Stays

I've read an article some time ago which said that a stainless cable which gets pulled and released to 75% of its breaking strength will fail after 11000 pulls. Despite its diameter.

My friendly catamaran dealer helped me make up my first replacement set - talk to Sawyer at Key Sailing. Much cheaper than going to West Marine. If you want to buy pre-made or custom stuff, Rick's shop (on this site) can fix you up quick.

I had a factory set of wires fail after two years. I think you can go longer if you do the fresh water rinse and keep an eye on it, espesh now that you know what to look for.

Murrays, Salty Dog, and your local Performance Cat dealer have the specs for Nacra 6.0NA stays. Trying to recall if the Express had the same mast but with double diamonds. New England Catamaran is also a good bet.

Kris
Nacra F-18

That process is called metal fatigue and we don't load our rig up with that much most of the time. Sidestays are typically loaded between 30 % and 50 % this increases the number of cycles before breakin enormously. Besides the magnitude of the change of loading is also important. You are talking about full release after each 75 % load. On cats the amplitude is much smaller.

I've been sailing with my Prindle 16 stays for 7 years and I bought the boat secondhand. Never had a problem and I sailed that baby alot.

Replacing every 2 years is too often for recreational sailing.

Wouter

The only sudden failiure I have ever seen is the eyesocket swedged type where the salt gets in and invisibly eats the cable. For some reason, these are now the more popular style.
I have seen maybe ten rigs come down. Most from a pin coming out, but people still call them shroud failiures? (because it is less embarassing I suspect?) I have never seen a thimble type connection fail.(where the cable wraps around the thimble and is swedged back to itself. I have seen broken strands and kinked cables a-plenty.
Has anyone actually seen a thimble type cable that did not already have broken strands fail?
I have sailed in outrageous conditions with three or so strands broken, and a crew of three or so too(when I was young and foolish, on other peoples boats) so I dont truly believe in shrouds suddenly parting. The loads are more than most realize, but the strength of cable is a lot more..
I am way more concerned about the little rope on trap lines, which is more dangerous for a single handed sailor. These break all the time. New, old, green and rotten. They all break coming off a wave, or just break.
My appologies to all the sail boat suppliers for taking this tack. Hope you make up in 5/16" superdoo line what you lose in shrouds.

Hi Dave

Two brand new thimbled halyard for the Sq broke before I went to the ring-and-hook type. Does that count?

Whoops, forgot to suggest interesting solution:

http://www.precourt.ca/

Works for our Fboat...

No. We are only counting shrouds!
Was it the cable that failed, or a loose swedge - caution - bad swedges are more likely if you change your shrouds frequently!!!
If the cable fails on first use, it is not fatigue. You cannot change your shrouds every half use.

If any of you guys want to get rid of any two year old H16 stays I would be happy to take them off your hands.

John

Original failure, original halyard, cable broke;
Replaced it with West Marine halyard, swedge broke;
Replaced that with a profess. riggers' made halyard, cable broke.

Went to hook and ring, priceless!

My 1977 always freshwater sailed N5.2 is still on its factory stays. I did have the mast come down last year though. The tang on the hull for the sidestay parted. I really should have noticed it was elongating.

tO HIJACK THE THREAD
Has anyone experimented with the halyard anchor points. The mast section above the halyard anchor point is subject to twice the compresssive force of that below it.
That is, if the halyard is anchored lower on the mast, the section above it will flex more and be more sensitive to gusts (light crew). If a halyard is hooked up top or a hook used, heavy crew. Could be a quick tuning tool.
Seems the silly class rules need to close this loop hole too, so only the average man can win.

I've seen a fair few shrouds break, but all that I can remember are on boats that are sat in the boat-park for long periods with the rigging left slack and the mast jerking about in the wind.
Saying that, I am a believer that shrouds should be changed ever 2 seasons. I have a workshop full of old ones.
It always amazes me when someone spots a shroud or trap wire fraying at the swage, they then go and just replace that one alone! Surely if one has come the the end of its lifespan, they all need changing.
I am also surprised when people only replace one broken J+H handle too! I like to relax a bit on the wire!

We just replaced all our shrouds (2 -3 years old) and diamond wires on our Nacra 6.o NA after finding several broken strands on the timble of the side shroud. Also replaced the diamond spreaders with new stainless steel spreaders, as the old ones were corroded. Went out today in 20 knots and 3=5 ft waves, confident in our new gear.... and down came the mast . The rod tensioning the bow foil broke at the edge, where it is welded into a T shape.
Lesson learned - it's what you don't replace periodically that gets you

Opher
Nacra 6.0 NA
Israel

Opher-
Thats too bad about the mast. I need to really give my boat a complete check. I ordered 2 new shrouds from murray's and am going to get a new forestay (can only get vinyl coated forestays from murrays, and it seems like there is already too little room to get the halyard line through the luff of the jib so I am going to get a non-coated wire for the forestay). I will inspect the diamond wires more closely the next time I have the mast down.
When your mast came down, did it damage anything badly (i.e. is your mast bent now? Damage to the hulls.. etc?)

how true that is Opher... I mean, parts that you don't even expect to have to replace can go at any moment if not properly maintained or setup:

Ouch! Which way does the mast fall when the hound gives way?
Luckily for us no damage other than the bridle foil rod. We were double trapped when we heard a lound bang and the mast slowly dropped to leeward, leaving us trailing in the water.... The fun part was beaching through the surf - luckily it was an onshore wind and we weren't too far off. Ended up getting the beach wheels and rolling her the mile home
With any luck we'll be out racing tommorrow