Article by Tor Pinney                                                                                                                                        Back to List of Tor's Tips

                  

BACKING UP THE SELF-STEERING
© 2011 Tor Pinney - All Rights Reserved

Good, Better, and Best Solutions
with a Close Look at Tillerpilot-to-Windvane Alternatives

 

Most cruising sailors agree that an autopilot is essential equipment aboard their boat. These tireless electronic crewmembers hold a magnetic or, optionally, a wind-relative course hour after hour, day after day. That translates into less fatigue for the watch keepers, greater crew efficiency on deck, and a safer, happier passage overall. That’s why smart skippers take extra precautions to ensure that their vessel will never be without self-steering. At the very least, this means carrying repair parts and components. However, for single-handers and couples planning blue water passages, self-steering is indispensable; repair parts alone may not be enough. For them and for anyone determined to avoid “the tyranny of the tiller,” additional and more versatile safeguards are called for.

Consider what happens if – or according to Murphy’s Law, when – the autopilot stops working offshore and can’t be fixed. If that’s all the self-steering on board, the crew is in for some long, tedious tricks at the helm. For a crew of 3 or more this is merely a big inconvenience. For a cruising couple or a single-handed ocean voyager it can be a more serious matter. Continuous, shorthanded manual steering creates fatigue, and fatigue begets bad judgment, something no mariner can afford.

To help avoid loss of your boat’s self-steering capability, here are a few solutions dubbed good, better, even better, and best.

A Good Solution

As mentioned, prudent sailors carry a complete set of spare parts for their autopilot. As long as the kit includes every breakable component of the autopilot system, plus tools and manuals, that should be enough for most coastal cruising. However, for longer voyages an entire spare autopilot is in order.

Repairing or replacing a broken autopilot should solve the problem. That is, unless whatever incapacitated the first unit also incapacitates the second one.

A Better Solution

What if the boat’s electrical system or battery charging system(s) malfunction, so there’s no power to operate an electric autopilot. More than one passage has been curtailed by engine or alternator problems, or by lightening strike damage to the electrical circuitry. This is just one reason many blue water cruisers value the versatility a windvane contributes to their self-steering repertoire. While windvanes alone usually won’t steer a boat that’s motoring, they will steer under sail more efficiently than an autopilot simply because they don’t consume electricity. That’s why you so often see the real passage-makers sporting windvanes. It’s practically a fraternal flag.

But what if the boat’s steering system becomes inoperable? It doesn’t happen often, but let’s consider the possibility.

Even Better

Some windvanes can function as an independent backup steering system should the vessel’s primary system fail. This could be a lifesaver in rare situations. Scanmar International sells an add-on emergency rudder, the M-rud, to accompany their popular Monitor windvane. On another tack, the Auto-Helm brand windvane (no relation to Autohelm autopilots) features a completely independent auxiliary rudder permanently bolted onto the boat’s transom, with a trimtab – a narrow rudder’s rudder - mounted on its trailing edge (see photo). The airvane steers the trimtab, which steers the rudder, which steers the boat. Simple, strong and efficient, this design bypasses the boat’s steering system entirely. No lines lead into the cockpit. If the boat’s rudder or steering linkage is damaged you can steer with the Auto-Helm’s external rudder instead, either by the wind (via the unit’s airvane), or manually (via lines to the trimtab or the rudder head), or (as we shall see) by autopilot. Now that’s a good backup, repeating two essential systems, the autopilot and the vessels’ primary steering.

A new Hydrovane model also employs an external rudder that steers while the vessel’s main rudder is locked off. This unit features its own tiller, allowing instant emergency hand steering when the vane is disengaged, and the tiller is designed to accept a tiller pilot. According to the manufacturer, the Hydrovane, without modification, provides "self-steering, emergency steering and a practical autopilot". These folks clearly recognize the multifunctionality of their product.

