Join Date: May 2002
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Re: The Infamous Leeward Shrouds
Did you ever see a dog take off running at full speed until he got to the end of his leash, and it jerked him off his feet to a sudden stop? Overly loose shrouds are like that leash, that is just long enough to let the dog get to full speed before it jerks him up short. I have sailed on boats that had shrouds so loose that the whole rig banged loudly in a chop, as the rig slammed back and forth. That's hard on the cables and hard on the connections.
I don't use a Loos gauge to tension my stays. For general daysailing and cruising, I want the mast erect and in column, and raked aft just enough to produce a light but adequate weather helm. When the mast is oriented approximately correctly in those respects, I snug each of the stays and shrouds, alternatively, and by an equal number of turns, just enough to take the slack out of them. Then I sail the boat in 10-15 kt winds, and watch the shrouds and stays. If the leeward cables go slack enough to "sway in the breeze," I tighten them alternatively and by an equal number of turns, until the leeward cables just relax in 10-15 kt winds, but don't sway loosely. In short, I want them just taut enough to hold the mast erect and in column and to restrain the mast from moving about excessively, and no more.
Tuning a sailboat rig isn't like tuning a guitar, where you want each string to vibrate at a specific frequency, to produce a specific sound, and that's why I see no need to use a Loos gauge. Your objective is simply to hold the rig erect and in column, which maximizes it's strength, to prevent it from moving excessively in a seaway, and to provide a proper support for your sails. If you adjust the cables with just enough tension (and no more) to accomplish those objectives, then the cables won't be so taut as to overly stress the rigging and chainplates. A Loos gauge is just one way of approximating the correct amount of tension.
Of course you can fine tune the rig for racing, or for sailing in light air, etc, but this question is only about basic tensioning, and not sail shaping.