Friday, December 23, 2011

Mister Monitor

Marathon, Florida
24 42.40 081 N 05.68 W

I never blogged before about Mr. Monitor.  He's one of most important crew members.  Actually, Mr. Monitor is our pet name for our self-steering gear.   When at sea, we engage Mr. Monitor immediately upon departure and let him steer Tarwathie until we reach port once again.

Those who have never sailed offshore don't appreciate the need for self-steering.   It is very impractical to steer manually 24 hours per day, day after day.  First of all, one needs sleep, potty, and food, sail trimming, and other breaks while on duty.  Secondly, human attention drifts as does the course.  Thirdly, it is exhausting; especially with tiller steering.  In rough seas after four hours on the tiller my muscles begin to knot and cramp.  The solution to all of that is to find a way to make the boat steer itself.

Joshua Slocum, the first man to sail alone around the world, was an expert sailor.  He sailed Spray mainly by adjusting the sails.  Then, according to his book, he would drop a loop of rope down on the appropriate spoke in his steering wheel to lock it in place.  Slocum wrote that he did that leaving Austraila and never needed to touch anything again until landing on a tiny island 8000 miles away.  Bulls... I say.  Even Slocum wasn't that good.

Today, many boats rely on electronic autopilots for self-steering.  They do a marvelous job, when they work.  "When they work," is the operative phrase.  Unfortunately, one of the most frequent stories we hear about offshore passages is that, "my autopilot stopped working."  In my humble opinion, they are far from reliable enough to depend on offshore.  They can break down.  They are also vulnerable to lightning hits or near hits that can wipe out all electronics on board in a microsecond.

We have a tiller master electronic autopilot, but we use it only on the ICW and inland waters.  It isn't adequate for offshore.  However, I once met another Westsail 32 whose skipper told me that he used an identical tiller master on a trip to England and back.

Instead of an autopilot, a so-called wind-vane type of self-steering is most appropriate for offshore sailing.   Ours is a Monitor brand.  I've been told that Monitor is the Cadillac of self-steering gear.  Some people like their own brands.  I'm not expert on comparing different brand.  Suffice it to say that the Monitor is solidly built, rugged, and seaworthy for one or more circumnavigations with little or no maintenance.   (If you watch the video below, you'll see a much cheaper self-steerer made with plastic parts.  It is certainly not sea worthy.)

So, what is a wind-vane self-steering gear?  It is the odd looking stainless steel thing hanging of the stern end of our boat.   The most common question we get from non-cruisers is, "What the heck is that thing!"   In the picture below, you see the Monitor at the stern of Zaftra (the W32 belonging to our frieneds Don and Gloria in Vero.)

In the following picture, you see a monitor in action at sea.  Nobody is at the tiller.  The Monitor is in control.    The Monitor keeps the boat at a constant angle to the wind.  That means if the wind shifts, your course shifts with it.  That's optimum in terms of speed and sail trimming, but it does mean that you need to pay attention and to readust the sails and the Monitor after a significant shift.   Holding course with a wind vane means +/- ten degrees.   It hold the course on the average.  When racing, an alert human can steer better than a wind-vane.  Note the qualifier; alert.

By Ben Eriksen

So, how does it work? Sigh. That's difficult to explain. I never understood it myself until we experienced Mr. Monitor in action. Fortunately, thanks to you can watch the video below. It is not a Monitor brand, but the video does a much better job of illustrating the principles than my words can. Key to the servo-pendulum method is that it takes power from the motion of the boat though the water to make very powerful forces to move the tiller (or wheel). The rougher the conditions and faster the boat speed, the more powerful the Monitor's actions. It is more than enough to turn a massive rudder.

Video: Mister Vee

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