Lifespan of SS standing rigging

[vyv_cox]

The only reason for the older wire being stiffer than the new is that it was like that when it was installed. There is no mechanism by which its strength, hardness or stiffness will increase, unless it has been treated very badly during its life.

If the rigging inspection shows it to be good throughout, particularly at stress raisers and any changes of section, then I would not replace it. The critical area is at the top of the swages, where fatigue failure takes place strand by strand. Broken ones are usually easy to identify.

 

[geem]

The only reason for the older wire being stiffer than the new is that it was like that when it was installed. There is no mechanism by which its strength, hardness or stiffness will increase, unless it has been treated very badly during its life.

If the rigging inspection shows it to be good throughout, particularly at stress raisers and any changes of section, then I would not replace it. The critical area is at the top of the swages, where fatigue failure takes place strand by strand. Broken ones are usually easy to identify.

Thanks, you might have just saved me £5k.
The masts are coming off next month as she goes in the spray shop for new hull paint. I will have a good look at everything with a magnifying glass. Do you think this would be sufficient or is there anything further to do such as dye testing?

 

[Matelot Joe]

Bronze rigging screws ?

16 years or once round the world (whichever is less) or so an Open 60s rigger told me.

I've only had stainless rigging break at its entry to the swage, usually the mast end, and only once had a standing rigging wire actually part.
Apparently much more likely to fatigue fracture are stainless steel rigging screws.Lulu (the rigger) only used bronze adjusters.
It's worth making a minute inspection, at regular intervals, of all your rigging especially at mast-entry end.

It has been mentioned to me that bronze rigging screws are better than stainless, can anyone give a reason for this, or why I should not use this method. I currently have Stay lock fittings and I am about to have the rig replaced.
Any advice would be appreciated.

 

[Fantasie 19]

When I changed my rigging on my last boat the old wire was so much stiffer than the new wire. What causes this hardening? Does the wire get brittle with this increase in stiffness?

On my current boat I suspect most of the rig is original (1980). I am planning on going trans-Atlantic but with a quote of £5k for replacement of the rig for both masts I am reluctant to replace it if it doesn't need it. A rigger has inspected the whole lot and only recommended some minor work. Nothing mentioned about wire replacement. Would you replace it?

You're going across the Atlantic trusting to 30+ year old rigging???

I wouldn't be able to sleep....

 

[vyv_cox]

Thanks, you might have just saved me £5k.
The masts are coming off next month as she goes in the spray shop for new hull paint. I will have a good look at everything with a magnifying glass. Do you think this would be sufficient or is there anything further to do such as dye testing?

Unless you are very experienced with dye testing I think you would find its interpretation difficult. I have used it quite a bit but for wires I think I would rely on thorough visual inspection. Put small bends in the region adjacent to the swages, viewing with your glass, I think you will be able to detect any broken or cracked strands. Cracks in the main body of the wires well away from the swages are highly unlikely. Don't forget to check the bottlescrews and other rig fittings.

 

[vyv_cox]

It has been mentioned to me that bronze rigging screws are better than stainless, can anyone give a reason for this, or why I should not use this method. I currently have Stay lock fittings and I am about to have the rig replaced.
Any advice would be appreciated.

Stainless steel bolted joints can be prone to galling, which effectively welds them together. There is a current thread on this topic. Molybdenum disulphide based grease is a good palliative. Bronze is not subject to galling, which is the main reason for its recommendation.

 

[Matelot Joe]

Stainless steel bolted joints can be prone to galling, which effectively welds them together. There is a current thread on this topic. Molybdenum disulphide based grease is a good palliative. Bronze is not subject to galling, which is the main reason for its recommendation.

Thanks for that vyv, its just what I have been told. So would you say that swaged stainless wire and bronze screws are a better set up than Staylock or any other method on a 12 tone cursing boat.
Thnaks.

 

[geem]

You're going across the Atlantic trusting to 30+ year old rigging???

I wouldn't be able to sleep....

The one thing you can do when you cross the Atlantic is sleep. Last time with just me and SWIMBO on board we entered a whole new level of exhaustion. Staying awake on watch was a problem
Two different riggers have checked the rig recenty and both have not suggested replacement. The wire is 12mm on the main mast. It just looks huge. Each strand is large. Having said that, the mast is large so I don't think the 12mm wire is over specified. The backstay was replaced a couple of years ago. I may do the caps and the forestay on the main mast. Mizzen is les of a concern. This would give me peace of mind and cut the costs. The lower rigging is relatively easy to jury rig if something goes wrong. Have been upto the spreaders in the Atlantic when the inner forestay snapped below a stay lock fitting. A spare staylock fitted to the bottom of wire and a lashing saw us safely to the Azores. Just turned the wire upside down so the lashing was at the bottom where we could keep an eye on it

 

[charles_reed]

Apart from galling, stainless bottlescrews have a much smaller cross section area than do bronze and are far more likely to suffer from fatigue, especially at the ends of the barrel where are the threads.
I suspect a lot depends on the method of manufacture - fabricated bottlescrews would have stress build up if no attempt has been made to preheat the components before welding - my daughters PhD paper was on warm prestressing, to avoid subsequent fatigue failure (admittedly of pressure vessels which were at that time being carved out of great blocks of EN3C).
For those interested UT bronze 586MPa 316SX 580MPa yield 221 and 206Mpa respectively.
Lulu showed me his "rogues gallery" of bottlescrews with dye cracks plain to see.
Ever since then I've stuck to chromed Al bronze, a lot stronger than stainless and about x3 the price.

