Anchor Swivels, Just Say No

We have never seen the point of anchor swivels. All they do is add a potential point of failure to the anchoring system and provide little or no benefits in return.

Our concern about swivels has always centered on the possibility of one of the two screws backing out, as happened to a friend nearly costing him his boat—anchor shackles are always moused with wire, so why not swivels?

And the fact that the swivel shaft—made of  stainless and therefore subject to work hardening—is torqued over the bow roller every time the anchor is hauled.

All of that was enough to make us eschew anchor swivels, but now we have seen the ultimate reason:

A visiting cruising friend showed us this massive swivel—it is just under 4″ inches (10 cm) long—that failed when his boat was subjected to some nasty katabatic gusting that caused her to surge back and forth and then come up hard on the anchor.

A close examination shows a disturbing weakness in the design that caused the threads holding the pin to strip when a shock load was applied off axis to the anchor shank.

You can see exactly how this failure happened by looking at another anchor swivel, this time in situ, in the photograph below. When the hard jerk from off to the side (as the boat came up short) was combined with the swivel’s inherent inability to align to the load and the lever-arm imposed by its own length, something had to break.

JHHGH1_1020147

In comparison, an ordinary bow shackle would have simply aligned to the new load without problems.

3/8″ G7 chain with an oversized end link attached the right way to a SPADE anchor using a Crosby 209 shackle that matches the chain strength. Oversized link is not required with G4 chain.
If you have an anchor swivel, we strongly recommend that you remove it and replace it with the appropriately sized bow shackle installed the right way.
If you really must use a swivel, do not connect it directly to the anchor as shown above; instead use a short length of chain between the anchor and the swivel.

Do You Really Need One?

That said, before you decide that you just have to have a swivel, consider this:

Sure, very occasionally our SPADE anchor comes up with the flukes facing forward so it is a bit difficult to stow, perhaps one time in 20. And yes, if we continue to run the windlass the anchor will suddenly swing into the correct orientation with a hell of a bang and possibly damage to the bow.

But most times all we have to do to solve the problem is surge a little chain and bring it in again.

And it that does not work, pausing the windlass, just after the stock comes over the roller, to let the anchor reorient gently, does—takes a bit of practice, but once we have the knack it works great.

Given that, my thinking is why introduce a potential failure point with a bad track record, like a swivel, when a good old galvanized shackle will works fine. Or to put it another way, why add a complication like a swivel rather than learn a skill?

The more you know, the less you need.
Yvon Chouinard, climber and founder of Patagonia

And we have been anchored for as much as a month on as little as 80 feet of chain without having any twisting problems that would require a swivel. So I think repeated chain twisting is more a function of a poor windlass, locker and/or chain setup, than intrinsic.

Further Reading

  1. Introduction
  2. 4 Vital Anchor Selection Criteria and a Review of SPADE
  3. SARCA Excel Anchor—A Real World Test
  4. SPADE, SARCA Excel, or Some Other Anchor?
  5. Rocna Resetting Failures and evaluation of Vulcan and Mantus
  6. Some Thoughts On The Ultra Anchor, Roll Bars and Swivels
  7. Specifying Primary Anchor Size
  8. Kedge (Secondary Anchor)—Recommended Type and Size
  9. Third Anchors, Storm Anchors and Spare Anchors
  10. Anchor Tests—The Good, The Bad, and The Downright Silly
  11. Making Anchor Tests More Meaningful
  12. We Love The Way Our Anchor Drags 
  13. Things to Know About Anchor Chain
  14. Selecting a Chain Grade
  15. Anchor Chain Catenary, When it Matters and When it Doesn’t
  16. Anchoring—Snubbers
  17. Anchor Rode Questions and Answers
  18. Q&A: Hybrid Rope And Chain Anchor Rodes
  19. Anchor Swivels, Just Say No
  20. A Windlass That Makes The Grade
  21. The Perfect Anchor Roller
  22. Install A Wash-down Pump—And Save Money!
  23. Anchoring—Kellets
  24. Anchoring—Chain: Stoppers, Termination and Marking
  25. 20 Tips To Get Anchored and Stay Anchored
  26. Choosing an Anchorage
  27. Choosing a Spot
  28. 15 Steps To Getting Securely Anchored
  29. One Anchor or Two?
  30. Two Anchors Done Right
  31. It’s Often Better to Anchor Than Pick Up a Mooring
  32. Yawing at Anchor, The Theory and The Solution
  33. Yawing at The Anchor, an Alternative Cure
  34. How To Use An Anchor Trip Line
  35. ShoreFasts—Part 1, When to Use Them
  36. ShoreFasts—Part 2, Example Setups Plus Tips and Tricks
  37. ShoreFasts—Part 3, The Gear
  38. Gale And Storm Preparation, At Anchor Or On A Mooring
  39. Storm Preparation, All Chain On Deck
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Carter