The Australian windvane, Fleming, advertises models that can be optioned for the connection of an electric autopilot. The Fleming's auxiliary rudder is driven by a servo paddle, a powerful combination, and the windvane's rudder can be pivoted out of the water. The unit comes with its own emergency tiller.

Reportedly, in some cases a servo-pendulum windvane can independently steer a well-trimmed sailboat with the windvane-to-helm steering lines disengaged and the helm locked. The servo rudder on the windvane then becomes the steering rudder for the boat.

The Best Solution

The best solution for backing up your boat’s self-steering is a multi-faceted approach involving all of the above items plus one more. Here’s the complete list:

1. The primary autopilot

2. Spare parts, tools and manuals for the primary autopilot, plus

3. A complete spare autopilot (or see #5 below!)

4. A windvane, ideally capable of steering the boat independent of the vessel’s own steering system, and

5. A tiller pilot set up to steer the windvane. Since this option is not so common, let’s consider it in detail.

Tiller Pilot to Windvane Self Steering

It takes some strength to steer a sailboat in a blow. Windvanes get their muscle from the force of the water passing along the unit’s steering paddle, servo-paddle, or trimtab & rudder, depending on the design. It doesn’t take much strength to change the angle of these in-water sections and cause them to steer the boat. Just the movement of the airvane responding to wind shifts is enough to cock a paddle or trimtab.

If a little wind can steer a windvane, imagine how easy it would be for even the smallest tiller pilot. Tiller pilots, linear autopilots designed to steer a boat by its tiller instead of a wheel, are relatively inexpensive. Carrying a spare is not nearly as daunting as duplicating a large vessel’s internal autopilot. In fact, the price difference could pay for your windvane! Modern tiller pilots can be interfaced and remote-controlled much the same as larger, internal autopilots. For the budget-conscious cruiser, a windvane and two tiller pilots may be all you need to ensure you’ll never be without self-steering. I cruised my last boat, a 37’ cutter with tiller steering, 30,000 nautical miles with just this combination.

Some windvane manufacturers warn against using the tillerpilot/windvane setup for extensive motoring because it positions the servo-paddle in very turbulent water from the propeller wash. This can cause excessive stress and wear on the windvane’s mechanisms. When in doubt, ask the manufacturer. A tiller pilot can always be used to direct any windvane under sail when a magnetic course is desired or in airs too light for the airvane to steer effectively, and also as a temporary emergency backup under power should the boat’s primary autopilot fail. Tiller pilot/windvane motoring does not harm the Auto-Helm windvane on my 42’ ketch, Silverheels, although that’s not why I originally chose it. The Auto-Helm is the only design I found that connects the upper section, the airvane, to the lower, in-water portion via flexible cables rather than by the rigid metal tubing or rods other designs employ. This complete separation of the upper and lower halves allows me to use my windvane while carrying a dinghy in davits, which I regularly do on short coastal and inter-island passages (see photo).

How and where to mount and connect a tiller pilot varies with the layout of your afterdeck, stern rail and windvane mount and the make/model/type of windvane. With a bit of ingenuity and tinkering, practically any combination can be accommodated.

To secure the tiller pilot on Silverheels’ deck I employed a simple oarlock socket at one end, raised on small Starboard blocks to compensate for the deck’s camber, and a wood cradle to support the body near the drive rod (see photo). Connecting it to the windvane was a little more creative. The Auto-Helm’s airvane steers an external rudder’s trimtab by means of flexible stainless steel cables inside Teflon sleeves. It was the trimtab (not the airvane) that I ultimately needed to control with the tiller pilot. So I asked the manufacturer to make me up a second, short pair of steering cables. I then modified a standard tiller pilot by adding an eyebolt in the end of the drive rod (see photo) to accept the inboard ends of the short steering cables.

Next, I bolted clips onto the trimtab control yoke to receive the small end shackles of either the short tiller pilot cables or the longer airvane cables (see photos). This allows quick changes between tiller pilot and airvane control of the windvane’s rudder. To switch between airvane steering (for sailing) and tiller pilot steering (for motoring or magnetic course sailing), I simply unclip one set of cables and clip on the other. On Silverheels the tiller pilot is merely a backup for the primary autopilot, which steers the wheel.

