Nylon vs Polyester

[boatman61]

Originally Posted by craigsmith

What has "newbies" got to do with it? Your South Africans apparently chose a poor quality product. If not, and it was something ostensibly decent like a Kong or WASI, then that would be unprecedented and maybe you'd like to get more details rather than posting vague alarmist anecdotes.

Barnakiel's statement is just wrong, fully five of the connectors in the YM test were as strong or stronger than the chain, precisely as would be expected.

Yawn.....

[tager]

SELL SELL SELL!

[s/v Jedi]

The swivels as below are stronger than same size shackles. Yes, these are 3.4" attached to G70 chain 3/8".

cheers,
Nick.

[dpons]

Originally Posted by craigsmith

What has "newbies" got to do with it? Your South Africans apparently chose a poor quality product. If not, and it was something ostensibly decent like a Kong or WASI, then that would be unprecedented and maybe you'd like to get more details rather than posting vague alarmist anecdotes.

Barnakiel's statement is just wrong, fully five of the connectors in the YM test were as strong or stronger than the chain, precisely as would be expected.

Your tone is arrogant. I don't know if you know everything there is to know, or you just think you do.

The anecdotes about boats that have been lost because of broken swivels are common. Many are well documented. A lot sailors have swore off those things in several public forums.

On this particular case I related (which was not vague or alarmist: I gave time, location, and what I remember of the boat name), I didn't feel like asking metallurgical or brand details to the owner, as he was offloading stuff on the coast. Just said that he lost his boat because of a broken swivel. The anchor, of unknown make to me, is still on the bottom.

If there is a lesson to learn is that swivels constitute a single point of failure in an anchoring system, yet are they are not deemed essential by most sailors (except perhaps you).

[craigsmith]

Originally Posted by dpons

If there is a lesson to learn is that swivels constitute a single point of failure in an anchoring system, yet are they are not deemed essential by most sailors (except perhaps you).

So do shackles and every link of chain.

I don't consider swivels "essential", don't put words in my mouth. But they are helpful on some boats, and good quality ones are fine.

There's no lesson at all to learn unless you detail the exact swivel model and the particular failure it suffered. Tarring all in a group with the same brush by way of an unknown anecdotal failure - if that's not "arrogant" I don't know what is.

[barnakiel]

Originally Posted by craigsmith

Oh nonsense.


Also nonsense. Be specific.

Well, I do not think what I said ("... swivels went first...") is all nonsense. I will try to find that issue of YM and report back. Not sure if still have the magazine around but will try to grab a copy of that report. I believe, though, that is what theYM found.

I might have misinterpreted or misread the information, but as I remember it, the YM pointed at swivels as being the least dependable elements of the rig.

I have also seen with my own eyes an apparently top brand swivel half torn open in the process of forced retrieval on an anchor. And it was the only time ever I have seen dramatic and dangerous failure of anchoring equipment in a couple of years of cruising.

You are probably that much older than me and have so much more experience that you have seen anchors, chains and swivels NEVER snap. But in such a case please be specific and let us know which brands DO NOT snap. We will buy only these! Otherwise, what you say is all nonsense.

OK, off to the other ship to see if the YM is still somewhere around.

;-)
barnie

[craigsmith]

Originally Posted by barnakiel

I have also seen with my own eyes an apparently top brand swivel half torn open in the process of forced retrieval on an anchor. And it was the only time ever I have seen dramatic and dangerous failure of anchoring equipment in a couple of years of cruising.

More anecdotal stories? What "top brand" and model? Was it attached to the shank of the anchor?

Originally Posted by barnakiel

You are probably that much older than me and have so much more experience that you have seen anchors, chains and swivels NEVER snap. But in such a case please be specific and let us know which brands DO NOT snap. We will buy only these! Otherwise, what you say is all nonsense.

You're right, proving negatives is clearly the way to go.

As have many I've seen plenty of failed anchor gear. Typically it's under spec'ed equipment of dubious origin bought on too tight a budget. What do you expect?

[barnakiel]

Originally Posted by craigsmith

More anecdotal stories?

SetSail » Blog Archive » Anchor Swivels – Why They Are A Bad Idea
Problems With Marine Anchor Swivels
Latitude 38 - 'Lectronic Latitude

All of the stories anecdotal. Unless YOU are in the boat.

YES, Craig, we all know there could be a length of chain between the swivel and the chain proper. Somehow, neither the manufacturers nor the SELLERS made it clear to the guys who bought the anecdotal swivels.