John
Perhaps the problem is due more to poor design rather than the swivel itself. What think you of the WASI?

A quick look around my marina revealed all boats with high test chains using standard half strength shackles. Just an observation not an excuse.

Your recommendation might be better stated as an appropriately sized high test strength shackle.

I always enjoy your thoughts and ideas. Thanks

David Nutt

In over 100,000 miles of sailing including a circumnavigation and a recent trip to Greenland we have never used a swivel. I have never found a need for one and as John points out it is just one more expensive piece of equipment in the long chain of items that can fail. It won’t fail if you don’t have it. Also, if I search really hard I am sure I can find another more reliable and utilitarian item on which to spend that elusive $400.

Matt Marsh

I always thought these things looked untrustworthy, unnecessary and ridiculously overpriced. My chain gets twisted all the time, and it never causes a problem- just let it hang and straighten itself out for a few seconds before hauling the rest of it in.
An extra $300 gets you a bigger anchor…or more rode…or a better windlass…any of which would do a lot more for anchoring securely than a swivel fitting.

Andy Fennymore-White

An interesting post but consider this; Three years back I was on the market for 200m of 1/2″ chain. I contacted a British manufacturer who claimed to make their chain in the UK, (and is a big name here). I asked for a sample of their chain that was supposed to be 100% proof tested to 4t. I had it independently tested as I am a paranoid skeptic and guess what? It yielded at 3.5t failing totally just over 4t, when its supposed minimum break was over 8t. When I told the company they just said;” Oh do you still want to place the order?”. They did not even bat an eyelid or ask to see the results; the sales assistant even admitted that they just brought it in. (And guess from which part of the world?) You need to be very careful with everything even if it meets all the specs and costs proper money.

Martin

Good to get the benefit of experience from multiple high mileage sailors, and even better to realise this means less equipment.

If exceptional circumstances should require consideration of a swivel (perhaps prevailing wind shifts, or tides, tend to rotate a vessel the same way every day), perhaps inserting the swivel a few chain links away from the anchor itself can avoid the lever arm illustrated above.
For myself, I have a faint feeling of unease with stainless steel being immersed, although we trust the manufacturers of such swivels are confident no crevice corrosion will occur in any part of the device. Apologise for thread drift, but does anyone here have an opinion on stainless chain (and stainless anchors)?

Martin

Paul

It’s clearly a case of not knowing how the swivel should be connected to the anchor. As mentioned, there should have been a large shackle attached to the shank of the anchor; then any swivel can be attached to the shackle. But better still, is to put about six links of chain between the shackle and the swivel. This ensures a straight pull on the swivel. FWIW, this is not a swivel I would have chosen. Not all swivels are created equal!

Adam

In my case, there was no simple way to connect 3/8″ chain to a 121 lb. Rocna anchor other than to use a swivel. No shackle that would fit through the chain had even 1/2 the rated strength of the chain itself (I don’t have an oversize final link, and don’t trust a welder to put one in).

As I am well aware of the failure modes of traditional swivels as pictured above, I hunted around for something built strong enough to exceed the next weakest item in the ground tackle system.

