SELF-TENDING TRIM

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H

HAL

I’m looking for tricks on trimming the boat and sails so they are as self-tending as possible in constantly varying wind and wave conditions. Most tips involve maximizing power and speed. At times I want the peace to observe and enjoy nature while relaxing sailing.
 

Ross

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Jun 15, 2004
14,693
Islander/Wayfairer 30 sail number 25 Perryville,Md.
If you have plenty of sea room you can trim for

a beam reach and just follow the wind. if you had wind vane self steering that's what would happen. It is only when you have some place to go that you steer a course and trim as needed.
 
Dec 11, 2005
74
Pearson 30 Wanderer NA
I would recommend a tiller pilot that interfaces

with a wind instrument. Also, I recommend a tiller pilot that has a wireless remote. That way you can dodge obstacles while sitting on your fore deck enjoying a cigar and a beer.
 
Feb 26, 2004
23,342
Catalina 34 224 Maple Bay, BC, Canada
Good try

but to meet your criteria of "...in constantly varying wind and wave conditions" you'd never find something that would work. When the wind changes, you have to, too. What I suggest you do is learn how your boat behaves. Here's how we do it: reef early, like before you leave the dock. An underpowered boat is usually easier to balance, and generally not that much (comparatively) slower than one with a full main up in winds over 10 kts. That said, as we became more experienced with our boat, we could find "the GROOVE" sailing upwind in winds in the 15 to 20 kt range with a full main and the boat would sail itself with the sails properly set. The autopilot has a lot less load on it -- or you can feel it in the wheel or tiller. I learned how to do this on C22, C25 and our C34 by playing with the sails when the autopilot was on and finding what trim minimized the autopilot's work. In many cases, once the boat is trimmed right, I can turn the AP off and still sail consistently. Also, the size of your headsail has a lot to do with balance, many are very oversized. So, learn your boat, there are no tricks except good sail trim and balance.
 
R

Rich

Plenty of resources for this idea

Hal, there are a number of good books out there including Lee Woas' classic "Self-steering without a windvane: A comprehensive manual of natural and sheet-to-tiller steering systems for sailboats" (out of print but available from various libraries through interlibrary loan). Woas has a lot of clever systems for adjusting for variable conditions. The stretchy rubber medical tubing he describes can be found as icemaker tubing at some Home Depot stores. Prior to the age of fiberglass most small sloops seem to have been rigged with self-tending jibs based on a "jib club" or loose spar laced onto the foot. Roller furling makes that impractical, but there are some good modern systems based on a deck-mounted swiveling spar. Harry Calahan's Classic "learning to sail" and "Yachtsman's Omnibus" have some description of the older system as used in the '30's. If you wanted to install a modern self-tending jib spar look around for information on the "Hoyt club boom" used on the Schock 20. I think that system sized for the 20 can be bought from Schock for less than $1200, but I'm not certain. It isn't essential to use a spar with the jib--if you have a short traveler built into the coach roof you can get the same effect. I've thought about trying to work out a "whip-spar" from fiberglass fireplace rods, but haven't decided if the result would be worth the trouble. Hope this gives you some useful ideas...
 
Jun 4, 2004
174
Oday 272LE Newport
Sometimes I think people over simplify ...

you are just not going to be able to make everything easy going downwind or tight hauled. Easyville is beam reaches on flat water. Even 10yr old girls can make that work. If the wind changes ... the course changes ... if there is nothing in the way ... fine. But anyone who tells you they can just trim and forget on a tight reach or dead down ... has to have some kind of magic boat. Hey a couple of weeks ago we went over an hour just sailing an easy beam ... didn't even bother to lock down the wheel. Of course when my 275 lb crew man decided to get a beer ... we did have to readjust for his weight moving around. but once we had the drinks up in the cockpit and at hand ... easyville. Vic "Seven"
 
Jun 6, 2006
6,990
currently boatless wishing Harrington Harbor North, MD
Autohelm x000 and the wind vane accesory

