Is there a Quality Anchor Swivel?

[sailorboy1]

I kind of wish I hadn't even read this thread. I just went though the new chain/anchor/swivel thing recently and felt I made as good of decisions as reasonable.

Now I'm starting to question my choices which is in direct conflict of the goal of having faith in my anchoring system.

Then again I have a few months for some other stress topics to replace this in the back of my mind before boat splashing.

Far as the swivel strength. It doesn't matter unless it is less than some other part of the system. I think that maybe the weakest part my system may be the boats' deck, don't know how I feel about this.

[Dockhead]

Originally Posted by Lagoon4us

Andrew do you have any data on failure of chains and kit to support this high winded technical opinion?

Do you consider just how many boats in this world are anchored right now? I don't see any drifting around me with anchorless chains hanging over the side.

Sorry i'm not having a go at you but fair dinkum mate?..

Andrew can answer for himself of course, but I think that it should be said that some kind of failure of ground tackle or anchoring mishap is probably the number one cause of destroyed sailboats, and so naturally a lot of us obsess over the right gear and technique.

Swivels and shackles are probably the number one failure point in the system. Everyone is entitled to his own opinion, but I would not use a swivel with load-bearing bolts in it, like this one:



attached directly to the shank of my anchor. The photo is from: Problems With Marine Anchor Swivels.

This conclusion is also supported by Vyv Cox's actual testing, here:

Connectors

He says:



"The design shown on the left relies on concentric screws to carry chain loads. This is the weakest link in the component: always the failure point. The design on the right uses forged lugs to carry chain load. The screw only clamps the components together. This design was found to be stronger."
Connectors

This is supported by other testing which shows that the Kong and Osculati swivels which don't have the load-bearing bolts are much stronger than other types, especially in a side pull.

Some people condemn swivels entirely (the Morgan's Cloud guy) and some other people condemn using swivels connected directly to anchors (Bash and others here). I am not as conservative, personally. I think a Kong or Osculati swivel directly mounted to the anchor is ok if the side load rating is in accord with the rest of the ground tackle's strength. But that's just my personal opinion.

But I think it is absolutely not a "how many angels can dance on the head of a pin" question -- your boat's safety depends on it. Yes, boats are wrecked all the time because of broken swivels and shackles. That is a highly stressed and critical component.

[Dockhead]

Originally Posted by Don Lucas

I kind of wish I hadn't even read this thread. I just went though the new chain/anchor/swivel thing recently and felt I made as good of decisions as reasonable.

Now I'm starting to question my choices which is in direct conflict of the goal of having faith in my anchoring system.

Then again I have a few months for some other stress topics to replace this in the back of my mind before boat splashing.

Far as the swivel strength. It doesn't matter unless it is less than some other part of the system. I think that maybe the weakest part my system may be the boats' deck, don't know how I feel about this.

LOL!

I think obsessive compulsive behavior where anchoring is concerned is probably rational

You are smart to think about the deck. I worried about that, too. I had been using my forward cleats, which are pretty massive, but I was belaying the chain with a nylon strop which was much less strong than the chain, plus there was an angle to the pull, chafe, not good. So I re-did that in the summer -- now I have a stainless steel chain shackled to my inner forestay chain plate with a fair lead to the anchor chain and a forged chain hook. My chainplates are super massive and this one is attached to a massive crash bulkhead between the forepeak and main cabin. That's better, but there are still some elements of the system which are not as strong as the chain, so I will need to work on it some more.

How do you belay your chain?

[sailorboy1]

Originally Posted by Dockhead

Attachment 52263

attached directly to the shank of my anchor. The photo is from: Problems With Marine Anchor Swivels.

I have 1 of those Kong swivels. Just installing it should make a user not believe you could side load. I have not concern or question that the pin and body has good strength against shear in a straight axis pull. But thinking that threads on the bot have much strength is foolish.

I can not remember for sure but I seem to recall that the installation instructions tell you to use a shackle between it and the anchor.

I have 2 shackles between mine and the anchor, because I needed to step down due to the oversize anchor. Unless the thing got jammed into a rock of something it never could have a side load of concern.

[Dockhead]

Originally Posted by Don Lucas

I have 1 of those Kong swivels. Just installing it should make a user not believe you could side load. I have not concern or question that the pin and body has good strength against shear in a straight axis pull. But thinking that threads on the bot have much strength is foolish.

I can not remember for sure but I seem to recall that the installation instructions tell you to use a shackle between it and the anchor.