Quickline’s Ultra Swivel fit the bill. Its design is similar to the WASI and the breaking strength of the 13mm version *at 90 degrees to the swivel axis* is 26,000 lbs. I’m comfortable that the chain would break (or the anchor would pull out) before the swivel parted, even if the latter somehow is forced to take a purely perpendicular load.

Nick Kats

Hi Adam
I looked at the Quickline swivel by Ultra. It is made of 316 stainless. This, I understand, has much less strength than regular galvanized steel. I did not pursue this any further. Have you researched the strength of the Quickline swivel, or did you accept Ultra’s statement at face value?
Nick

John – splendid article on swivels. Like you, I was never able to see a reason to put one on an anchor rode. Thanks.

Craig Smith

Since the WASI PowerBall and its copy by Ultra was mentioned: in addition to my response below, my opinion on these “ball-and-socket” designs is that they’re pointless.

The objective is ostensibly to alleviate the lateral loading on the swivel joint. However the more important issue is not this but rather the lateral leverage on the jaw sides when attached directly to the anchor, which both these ball designs still do!

Furthermore, the ball-and-socket allows an articulation of only 30 degrees. Hardly the 90 you might think is required. What is the point? It is a gimmick.

As to the Quickline specifically, it is produced in Turkey by the same outfit that make the “Ultra” copy of the Spade anchor (from only weak 316 stainless). Given the character of most imitators I would consider the quality suspect unless proven otherwise. There is a promo video which purports to demonstrate a supposed self-righting feature of this swivel in action, but it is really total nonsense, and the contents of their other literature does not inspire confidence.

Craig Smith

This example is much more an example of a poor product – poor design combined with inadequate materials – rather than any fundamental issue with swivels that will cause the sky to fall. The boater in question needs to seriously examine his product selection process/criteria, rather than erroneously conclude that he has proven that swivels per se are to be avoided.

Buying a cheap shackle of dubious quality from the sale bin in the chandlery is likely to prove equally disastrous.

Swivels are considered useful or even necessary by some, depending on the particular combination of anchor, bow-roller design, and anchoring habits. The general advice should be that if you don’t know you need one, you probably don’t… but to rule against them because there are some poor quality examples out there is great over-reaction.

Jaw-to-jaw swivel designs such as pictured are fundamentally flawed in the way they are designed to attach to the anchor. Do NOT use them in this manner; the failure mode is typically that pictured. They can have a length of chain installed regularly between them and the anchor, or at least a shackle. The ideal swivel design is an eye-to-jaw configuration, with a pin through the chain and a regular eye to be shackled to the anchor shank.

Regarding stainless steel in anchoring components. There is nothing wrong whatsoever in stainless used for anchor gear (with the one exception that it shouldn’t be used permanently immersed and is a no-no w.r.t. mooring set-ups for example). The problem is again one of quality. Stainless steel is very expensive – quality 316 chain costs around 4x that of stronger G40* galvanized from the same manufacturer. The price of more useful stronger G50 stainless is just ridiculous. In general stainless items should cost between 3 and 5 times the equivalent (in terms of both quality and strength) galvanized product – if not, you are getting what you pay for. The typical cause of many of the stainless steel “horror” stories is not some evil character of the metallurgy, but rather this factor in action.

*316 has roughly the same strength as mild steel, weaker than the 400 grade steel used in G40 or what Americans call high test chain, and far weaker than true high tensile 600-700 grades used in high tensile chain, high load shackles, or quality anchor shanks. John’s comments about brittleness are wide of the mark, 316 is fairly ductile with the exception of poor quality castings or very work-hardened fabrications; and the issue of laterally loading the swivel joint during recovery over the roller is not a serious matter – even a poorly designed swivel of inferior material will handle these relatively small forces without problem.

Of course the pricing discrepancies between stainless and galvanized products of comparable strength/quality means that the stainless option is one of greatly reduced value to the vast majority of people. However some small components like shackles, and indeed swivels, remain affordable and stainless brings good advantages. Just make sure the quality is good!

