Self Steering

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Copy Write 10/14/2000 ©   Updated  2/13/2006

According to the Book   Another Idea   Real Life   Motor Steer   Windward   Disclaimer    E- Mail

May 5, 2001   May 20, 2001   May 28, 2001


Years ago I stumbled across "Self Steering for Small Sailing Craft" by John S. Letcher Jr.
Copyright 1974 by International Marine Publishing Co. of Camden Main.
Library of Congress Catalog Card # 74-81711 as of print date.

Basically John chronicles adventures of crossing from California to Hawaii with no Loran or GPS in a 20' hand made sloop named "Island Girl" using twin headsails in the late 60's and early 70's. Also cutter rigged 25' "Aleutka" to Alaska and back. There are chapters for wind vanes and some other self-steering stuff. The primary focus of the book is "Sheet to Tiller Rigs". I became fascinated by the concept and I have wanted to experiment setting these up for all points of sail.

Up until recently I haven't been smart enough to adapt the designs to my boat. Like the SC 22 the writer used boom end sheeting. Personally it seemed running the mainsheet of my boat back to the tiller would entail a complicated arrangement of lines for my mid boom main sheets.

The other idea presented in the book is to use jib sheets. Recently with the realization that by using a jib pendant the jib sheets have to be lead aft, the concept of "Sheet to Tiller Rigs" has once again come to the surface. My policy is to try new things in light to moderate winds from there adept as the wind increases. Of course in a bay or ICW the wave frequency is short so if the wind gets too high I don't believe self-steering is advisable. Out on the open ocean things may be different; if I ever sail around the world in "Don't Ask" I will be sure to pass along my experiences.

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According to the book

Jib sheet under load is led aft to a block. Across the stern to the windward side through another block and tied off on the tiller. On the lee side surgical tubing (recommended in the book) is attached to the side of the boat and the tiller. By adjusting both the jib sheet & tubing a balance can be maintained where the boat will hold a heading. If the wind puffs up the jib sheet pulls the tiller to wind and slows down the boat vice versa for a lull. As waves affect the boat same thing.
Initially it takes some work to find the proper lengths and adjustments. With a little practice it becomes second nature, according to the book.

I know it sounds complicated but it's not. Now what's those famous last words?

"I don't think so".
Jib Sheet Self Steer Diagram
Blue Line: Jib Sheet     Red Line: Latex Tubing     Arrow: Wind Direction

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Another Idea

I hang out regularly in several sailing related message boards . Somebody mentioned "Sheet to Tiller Rigs". After some discussion the other person mentioned running shock cord to the winch to be able to adjust the tension of the shock cord. Hmmmmmm Using a line with a loop at one end to go to the winch. The loop end is used to attach the lengths of shock cord or tubing. Just might be a good way to make minor adjustments without re arranging everything.

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Motor Steer

During a discussion with my Dad about self-steering the other day, he brought up an interesting concept.
The motor mount is on the port side; usually I sail with the motor up for obvious reasons.
If on a port tack would it be possible to lower the motor in the water just enough to create enough drag to balance the boat on a port tack???
This idea has a great deal of potential for short-term sailing. If I wanted to take a break and was able to use the motor to balance the boat there would be nothing to hook up. Just adjust the way the motor drags in the water to achieve the desired effect.
Hmmmmm, I will be getting back to this idea another time October 2001
With steady light wind, beam reaching port side lowered the motor in neutral moved the MOB line over to the port side. Using the length of shock cord and some line the tiller is tied off. The drag of the motor was just enough to keep the boat balanced. The keel was full down. Additional experimenting is needed under differing wind and wave conditions to see how well this concept holds up.
I don't think this idea will work well if the seas are choppy or in a following sea situation.

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Windward Self Steering

Here is an idea passed on to me from a Canadian sailor.

1. Sheet the main and jib for maximum speed for a windward beat

2. Backwind the main just a bit so a very light soft spot appears in the luff

3. Lock the tiller so she will just barely turn up wind from a close reach

4. Sit back and enjoy

As the boat falls off, she gains speed and starts the slow turn to windward. As the main starts to back wind she slows down and starts to fall off before stalling.
I have not played with this yet!!!

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Real Life

My early experiences have included the use of small diameter shock or bungee cord. I think I purchased a 4' length. Actually it is a pain to set with a single length cord. Although the one time I tried it the boat held a good course reaching in about 10K wind. The lulls posed adjustment problems often corrected by hand steering through them. I sailed for over an hour set this way. The only disappointing thing is the ballast situation. I am a big part of balancing the boat. Where I sit makes a big difference. I can't help but wonder if I ever sail deep water with the keel down how things will set. I would like to be able to move about the boat and still keep a heading. With the shock cord the boat would hold a heading much longer than an untended or tied off tiller, eventually drifting to one side or the other. Often drifting slowly, if enough sea room I could actually go forward to do something for a BREIF moment. I have yet to play with the surgical tubing so the jury is still out. I have in the past used the shock cord to tie off the rudder. If done right sailing downwind self steering has been possible, the shock cord allows manual override for wind shifts.

I have purchased some thick walled surgical tubing and if I have the time will be playing around with it to see how things work. The tubing is to be cut in equal lengths with the ends looped. One looped end is attached to a cleat or something and the other to the tiller. By using multiple lengths of the same length varying degrees of stiffness can be used to adjust for wind pressure on the sail. By using different lengths for different sets of sail self-steering can be obtained for all points of sail.