I have 2 shackles between mine and the anchor, because I needed to step down due to the oversize anchor. Unless the thing got jammed into a rock of something it never could have a side load of concern.

In my opinion, for whatever it is worth, you are ok there.

The Kong swivel is the one on the right in Vyv Cox's photo. It has forged lugs to take the chain load. The bolt does not carry those loads, it just keeps the swivelling halves together. The bolt does not carry any of the lug loads because that locks together itself.

To my mind, that is the far superior design for a swivel. Kong is a good company which makes climbing gear and so has the right kind of life-and-death process control and quality control. They specifically certify their swivels for side loads, so you can check whether the parameters are in line with the rest of your ground tackle.

There is a lot of good info here: http://www.kong.it/doc/KONG_SWIVEL_ANCHOR_CONNECTOR.pdf

Of course if you can get a plain bow shackle and/or a few links of chain between your anchor and the swivel, it's that much safer.

But you shouldn't underestimate side loads -- shattering side loads can be exerted when yawing in a storm. That's how swivels get broken. You've got a pretty long lever arm which multiplies the force. The swivel needs to be really massive if you're going to expect it to handle those. The Kong is the only one I've seen that looks up to that job, to my eyes. It is said that the Osculati is equally strong.

And even with the Kong there are reports of failures and wrecked boats, so you need to be careful in any case.

[Lagoon4us]

Originally Posted by Dockhead

Andrew can answer for himself of course, but I think that it should be said that some kind of failure of ground tackle or anchoring mishap is probably the number one cause of destroyed sailboats, and so naturally a lot of us obsess over the right gear and technique.

Swivels and shackles are probably the number one failure point in the system. Everyone is entitled to his own opinion, but I would not use a swivel with load-bearing bolts in it, like this one:

Attachment 52263

attached directly to the shank of my anchor. The photo is from: Problems With Marine Anchor Swivels.

This conclusion is also supported by Vyv Cox's actual testing, here:

Connectors

He says:

Attachment 52264

"The design shown on the left relies on concentric screws to carry chain loads. This is the weakest link in the component: always the failure point. The design on the right uses forged lugs to carry chain load. The screw only clamps the components together. This design was found to be stronger."
Connectors

This is supported by other testing which shows that the Kong and Osculati swivels which don't have the load-bearing bolts are much stronger than other types, especially in a side pull.

Some people condemn swivels entirely (the Morgan's Cloud guy) and some other people condemn using swivels connected directly to anchors (Bash and others here). I am not as conservative, personally. I think a Kong or Osculati swivel directly mounted to the anchor is ok if the side load rating is in accord with the rest of the ground tackle's strength. But that's just my personal opinion.

But I think it is absolutely not a "how many angels can dance on the head of a pin" question -- your boat's safety depends on it. Yes, boats are wrecked all the time because of broken swivels and shackles. That is a highly stressed and critical component.

This swivel is a toy compared with a Wasi, Ultra etc, i have one on board that came with the boat, it's not as bad as this pic but the sides have bent nonetheless.

This is why we went the Ultra route, there was also a sophisticated Anchor watch which has a transponder that relays an alarm if the anchor comes unstuck.

The bronze unit also connected to the shank BUT had the same side cheeks that can fail under side load, ciao to that piece of equipment as well....

Don't get me wrong i accept criticism of products if it's warranted and justified. I would like to know details of failures when considering any bit of new kit BUT not just blanket negative opinion without basis.

The common SS cheeked units are dodgy at best however if not mounted directly to the anchor shank they would likely succeed in straight line and angular pull nicely but they just don't cut it on Ultimate failure values.

Loading comes back to cleats, bitts or pad eyes/eyebolts and i agree that is where the weak link exists and that's most desirable considering the possibilities.

Cheers.

[River Cruiser]

After reading thoroughly all replies that had bearing on my question, and the others that had information to consider I purchased a Kong swivel. The clevis with the Allen pin will be on my list if I ever buy another clevis, it was my 2nd choice, thanks to everyone who took the time share your opinions.

[Andrew Troup]

Originally Posted by Lagoon4us

As a general and very crude rule, higher tensile materials tend to fail by pulling planes of atoms apart (ie brittle failure) rather than sliding them across each other (ie ductile failure) which is more often the case for 'weaker' materials.

Naturally the former tends to happen suddenly and unexpectedly, and most materials prone to this failure mode are adversely affected by immersion in electrolytes, especially containing chlorides and the like.

Can't win SS is too soft and Hi-Tensile too tough! At least negatives are balanced between posters!!!!

