Shroud and forestay tension

Started by Mike Rog, Nov 06, 2023, 08:26 PM

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Mike Rog

Evening All
New to sailing so I appreciatte your help
Purchased a used American Sail 14.6. , sailed a few times and all was good

I do need some advice on shroud and forestay tension
Any tips or advice on what to use as a gauge  Im not racing ,just dont want it to be too loose or too tight
So looking for some general guidelines

Thanks for your help
Take care

Charles Brennan

Mike, The conventional method is to use a hideously expensive Loos gauge, which you indicated might be overkill for your application.  You can find on-line You-Tubes, where you get on one tack and check how loose the side shroud is and then get on the other tack and check how loose that side is.  The idea is, that you tighten up a little on each side progressively, until there is little slack on either tack.

As a musician, I simply tune by ear.
1) Get the hull level and the mast vertical, on the trailer.
2) Tighten up the shrouds until they just begin to "twang".
3) Get the same pitch of "twang" on each side.
4) Go up a minor third on each side.
5) The max you'd want to go, is a major fifth.
Even if you don't have much pitch, you can do: "Do Re Mi Fa" and use that as your guide; a pitch pipe might help.

On my 18-foot Windrose, going up a minor third from just barely tightened ("twang") puts the tension very close to proper tension specs when checked with a Loos gauge.

Hope this helps,
Charles Brennan

Mike Rog

Hey Charles
Thanks for getting back
Much appreciated

Listed below is the style of shroud adjuster that is on the 2 shrouds
"Viadana 316 Stainless Steel Rigging Shroud Stay Adjuster 120mm Channel Style". It adjusts in about 1/4"increments

The manufacture recommends using the 4th hole from the top on the adjusters that came factory installed

Can I use the 4th hole as the manufacture recommends and do the fine tuning with the turnbuckle on the forestay ?
I believe I can see that using maybe the 3rd or 5th hole ,the vertical attitude of the mast would be affected
If the mast is slightly forward or aft does that have a big affect on the safety or performance of the boat ?
My reasoning may be way off so please feel free to correct me

As you mentioned using an expensive gauge would be overkill for this boat

Thanks again

Frank B.

Mike, I use a Loos gauge on my Compac 23IV.  I think , as others do, it might be more than you need for your boat.  I bought it used on Ebay and it was not that costly.  Additionally, I made a few friends in my marina loaning them the gauge to tension their rig.  As the folks at Loos say, most folks come up way short on their tension, and that was my case.  I tensioned by "Feel" and "twang" first, then checked it with the gauge and found I was several hundred pounds short of the MINIMUM recommended tension.   

Brian N.

Alternative method that I use:

Rig should just yield to moderate hand pressure for initial setting, then take her out sailing. On a beam reach in 8 - 12 knots the windward shroud should be taught and the lee shroud should yield fairly easily (but not slack). Like Charles said, your initial setting should  just "Twang". Avoid piano string tension - think guitar string. Forestay tension should be stiff, but still yield under moderate hand pressure.

I'm not familiar with the adjustments on the American 14.6, but adjust incrementally when you return to the dock (sails down, of course). Each boat has a "sweet spot" for the average wind speed and conditions you'll be sailing. It may take a few outings to fine tune.

When I raced in the Ensign fleet, we found the Loos gauge settings were a bit on the stiff side for the average conditions we sailed in. The American (as I recall) does not have a backstay. It may take a bit of tweaking to get the forestay tension just right for your sailing. 
Fair winds
Brian N.

Mike Rog

Hey Frank and Brian

Thanks much for your info . Really appreciate it
As mentioned above the Loos gauge may be more than my boat deserves  :)  :)  :)
Its just a small used daysailer 

I think my main concern may be safety and not putting too much pressure on the standing rigging

The way I see it the 2 shrouds and forestay make a triangle
The shrouds adjust the rake of the mast and the forestay turnbuckle adjust the tension on all 3
So if I adjust the shrouds until the mast is plumb and then adjust the forestay turnbuckle following the procedure you mention above , I should be ok ??

This theory may be totally wrong so please feel free to correct it

In adjusting the rake of the mast , are you adjusting the mast with the boat level on a trailer or sitting empty in the water . It seems like the plumbness of the mast could be changing a lot when the boat is in the water , depending upon number of people in the boat , load , etc

Im not new to boating ( 4 Winns , Robalo 160 ) but I am new too sailing.  Really looking forward to a boat with no motor and no noise

Thanks again for your help