Craig Smith

Of course it’s perfectly feasible to weld stainless, again it’s just a matter of quality. There was a Chicken Little piece published in a Caribbean centered magazine just recently where the author complained bitterly of a stainless steel chain failure, and screamed to high heaven about the need for everyone to learn from his tale of woe and avoid stainless or else…

His chain had failed where the weld of a link had totally vanished, probably as a result of sensitization from welding leading to what’s called inter-granular corrosion which essentially occurs because the all-important chromium in the stainless is depleted and permits subsequent rusting. The weld possibly also used the incorrect filler materials (the likely cause of such fast corrosion that you mention in your own example). Additionally welds must be properly passivated then cleaned. All of this is basic and standard and should not be an issue with any competent manufacturer. Basic rhetorical question: did the chain cost what it should have.

Near the end of the piece, it becomes clear that the author has no idea who manufactured the chain or where it came from. Ostensibly it was 316Ti, similar to 316L, but the veracity of this was not investigated.

Similarly, poor quality steel welding with pin-holing or the wrong materials can lead to problems with galvanizing and ultimate early failure. It is just a matter of having faith in the origin and quality of your gear.

Of course stainless is (or should be, as my much labored point boils down to) much more expensive, and obviously there’s little benefit to the vastly increased cost to the majority of boaters. If you can’t afford quality stainless, buying cheap junk is hardly an improvement over quality galvanized gear.

Mark Hoenke

I am not impressed with the usual (boat jewelry) swivels chandleries push at recreational boaters. My windlass has trouble with twist and the chain jumps in the wildcat so I needed to find a viable swivel. I looked for swivels where commercial operators shopped. What is needed is called a swivel forerunner.

http://www.google.com/search?q=anchor+forerunner&hl=en&rls=com.microsoft:en-us:IE-SearchBox&tbm=isch&tbo=u&source=univ&sa=X&ei=XigyUf-BFIWFyQHHioCQAQ&ved=0CD8QsAQ&biw=1144&bih=607

Wow – that’s a long link. A forerunner costs a lot less and is made down to about 7/16 as the smallest. Note that attached with a Kentor link, the swivel is some distance form the ancchor, as it should be. I am buying one this winter for my new Rocna 55. I was quoted 180 bucks galvanized.

John Court

Couldn’t agree more. I almost lost my anchor through the under-cap rail bow roller when the swivel just came undone as the anchor was being lowered. Luckily, the release from the chain allowed the anchor shank to rise and jam so my $1500 Manson Supreme anchor didn’t go overboard. A shackle is to be used from now on.

Nick Kats

This summer I visited many marinas in Spain & Portugal. Marinas are great a chance to eyeball other boats..

The anchor swivels, as photographed above, were common wherever I went. Perhaps half of all sailboats I saw had these particular swivels on their anchor chain.

In most cases the swivel was attached directly to the anchor.

In the few cases where a shackle separated the swivel from the anchor, the shackle was usually inferior, being of significantly smaller diameter, or of stainless steel. Often there was no mousing.

Whew! What can I say?

EW (Ted) Clucas

John ,
May have missed it in the reading : I do not see any mention of the old stand by
galvanized jaw- bow eye swivel ? They certainly appear more hardy . Have used one for a # of years . Your thoughts
Ted

Marc Dacey

John, while I can see your logic, would you make an exception for a stern anchor? A swivel in the sort of rough conditions (and laid out as you indicate) a stern anchor is typically deployed might reset that much quicker should the main anchor foul, drag or break out and/or its rode part. This is pure speculation on my part, but I can see where a stern anchor, were it forced to take the full load, would lurch about. A swivel might help a quick reset on a dark and stormy night.

Marc Dacey

OK, thanks, John. As I said, I was just mulling scenarios inspired by the sight of my Fortress at the stern, the rode coiled down into a bucket.

