Thursday, February 13, 2014

The Magic Number Three

Boot Key Harbor, Marathon, Florida

Ivan from the sailing vessel Moriah, is a wonderful old salt who gives seminars about all things nautical. Last week I learned something from Ivan that I had not fully appreciated before. It has to do with three, which is a magic number where boating and sailing is concerned.

Ivan was talking about belaying a line to a cleat. But let me begin with another magic number three applied to winches on a boat. This is something I learned by experiment on my first sailboat, an O'Day Mariner 19'.

Wrap the line around the winch only once and the wind will rip it tight out of your hand, perhaps with some skin with it. See below.


Wrap it twice and it will hold weakly if you pull strongly on the tail (the part of the line exiting the picture on the bottom).

Wrap it three times and it will hold securely in nearly all conditions, even if your let go of the tail. Three is magic.

To bring in more line, you must pick up the tail and pull gently as you turn the winch. This is called tailing. Shaking the tail with a loose grip lets the line slip through your hand and more line pays out. Thus you amplify small forces on the tail to enormous forces on the working end of the line. That's what winches are for.

But an unsecured tail is fragile. If you kick it or bump it, it might momentarily become less than three turns and slip. Secure the tail end, or use the self-tailing feature on this winch. (See below) The self-tailer is the metal finger and the double row of plastic rings at the top. Using the self-tailer frees one of your hands to do other things as you crank on the winch.

Put more than three turns on the winch and you are asking for trouble. It can cause the line to cross over itself and foul. That is a starting to happen in the picture below. Exactly three wraps; no more, no less.


Your winch may be as narrow as your wrist, or as wide as a pizza; no matter what the size, the magic number of turns is always three.

By the way, on boats it is always three clockwise turns. All winches on all boats work clockwise so that you never have to guess which way to wrap even if you are upside down, in the dark, and you don't know which is port or starboard.

Now for Ivan's point. What he said was, "if you ever worked on a tug boat, you soon learned that putting a locking turn on a cleat will get you fired. Three turns of any line on any cleat is sufficient. The line will break or the cleat will get pulled out of the deck before the wraps slip." The picture below shows what Ivan meant. The shape of the cleat helps jam the wraps in place.

Below is the way I've been doing it for years. One 360 degree wrap and one locking turn. The rope crossing under itself makes a locking turn. The problem with locking turns is that extreme force on the line causes the locking turn to pull tighter. On a tugboat it may become impossible to ever remove that turn. But on Tarwathie, my way served me well for years, including hurricanes. But now I'm going to change.


But on a sailboat, the lines are small and light. Kicking the tail can make three wraps become two wraps easily. Below is my new post-Ivan way of doing it. Three wraps plus a locking turn.

Below is the amateurish way of doing it, a half wrap plus multiple locking turns.


Below is the (incorrect) way that most nautical books teach you how to do it.


Maybe there are more uses of the magic number three on a boat. Let me know if you think of some.


1 comment:

  1. I find that three glasses of rum is just the right amount. ;-)


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