The wind vane accessory allows the autopilot to adjust course for changes in wind. The Autohelm already has the smart steer software that learns the wave pattern after 5-10 minutes. You could also go with a wind vane self steering system. The only problem with either of these is you will not be sailing a straight course in varying winds so you will need sea room or have to keep a closer watch on what the boat is doing. Which I think defeats the whole purpose of what you are trying to accomplish. To actually sail a straight course you would necessarily have to adjust the sail trim and I know of no way to do that automagickly.
 

shorty

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Apr 14, 2005
298
Pearson P34 Mt Desert, ME
Lobster pots

Hal, like me, is in Maine & we have lobster traps, depending on the bay, you can walk across them. Slalom sailing.
 
Jan 15, 2007
226
Tartan 34C Beacon, NY
There is no easy answer to this question.

There is no easy answer to this question. Each boat is different and some will sail by themselves and others won’t. As a boat rolls the distribution of volume underwater may change on some boats and this will cause the boat to trim differently which upsets balance. As a general rule a long keel does better then a short fin and a CCA style instead of an IOR style does better. The modern boat has a lot of beam and volume aft so she trims down by the bow when she rolls. My first solo trans-Atlantic was done in a 22 foot Sea Sprit without a windvane. She sailed the trip by herself and self-steering is easy on the Sea Sprite by just using sail trim. First, each point of sail has its own problems and you need to use a different setup when running or reaching etc. Also I did not have much luck beating or reaching until I trimmed the boat so that she was down by the bow just a little bit. I suspect that if she is heavy in the stern the transom edge dips into the water as the boat heels at times and makes large changes in trim as it forces the bow down. Running is the easiest point of sail to describe so I will start there. Downwind is also the only point of sail that I could not make the boat sail herself with standard sails and equipment. The boat is not inherently directionally stable downwind so I had sails made suitable to use on that tack and lead the sheets to the tiller. My downwind sails were cut with high clews and had the piston hanks put on so that a pair of headsails had hanks for the starboard sail at even heights and the sail for the port side had hanks at odd heights. This let me have both sails of the pair on the same headstay without having the hanks interfering with each other. I also had the pulls for the hanks on the starboard side for the starboard sail and on the port side for the port sail. This way in the dark or during bad weather I could unclip one sail and know for sure that I was only unclipping one sail and not some hanks for one and some from the other sail. I used two whisker poles and ran the sheets to turning blocks and then to the tiller. By having the two sails trimmed far enough forward when the boat was off course the windward sail would pull more then the other and pull the tiller to correct the course. You could trim so that you could use this system from the wind on the quarter to dead downwind with no problem at all. You could also put up the spinnaker while using the two working jibs to steer the boat. Close hauled and reaching were similar in setup with the difference being just one of degree. After you trim the boat and sails on a reach so the rudder has just a small bit of weather helm you can then trim the headsail in a little more and trim the main out a little bit and then tie off the tiller. If the boat wanders off the wind the main becomes more effective and the headsail less so and the boat rounds up to the course. If the boat wanders towards the wind then the headsail is now trimmed better and the main loses drive because it's grossly under trimmed so the boat falls off to the course. In either case the boat sails a course of gentle s turns up to 5 degrees off course each way but averaging a better course then you would after a few hours at the helm. The amount of over or under trim is greater for reaching then close hauled and in fact I found that if the conditions were right the boat would go to windward by herself trimmed very closely to what you would consider proper. Now, the ifs ands and buts. Nothing on a boat is straight forward and the problem in describing this are the exceptions to the rule. To make it work on a bad day with the seas on the quarter and the wind fine on the bow for instance you need to add shock cord to the rudder and lead the jib sheet to the lee side of the tiller. By playing with the placement of the shock cord (that adds or reduces tension on the tiller) and moving where the jib sheet is attached (changes the amount of pull on the tiller) you can get the rudder to pull to windward when the stern is bounced off course. If you don't do this the sudden change in course is too much for sail trim to handle and thing get out of control when the jib gets backwinded. There are other things you can do with this system to make the boat self-steering. For instance when running with the wind on the quarter you can have the windward headsail sheet going to a block on the tiller and dead ending on the coming. This makes the windward sail add more force then the lee sail and when the boat turns the windward sail will not only turn the tiller but will trim the lee sail in a bit. Things like this will let you use a small jib to windward and a Genoa on the lee side and still have the system work. You need to experiment and get a feel for all the combinations so that you can combine the ingredients in the proper proportions to make this work. The Sea Sprite is not very heavy compared to your weight and the boat will change trim as you move forward and aft. I would balance things and trim everything and then sit or stand were I was going to be and do the final trim. Otherwise the boat would wonder after I moved. If I was going below to sleep I would do the final trimming while standing just aft of the cabin bulkhead because my center of gravity would be in that spot when I was lying down in my bunk. On word of warning about doing this type of thing. I started out sailing when I was thirteen without a harness and tether to the boat. On day some 500 or so miles out to sea on the way to England during my first crossing when I was twenty-one I had the boat sailing herself and I was in the cockpit. I decided to get a picture and walked to the stern. While framing the shot I lost my balance and fell overboard. While thrashing about and cussing my stupidity I was hit in the head by something solid and as any drowning man would I grabbed at it and came up with a handful of line. I hung on for dear life and was slowly dragged in the water. When I came up I was surprised to see that I had hold of a Genoa sheet on someone's boat. I was hollering for them to get on deck and help but no one showed up. Being on the lee side and the boat not having much freeboard I was able to get onboard. As I lay on the deck and caught my breath I realized I was on my own boat and the Genoa was backwinded. The change of trim when I fell off was enough to upset the steering and the Genoa became backwinded so the boat turned around and ran over me. I don't think that would happen again if you fell off your boat a million times so I now wear a harness and when offshore stay attached to the boat even if I am on a boat with crew. Just a word to the wise, if you do this, stay on the boat. All the best, Robert Gainer
 
