Hi Daria,
Pretty dramatic pictures.
I have seen this before, but it is not as common as the "jaws-pried-open" failures that have gotten more press. With all the publicity it is hard to believe that people still attach this style swivel directly to the anchor. It is a failure waiting to happen.
My understanding of this particular failure underlines why I believe stainless steel has no place in ground tackle. I see this failure developing when side loads (or poor manufacturing) give rise to a crevice which then blossoms into crevice corrosion in hard to inspect places. This leads to the catastrophic failure that stainless steel can be prone to.
My best, Dick Stevenson, s/v Alchemy

In Flying Fish 2014/2 Red Knickers covers the loss of the anchor after the anchor swivel shackle failed with bent jaws (photo pg98). This is possibly because the swivel was attached directly to the anchor shank – in fact as shown in the photo on pg14 of the same FF. This potentially puts a great deal of strain on the swivel if there is any sideways force on the anchor shank, e.g. if it gets caught on a rock or even when it re-sets itself with a wind shift. We have a short length of chain (about 1m) between the anchor shank and the swivel to avoid this i.e. anchor, 1m of chain, swivel, rest of chain. We initially did not have a swivel and had frequent problems with twisted chain – this came to a head when we were anchored in Brazil and a moored vessel dragged onto us - we had to dump our anchor and chain to the bitter end to escape, and this was slowed down by twisted chain. Since then we have always had a swivel.

Hi Shills

I may have posted this earlier, but here is a link to a page where we discuss swivels, where to place them (as you also suggest), and the problems associated with them.

http://features.coastalboating.net/Editorials/swivels/

Hi Shills,
Your described motive for the swivel originated (in part) by the chain not coming out of the locker smoothly and fast in a fire drill, an understandable safety concern. You also suggest prior troubles with chain twist and suggest that these problems have been alleviated by the use of a swivel.
As to chain coming out of the locker and getting jammed in a fire drill: this does not surprise me. When emerging at a moderate rate, the links can separate and flow easily, especially if there is sufficient distance from wildcat to the top of the chain pile (assuming a reasonably configured locker where chain piles do not need to be knocked over to accommodate the chain and the chain is brought in by the windlass-ie not dumped). All bets are off with a very fast rate as links will have insufficient time to separate and can easily get jammed as the chain is jumping about.
As to twist when recovering the anchor, I have never understood the forensics of how chain twist gets induced. Do you have an explanation of what takes place that your chain gets twisted?
My observation: If chain goes out un-twisted as it would if going over a free-wheeling wildcat (or even by hand) I do not see how the chain could get problematically twisted in a few days of anchoring. Maybe a few wind shifts and rotations, but these would be easily “un”-twisted when the anchor hangs free coming up to the boat and absorbed by the snubber when at anchor. So I do not see a way for twist to get induced. How do you understand it?
Probably most powerful argument for me is that in many thousands of anchoring experiences, I have yet to find a problem that makes a swivel worth the added vulnerability to my ground tackle system. The only time I wish for a swivel is when the anchor comes up in a way that makes it harder to get it onto the roller: a swivel might make this easier to remedy, but even there I am in doubt.
I would suspect that there is an alternative solution to your chain twist, but without understanding the mechanics inducing the twist, I am unable to make suggestions. I am clear that I consider swivels an unnecessary added vulnerability in a ground tackle system that should be avoided.
My best, Dick Stevenson, s/v Alchemy

Hi Daria and Alex,
I read your article on swivels and believe it to be the most thorough and thoughtful examination that I remember, and I tend to read a lot about ground tackle issues.
I agree with you that swivels have not made a case for inclusion in a ground tackle system, and that goes double for those products that are stainless steel. I think modern equipment manufacturers are selling a myth that swivels are important.
What I would wish you to consider is that you collude with this commercial myth-making on the manufacturer’s part by dedicating a long article to reviews of the various swivels, their design and materials used. I would wish first for an article examining whether they serve any realistic function: whether they actually solve a problem. And examining real world reports and investigations. This has yet to be determined and the companies should be taken to task to document their claims. Only after a realistic function is determined and documented should an article such as yours be undertaken. In some way, an article of your length and breadth gives (maybe) an unintended validity to swivels having a place in an anchoring system even with your caveats.
You conclude your review with a qualified statement advising against swivels, and then undermine this stance by essentially saying (in my reading) “whatever” when you say the choice is up to the individual mariner, which, of course, it always is and need not be stated. I may be holding you to a higher standard, as professional marine journalists, to take a position that equipment needs to be justified and should not be promoted until it has done so. I may also be picking on you as I find the marine industry journalistic efforts woefully inadequate at informing the reading public: at being more than cheer leaders for products.
My best, Dick Stevenson, s/v Alchemy

Hi Dick

I do agree with your sentiments and arguments. We too have anchored thousands of times, and have swung happily at anchor of weeks at a time in changing winds. Yes, the chain was twisted, but, as you correctly state, it untwisted when the anchor hung freely off the bow roller. Any twist there may have been cannot get past the gypsy/wildcat.

caveats:

Some people have complained to me that their anchor always hits the bow roller upside down. My response: remove the shackle and reattach the other way around.

