BoatBanter.com - View Single Post - Sheet to Tiller self steering question .. ??

Mark Borgerson

In article ebS%g.7278$ke4.1160@trndny02, says...
Lauri,,, I agree and disagree ... both.

Yes, a wind vane that will work in all conditions must be of high quality,
and probably expensive..

No, a wind vane that will work ok, but not great, and won't be used in all
conditions, just something to take the edge off.

That is why I got looking at the sheet to tiller self steering system. Not
for going around the world, just a system to take the edge off along the
coast of New England.

The question in my mind is: what did the lone sailors do before the wind
vane? How did Joshua Slocum steer the Spray?

The Spray had several advantages that you might lack when it comes
to setting up the boat to self-steer:

1. A full keel to make the boat more stable in holding a course.
2. A yawl rig.

The yawl (or a ketch) rig makes it easier to balance the sails for
limited self steering.

Did they tie off the helm? And if yes, how long would the boat stay on
course?

I was able to keep my Islander 24 (full keel sloop) on course for
15 to 20 minutes in light seas and moderate winds by doing the
following:

1. Trim the sails for a moderate amount of weather helm
2. Attach a bungee cord from the tiller to the weather
cockpit coaming.
3 run the main sheet through a block on the leeward cockpit
coaming and to a jam cleat on the tiller. (4-part tackle
on the mainsheet)
3. Adjust tension on the bungee cord until it pulled hard
enough to overcome the weather helm and mainsheet pull.

If the boat fell off to leeward, the extra strain on the
mainsheet overcame the bungee and pulled the tiller to leeward.

If the boat pointed too high, reduced tension on the main
sheet allowed the bungee to pull the helm to weather.

This system worked only over a narrow range of courses and
wind speeds. I could go below for a few minutes if the
wind was somewhere between 30 degrees off the bow to
about 20 degrees aft of the beam. With some watching
and tweaking, it could get me time to eat lunch and
read a guide book or charts for a while.

I would never trust it with the wind further aft for fear
of an unintentional jibe.

I did try one of the simply plywood vanes with lines to
the tiller for a while. It never worked very well except
under optimum conditions. In light winds, there
was just too little energy to pull the tiller lines.

I never did take that boat very far offshore, and traffic
in San Francisco Bay wasn't very amenable to an
untended helm in any case, so the bungee/tiller/sheet
arrangement served for head calls and snacks.

If the winds were light and aft of the beam, heaving to
was the alternative.

SNIP

Mark Borgerson