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May 5, 2001

May 5 2001 Winds this afternoon around 10-12K with gentle puff up to around 15K or so. Set up a line for the latex tubing. The line is long enough to run from the tiller along the gunnels forward to the winch. Previously 6' of latex tubing was purchased it was cut in half and tied into two looped lengths. These lengths of latex ran through the eye of a bowline knot on the end of the line. The other end of the latex slipped over the end of the tiller like a big rubber band.

Rigging this mess under sail was a bit more complicated than I originally thought. Set the mainsail traveler in the middle and adjust to get the boat moving. Wrap a few turns around the lee winch with the tubing line so the tubing is not putting any tension on the tiller and the tiller is centered. Manually haul in the jib sheet. Once the jib is hauled in enough to start driving the boat wrap some jib sheet around the tiller. From there adjust the tubing and the jib sheet to set the boat heading. Once the jib was set I would pull the traveler up and do any fine-tuning. The first few times was bumbling and fumbling, by the third and fourth time I was getting the hang of things.

With the sheet to tiller set and the keel ¾, sailing without having to constantly steer was quite pleasant. Under stable winds the hold a heading quite well. As the wind puffed up the boat would head up into the wind. According to the book as the boat turned into the wind it should have luffed up then fallen off the sails filling and continue on its merry way. My experience was the boat would go from a broad reach to a close reach then into irons. As the tubing continued to pull the tiller I am of the delusion the boat would eventually tack. About the time the boat went into irons I manually corrected. During lulls the boat would fall off until it slowed and the wind either picked up or the boat equalized on a parallel heading with the next puff pointing the boat back up and almost back on the original heading. Occasionally a correction was needed to reset the heading, the corrections were minor movements of the tiller. If the winds eased off for a while the tubing line was eased a bit and tightened during extended periods of higher wind.

The wind was from the east and after a long tack south and return back north I decided to stay in the middle of the bay and lower the keel all the way down. I haven't sailed keel down in such a long time. Compared to ¾ keel the boat is much more stable. Puffs that may require easing of the main at ¾ don't or you can wait a lot longer before easing. The heeling situation is much slower. ¾ keel the boat goes right over to a point then resists going much further. I don't believe dragging the rail makes the boat go any faster, usually by then I am adjusting something. With full keel heeling is much slower and the resistance much more noticeable. At this time I don't have a way to track speed over water but it seems the boat goes faster ¾ keel in moderate winds than full keel. With proper trim ¾ keel gives a bit more weather helm than full keel (not excessive).

With full keel and sheet to tiller, bearing up or down in relation to wind speed was less dramatic and the boat seemed to hold a heading better.

Due to the lay of the bay and wind direction the southern tacks were mostly beam reaching to not quite broad reaching. The northern legs where beam reaching to close reaching (not close hauled). Another day I will play with other points of sail

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May 20, 2001

4pm Slipped out for an evening cruise winds pretty high going out. By 6:30pm the big sea breeze gusts had calmed and probably looking at 12 to 15K steady winds for the down wind run back home. Keel down 10 cranks and flying my old jib to the port side broad reaching. With just one sail flying the boat was technically unbalanced for sheet to tiller rig. Probably would have done better with the main flying as well. Set the jib up free and adjusted.

Seemed to do fine but the boat wanted to turn into the wind. The wind would rise and fall allowing the rubber to pull the boat into the wind if untended. I would get everything adjusted then the wind would puff up or falter meaning manual adjustments. Still the boat handled better than times I tied off the rudder and my early experiments using shock cord.

I was able to move around the boat and do things. Then I got the bright idea to go forward and set the whisker pole. I left the sheet to tiller in place. With the jib already trimmed it was tough getting the pole in place. Once I did the boat picked up noticeable speed and the sheet to tiller was out of whack so a quick trip back to the cockpit before we broached. After readjusting everything the boat settled down and sailed better with the jib poled. I was able to put the mainsail cover in place and do other things normally not possible or hard to do.

Then came the magic. Cruising home steady wind and night falling all around. Other than some adjusting (still wanted to round up into the wind) it was a nice lazy sail back.

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May 28, 2001

Coming back from a Memorial Day trip to Big Lagoon I tried to set my sheet to tiller rig for a run and broad reach in a stiff wind with main and jib sails. Due to the short nature of the downwind runs and the long broad reaches I didn't set the whisker pole. Also the wind was pretty stiff and sailing solo didn't want to have to go forward unless necessary.

Running downwind the main blanketed the jib too much to get a jib sheet to tiller set up and working like it should. Flying just a 110 jib would have been too slow for what I wanted. If I had a 130 jib I could have flown that with no main, the sheet to tiller would have worked better.

I need to go back to the book and refresh on sheet to tiller using the mainsail.

Something else to play with

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Disclaimer

The information on this page is not intended as a "definitive" guide to sailing .
Rather it is a collection of things that work for me also ideas I have learned from other sources.
The information is specific to my 22' swing keel South Coast Seacraft Eclipse.
The sailing area is local bays and ICW
Use at your own risk
Any good sailing resource book should provide a comprehensive review of sailing theory.





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