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Rigging tension

Posted: Sun Nov 27, 2011 2:37 pm
by mariner
So I got all new standing rigging this year, but it did not get installed, looks like it will have to wait till the spring, so here is my question, what is the proper tension to place on the rigging? I have seen tension gages out there and I would assume that they would be handy in determining port to starboard and for and aft tension, but what should that be? Any thoughts? Thanks in advance for the help. :idea:

Posted: Sun Nov 27, 2011 5:51 pm
by LeatherneckPA
Since you've already taken yours apart once I think it's safe to say that you know more about this than I do, but I remember reading somewhere that it has to do with more than just tension. I seem to recall that while we do have to have somewhere near the right tension one can also use that tension to "tune" the rigging. From what I remember you can"adjust" the bend of your mast both fore-and-aft as well as side-to-side. For the life of me I can't remember the reason for doing it though. It probably had something to do with racing, which is not my bag.

It seems to me, for cruising anyway, that one would try to get the same (or nearly the same) tension f-a and s-s while keeping the mast as close to plumb as possible. I'll be interested to hear how one manages that while the boat is rocking in the slip or how one ensures a level baseline for a boat on a trailer.

Posted: Sun Nov 27, 2011 6:40 pm
by mariner
I found some additional info on the subject at the loos website...

http://loosnaples.com/how-tos/tension-gauges

http://68.171.211.157/how-to-use-90-91

I'll start there and ask a few question at secosouth...I'll post any additional info as I find it, looks like I'll be asking Santa for a tension gauge!

Posted: Mon Nov 28, 2011 10:52 am
by Windward
I don't have any reference books handy at work, but Ivan Dedekam has one on sail trim and rig tuning that I like. Also have something at home from Selden masts, recommended to me by Brion Toss, and a bunch of notes from various sites. I carry more tension than most other boats at our dock, the exception being few larger, newer boats that have been set up by a pro. Those rigs tend to be quite taught.

Windward's cap (upper) shrouds are usually adjusted to about 27 on the Loos, corresponding to about 15% of breaking strength. I adjust forward lowers to provide about an inch of prebend, then adjust the aft lowers to limit max bend to 2" or so when the backstay's on hard. The Pentex main is a flatter cut than the dacron sail, and wants less prebend.

The backstay is 5/32" My "B" Loos gauge does not have a scale for 5/32, so I just use it to establish a relative, repeatable tension. Believe I have the baseline tension there set to about 7.

I then go sailing and tweak the tension to avoid visible slack when going to windward hard pressed, and to minimize any mast pumping I experience.

As the breeze picks up use the backstay adjuster to increase mid-mast bend and reduce headstay sag, depowering the rig somewhat.

Your mileage may vary, etc, etc.

Posted: Mon Nov 28, 2011 5:08 pm
by Paul
The Chrysler owner's manual has a section on rigging your vessel. As for the shrouds, they say to have them tight enough initially to make the mast straight while sighting up the sail slot. Then go to a lake and fill the sail from the port side. If the starboard shrouds are too loose, tighten them, come into the wind and tighten the port shrouds the same amount. Then, like the shampoo instructions says, "rinse and repeat". Keep doing this until you have the tauntness you like.

Paul

Posted: Tue Nov 29, 2011 7:06 am
by CaptainScott
Paul wrote:The Chrysler owner's manual has a section on rigging your vessel. As for the shrouds, they say to have them tight enough initially to make the mast straight while sighting up the sail slot. Then go to a lake and fill the sail from the port side. If the starboard shrouds are too loose, tighten them, come into the wind and tighten the port shrouds the same amount. Then, like the shampoo instructions says, "rinse and repeat". Keep doing this until you have the tauntness you like.

Paul
Good post Paul!
I'm glad this was found.

It can be and is that simple. Especially on the 22's and smaller. Don't go piano wire tight though because you are indeed increasing compresssion on your coach top.

If I'm sailing in heavier winds and see the leward shrouds a little lose I do not worry.

If you race ( I don't ) or sail regularly in heavy seas ( different from heavy winds ) then a different strategy would be used.

For most weekend, lake sailors, or causual sailors Pauls method is very adequate!


Happy sailing!
Scott

Posted: Thu Dec 08, 2011 8:09 am
by mariner
Thanks, as an avid arm chair sailor I tend to over analyze! i'm sure that I'm the only one!