This blog is devoted to my John Welsford designed 15' Navigator yawl Ellie. I built her in my garage over a period of 18 months and launched her in 2011. She sports a sliding gunter main, roller furled jib and sprit-boomed mizzen. Her construction is glued-lapstrake over permanent bulkheads and stringers. This blog is a record of her construction and her voyages here in the Puget Sound area and (hopefully) a useful resource for fellow Navigator builders.

Monday, May 6, 2013

The Incredible Self-Steering Ellie

Yesterday's daysail was one of the best sails I've ever had. It was a beautiful and interesting day. The day started off with very little wind.  I had to motor-sail from the launch, but a short while later the afternoon breeze kicked in like someone flipped on a light switch. While I sailed towards Hat Island, the wind steadily built until I finally had to heave-to and don my rain gear. Later, as I rounded the NW side of Hat (Gedney), the wind calmed down and it turned into the most pleasant of conditions.

You know those conditions.  When the winds are a steady 10 knots, the seas have calmed, the sun is warm on your face. The only sounds are the waves on the hull, the breeze in the rigging, the occasional cry of a gull, and all those utterly delightful little squeaks and creaks that only a wooden boat can make.

Those are the conditions that cause the mind to wander, much as they once did for Albert Einstein.   Einstein, in the summer of 1939, was seeking a unified field theory to unite his general theory of relativity with electromagnetism. He spent many hours aboard his 15 foot wooden sailboat Tinef (Yiddish for "worthless" or "junk,") lost in thought, forming his theories and exercising some of the thought experiments that he is so well known for.  As I sat aboard my own 15 foot wooden sailboat lost in thought, I wondered if there could possibly be anything that Einstein and I had in common.  Perhaps how we both enjoy sailing small wooden boats and how we both experienced the way the peace and solitude caused the mind to drift.  Then I realized how reassuring it was that even a genius like Einstein can still be a poor sailor, like me.

I daydreamed about self-steering.  Long ago I had read that a yawl can self-steer all by itself.  No wind vane steering mechanism.  No sheet-to-tiller steering.  No tiller tamer.  No auto-pilot.  No bungee cords.  A properly designed yawl, I vaguely recalled reading, can somehow be made to steer itself just by setting the sails some certain way.  But how?  How are the sails set?  How does it work?  And was it really possible or just a legend?

It had to be some sort of balance between the jib and mizzen, I reasoned.  They would have to be set in a way that would cause the boat to round up if it were to fall off, and fall off when it rounded up. In between, the boat would have to sail balanced.  That means the boat's natural weather helm would have to be neutralized.  I knew that could be done by easing the mizzen.  Hmm.  Time for a thought experiment of my own. What if I kept the main and jib sheeted in tight but eased the mizzen out until the helm was neutral?  How would the boat react?  Seems like she'd sail straight with a neutral helm.  But what would happen when she veered off course?  I imagined when she fell off, the mizzen would catch more air which would then turn her back into the wind.  When she headed up, the mizzen would catch less air, begin to luff and lose power, and then the jib would cause her to fall off.  That's it!!!  She'd self-balance.  It made sense.  It seemed like it would work.  All that was left was to give it a try.


And much to my amazement, it worked!  It really, really worked!  For over an hour, while I ate lunch, recorded some video, took some photos and enjoyed the sun, Ellie cheerfully sailed herself.

Initially I had a small line going from the tiller to a cleat, but it didn't seem to be doing anything, so I removed it.  Sure enough, Ellie still self-steered completely unassisted.  I tried shifting my weight around.  I sat on the front thwart, I stood on the aft thwart.  Didn't matter - it still worked.


I never touched the tiller in all that time until I finally had to call an end to it, or run aground on Camano Island.

No doubt there are experienced sailors out there who would pass this off with a yawn and a shrug and a "nothing to it, I do it all the time".  But they would be missing the great joy that I experienced yesterday.  The joy that a fellow mediocre, but thoughtful sailor spoke about when he said:

"Joy in looking and comprehending is nature's most beautiful gift."
-Albert Einstein

Lastly, I hope you enjoy this little bit of my delightful sail home.





5 comments:

  1. Joel,

    These videos really show how gorgeous the day was for you and Ellie and watching them makes me homesick for the PNW. Thanks for documenting the balanced self-steering experiment, too.

    Michael H.

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  2. Very nice Joel. Thanks for posting the videos.

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  3. I use this compass. I don't know how expensive they are your side of the pond but it has been brilliant

    Anyway I heard you was lookin for one!!!
    http://www.gaelforcemarine.co.uk/37452/Silva-70UN---Universal-Compass.html

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  4. That's pretty good Joel... and in some ways better than that darn push pull tiller I have on my yawl- which will try to escape by jumping in the water at every opportunity! I have to strap it down to do steer without my hands, but I've never been as successful as you.

    -Bruce

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  5. Logically this should work, as the authority of the mizzen with regard to yaw should be far higher than that of the main with regard to the change in wind load as the boat rounds up or falls off. I'm wondering if a mizzen added to an ordinary sloop could serve as self steering in lieu of an expensive wind vane, and have other benefits such as a riding sail, and a bit more drive.

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