Shroud Tension Question

kpgraci · Dec 22, 2011

Good question - I had (have) the same one. It is very subjective. To me 'taught' is a a few notches above 'no slack'. lol.

So I went to no-slack, then put another 3 turns or so untill it felt nice and snug. The next step is to get both sides the same, and for that you probably need a gauge (which I don't have) so I go by feel and the tone it makes when plucked.

Uppers taught, lowers less taught (I back off a turn), forestay taughter (so that it does not deflect much under a full jib), backstay less taught than the forestay. On a beam reach the leeward shrouds should go slack, but not loose and banging around.

If you have a gauge and once you get the rig the way it seems 'right', you could record the numbers so you can replicate it in the future.

I know the 'standard' of 20% breaking load used on boats bigger than mine is waaaaaay too much for the light rig I carry.

In answer to why its defined this way (my 2cents) - one word: trailerable. First, I believe the rig is designed to tolerate some variations - you will never rig it the same twice. Also, they know the trailer sailor was not going to own an gauge, whose purpose was to tune permanent rigging.

Stu Jackson · Dec 22, 2011

Hi.

Ken's got a good approach. In addition to his first steps, then add: "Go sailing!"

That's the fun part. Go on a port tack and watch the starboard shrouds. You want the upper shroud to be "solid" and not flapping. Solid, not taut. The lowers can be just to the point of flapping.

Then flop onto the opposite tack, and do the same.

Many will suggest that you "only go halfway" on the first tack, but if you don't perform what I suggest, how are you going to know what those suggested "tensions' really should be, without having some experience or a gauge.

Then do some more sailing and sight up the mast both ways. Adjust a little bit as necessary for the next few sails.

Catalina published these suggestions in their boat manuals for masthead rigged boats for over 30 years.

It's worked well with me on a C22, C25 and now our C34.

Should work for you with yours, nice boat BTW.

Have fun.

Oh, and once you get it all set up, you can do more research and find a technique that works best for you. It's kinda one of those "art not science" (unless you're a racer).

That said, I subscribe to the theory that there is only one way to set sails: the right way not cruising or racing.

Jackdaw · Dec 23, 2011

Good advice so far... Did O'day publish rig tuning numbers, or is there some generally accepted ones? We're got a Loos PT-2 gauge on our boat at the WYC, ping me and you can borrow it any time. Even if they did not publish numbers, you can make sure you are inside of the safety range based on the diameter of the shrouds. It many not be necessary for just cruising, but it will help you feel better your first season. After that, you'll have a much better feel for it, and more confidence in your rig setup.

EDIT - And Stu is right, with a masthead rig, its a much more straightforward affair than a fractional dial-in would be.

kpgraci · Dec 23, 2011

Stu Jackson said:
Go on a port tack and watch the starboard shrouds. You want the upper shroud to be "solid" and not flapping. Solid, not taut. The lowers can be just to the point of flapping.

One additional note that is both obvious and not obvious - be sure your turnbuckles have the lock nut, pin, wire, or whatever the locking mechanism is in place - when they are slack they have a tendency to work loose otherwise. This has happened to more than will admit it, I'm sure.

Not me, you understand...

Herco Dunlop · Jan 31, 2012

I have an Oday 23, 1978 and I need to replace the outer shroud on the starboard beam side. It is frailed. Should I replace all the standing rigging? The others look fine. Would this involve removing the mast? Where can I buy/order the part? Thanks in anticipation.

Joe11688 · Jan 31, 2012

This guy can get you what you need Herco.
http://www.drmarine.com/

Herco Dunlop · Jan 31, 2012

Thanks

Joe11688 · Jan 31, 2012

cb32863 said:
Need some help with a definition so to speak. The O' Day manual for my 25 says that the upper shrouds should be "taught" and the lower shrouds should be "a bit slack". OK, so what is "taught" and what is "a bit slack"? Should I just get a tension gauge and tighten to a certain value? If so, what value?

Rhetorical question forth coming.... Would it have been that difficult for them to give an actual tension number?

Years ago I had that same question so I went out and bought a Loos Gauge. They were a little cheaper back then. The gauge has a range of numbers that correspond to the thickness of the stays and you have a few choices in between. All I did was pick a number for my upper stays like number 15. For my lower stays I picked number 12.
What I'm looking for is a good tension that is a happy medium. I don't want my stays too tight, and I don't want them too loose but I want even tension all the way around so that my mast is straight.
Usually the books tell you to use you main halyard to mark a reference point on a designated mark on the boat's beam. Then they tell you to lay on the sliding companionway hatch and sight up the mast to make sure that there are no wows.
To my way of thinking, if you can use the gauge and get the same number on your uppers and set your lowers with a certain number, your mast has got to be straight. Just don't ask me how to tension a stay with a roller furler on it because I don't know. I fudge on that one. Actually, I have Johnson Handy-Lock on my backstay and I usually keep it set to a predetermined setting and it's left alone.

Today I was at a marine consignment store in Newport RI and I saw a Loose Gauge "B" for sale down in the cellar. They were asking $25.00 for it. I've seen the A gauge in that shop for $5.00.