Sheet to Tiller Self-Steering

Stu Jackson · Jun 25, 2012

Lord Nelson is also correct. Letcher also covers jib sheet to tiller steering in his book, too, as well as good downwind methods. For those of you who may think books are way old 20th century technology, I'm sure there are videos out there.

Perhaps what the OP meant to say is that "for short distances" there would be no difference. What the respondents have been saying to him is that for longer distances it won't be the same, because once the winds shift - even a small amount...they won't.

mark_swart · Jun 25, 2012

Breezy -- I have used 'tiller tamers', a lashing system, on several boats. The issue is that any change in anything.... weight distribution from moving around, wind speed variations, will affect whatever course you have set with the tiller. Sooner or later the boat will go off course. That's the whole point of the sheet to tiller setup, it can compensate for wind variations.

I can't tell you how many times my three smaller boats ended up going off course with a tiller tamer (O'Day 23, 26, 272). Your Mac isn't drastically different and will also be sensitive to weight and wind variations. Unless your helm balances perfectly it's going to go off course using a lashing system.

Back to your original experiment -- the boat with the lashed tiller will go off course as soon as the wind fluctuates. Guaranteed.

With my current boat, which also has a tiller, I sucked up the $400 for an autopilot. Money well spent because I can go anywhere on the boat, under sail or power, as well as handle moderate gusts, and she will hold her course.

BreezyCricket said:
To Joe:

You say that I assume the only factor affecting the boat's direction is the rudder, and this is simply not true.

I have made it abundantly clear that sail settings and wind direction is what affect's a sailboat's course over ground, and this is not all, as you say, 'theory and conjecture', it is fact.

Any opinion to the contrary certainly can only be classified as extremely sophomoric.

As to your suggestion that I build a case for my premise with some actual experience, I am sure that anyone with even very limited sailing experience will confirm that a boat sailing unattended with the tiller lashed, as when a lone sailor has fallen overboard, will continue sailing, and that is an absolute certainty.

Finally, if I am incorrect in claiming that a boat under these circumstances, either attended or unattended, will continue sailing a course in relation to the wind direction, what would you suggest will determine the course this boat would take?

kenn · Jun 25, 2012

BreezyCricket said:
I am sure that anyone with even very limited sailing experience will confirm that a boat sailing unattended with the tiller lashed, as when a lone sailor has fallen overboard, will continue sailing, and that is an absolute certainty.

... if I am incorrect in claiming that a boat under these circumstances, either attended or unattended, will continue sailing a course in relation to the wind direction, what would you suggest will determine the course this boat would take?

The key phrase is "sailing a course" . What's "sailing a course"? It is the ability to sail in a predetermined direction, relative to the apparent wind (for windvane and tiller-sheet systems) or in an absolute direction (electronic systems using compass or GPS feedback).

Obviously, everyone agrees that if the tiller's lashed, the boat will sail 'away' . But at some point, could be several minutes or more, the boat will head up and maybe go in irons, or bear away, maybe get knocked and round up, etc. This is hardly "sailing a course".

There might be a boat out there whose sailplan is so perfect that when it's trimmed just so, and the tiller is lashed just so, and the wind is just right, and there's no waves, and nobody changes position... it will hold a course. I have not yet seen or sailed that boat.

Charlie Jones s/v Tehani · Jun 25, 2012

Are you serious??? Or trying to be funny?

You asked a question and got quite a few in depth responses as to why your theory was incorrect, from some highly experienced sailors. I don't know the others, but I just returned from some 7000 miles of sailing, 2200 miles of it a single hand, both coastal and open ocean.

Your theory was incorrect, but if you still can't see that, perhaps it IS time to put this to bed.

weinie · Jun 25, 2012

Don't put it to bed just yet! I am interested in the physics of all this!

I think Breezy, you are correct (and I'm a newbie and no expert) in that a sailboat with sails fixed into position should be able to follow the same angle off the wind with small changes in wind direction. One side of the sail should see an increase in pressure, the other side a decrease, and the net effect would be to push the boat onto a new compass course but a keep the same angle of incidence with the wind.

Somebody correct me if I am wrong so far.

Now, what would push the boat off of the original bearing off the wind? Well, I would venture to guess that a large increase or decrease in wind speed or direction would disrupt the steady flow of air on either side of the sail, causing a loss of lift and causing a stall. A large wave or current would probably do the same. Hence the need for a rudder correction to counter act this change so that the air flow over the sails is not disrupted.

Do I win the free monkey?

Stu Jackson · Jun 25, 2012

The answers to your questions (the detailed physics) are in the book I suggested. All of the answers. All of them. The pages and pages of vector diagrams and explanations arer too detailed to include in a forum like this. That's why people write books.

Reply #6 on page 1 of this topic also has some good discussion.

