Techniques & Tactics
- Category: Techniques & Tactics
- Created: Tuesday, 26 January 2010 00:00
- Written by Charles Doane
I am a huge fan of self-steering windvanes. They work extremely well, are perfectly energy efficient (i.e., they draw ZERO power), and are easy to service and maintain. They truly are as simple as bicycles, and as you may have gathered from my recent Zen of DIY post I like simple gear. I also like bicycles.
Windvanes aren't nearly as popular as they used to be, primarily because electronic autopilots are now reasonably reliable, surprisingly energy efficient, and amazingly versatile. Back in the day, when I first started ocean sailing, this was not the case. I gained a lot of valuable experience steering in big waves when I was crewing around on other people's boats precisely because every time I went sailing the autopilot on whatever boat I was on always broke. Once I crewed on a boat with two autopilots, and they both broke. Consequently, the first thing I did when I bought Crazy Horse and prepped her to go offshore was remove her autopilot. I replaced it with a Monitor servo-pendulum windvane that never gave me a lick of trouble during two-plus years of wandering the North Atlantic.
What you see up top is the Aries servo-pendulum vane that came with Lunacy when I bought her. There the vane is working as a simple windvane, as designed, but down below you see the same device working in what I call "electric vane" mode. If I was Al Gore I might claim to have invented this concept, but, alas, I am just me, so I must confess I read about it first in some magazine. It seemed like a great idea. Fortunately, Bob Petterson, from whom I bought Lunacy, evidently read the same magazine, as he had already electrified his Aries vane long before I ever came along.
The concept of the electric vane is simple: instead of having the servo-pendulum's controlling input come from a wind paddle that juts up into the air and flops back and forth in response to changes in the boat's course or in the wind direction, it is provided by a small electronic tiller-pilot that steers only to a compass course. Because the pilot's ram is not pushing and pulling a tiller back and forth, but only the head of the servo gear, it draws very little power. All the heavy work of actually steering the boat is still performed by the servo-oar.
One big advantage of the electric vane is that it works well both when you're sailing and when you're motoring. On Crazy Horse, once the wind died, I always had to hand-steer after firing up the engine, which was a drag. Sometimes I dope-slapped myself for uninstalling the autopilot. It was an underpowered pedestal-mounted unit that couldn't cope with strong bluewater conditions, but it was perfectly adequate for motoring in calm conditions. At such times, of course, the engine's alternator was also putting out more than enough power to feed a pilot. The lack of an autopilot did provide me with a positive incentive to use my engine as little as possible, and this improved my sailing skills. I also became quite proficient with the windvane, even in light conditions.
On Lunacy I've had ample opportunity to compare the electric vane to the straight windvane, and on the whole I now find I use the electric vane more. The primary disadvantage of electric mode is that the vane cannot follow wind shifts. If the wind shift is small this is a drag, as you must either shift course or trim sails to keep the boat sailing its best. Lots of times you don't bother and instead just leave the boat limping a bit on the assumption the wind will soon shift back. But if the wind shift is big, the vane's inability to follow the wind is more of a blessing, because usually you want to know about big shifts and react to them promptly. Sometimes when steering with a straight windvane it takes a while to notice a large windshift, as the boat obediently follows it and maintains the same apparent wind angle, often without making any noticeable fuss.
When sailing in electric mode you also don't have to balance the sails as carefully as you do in windvane mode, though some semblance of balance is still required. If things get too far out of whack, or if you make too many small course adjustments without re-centering the steering oar, you eventually need to disconnect the control lines from the helm and reset everything. Normally this is not much of a bother. To re-center the pilot ram and steering oar you need only punch in a course change with the control lines running free.
What I like best about electric mode is being able to shift from sailing to motorsailing or flat-out motoring, and vice versa, without re-rigging anything. When strong weather comes, I do prefer to sail in windvane mode, primarily because I reckon the straight windvane must be stronger and more weatherproof. This means having to remove the tillerpilot and replace with it the wind paddle while underway, which sometimes is not easy, particularly when I'm alone and the wind and seas are up. To make the switch I must first get the boat to steer herself for a bit. While she is doing this, I must then dangle off the transom while trying to slot a small bolt through a small in the bottom of a rather unwieldy piece of flat plywood that is designed to catch the wind. A couple of times in big blows I've just punted instead and let the tillerpilot carry on. So far it has performed admirably in these situations.
Having sailed many miles now with both a Monitor and Aries vane, I can also make some comparisons in this department. Really there is little difference between the two, and both work very well. The fundamental designs are nearly identical; distinctions are found only in the details. For ease of use, I like the racheted line control on the head of the Aries servo unit. "Counting clicks" is an easy way to keep track of the adjustments you are making in the angle of the vane relative to the boat's centerline. The rachets also hold the vane firmly in place, so the angle is locked in and cannot shift without your knowledge. On the Monitor the line control is continuous, which means you can fine-tune it more easily, but the line also starts creeping and changing the vane angle if you don't keep sufficient tension on it. When the lines does start creeping and screwing things up, it sometimes takes a while to realize what is going on.
One thing I like very much about the No. 5 "Lift-Up" version of the Aries vane I have is that it very easy to break it down into pieces and remove it from the transom. It's just as easy to put it back on again. I can literally install or remove Lunacy's vane in a couple of minutes without using any tools at all. On the other hand, one thing I really miss about my old Monitor vane is being able to quickly and easily flip the steering oar out the water. A spring-loaded catch in the middle of the oar is what made this possible. Evidently, some Aries vanes have the same feature. But on the one I have, you must first remove the head of the servo unit and then flip the entire body of the unit back on to itself to get the oar out of the water. The entire unit is more inboard and more secure this way, but it takes some doing and I would never want to do it while underway, except in very calm conditions.
Of course, the primary difference between the two is that the Monitor is built primarily of stainless steel and the Aries is primarily aluminum. Many hardcore Monitor fans cite this as an indisputably superior feature. As the owner of an aluminum boat, I must, on principle, quarrel with such assertions. My Aries vane has many years on it now and suffers from no galvanic corrosion, though I do worry about this and so rinse the unit with fresh water whenever I can.
On Sophie I had a trim-tab self-steering windvane (a more-or-less custom unit built by Ratcliffe of Pembroke, Massachusetts), and I will say that I find servo-pendulum units on the whole to be stronger and more reliable. A trim-tab system is even more facile than a servo gear and consists simply of a small trim-tab rudder on the back of the main rudder that is linked to a windvane. Usually you must have a transom-hung rudder to install one. Sophie's Ratcliffe gear had some clever features (you could, for example, lock the trim tab in place and offset its angle to neutralize prop walk when motoring), but in strong winds I needed to keep the boat under-canvassed for it to work well. The gear also lost control of the boat more quickly when the wind went light. In my experience, it generally required closer attention than a servo gear, and this was on a boat that sailed itself well in the first place.
Would I rather have a proper belowdeck autopilot than a windvane??? In an ideal universe, I suppose I would have both. Many serious cruisers now carry windvanes only as back-ups for powerful modern autopilots, and this is an excellent practice. You must be sure, however, to practice using the vane before you need it, as you don't want your first tutorial to be in extremis. On Lunacy, unfortunately, installing a belowdeck pilot is pretty much out of question. And if it's a question of one or the other, I'd definitely prefer to have a windvane.