Actually you have my input exactly backwards. I'm not saying Hi-Tensile is tough. Under certain circumstances, I'm saying it might not be tough enough.

Toughness and high tensile strength are not positively linked. Usually the opposite is true.

Toughness measures the ability to absorb suddenly applied force without failure.

Wood is incredibly tough but not particularly strong (It is particularly stiff, kilo for kilo, but that's an independent variable)

Glass is very strong but not at all tough, unless specially treated.

Brittle materials are usually strong

Ductile materials (like mild steel, copper and to a lesser extent 300 series SS alloys) are usually tough.

17-4PH is a miraculous material, one of my favourites. It's remarkably strong, machines beautifully, and the heat treatment to achieve a high tensile strength consists of heating it to a conveniently low and not at all fussy temperature (no distortion, no expensive atmosphere controlled furnaces, no risk of cracking) and holding it there for at least long enough, more or less. (To anyone used to heat-treating high-tensile steels, this characteristic seems too good to be true the first time they come across it)

But I wouldn't ever use it where it doesn't have regular access to oxygen, preferably every few minutes, but certainly every few hours. If this limitation is respected, corrosion resistance is formidable.

The risk in the case where the period is days might be too small to quantify, but I'm a simple engineer, not an economist or a marketer.

I don't see the point using a wonderful material in circumstances where its only deficiency is constantly being probed. The resultant corrosion can happen largely internally, leading to catastrophic failure under much reduced loads. It's nothing like corrosion wasting from the surface that we're used to with the usual run of ferrous metals.

- - - -

"High test" chain is a relative newcomer. Many early adopters are likely to be knowledgeable enough to replace it regularly. Some of those less knowledgeable may only anchor infrequently. And only certain marginal and rare conditions will expose the chain's limitations.

I don't find the "where are all the broken chains?" argument convincing, but not just for these reasons.

"Show me the data" is particularly ill-suited, it seems to me, for stealthy onset problems, and/or low probability/highly consequential problems.

Think of fibreglass osmosis - for twenty years, people were saying "I don't know anybody with boatpox; this is a made-up story, a mass neurosis"

And how many nuclear reactors have been knocked out by tsunami? Does that mean it won't happen?

- - - - -

What is incontestable is that regalvanising high-tensile chain is a bad idea unless the cleaning step is done by grit blasting.

If you're fortunate enough to find a galvaniser who is equipped to and will consent do this to chain to "white metal" stage (on all facets of every link), and then dip it with no delay, in addition to the PITA process of removing it from the molten zinc in such a way that no link adheres to its neighbour, and without rubbing off the zinc*, you would be well advised to marry him or her, I reckon.


*(neither of which are straightforward, and doing both at once to the required level of thoroughness is downright difficult)

[Dockhead]

Originally Posted by Lagoon4us

This swivel is a toy compared with a Wasi, Ultra etc, i have one on board that came with the boat, it's not as bad as this pic but the sides have bent nonetheless.

This is why we went the Ultra route, there was also a sophisticated Anchor watch which has a transponder that relays an alarm if the anchor comes unstuck.

The bronze unit also connected to the shank BUT had the same side cheeks that can fail under side load, ciao to that piece of equipment as well....

Don't get me wrong i accept criticism of products if it's warranted and justified. I would like to know details of failures when considering any bit of new kit BUT not just blanket negative opinion without basis.

The common SS cheeked units are dodgy at best however if not mounted directly to the anchor shank they would likely succeed in straight line and angular pull nicely but they just don't cut it on Ultimate failure values.

Loading comes back to cleats, bitts or pad eyes/eyebolts and i agree that is where the weak link exists and that's most desirable considering the possibilities.

Cheers.

Well, I'm not bashing your choice -- you're entitled to your opinion, and only you are responsible for the safety of your boat. We all have our own way of analyzing how strong we think something like this will be. You have yours, and I have mine.