 

[angelsson]

Nonsense. Age hardening is a very specific metallurgical process requiring two heat treatment cycles, typically to between 200 and 300 C. It is also known as precipitation hardening, used in superior stainless steel alloys such as 17/4 PH. The hardness of 316 stainless steel, usually manufactured in a work hardened condition for cables, rigging fittings, etc will remain totally unchanged throughout their life.

Virtually every rigging failure that you or I will ever see occurs due to fatigue. Cracks initiated at stress raisers, such as swaged ends, turnbuckle changes of section, holes, etc.

You sound like you know what your talking about, but try not to preempt it with 'Nonsense' you will be listened to more

 

[KAL]

Er - seems I've opened a can of worms here - sorry!

I'll get the rigger to do a top to bottom check and see what he says. Heartened by the reports of long life on some boats. Not planning to go transatlantic just yet!

 

[claymore]

You sound like you know what your talking about, but try not to preempt it with 'Nonsense' you will be listened to more

It was nonsense. The OP asked a good question that deserved an accurate response. Inaccuracy, in the context of engineering constitutes nonsense. Simples

 

[Rossynant]

Er - seems I've opened a can of worms here - sorry!

No can of worms but quite common misunderstandings.

Briefly looking over the topic - everyone tells some opinion, but nobody said what kind of rig or wire or end-fittings he is talking about

Nonsense. Age hardening is a very specific metallurgical process requiring two heat treatment cycles, typically to between 200 and 300 C. It is also known as precipitation hardening, used in superior stainless steel alloys such as 17/4 PH. The hardness of 316 stainless steel, usually manufactured in a work hardened condition for cables, rigging fittings, etc will remain totally unchanged throughout their life.

Virtually every rigging failure that you or I will ever see occurs due to fatigue. Cracks initiated at stress raisers, such as swaged ends, turnbuckle changes of section, holes, etc.

Now you've heard it.
Reused 60 year old wire once. It was OK. Only cut off the splices - those were fatigued. 7x7.
Then saw 5 years old shroud break - 1x19 at swaged fitting, at sea - this is normal, pressure applied destroys the wire putting permanent internal stresses into. Can happen, should be watched. 1 strand gave, another in a week of hard sailing, then was replaced at first harbour.
With 1x19, not oversized, cold swages - this is throwaway stuff, stiff, not reliable (not many wires so one breaking will cause a failure of the rest), undergoing stress fatigue - I would discard after 10 years of sailing. Sailing, that is

7x7 or 7x19, not small diameter or not overstressed (as in good auld boats where they put a milimeter or two more than minimum) is elastic rope, not much affected by bending or sharp loading; will show breaking individual wires before failure, this is easy to controll. After 30 years I would inspect the wire and talurits if still good... and go sailing with confidence.

This is personal opinion, so better Dont't You Believe It

But I see no flaw in my wires after 40 years, though will replace tops for one size bigger this spring. Just to be sure and 'cause I want a size bigger, not going to throw them away
And three able, experienced people, two of them surveyors, had same opinion.

 

[William_H]

Rigging Life

This subject comes up fairly frequently. The answers come from A) those who reamain and want to remain hopeful that their old rigging is OK and B) those who have or know of failure.
I am in the last category. My score now is 4 masts lost to friends at yacht club due to rigging wire failure.
The factors that are obvious.
It is age itself that causes failure.
Rigging wire seems to fail with no actual sailing for most of its life or with a lot of hard racing.
Actually hard racing makes no difference as any sailing will make the boat heel which is a sure sign of strain on the rigging wire.
Failures have been at the entrance to the swage. Both roll swaged into SS fitting or the wire around a thimble copper swage. In each case the failure was at the bottom and in each case a side stay.
Note under pressure a cap shroud and intermediate shroud are just as critical. ie mast broken with either failure.
failures have been on both mast head and fractional rigs.
Some history... a friend bought a 21ft mast head rig boat about 25 years old. It had sat on a swing mooring for 20 odd years with almost no sailing. cap shroud let go with no single strand failure or other warning. Mast broken.
Yet another but my memory has slipped similar details on a 21 ft boat.
Another friend has a Cole 26 perhaps nudging 30 years old. Cap shroud failed no warning mast lost.
Just 4 weeks ago another friend with a Whiting 32 more of a racer fractional rig about 25 years old intermediate side stay failed without warning or strand breakage. Very expensive mast broken in the middle.
I also used to care for a fleet of 10 junior 10ft training boats. Despite their being layed up indoors with masts down for most of the year and perhaps 30 hrs actually rigged each year. All 30 of the 3/16 1X19 wires started to show failure of strands after about 20 years. It seemed the samller wire was more susceptible.
Now I don' know if it is fatigue failure but calender age seems to be the primary cause of failure. No amount of inspection will find imminent failure. I certainly would not cross the Atlantic without new wire at least on side stays and forestay. My own boat is on its 3rd set of stay wires. If you want to take your chances good luck olewill