For those boats where the brawny one insists on remaining at the helm and in control, and where the mate has to do the heavy work, and there is a risk of fingers getting caught righting a twisted anchor, I do recommend a swivel. In this case I recommend to look for one that actively orientates the anchor as it comes up and over the bow roller, is designed to withstand lateral loads, and has no hidden parts, where rust WILL occur.

A third caveat is on our mooring. This does not apply to every mooring. Ours is located in a hole where the water swirls around in opposite directions with the tidal flow. (Hence the reason there is a hole there.) Even with a swivel, the riser may get twisted, but the swivel does do its job and keep things right. I do have to replace the (heavy galvanised) swivel every year or so.

Hi Alex,
I suspect we could get into dangerous territory if we attempt to discuss those (usually) marital decisions which lead to the brawny one staying at the helm. In fact, this is a pet peeve of mine as it strikes me that it is (generally) a completely unnecessary decision that could be dangerous to the least brawny crew. Brawn is usually not evenly distributed among crew so jobs where occasional use of brawn (like anchor handling) can be a safety issue should go to the brawny one. Brains are usually more evenly distributed among crew and brains, with experience, allow anyone to be helm in the usually quite undemanding task of handling helm while raising anchor.
I have never solved the anchor-hitting-the-bow-roller-upside-down problem. Your suggestion is excellent for those whose chain never leaves the wildcat. When deploying the anchor, I usually “dump” a lot of chain after the anchor gets to the bottom and we have slipped a bit away and in this dumping the chain gets separated from the wildcat. So, it can be a bit of a crapshoot where the anchor will position itself upon retrieval. Those whose deployment/retrieval techniques lead the chain to always lie in the wildcat would do better for sure, but I would still doubt it would approach 100%.
In any case, it is not nearly enough of an issue to warrant the vulnerability that a swivel brings to the table. And I doubt that swivels allow the anchor to position onto the roller 100% of the time.
And agree, swivels can have a place in mooring design in certain areas. Mooring design is, in many respects, quite a different design challenge than a ground tackle system and may/likely demands an article/book of its own.
My best, Dick Stevenson, s/v Alchemy

Your upside down anchor issue can be solved with the right kind of swivel. There are one or two swivels on the market (we tested one) that will force the anchor to rotate in the correct orientation as it hits the bow roller. (Note that I am not naming brands here) I may not be a proponent of using swivels, but this does work 100% of the time. The one we tested also has a breaking strength that exceeds our chain.

As to moorings, we already have a section on moorings in our book. For the next edition, I have expanded this.

Hi Alex,
As said in the last email, the anchor coming up backwards on the roller is not a big deal and certainly not worth the added vulnerability of any swivel. I suspect I know I know the swivel you are referring to and it is stainless and I believe that stainless steel should have no part in any ground tackle system, regardless of breaking strength.
When last I casually went over swivel stats, the manufacturers did not specify the tests done to determine breaking strength nor did they specify safety factors. And I suspect they were not including even a little of side loading in the figures they give out. Even chain (if memory serves), a much more regulated industry, ranges from 3-1 to 6-1 in some of their safety factors.
In any case, I suspect we are spending far too long talking about swivels. Even your 3 caveats do not really apply: it is quite easy to position an upside down anchor on the occasions when that occurs; brawn can go the bow, and the third caveat applies only to moorings, not to anchoring situations and which are quite different design challenges.
I would espouse the position that swivels have no place in any ground tackle system as they only add complexity and vulnerability and any problems they solve are minor and can be gotten around easily in other ways. Certainly in everyday anchoring life, swivels are not a problem or issue. My stance is predicated on the premise that one should be prepared at all times for things to go pear shaped and ones ground tackle system is an on-board system that needs, at all times, to be bulletproof.
My best, Dick Stevenson, s/v Alchemy

Dick, I feel your frustration! I am in total agreement with you that a swivel has no place in an anchor rode. Why anyone adds such a weak link into a critical system is nuts - doing it with a material that has inherent susceptibility to crevice corrosion is asking for trouble. The idea that it facilitates the anchor rolling onto the bow roller is a poor and frankly questionable excuse in my opinion. My anchor often comes up the wrong way round - a simple nudge with a boat hook is all it takes to turn it around.
I have to say it concerns me that Alex with his book on anchoring technique would not come down firmly on the side of eliminating swivels altogether. By all means keep them on a mooring - different situation entirely.

Bill Balme