top of the mainsail. You can also use the assistance of a barber-hualer from the end of the boom to the stern cleats on either side. Pulling the boom to center line coupled with the rise with the boom kicker the top will open up and fly nicleyConnie

 

[Jack h23.5]

My take on this..

I'm new to the hunter, but spent 10 years sailing my P-165 which has a fractional rig and no backstay like the hunter. All of the perfomance manuals all refer to the backstay to bend the mast and alter twist. That tells me that some method of bending the mast should fix your twist issue. On the Hunter, I have also struggled with twist. I put a doubler on the vang to allow me to let out the main and keep the boom down (like a traveler would). This seems to help pull the leach to windward. If your main has a leech line in it, you can try loosening the leech line to open the leech up a bit. Adding a small length of shock cord to the topping lift allows a small amount of lift on the boom in light air helping to open the leech a bit.

 

[VT Fitz]

Connie, Jack

Thanks for the replies. More food for thought.Connie, your first hand experience in dealing with both Hunters & sailmakers seems particularly apt. Could I impose on you to explain a bit further the barber-hauler idea. I've heard the term before, but have had no idea what it actually meant. A google tells me it's normally to alter the jib sheeting angle by pulling it to weather. Are you suggesting this method to make up for the lack of a traveller on stock 23.5's?Jack, could you explain a bit further how you've rigged the second vang? Perhaps a picture? It sounds like you & Connie are suggesting similar methods. I have extra fiddle & camcleat/fiddle/becket that I could use to experiment with these ideas.

 

[Jack h23.5]

not a second vang, just..

another block to double the 4 to 1 to an 8 to 1. I allows for an easier pull to close the leech. I'll see if I can find a picture.

 

[VT Fitz]

Thanks, Jack

I appreciate your efforts!I get what you're saying now. I originally read it as a "double vang" rather than "doubl-ER vang."

 

[Wanderer138]

Bu wait, there's more!

Here's something else to think about. Mainsail trim changes as boatspeed changes. Why? Because we trim our sails to the APPARENT wind, not the true wind. As the boat accelerates (assuming you maintain the same course and the true wind speed and direction don't change) the apparent wind increases and moves forward. To maintain proper trim, you should sheet in a bit more. As the boat slows, you have to ease sheets.On a boat with no traveler, the angle of attack of the sail is controlled only by the mainsheet. The problem there is that as you try to sheet in that last bit, what you're really doing is pulling down on the boom. This tightens or "closes" the leech of the mainsail, causing the sail to be overtrimmed, hence the stalled top telltale. You probably also have excessive heel (about 15 degrees is the limit) and noticeable weather helm.The best solution is to get a traveler, which allows you to change the angle of attack of the mainsail without pulling down on the boom. Unfortunately, the H23.5 isn't set up for adding an aftermarlet traveler.The next best solution is to play the mainsheet to keep the boat balanced. You should bave the tiller in one hand and the mainsheet in the other. Or, you can let your crew/guest/S.O./Admiral drive and you trim the mainsheet. In that case, you are obliged to ask periodically how the helm feels, especially in a fresh breeze or gusts. If the tiller starts to load up, i.e., you have to pull harder to keep the boat on course, ease the mainsheet slightly until the tiller feels more comfortable and/or the heel is manageable.This has to be a fine adjustment because as you ease, two things are happening to the mainsail at the same. The angle of attack increases and the leech opens. Both of those actions depower the sail and if you're not careful, the boat will fall right out of the groove and slow down. It takes practice to get this right, so if you're having too much trouble, you may want to consider a two-speed mainsheet tackle (they're made specifically for this purpose). Good luck.PeterH23 "Raven"

 

[Rick Macdonald]

Traveler on a H23.5

I actually spoke with a fellow in Texas who added a traveler to his H23.5. I didn't see it in person though. I've been tempted to do the same. He added jib car rails too. This weekend may be my last sail of the season, but I think I'll try Connie's idea of a barber-hauler on the boom end.Rick

 

[Jack h23.5]

Peter, You can use a vang..

in place of a traveler to accomplish the same thing. A tightened vang will hold the boom down while you let out your main just the same as a traveler. You have to make sure your vang attachment points are solid and that you up your mechanical advantage from 4 to 1 up to 8 to 1. The Precision line of sailboats also do not come with travelers, so vang mods have been standard to accomplish what we are talking about.

