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CP-27 Rig Tension

Started by Jma1_nemo, August 17, 2016, 11:47:25 AM

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Jma1_nemo

Has anyone ever come across, or determined the best or recommended tension for the various standing rigging components? Gerry of Com-Pac did not have any numbers, just recommended tight enough to give good weather performance.

BobK

Since our rigs are deck stepped I don't like to keep too much tension on my standing rigging.  After making sure the mast is centered I make adjustments on the water while sailing 1/2 turn at a time.  I tighten until the leeward side has just a little slack on a tack in 12-15 mph wind.

BobK

Allure2sail

Hi BobK:
I would say that your pretty darn close, you could use a tension gage but I would say that your there already. I've looked at two many boats with compressed cabin roofs from over zealous tightening of the standing rigging.
Bruce

cdreamIII

I recently ran across this From John Vigor's October 6,2016 blog "Rig tuning the cheaper way" regarding this subject.

"HOW DO YOU TUNE your standing rigging if you can't afford those expensive tension gauges? Well, there is a way.

It just so happens that the elastic stretch of stainless-steel wire increases in rough linear proportion to the load, up to about half the wire's breaking strength. Therefore, stretch is a good indication of load.

Thus, when a 33-foot-long 1 x 19 stainless-steel wire (of any thickness) is loaded to half its breaking strength, it will stretch 2 inches. Little wonder, then, that the leeward shrouds sometimes look a little slack.

Nevertheless, you can use this principle to tune your rig. Here's how:

Take all the load off a wire and mark on it as accurately as possible with tape or a marking pen a length of 1,980 mm.(77.95 inches)  Do this anywhere along the wire, where it's most convenient.

Now tighten the turnbuckle and measure the length again as you do so. You will find that every extra millimeter of stretch (up and above 1,980 mm) induces a load in the wire of 5 percent of its breaking strength.  In other words, an increase of 2 mm, with a space between your marks now of 1,982 mm, indicates a 10 percent load.

You can find out the breaking strength of the wire from the manufacturer's or retailer's catalog, and from that you can calculate the load in actual pounds or kilograms if you like. But it's just as easy to reckon that a moderate pre-load for the average rig is about 25 percent of the breaking strength.  In which case, you need to stretch your marked length by 5 mm (0.197 inches)to 1,985 mm.(78.15 inches)

That's it.  No need for expensive tension gauges. All you need is a tape marked in millimeters and you're good to go."

Bille

deisher6

The yard snugged all the turnbuckles up by counting the threads.  I then adjusted the stays so that the mast was straight.  (all this while on the hard)  When afloat I rechecked the mast for straightness and stays for (snugness) tension.  When sailing the leeward lowers sag just a bit.

There is a definite difference between the stay tension on the hard and afloat.

Sounds like how Bruce and Bob tune their rigs.

regards charlie