Feb 6, 1998
11,759
Canadian Sailcraft 36T Casco Bay, ME
What kind of boat?

Your hull form will depend a lot on how easy it is to balance your sail plan and have her sail a straight line. You could buy an autopilot..??
 
H

HAL

Thanks

I couldn't find this thread again in its usual place. Only one day results would display. I want to thank everyone for their ideas. I have a lot to work with now. I have just come around to the idea of clipping on even near shore and after the fall story I'm convinced. The water is cold especially off-season and time is short. I have a simrad WP32 with remote and am working on the self tacking jib idea .I feel that this boat might sail almost as fast and better reefed as suggested. There would be less heel inducing power aloft by lowering the CE with a reef. The boat is a h260 so it is light displacement, centerboard, water ballast, with form stability and beam aft which I think makes the helm change a lot upon heeling. If I could trim the sails to spill power in gusts instead of inducing heel I think things would be a lot calmer. Raising the centerboard some to allow sideslip seems to create too much lee helm no matter what sails are up. Twist in the main is limited because it sheets center cockpit. Suppose this is all silly because it is Maine and just when you think your clear of lobster buoys one appears and you dodge again.
 
Sep 24, 1999
1,511
Hunter H46LE Sausalito
twist

The more twist the more versatile the trim, an especially important principle in shifting winds or seas. Think of it this way: some part of a twisted sail will almost always be in perfect trim, while a flat sail will often be 100% stalled. The added bonus of saiing with more twist is that the boat stays in the groove longer, especially upwind. To introduce mainsail twist in light air ease the vang, bring the mainsheet traveler to windward and then ease the mainsail for trim. To introduce jib twist in light air move the fairleads aft, sheeting in until the middle telltales are happy.
 
H

HAL

Unorthodox sheet

Thanks again for tips Moving the traveler to windward positions the sheet so there is less downward pull, this allows the boom to rise on gusts making the sail somewhat self adjusting by twisting. If this is right, then I was wondering if nylon was used for the sheet, would the stretch allow the boom to somewhat adjust on a boat without a traveler. Would this stretch add a little latitude or make things uncontrollable. The sheet is now a 4:1 with Samson xls
 
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