Tuning a CD27

[Steven Cutchin]

I would like to have some information on tuning a CD 27. Does anyone have the standard tension settings for both stays and shrouds?



angus@mindspring.com

[Duncan Maio]

I would like to have some information on tuning a CD 27. Does anyone have the standard tension settings for both stays and shrouds?

The manual says:

"Headstays and backstays should never be taken up so tightly that they will not 'give' an inch or so if you pull on them with moderate force."

"Upper shrouds should also be tightened equally tnd have about an inch of 'give' to them. Forward lower shrouds should have one to two inches of 'give', and the aft lowers slightly more."

I just have the yard do it when they put the boat in the water.

Duncan Maio
s/v Remedy
CD27 #37



dmaio@att.net

[Steve Alarcon]

I would like to have some information on tuning a CD 27. Does anyone have the standard tension settings for both stays and shrouds?

Steve,

All rigging has some elasticity and streches. Brion Toss's (master rigger) book THE RIGGERS APPRENTICE specifys something like 15% for uppers and 10% for lowers. The percentage refers to the total strength in working load (I think). I am ashamed to say that I can't remember the exact figures, and the book is on the boat. I'll try to remember to look next time I'm there. You can tell when the rig is tight enough because if you rap it with a stick (or some such) it will just start to have a "twang" at the proper tension. Probably not too far from what Duncan was referring to.

More importantly, the above figures are a starting point, and help while getting the stick straight up and down without any bending. The second step is to go sailing, and feel the leward stays and shrouds to insure that they aren't too loose. If they are, take a turn or so on the turnbuckle to take up the slack, then come about and do the same on the opposite side. Don't forget to put cotter keys in the turnbuckles when you are finised!

BTW, throw out these rules when dealing with the stay'sl stay; I understand it is not "structural".

Steve Alarcon
CD30 Temerity
Seattle



alarcon@cwixmail.com

[D. Stump, Hanalei]

Steven,
From what I gleaned from the CD-30 owner's manual and from other "Salty Dogs" around our marina, one thing you don't want to do is make the rigging "Bar" tight. The other answers seem on the right track, but one way to check the adjustment is to beat to weather in say 10 to 15 knot wind, stand directly in front of the mast and look up. If the mast is exactly straight, the rig is adjusted correctly. If the head of the mast falls off to windward, the upper on that side is to tight. If it falls off to the downwind side, the upper on the upwind side is to loose. When Hanalei went in last spring(our first launch), I read the manual about adjusting the shrouds and stays, and let the yard do it! All seemed well, until I checked as stated above, the head did lean to windward when beating! A turn or two on the upper turnbuckle, and all was well. The overall tension was very firm, but it didn't seem overly tight. I asked the yard guy if they used a tension gauge, he said he had one home for a keepsake, but relied on experience to get it right.

Hope this helps....

Dave Stump
Captain Commanding
s/v Hanalei (CD-30)