 

[mocruising]

We have a heavy Sweedish boat and she is 16 seasons old with the original standing rigging. She sailed to the states and was shipped back and we have sailed her to the Eastern Med. I have asked this same question before. The same views and interest was expressed. My insurers say it should be inspected periodically by a competent person. We plan to cross the pond sometime and I will get the mast down and renew all the rigging prior to setting off. Just watch out for signs of rust from the ferrules and cracks in the fittings and bottle screws. Also remember not all yachts are constructed equal I suppose this is a bit of a jibe at your AWB.

 

[vyv_cox]

This subject comes up fairly frequently. The answers come from A) those who reamain and want to remain hopeful that their old rigging is OK and B) those who have or know of failure.
I am in the last category. My score now is 4 masts lost to friends at yacht club due to rigging wire failure.
The factors that are obvious.
It is age itself that causes failure.
Rigging wire seems to fail with no actual sailing for most of its life or with a lot of hard racing.
Actually hard racing makes no difference as any sailing will make the boat heel which is a sure sign of strain on the rigging wire.
Failures have been at the entrance to the swage. Both roll swaged into SS fitting or the wire around a thimble copper swage. In each case the failure was at the bottom and in each case a side stay.
Note under pressure a cap shroud and intermediate shroud are just as critical. ie mast broken with either failure.
failures have been on both mast head and fractional rigs.
Some history... a friend bought a 21ft mast head rig boat about 25 years old. It had sat on a swing mooring for 20 odd years with almost no sailing. cap shroud let go with no single strand failure or other warning. Mast broken.
Yet another but my memory has slipped similar details on a 21 ft boat.
Another friend has a Cole 26 perhaps nudging 30 years old. Cap shroud failed no warning mast lost.
Just 4 weeks ago another friend with a Whiting 32 more of a racer fractional rig about 25 years old intermediate side stay failed without warning or strand breakage. Very expensive mast broken in the middle.
I also used to care for a fleet of 10 junior 10ft training boats. Despite their being layed up indoors with masts down for most of the year and perhaps 30 hrs actually rigged each year. All 30 of the 3/16 1X19 wires started to show failure of strands after about 20 years. It seemed the samller wire was more susceptible.
Now I don' know if it is fatigue failure but calender age seems to be the primary cause of failure. No amount of inspection will find imminent failure. I certainly would not cross the Atlantic without new wire at least on side stays and forestay. My own boat is on its 3rd set of stay wires. If you want to take your chances good luck olewill

Each failure you describe is absolutely typical of fatigue failure. Yes, it is age related but not because the wire itself hardens or ages, but because it takes time for fatigue cracks to initiate and then propagate to failure. I know of many failures similar to those you discuss, one, of a forestay, is shown on my website.

I experienced a fatigue failure of a forestay on a Hobie 16. Although its sailing hours were few, its parked hours, with the mast rotating in the wind, were many. Failure was at the upper Talurit fitting.

If you would like to post photos of any of your failures I would be pleased to comment further.

 

[Rossynant]

Vyv_cox, I would like to ask:

Failures have been at the entrance to the swage. Both roll swaged into SS fitting or the wire around a thimble copper swage. In each case the failure was at the bottom and in each case a side stay.

This correspond with what I saw. I'd guess there is more chance of crevice corrosion - or oxygen depletion, however it's in English - aggravated with salt collecting there. But maybe a better explanation there is?
BTW, on fresh water lakes this is not so often, if something breaks it's more in 'random' places.

 

[vyv_cox]

Vyv_cox, I would like to ask: This correspond with what I saw. I'd guess there is more chance of crevice corrosion - or oxygen depletion, however it's in English - aggravated with salt collecting there. But maybe a better explanation there is?
BTW, on fresh water lakes this is not so often, if something breaks it's more in 'random' places.

I agree, the swaged fitting at the lower end of a shroud would seem to be a prime site for crevice corrosion. Despite that, I have never actually seen it there. If anyone has a photograph I would be pleased to add it to the website.

I have seen quite a few failures where the wire enters the swage. From the William H post it would seem his were all there. If you look at http://coxengineering.sharepoint.com/Pages/Fatigue.aspx part way down, you can see a typical fatigue failure of this type.

I have never seen a failure anywhere other than at an end fitting, other than ones caused by damage. This is exactly what would be expected in fatigue, where the stress concentrator dictates the location of the fracture.

I apologise for the overlapped appearance of the photos in the link. If I open the site and follow the sidebars it does not do it. Weird.

 

[Rossynant]

Did look already thanks a lot.

 

[ukmctc]

Can anyone advise on the typical lifespan of standing rigging for a boat used as a normal cruising yacht (no racing)?

yep, 10 years for insurance purposes. some companies say 7.