Dan Pfeiffer · Jun 25, 2012

[FONT=&quot]Interesting topic. I used to play with this on my Pearson 26 and wrote up a bit here on tiller lashing (with adjustment):[/FONT]
[FONT=&quot]http://dan.pfeiffer.net/p26/selfsteer.htm[/FONT]
[FONT=&quot] [/FONT]
[FONT=&quot]Couple of points:[/FONT]
[FONT=&quot] [/FONT]
[FONT=&quot]Someone wrote:[/FONT]
[FONT=&quot] [/FONT]
[FONT=&quot]"I am sure that anyone with even very limited sailing [/FONT]
[FONT=&quot]experience will confirm that a boat sailing unattended [/FONT]
[FONT=&quot]with the tiller lashed, as when a lone sailor has [/FONT]
[FONT=&quot]fallen overboard, will continue sailing, and that [/FONT]
[FONT=&quot]is an absolute certainty."[/FONT]
[FONT=&quot] [/FONT]
[FONT=&quot]This is not really certain and certainly not absolutely certain. The boat may hold a course (relative to wind) or it may not. Depends on lots. If it's a small boat the loss of the sailor may upset the balance enough to alter the course and cause round-up or an accidental jibe which may leave the boat in a hove-to state. Once balanced my P26 would hold a close reach very nicely with tiller lashed (flattish seas, 10-15 knots). Moving around on the boat would change course. On my P26 (5400 lbs) moving to the high side shrouds would make it head up 5 to 10 degrees, to the low side it would fall off 5 to 10. By moving on the boat I was affecting the balance. Any wind surfer will understand that. The bigger the boat the less the effect. Falling off would also upset the balance. And minor adjustments to the sails would do the same. Sheet in the main a wee bit and the boat would head up a bit. Let it out a bit and it would fall off a bit. [/FONT]
[FONT=&quot] [/FONT]
[FONT=&quot]I also observed that, with tiller lashed, the boat would not hold a steady course but would oscillate around a given course (wind course). Sometimes it would be stable, sometimes not. Sometimes the oscillation would increase in amplitude with each cycle until it got beyond the point of self correction and the boat would go into a jibe or round up. The sheet to tiller systems serve to control this oscillation and better keep the boat in that self correcting zone with feedback from the sheet. But it all depends on balance and if the oscillation grows too large the boat will not self correct. The keys are balance and keeping the oscillation stable. Wind (shifts and puffs) and waves will also make input to the stability of the oscillation. If any of these inputs is large enough (like a big puff or motor boat wake) the oscillation looses stability. The lashed tiller or sheet to tiller is harder to manage in puffy or wavy conditions and in smaller boats. The mass of a larger boat dampens the oscillation. My current boat (Pearson 10M - 13,000 lbs) is slower to react and easier to keep in the stable zone of the oscillation and will hold a course longer. And moving around has less of an effect. So would falling off though I have not tried that. [/FONT]
[FONT=&quot] [/FONT]
[FONT=&quot]And you need to understand how to control balance in the boat with sail trim and rudder input. You need to understand weather helm. The sheet to tiller system uses that for the feedback. Boat is trimmed for weather helm and tiller secured. Boat heads up and sail trim degrades. Heel changes, weather helm decreases and boat falls off. Boat falls off a bit and weather helm increases bringing it back up. All with no input from the tiller. Adding tiller input with a sheet to tiller system speeds up the reaction time keeping the oscillation smaller. Boat heads up a bit and tension on sheet increases pulling tiller making it head off a bit. Boat falls off a bit and sheet slacks letting the tiller move down and making the boat head back up. [/FONT]
[FONT=&quot] [/FONT]
[FONT=&quot]And all this is with regard to wind course as in course relative to the wind. If the wind shifts so will your course of course. That is of course unless your course is held by Mr AP (electronic auto pilot that is). AP will be compass or GPS (COG) though you can integrate them to a wind instrument if you have one. Auto pilot will also be happy to let the boat round up or jibe if the wind changes and is simply driving to a compass course. A wind vane is analogous to a sheet to tiller system with some added versatility. But the feedback system is essentially the same.
[/FONT]
[FONT=&quot] [/FONT]
[FONT=&quot]Here are some books to look at (first has been mentioned), I bet Amazon can find any of them used:[/FONT]
[FONT=&quot]Letcher, John S. Jr(1974)Self-Steering for Sailing Craft, International Marine[/FONT]
[FONT=&quot]Woas, Lee(1982)Self-Steering Without a Windvane, Seven Seas Press[/FONT]
[FONT=&quot]Dijkstra, Gerard 1979 Self-Steering for Sailboats, Sail Books, Inc.[/FONT]
[FONT=&quot]The Amateur Yacht Research Society 1970 Self Steering 2nd Ed., AYRS[/FONT]
[FONT=&quot] [/FONT]
[FONT=&quot]Dan Pfeiffer[/FONT]

anchorclanker · Jun 25, 2012

Wow.

That youtube video really shows how neat it works. Almost the same reactions as a human.