I do not have the mag with the test anymore, but I will try to find a copy, will re-read it, and forward my apologies to the forum for misleading us, if applicable.

Where you claim the test prove swivels outdid the respective chain we are clearly thinking of two different tests.

barnie

[CarinaPDX]

Since we are discussing swivels and shackles, let me put in my 2¢ worth.

All quality shackles and swivels should be marked with their safe working load (SWL). To get a shackle or swivel that matches the SWL of high tensile chain requires a pretty large part. IIRC it also requires oversize end links on the chain to get the clevis pin through. As a result a lot of cruisers use undersize parts, and of course they become the "weakest link". But I don't see any reason to say they are a danger if properly sized (and seized).

While I suspect that one might get away without a swivel in an all chain or chain and braided rode, 3-strand twists too much to do that. If the rope is allowed to hockle then its strength will be compromised. So with 3-strand a swivel must always be used - it just needs to be strong enough.

How many of you have oversized end links installed by the factory?

[thinwater]

Does 3-strand really twist when secured at both ends?

In the crane and rigging business there are always precautions when using a 1-part whip line, as it will do what you say, but on the main hoist (multi-part), never. If you add a swivel, it can twist when loaded, but if secured at both ends, no. This is one reason it would be unwise to use 3-strand on a sea anchor, since the anchor can rotate. In fact, most 3-strand rope manufacturers advise against using 3-strand rope in highly loaded applications where rotation is probable.

In my case, I have enough chain so that he anchor is on the bottom before the fiber comes out, and I have never seen twisting.

Why wouldn't a swivle make the 3-strand problem worse? The exception, of course, is if the boat is anchored through many tide cycles. In that case, I agree. That is something I never do, never more than a few.

[SailFastTri]

Originally Posted by CarinaPDX

Since we are discussing swivels and shackles, let me put in my 2¢ worth.

All quality shackles and swivels should be marked with their safe working load (SWL). To get a shackle or swivel that matches the SWL of high tensile chain requires a pretty large part. IIRC it also requires oversize end links on the chain to get the clevis pin through. As a result a lot of cruisers use undersize parts, and of course they become the "weakest link". But I don't see any reason to say they are a danger if properly sized (and seized).

While I suspect that one might get away without a swivel in an all chain or chain and braided rode, 3-strand twists too much to do that. If the rope is allowed to hockle then its strength will be compromised. So with 3-strand a swivel must always be used - it just needs to be strong enough.

How many of you have oversized end links installed by the factory?

First let me go on record that I'm impressed you have 2¢. Most people have $0.02 these days because they don't know how to navigate extended ASCII characters. 2¢ are hard to find anymore

Back on-topic -- you don't need oversized end-links if you can find HT alloy shackles. Here in the US they're sold by Hamilton Marine Welcome To Hamilton Marine I'm using HT 3/8" shackles that match the WLL of my 5/16" HT Acco chain.

[CarinaPDX]

The fact that the ends are secured doesn't magically make the torque of the unlaying twist go away - it just prevents it from showing. There will be a torque applied to each end, and when the rode unloads and loads it can hockle. I have used 3-lay for a snubber and it usually does turn into a twisted mess - I don't do that anymore.

[boatman61]

Originally Posted by CarinaPDX

I have used 3-lay for a snubber and it usually does turn into a twisted mess - I don't do that anymore.

I must buy different rope... or maybe EU rope is resistant... never ever had that happen... assuming that my interpretation of snubber is the bit of rope you tie to the chain and cleat off so the cable clunking on the rollor don't keep you awake all night..

[CarinaPDX]

Yes, HT shackles are available and are a great solution if you have them. The normal cheap shackles on the Hamilton site are "load rated" (i.e. don't provide SWL) and for the good US galvanized shackles it requires 1/2" to get the 2 ton rating of the 5/16" HT shackles. To get 2 tons out of the swivels it takes 5/8" (galvanized or stainless) unless you opt for the expensive ones designed to go over rollers smoothly. All that for HT 5/16" chain. No wonder there are failures at the swivels...

[CarinaPDX]

To be more precise, I usually attach the snubber with a rolling hitch to the chain. With the loading/unloading of the 3-lay the twisting often causes the chain and rope to tangle around each other. A mess, and also a potential source of weakness.

Just about all of my rope is European as well :-). I was there for more than 12 years until a couple of years ago.