It’s different with a servo-pendulum windvane (below). To hook up a tiller pilot to a Monitor, for example, Scanmar International recommends the following: “Attach the tiller fitting for the autopilot to the airvane’s counterweight (see photo). The tiller pilot will manipulate the counterweight and provide input to the servomechanism. Alternatively, you can attach it to a short “stump” airvane, which the factory will supply on request. The height of the windvane mounting on your boat and the design of the stern pulpit will determine the most practical way to position the parts (see photos below).”

At least one European windvane manufacturer, Windpilot, has offered an optional tiller pilot connection at the vane holder since 1984. However, cruisers have figured out all kinds of variations on their own, many of which call for mounting the tiller pilot fore & aft (see photo), rather than athwartships as I did. When a direct connection is problematic due to the deck, railing and windvane configuration, some kind of cables may work. One sailor’s blog affirms, "After a lot of windvane experiments… (nothing) could beat the autopilot controlling the trim tab, especially in bad seas… You can use cables so you don't have to hang the thing out over the transom." Another blogger agreed, “I have a Cape Horn. I mounted (the tiller pilot) in a fore-and-aft orientation inside a cockpit lazarette and use a control cable to connect it to the windvane. The control cable gives you the flexibility to put (the tiller pilot) anywhere.”

Here are a few more installation tips:

• Make it easy to connect and disconnect the tiller pilot, even in the dark.

• Mount the tiller pilot with the pushrod midway in its throw, and the windvane in its neutral steering position.

• Be sure the tiller pilot’s electrical connection is truly waterproof and properly fused, preferably with its own breaker.

• The tiller pilot should have adequate RFI protection on boats with SSB or Ham radios.

• Even small tiller pilots develop 80-100 lbs. of thrust. Be aware that the tiller pilot, the windvane, or both could be damaged if someone resumes manually steering the boat and forgets to disengage the tiller pilot.

Cover the tiller pilot to protect it from rain and spray. A vinyl or Sunbrella sleeve with a clear, flexible plastic window over the controls and readout works well (see photo). Plastic cling-wrap is better than nothing in wet conditions.     Sheet to Tiller Self-Steering

No discussion of emergency self-steering would be complete without mentioning the little-practiced sheet-to-tiller system. Here is a quote from the book, “Ready for Sea! – How to Outfit the Modern Cruising Sailboat” (Sheridan House) written by yours truly: “It is difficult to overemphasize the value of self-steering to the short-handed and single-handed sailor. When (not if) your primary systems fail in mid-ocean, a solution will be as precious to you as the proverbial glass of water in the desert. For a last ditch, $10 back-up self-steering system, see if you can find either of these books: Self-Steering for Sailing Craft by John S. Letcher, Jr. (International Marine Publishing Company, 1974) or Self-Steering Without a Windvane by Lee Woas (Seven Seas press, 1982). Both offer detailed explanations of the sheet-to-tiller system of self-steering, which requires little more than some small blocks, shock cord and patience to assemble. Unfortunately, both books are out of print, but you can occasionally find used copies. I once tested this system myself on a sail from St. Petersburg, Florida to Key West. It definitely works, although it’s a chore to set up and to adjust and so is practical only as a backup to a primary self-steering system. Try using it before you need it to be sure you have the necessary pieces, then stow it away as emergency gear. You just might bless your foresight someday.”

Of course, most cruising sailboats employ wheel steering these days, and I’ve not heard of this system working on a wheel helm. In a pinch, however, sheet-to-tiller may still work by connecting it to your vessel’s emergency tiller.

Aboard a boat setting sail for distant landfalls, self-steering is too important to leave to a single mechanism. Anything can break; everything eventually does. Smart skippers will ensure their vessels are prepared for autopilot failure by providing backups and alternatives that are ready and able to “take the helm and hold the course.” 

~ End ~

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