 

[VT Fitz]

Traveler/Jib Sheet Cars

Thank you all for your continued input. It looks like I touched on a subject that is on many more people's minds than just mine!I've definitely had a traveler on my list. As soon as I had agreed to purchase Grasshopper last December, I watched eBay & picked up a Harken traveler car for very cheap, as well as small Harken blocks to increase purchase. I keep monitoring eBay for small Boat Control Ends with double sheaves & cam cleat, but haven't come across a bargain yet. I'll probably have to just get the track from Defender, probably the control ends too. I understand the vang can accomplish a similar end, but it would certainly be more convenient to reach/adjust a traveler rather than the vang.I searched the archives & have seen more than a few folks have added a traveler. Location has been the biggest debating point. I'm thinking I'd locate it either just aft of the companionway cockpit shelf bridging across the current post, or on the aft edge of the shelf itself. The latter location would allow a wider track but be more of a trip hazard/seating inconvenience; the former a more limited track range. The nutty tinkerer in me has a notion that a removeable bridge further aft would be a good idea. An arrangement you can remove when at anchor or docked. I seem to recall there are other designs (non-Hunter?) that utilize this idea to get optimal sheeting angle/purchase but avoid a permanent obstruction in the cockpit.Does anyone have a traveler installation? If so, could they post a photo?In addition, as I have been thinking & reading here about sail set, I have definitely had jib tracks in mind as well. However, since many commenters have made remarks that I infer as suggesting the jib is so minor a factor compared to our large mains, comparatively speaking, that the effort to install a jib track is not going to result in a sufficiently positive outcome to bother messing with it. Thoughts?

 

[sea_casper]

I don't get it

Talking about getting a tenth of a knot in hull boat speed or even a half a knot to arrive at a destination sooner. Sailing in tidal waters here in LI Sound, BI Sound or Fishers Island Sound the tide and sea and wind direction determine how soon I arrive at a destination, more than if I maintain 90% or 99% of sailing efficiency.Indeed on most days I have no destination, and my direction depends on wind and tide.No matter my destination, I doubt I would I would leave at 5:00 AM to arrive at a destination in less time then if I left at 9:00 AM.The charm of a sailboat is the sailing, I know there is a challange to sailing at top efficiency, but if the bimini is up I can hardly see the sail much less the upper tail.Remember a powerboater uses his speed to get where he wants to be, a sailboater is always there.

 

[VT Fitz]

You don't get it? You don't have to...

