swage fitting inspection

I just replaced an upper shroud on the E38, per survey mandate.

Here is a picture of the hairline crack that rendered the otherwise fine looking stay a candidate for the trash bin.

Can't see it?

I guess that's the point. It is almost invisible to the eye, as well. Check the tops of the stay swages. Any crack there, however small, is newsworthy.

swage

thanks for the heads up. I've had perhaps 4 marine surveys; never did any surveyor to up to check rigging etc.

Replace one you should replace the whole rig

That broken and swollen shroud, (the swelling internally is what made it crack, along with work hardening of the cable going into it), is the canary in the coal mine.

It is time to replace the whole rig. Don't wait till something breaks to replace the rest of it. Something breaking can easily mean the mast in the cockpit with you.

Most surveyors are very poor at inspecting rigging. I have heard too many of them say that "shit runs down hill, if there is anything wrong it is going to be at the bottom". This is unfortunately untrue, problems can occur in a wide number of places in the rig, not just the bottom end where the on deck surveyor can look at it.

How old is the rig? A year or two, then the fault could be a bad swage, but there is a bit of corrosion showing in the photo, enough so that I would guess that the rig is getting up there in years. Most people don't want to admit it, but the rig should be replaced about once every 10 years here in CA. A little longer in the PNW, and a bit longer than that in the great lakes, if and only if in the great lakes you take the mast down for winter storage!.

Guy

my pore ole roller furling

Not wanting to step on a thread...but I've been meaning to ask this and this seems like a good time. In looking a furlings, i've seen some makers want an 8 mm headstay; which is larger than the 9/32's on my E-34. (9/32 is closer to 7mm than 8) (8mm is larger than 5/16"s). I would like to stay with the original size rigging; everything else being equal. But. Did/do boatbuilders sort of undersize rigging (the way they undersize motors)? Is the oem rigging optimized for a 100% foresail; and not necessarily the minimum standard for a larger genoa? Simply said: Is it advisable to go larger when re rigging?

I want Christian's Surveyor!

original wire size

EGregerson said:

Not wanting to step on a thread...but I've been meaning to ask this and this seems like a good time. In looking a furlings, i've seen some makers want an 8 mm headstay; which is larger than the 9/32's on my E-34. (9/32 is closer to 7mm than 8) (8mm is larger than 5/16"s). I would like to stay with the original size rigging; everything else being equal. But. Did/do boatbuilders sort of undersize rigging (the way they undersize motors)? Is the oem rigging optimized for a 100% foresail; and not necessarily the minimum standard for a larger genoa? Simply said: Is it advisable to go larger when re rigging?

Click to expand...

Simple Answer- no. First have the rig evaluated. A good guide is the Riggers Apprentice by Brion Toss.
His site: http://briontoss.com

He points out in his book that it is incorrect to assume that your original rig was undersized by the builder.

FWIW I doubt that EY under-spec'd the wire and fittings.

Loren

Oversizing the rigging Headstay size for furler.

The furler sizes are generally a maximum recommended stay size, not a you must have this size recommendation. The 8mm corresponds to the alternate measurement system about 9/32. I have not run into any of them that would not be fine with either an 8mm or a 9/32 wire if that is the size they are specked for.

Rigging wire size is designed to safely handle the forces that your rig and boat. (Yes the hull makes a lot of difference for the rig). The size of the wire is set to match the load that your boat is likely to put on the rig under extreme circumstances. Then a safety factor is calculated, and that is the size wire rope that is used. The safety factor is normally about 5:1. This safety factor is much misunderstood by a lot of people, including some riggers. (The safety factor has nothing to do with the idea that the rig will age. The rig should always have a 5:1 safety factor. As that wire gets older and work hardens and corrodes, it frequently is a lot less than 5:1. Which can result all too fast into the mast sharing the cockpit with the crew.)

The safety factor is there because we can't accurately model reality with mathematical equations and human assigned numbers for variables. For instance, what happens when the boat falls of a 3 foot wave just as a gust of wind strikes the sails. There is a lot of modeling that would have to be done there to calculate what the load would be on say your aft lower port shroud, (port aft d1 for those that want to speak modern rigging). So through a lot of trial and error in the past, and quite a few dead people, we arrived at the idea that we need about a 5:1 safety factor so that the mast does not fall down. The boat design is then finished allowing for the size of the wire that gives us that 5:1 safety factor. The chain plates are correctly sized, out of the correct material, with the correct fasteners, and the correct size pin holes in them. They are glassed to the hull with the correct schedule of layup to support the load on the chain plates, etc... All the way down through the keel bolts and the mast step.