Charlie Jones s/v Tehani · Jun 25, 2012

Actually, STT can often do BETTER than a person- It's always paying attention, never distracted by something happening in the cabin, etc. What it can't do as well is anticipate a gust or wave, so has to catch up afterwards. But when sailing to weather on my boat (See vid reply #6) the tilller will only move a half inch to an inch or so as it steers.

Joe · Jun 25, 2012

BreezyCricket said:
I was hoping to get one or two replies to my theory and this hasn't happened so I guess it's time to put this subject to sleep.

You got plenty of replies........ just not the ones you wanted.

Your theory is just that...... a theory... and it will remain so until you can offer proof.........

Most of us saw the flaw in your logic... it's up to you to re examine the process that brought you to your conclusion. I think a good place to start is with your understanding of HOW a sheet to tiller self steering system works. You have been provided excellent links by Stu and others..... take it upon yourself to look closer at the system... then go from there. Good Luck.

timxgo · Jun 25, 2012

Long ago and far away, I taught sailing for a living. On several occasions, when time and weather permitted I would take a Caravelle out by myself. I would remove the rudder and proceed to sail wherever I wanted. I used the sails, my weight and the lines of the boat to tack and gybe all over the bay. So a rudder, lashed or otherwise, is not necessary as long as you have immediate control over all the hydro and aero dynamic forces of your environment.

Orion253 · Jun 25, 2012

Not all boats will work well with a locked off tiller. It really only works up-wind. You just have to set the sails correctly and the boat will keep the same heading toward the wind. I brought a Beneteau 43.3 back from Bermuda to NYC over a 5 day sail and didn't touch the wheel till NY. I have done the same with my hunter 40 and a La Coste 42.

centerline · Jun 25, 2012

BreezyCricket said:
I was hoping to get one or two replies to my theory and this hasn't happened so I guess it's time to put this subject to sleep.

Ok.... you cant take an explanation or a hint so maybe a point blank reply to your theory is what you are looking for....

your theory is wrong. it doesnt work the way you think it should. this isnt the first time someone has had an idea of how they could make it better, but the system as it is, is simplicity itself.... it does exactly everything it is intended to do and it does it very well with a minimum of parts and rigging knowledge. there is no moving parts that wouldnt already be moving, and all that is needed is one short piece of line, which you already have to lash the tiller, a turning block and a piece of elastic tubing..... and common sense enough to tie it all together......

if your looking for someone to validate your theory and tell you it sounds like it should work just the way you think it should, even though we know better, just spit it out and say so.... we can humor you along, and possibly even give you plenty of other barren ideas to dwell on....

centerline · Jun 25, 2012

weinie said:
Don't put it to bed just yet! I am interested in the physics of all this!

Now, what would push the boat off of the original bearing off the wind? Well, I would venture to guess that a large increase or decrease in wind speed or direction would disrupt the steady flow of air on either side of the sail, causing a loss of lift and causing a stall. A large wave or current would probably do the same. Hence the need for a rudder correction to counter act this change so that the air flow over the sails is not disrupted.

Do I win the free monkey?

the monkey is still up for grabs.... you cant get there from here because your rudder is lashed (according to the proposed theory).... if you had a self steering system, the rudder would in fact be able to be corrected for these variations, and do it automatically while you are looking at it and trying to figure out what kind of magic is in the rubber springy thingy that makes it work so much better than a rope tying the tiller down....

cwkemp · Jun 26, 2012

I'm not a seasoned sailor, but I have a good many hours single-handing my Cat 22 on inland lakes. My observation on this subject is simple. My boat (nor any of the other boats I have owned or sailed) will not indefinitely maintain compass course or attitude to wind without my input and corrections in response to changes in wind direction and intensity and waves. Balance of sail and hull trim is defintely the ideal but it is also a moving target. Therefore it is only reasonable to expect that a successfull self steering system would have to be somewhat self-correcting, that is, responsive to the changes that require my activity otherwise. I would not expect a boat to sail itself any more than I would think that a bicycle pushed and left to roll would remain upright without a rider. Even a powerboat with the wheel lashed will not stay a true course. It's only logic, but it is based on first-hand experience and observation.
Clint

J. Burl · Jun 26, 2012

The old dream

Over the last 50 years I have tried to solve this. There are some rather complex and expensive solutions, but the truth is nothing will replace the human hand on the tiller. This is particularly true in small to medium size boats. My solution is always have a sailing buddy who can take the helm from time to time.

kenn · Jun 26, 2012

BreezyCricket said:
I now intend to start selling my tiller lock system and will include in my marketing strategy that the majority of member's on this forum strongly endorse the product as being 100% effective, which my reading of the replies seem to confirm.

I am including a photo of this which is being sold for $ 129.95 and it comes with a complete set of installation instructions so there should be no problems with the setup.

I have a Tiller-Tamer, which apparently is but a crude knockoff of your clearly unique concept. But the rope running through my TT squeaks, which drives me nuts. If yours is silent, put me down for one.

if it comes in Pacific Blue, I'm good for 2.

Sheet to Tiller Self-Steering

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