Marc Dacey

Understood, John. The guy who sells me coffee has sacks fit for purpose. I’ve been using them to cover over the kitchen chairs, but “rode sack” works, too. It’s only in a bucket because that keeps it tidy on deck. We’re not even anchoring regularly yet, and certainly not by the stern. Good tip, though.

Eric Klem

Hi Marc,

In addition to John’s good comment about stuffing the rode into a bag, there are a few other tricks worth knowing for how to deal with long, large diameter lines. Ballantine coils are an excellent way to make sure a line pays out correctly and what I use if I am expecting to need a line in a hurry but have the luxury of laying it out ahead of time. If you start with a coiled line and need it quickly, you can also just lay it out, loop by loop from the coil but walking the loops back towards you slowly so that it looks like a large coil lying down that has been spread out sideways a bit. I used to handle lots of very long, large lines and both of these tricks saved me many times. Whenever someone tried to cut a corner, they would end up with a ball of 400′ of line that could take 20+ minutes to untangle. I was always amazed at how many people didn’t know to throw the bitter end out of the way so that it couldn’t go through the center of the coil.

Eric

Marc Dacey

Good tips; thank you, Eric. We customarily lay out rode on deck first in loose “snake” fashion to check for kinks. It’s made possible by six-inch pipe rails to keep it there. I had to look up “Ballantine coil” and I’m glad I did. We typically Flemish coil our halyard tails, but this is a great idea for a long bit of rope rode.

Patrick Genovese

I am in the process of replacing my old 8mm chain with Grade 70 8mm chain but I am having a bear of a time trying to find a bow shackle that matches or exceeds the chain strength. The chain I am buying has a WLL of 1400KG and a BL of about 7000KG. Any suggestions on an appropriate bow shackle. ? The only thing that comes close is the Wichard range of Stainless Steel HR swivels that exceed the working load of the chain but have lower breaking loads. I would like to avoid Stainless Steel if possible.

Rolf

Hi John,

I am just in the process buying a new anchor chain (I chose Aqua7 high tensile chain). I am thinking about which shakle to use. I also found high tensile shakles called Green-Pin. I am wondering if I should use following configuration: Anchor->shakle 1 (eye to anchor)->shakle 2 (eye to bolt of shakle 1) -> chain to balance the loads when anchor is swinging in tidal waters. Or is it ok. to use this configuration: Anchor -> shakle (eye to anchor and bolt to chain) ->chain.
Thank you very much, and – your books are very interesting and helpful
Best regards
Rolf

Paulo Reisdorfer

Hi John,

This is my first message here on AAC, but I’ve been an avid reader of the your articles and learned so much from so many experienced contributors these past couple of years.
One question about linking chain to anchor:

You mention that it’s better to use a single shackle as described above. In one post from 2010 named “Two Crosby 209A shackles attach high tensile chain to the shank of the SPADE anchor on aluminum sailboat Morgan’s Cloud.” I see two back-to-back shackles between the chain and the anchor shank head. Which way would you say it’s a better way for the anchor-chain link? Deciding which way to go as I finally toss my swivel where it belongs…to the trash bin!

Thanks for the insight!

Ricardo.

Paulo Reisdorfer

Hi John,

Thanks for the reply. We have a Spade as well (thanks to all the knowlwdge I’ve read and gathered here before buying our first vessel). In 2 years never dragged an inch and only failed to set once.

Had up to F8 winds here at the Balearics 10 days ago and we were anchored on sand. Needless to say I slept like a baby. Next day Spade came out effortlessly after 48 hours of strong winds and a lot of swinging.

I’m ashamed to admit though that I’m only now getting rid of our swivel 🙁

So one shackle it is for us!

Cheers,

Ricardo.

Rolf

Hi John,

my decision in buying a chain is coming into the final steps and I have a question.

The chain will be delivered with a “high tensile” shakle from gunnebo-factory in sweden. http://www.toplicht.de/de/shop/anker-und-ketten/kette/kette-stahl-verzinkt/endglieder-fuer-die-ankerkette-aqua7
Breaking-load is 70 KN – same as the 8mm G70 maggi chain. So far so good.

