Windvanes on Ketches and Yawls: Show and Tell

[Jason Flare]

Originally Posted by akopac

The are some picks of our Morgan West Indies 38 ketch Autohelm wind vane. The rudder with trim tab is off, but goes on the aluminum frame on the transom. The rudder trim tab is attached to the vane with stainless steel cables in tubes under way. Very very reliable. The boom clears everything on the davits. Attachment 195462Attachment 195463

Are you happy with the performance of the Autohelm?

How accurate is it on various points of sail?

The Autohelm is on my list of possible windvanes.

[akopac]

This was a perfect match. I planned it that way. I knew that this was the best way to do it with our setup. We can still hang our dinghy our kayak from the davits. We can’t use it to go dead down wind because anybody will tell you the apparent wind will wander everywhere downwind and a wind vane is useless down wind. Other than that it works awesome. I sailed here non stop to windward from Panama to SF, CA. 64 days with slight tweaks a couple times a day. I put reflective tape on the top leading edge of the wind vane so I could check it from the cockpit at night. I have a small tiller pilot I’m going to rig up to it so it can be used under power and down wind. The autohelm will correct course extremely fast underway. Like real time underway. We’ve been surfing down waves (not dead down wind) and it will correct real time and stay on course according to our chart plotter when you look at its course over distance.

[blackswan]

Originally Posted by bobnlesley

No photos I'm afraid, but we have friends that used to sail a Nantucket Clipper Yawl fitted with a Monitor Vane.

The mizzen boom was very low relative to the vane, so they made their own wind-blade; I can't give precise sizes, but as I recall it was perhaps 2' high and perhaps a bit more (26/28"?) wide, I remember being told that it was of a fractionally larger overall area then the standard blade.

Must've worked OK, they sailed from the Med to Australia using it

Hey Bob and Lesley,

Good memory guys its been what ten year or more?

To the OP, bobnlesleys memory is pretty accurate: To make up for the reduced height and therefore leverage we made the air vane double the width plus about another twenty percent.

From the photos (apologies bit blurred) the height of the main windvane frame can just be seen. We could only fit an air vane of about 90 centimetres long. This custom air vane filled in just about all the height to the underside of the boom with about an inch of clearance.

Worked well in most conditions (cept high winds where we'd change to the smaller vane) and all points of sail.

In light airs it paid to furl the mizzen, offset the boom and swap the airvane for the standard monitor vane. In those conditions we'd get the power from a mizzen staysail and/or a light weight 140% genoa so didnt miss the mizzen.

Occasionally the mizzen sail may have reduced the air vanes ability to feather accurately into the apparent wind. But I never found this reduced steering accuracy or performance enough to worry too much. If it became an issue we'd just drop the mizzen. The mizzen added most when the wind was forward of the beam anyway where the interference was minimal.

[akopac]

Originally Posted by akopac

The are some picks of our Morgan West Indies 38 ketch Autohelm wind vane. The rudder with trim tab is off, but goes on the aluminum frame on the transom. The rudder trim tab is attached to the vane with stainless steel cables in tubes under way. Very very reliable. The boom clears everything on the davits. Attachment 195462Attachment 195463

Wanted to ad this pic too. The 4th panel was added a few months later.

[GTom]

Originally Posted by seadago

Done, at last!

This is The Hebridean (www.windvanesflsteering.co.uk)

I purchased the kit containing all metal pieces, licence to build, and blueprints for the timber. The timber itself I already had - Indian teak, though the design specs called for white oak - and I built it on my (domestic) workshop.

Build instructions are fairly clear, and it is not very difficult to build, but a good set of medium duty tools is required, as the build tolerances sometimes are less than 1 mm. I had to equip the workshop with several of such tools (mainly wood working stuff, vertical press drill, etc) specifically for this project. Lots and lots of patience and fiddling around required to get it working right though, particularly on adjusting the turret worm drive mechanism.

This is a servo wind vane; i.e. the vane itself picks the signal from the wind and transmits it to an oar trailing in the water. The oar picks up energy from the water flowing by it, amplifies the signal from the vane, and transmits it to a pendulum, which in turn turns the rudder through control lines.

The mounting frame supporting the vane on the transom is my own engineering, and it is not particularly elegant. In my defence, design options were constrained by the need to accommodate the turning rudder stem within it, and the fact that it is constructed strictly with standard OTS components available over the internet.

The philosophy of the whole project, both vane and mounting frame, was to have something that, in case of accidental breakage, or wear-and-tear, could be replaced with ease anywhere in the world, and with minimum access to tools and/or workshop. The only components which, if broken, needs to be replaced from origin (rather than fixed) are the black plastic bits in the adjusting mechanism of the vane’s turret. Everything else can made by cutting, bending, and drilling SS sheet material, and std size nuts and bolts

Now, the most difficult part starts. I’ll be sea-trialling this contraption over the next few weeks. Will report progress if of interest to others.

Cheers

Rafa

Beautiful design!

I was wondering if the oar could be used as emergency rudder?

Any experience in heavy weather/various wind angles?