Now if you for some reason think... Hey if 5:1 is good, then what if I double the wire size and have a 10:1 safety factor, after all I live in America, and bigger is always better right!? Errr no... That wire is going to be a lot heavier, and the boat is going to sail a lot worse because of it, then that added weight adds a lot more loading to the entire rig from that mast step, all the way through the spreaders to that tippy top tang on the cap shrouds (Vx/Dx for those trying to speak modern rigging words). Then add to the fact that if you are using SS wire rope, those shrouds have to be tuned at a minimum of 10% of their breaking strength to not work harden and break, and you can see that even if you were to drill out the chain plates for the larger pin size needed (Which would of course weaken the chain plate connection because they were no designed to be drilled out), you would now have at least twice the static load on the rig and chain plates before we even started trying to tune it. And down through those fasteners and layup etc. So instead of a larger safety factor, you are now overloading the structure and have a significantly smaller safety factor!

Once we start trying to tune it, we run into even bigger problems. In tuning the forces on the rig, and the forces generated by the rigging all balance out. Changing the forces genereated by the rigging alters the tuning, in most cases making a good tune impossible if the previous owner has decided to up-size the rig.

Guy

Thanks Christian for starting this thread and your photo. I had no idea the cracks could be so fine. You inspired me to take a look. Thanks Guy for your expertise.

I did a very close inspection of all the bottom swages on my boat and found 3 had hairline crack(s). I have no idea how old this rig is and no way to find out. It looks clean and fairly rust free. (bought boat from an estate) Guy suggests replace all. OK. I will aim to get that done after July. Can't do it now.

I am going to get an inspection done but not tell them of my findings.
Any ideas about the risk factor of a break?

Ah, risk factor.

Are we up to date on the colonoscopy? HOw about that engraved gift for Mother's Day--proving you thought of her well ahead of the deadline? Shingles shot? Now about that life insurance policy, is it adequate?

Most people don't even know about stainless fatigue, hairline cracks, recommended replacement schedules and they sail on happily forever. Few rigs actually go over the side. Even when they do, it's usually to leeward. i

I believe we all have to resist worrying about everything, and play the odds with a grin.

There are many human factor in risk assessment that are more important that the stainless replacement schedule.

We control the risk, stainless steel doesn;t.

The previous owners of the boat had kept fairly good records and I could find no mention of the standing rigging being replaced since it was build 25 years ago.

We had a separate rigging survey done (by a rigger) and, surprise, he recommended replacement. I think he mentioned the usual replacement cycle was every 15 years, still it seemed we were long overdue. He charged about $4K overall, half parts, half labor. It seemed a reasonable investment and will probably never have to worry about it again. Attached is the invoice.

3 out of 4 lowers have hairline cracks on the swages. OK, let's say I am going to replace the 4 lower stays on this boat. I have a friend a few boats down who is a retired sailmaker who will help me do this job. Where are good places in the southern Chesapeake Bay area to get the materials and get the swages pressed on. What about online/mail order? Any suggestions will be appreciated.

rigger

Jim Miller at doyle in Hampton has a rigger he works with;

I can highly recommend rigging only. http://www.riggingonly.com/
I have worked with them multiple times and have always been impressed with they're service, knowledge and price. Fast turn around too.

+1 for Riggingonly. I was very happy with their service. I emailed them my specs and they sent exactly what was ordered. Reasonably priced, too.

I suppose I should replace mine on general principles. But I worry somewhat more about the embedded - unobservable - chain plates.
Then I remember that Robin Graham was dismasted twice during his little jaunt, and sailed a significant fraction of his circumnavigation with a jury-rigged boom and sideways corner of his main, with no apparent reduction in speed. Amazing what you can accomplish when EPIRBS haven't been invented yet.
Not that I was planning to do that.

Good worry!

Chain plates on our old boats are getting very long in the tooth. Especially as most of them are very difficult to bed correctly the way the boats were made. (This is true of most boats even today).

They are the leading cause of dismasting according to boat Us insurance.

Start by drilling a small hole in the bottom of the fiberglass covering each of them. A lot of the time some really rusty water comes out. That rust is part of the chainplate.

316 SS is only stainless in the presence of free oxygen. When deprived of that free oxygen it starts to corrode. The most common form is crevice corrosion. It appears often as rusty spots or small pits on the outside of the chainplate, but rapidly opens up to a larger damaged area on the inside of the chainplate. Kind of like the opening to an extensive cave system.

They need to be removed to be correctly inspected as the area that is most likely to be corroded is the area where the chainplate actually goes through the deck. This area is impossible to inspect without removing them.

Once you have them removed, most of the work is done, so I generally recommend that you just replace them with grade 5 Titanium, which is a much better fit of material to purpose than 316 SS is.

Guy