Different strokes for different folks.Candidly, Casper, I find your post troubling, perhaps even a bit judgmental. Nevertheless, I’ve taken some time to consider your comments.In my days as an active golfer -- which are now on hold as the family has made sailing a primary summer activity -- I often reflected on the adage, "You play golf the way you play life, and you play life the way you play golf." If you cheat or swear or throw tantrums in life, you probably do so on the golf course. If you play golf by the rules, roll with the rubs of the green, strive to make your best shot each time -- one shot at a time -- you probably play life that way too. Perhaps sailing is a less exact analogy for life -- perhaps it is more exact -- but I certainly believe the way each of us sails is a reflection of how we navigate life. I strive for efficiency in everything I do; I'm constantly trying to learn and to improve. The reintroduction of sailing into my life is infused with that spirit. Yes, I too enjoy the journey, but our experiences, our lives, are different. Being mostly weekend trailer sailors, we have a very different agenda and different needs from someone who slips/moors their boat off the cottage on BI.You like to go where the winds and tides take you, and that's great, but we might not all have that luxury or desire. It's a potentially hazardous mistake to sail by a schedule, yes. Yet there are times -- trying to make a destination UNDER SAIL (yes, the iron jenny is always an option, but I try to move under canvas as much as possible) before the tide turns, the forecast unfavorable wind shift occurs, the squall hits, the drawbridge closes, darkness falls, happy hour is over, etc -- where it’s critical to optimize Grasshopper's performance/potential. (Moreover, my personality -- a character defect, really – is such that I have an obsessive need to know I’m sailing her to the maximum.)A case in point, the week before Labor Day '06, we had planned a LI Sound cruise from Milford to Mystic Seaport and back again. Well, the first half went to plan, and our stay at the Seaport was a treasure, but the remnants of Ernesto decided to spoil the return plans. In order to salvage a last day of the cruise and get back at least to Clinton before the worst of it blew in, we shipped out of Mystic at 0730 to make the first drawbridge opening and to catch the favorable NE winds before it shifted to on the nose. It was very, very important to us to move as efficiently as possible. It was a great sail, but the winds did start to shift and to build toward the end, making dousing the sails a trial as we turned to Clinton Harbor. We got to port in time to get a ride back to Milford, grab the truck, return and haul during the lull in the winds on the tidal change. We felt we had just made it under the wire. A leisurely cruise that day in which I paid no attention to trim and boat speed could have been catastrophic or at least, as the British say, a bit spotty! So perhaps a tenth of a knot doesn’t seem that important in the abstract, but I assure you on this day we didn't have many tenths to waste.Also, while my kids enjoy sailing, they don't enjoy it as much as I do. For them saving 30 minutes on a 30 NM cruise to the next marina or anchorage could make or break enjoying the day.You don't get it? That's fine. You don't have to get it. As I wrote to commence, different folks, different strokes. However, just because you don't, it doesn't invalidate its value to others, just its value to you. Again, that’s fine; it’s your choice, your life. My choice of what matters isn’t better or worse, just different. This issue IS important to me, and I've gained greatly from the input on this thread. So thanks to everyone who has contributed his or her experience, strength and hope, including you, Casper.~ Kevin

 

[Jack h23.5]

VT.. I get it, agree with you, and I'll add...

I hate to be passed period. Now if a melges sails past me thats one thing, but when a Catalina 22 comes up, thats fighting time I'll will tweak everything I can short of throwing the wife overboard (that would be a bad thing) to outrun a boat that is trying to pass me. I applaud your quest for excellence in this most confusing sport. I sailed a Precision 165 for ten years that had a monster 204% genny. That boat was about the fastest cruiser afloat in winds under 10 knots, but is suffered from a short water line when the wind increased. Since I bought the Hunter, I've been struggling to get the light air performance up to that of the precision, and maximizing tell tale performance is one way. In November, I'm going on my first 4 day cruise with the Hunter, and will be sailing with several Precision 23's. The last thing I want to do is to be left behind while they sail away. The Hunter 23.5 is rated as a slightly faster boat, so its even more important that I get my boat into its "groove" quickly and keep it there. Also speed important as it is relevant to something else. It doesn't matter if you sail at 6 knots or 5 knots, but it does matter if you are sailing 3 knots and the boat behind you is sailing at 3.1 knots

 

[sea_casper]

Touched a competitive nerve

Kevin, I am sorry you did't get what I was trying to tell you. There is nothing wrong with striving to improve our skills. I was trying to say, focus on the overall picture, instead of all the details. I have learned long ago as an engineer, it is not necessary to calculate eveything to 3 decimal places. Sailing like life is not a straight line, it does not matter, how fast we are going, if the direction chosen is not right.Every sail should not be a race, it is important to know when to slow up.The most important consideration for you is to involve your crew and make it fun for them, and a longer sail will not be a problem. Otherwise sailing could end up like golf, replaced by another family activity.P.S. I keep my Hunter and sail weekends in Groton not BI, I do trailer our CL14 to BI for our 2 week vacation every year.