I am a bit concerned about the two pins holding the bolt. I have written to gunnebo and asked if it’s reliable, but didn’t receive an answer yet.

Maybe securing the pins with loktite is advisable. What do you think?
Do you know these shakles?

Best regards
Rolf

Rolf

Hi John,

to me it also seems more safe using loctite.

But perhaps I have another solution and perhaps this is a good hint for european sailors.

I found titan shakles which with 10 mm bolt which have a breaking load of 6250 kg coming nearly into the range of G70 chain. I hope that 10mm shakle can be fitted to 8mm chain. But I think it should work.

Manufactored in Canada ;-))
http://titanmarineproducts.com/

Best regards
Rolf

Rolf

Hi John,

thank you very much for your answers.

The Aqua7-chain I am going to buy is a maggi chain.

Well, about the shakles I will have a look if I get a dealer Crosby or Acco here in Germany.

Otherwise I have chosen Green-PIN shakle but I will need that in 11 or better 13 mm to get the strength of the chain, which is a 8mm-chain. I hope that works.

Best regards
Rolf

Jeff Stander

Like John I always eschewed anchor swivels. They are a weak link. However, lately we have been anchoring for long periods of time and as the chain came aboard with lots of twist it was continuously jumping off the gypsy. So I decided to install the anchor swivel while we were in benign anchorages with the idea of removing it for voyaging.

What I noticed was that most of the photos of failed swivels showed them spread apart. Attaching a swivel directly to the anchor introduces a huge amount of side-loading. Side-loading is always a problem in equipment under tension; lack of articulation in standing rigging terminations is an example. The “fix” to attaching an anchor swivel, if you decide to use one, is to cut a length of chain (at least 4 links) to go between the anchor and the swivel.

Reading the comments above I saw links to a “kenter” and “swivel forerunner” which server the same function.

Jeff Stander
s/v Beatrix

Paulo Reisdorfer

Hi Jeff,

I’ve found this forerunner from a Dutch manufacturer:

http://akfanchorchain.com/products/chains-accessories/swivel-forerunner/

Although they call it a swivel, I think the name is a bit misleading as I don’t see it as a traditional swivel we are used to seeing.

So, I was wondering if having this forerunner with suitable D-shackles on both ends (anchor and chain) would “solve” the issue of having a swivel and at the same time avoiding possible (although rare) problems with chain twist?

Anyone has experience with this arrangement? Any real benefits to this added “complexity” to a system that should be as simple as possible?

Any thoughts John?

Cheers,

Ricardo.

Paulo Reisdorfer

Thanks for the feedback John.

I agree with you, your solution is safer and simpler, and I find there’s a certain elegance in simplicity.

I decided to go with the following Dutch-made Greenpin:

https://eurorope.nl/sales/shackles/green-pin/standard-shackles/bow-shackles-safety-bolt-g-4163/

Our specifically is the 1.5 WLL shackle with a safety bolt and a safety factor of X 6 giving us a 9t breaking load, which is more than sufficient for our 8t plastic vessel and it’s SPADE attached to a 10mm G40 chain.

Does this seem like a decent solution? Any suggestions are appreciated!

Cheers,

Ricardo.

Rob Ramsey

Hi John! Still being a newbie but reading the above might I suggest the Mantus swivel. Seems to tick all boxes ecxept SS. Might also be a solution for G70 chains having size trouble. And for those doing 360’s around their anchor.
https://www.mantusmarine.com/mantus-swivel/

Rob Ramsey

To add : they have the S2 swivel for 8mm G70 chain with a WLL of 4300 lbs and a safety factor of 5!

Kenneth McCallum

We’ve been using the Ultra Anchor swivel on our liveaboard yachts for the past eight years with excellent results, oversized swivels with oversized anchors… we sleep well at night. The Ultra swivel is actually stronger than the 12mm chain.