I don't like the Ultra swivel -- which is just my personal opinion maybe not worth much -- for a few reasons which seem to me to be objective. First of all, it has load-bearing bolts which have been identified by real destructive testing to be the main failure point of swivels. It seems to me an inferior engineering solution to the lugs of the Kong swivel, and this opinion is shared by Vyv Cox, who is a real engineer who did real testing, by Craig Smith, and by many others. I also don't like the 28 degree ball type swivel which seems to me to add length to the assembly, increasing the lever arm and so breaking force in a side pull, without providing any benefit. That relatively thin neck which connects the ball to the rest of the Ultra swivel looks like a weak point to me, and one which serves no useful purpose. Lastly, the provenance of the Ultra swivel is not encouraging to me -- they are produced by an unknown Turkish company with no experience, that I have been able to find out about, in the lifting or climbing worlds, and no qualifications, that I can find, in the rigorous and very specialized quality control procedures used for forging metal parts like this whose integrity may be matter of life and death. This is in contrast to companies like Wichard, Crosby and Kong. A large number of Ultra swivels were sold which were produced by casting and which turned out to be disastrously unsafe. To the credit of the American company who sells them under their stencil brand, Quickline, these were all recalled and replaced with stronger machined ones. But such a thing would never happen in the first place with a company which sells parts into the lifting or climbing industries because it is impossible with the type of testing and quality control used in those industries. It does not inspire confidence.

But again, that is just my own personal opinion, and everyone is entitled to a different one. I don't claim to be professional metallurgical engineer or to have any other great qualifications here; I'm just a cruiser like the rest of you.

The Kong swivels also have cases of documented failures, and they have a known propensity for the jaws to splay over time. So although I think they are the best ones, I think they also have to be watched carefully and have to be replaced regularly, especially if they are attached directly to the anchor shank.

There is no ideal swivel, and I'm glad, personally, that I have now managed to set up my ground tackle without any swivel at all. They are an inherent danger point, especially if attached directly to the anchor shank.

[Lagoon4us]

Can you provide the links where currently available ULTRA Swivels have been tested and failed below their respective SWL's please.

'Tis interesting all toggles on most rigging rely on a loose pin in side load with 3mm cheeks held together via a split pin, our jumper struts to our prodders take misaligned loads every day without failure.

Our ULTRA swivel has a 16 Tonne SWL that far surpasses any shackle we could ever fit.

Our decision is not taken lightly and i don't simply run on opinions, if i can see failures i will take ULTRA to task in person.

Cheers.

[Al Mc]

I just bought an ultra anchour and and ultra swivel, amazing, never gets hooked up.

[congo]

Hi Lagoon4

Rex here from Anchor Right Australia, swivels regardless of brand and stregnth they are all proan to whare, the load bearing that is rated on a swivel from new will reduce from day one that you employ it.

All recognized tested then rated lifting equipment such as shackles chain excetra must be retested every twelve months when in use for over head lifting equipment, to be sure you would need to test also your swivel every twelve months, as you have stated the cost is an appittence to what your boat is worth.

You say your swivel has been tested, ask to see these tests, by whom were they tested, these tests should have also been whittnessed,what grade of stailess, ring a boat survey officer for advice on shackels if you really want to be sure of what you are being told.

The best and most reliable swivel are the old back to back D shackle shape, easy to inspect for whare and can be replaced at a pittence of the cost of a stainless, further stainless does not like impact, we have had a number of customers loosing there anchors upon retrievel over the bow roller, the stainless swivel has snapped only to see theire anchor dissapear.

And yes its great to see most of you have learnt that fitting a swivel direct to the shank of an anchor does not work, not only does fitting a shackle direct to the anchors shank interfere with its performance but will snap swivells of regardless of how strong they are, all swivells must be able to articulate to a straight line pull.

Furhter why build strenght into an anchor if the customer is going to fit a weak link. If you can get away withpout a swivell then by all means do so.

Just my opinion.
Regards.
Rex CEO of Anchor Right Australia.

[Lagoon4us]

Originally Posted by congo

Hi Lagoon4

Rex here from Anchor Right Australia, swivels regardless of brand and stregnth they are all proan to whare, the load bearing that is rated on a swivel from new will reduce from day one that you employ it.

All recognized tested then rated lifting equipment such as shackles chain excetra must be retested every twelve months when in use for over head lifting equipment, to be sure you would need to test also your swivel every twelve months, as you have stated the cost is an appittence to what your boat is worth.

You say your swivel has been tested, ask to see these tests, by whom were they tested, these tests should have also been whittnessed,what grade of stailess, ring a boat survey officer for advice on shackels if you really want to be sure of what you are being told.

The best and most reliable swivel are the old back to back D shackle shape, easy to inspect for whare and can be replaced at a pittence of the cost of a stainless, further stainless does not like impact, we have had a number of customers loosing there anchors upon retrievel over the bow roller, the stainless swivel has snapped only to see theire anchor dissapear.

And yes its great to see most of you have learnt that fitting a swivel direct to the shank of an anchor does not work, not only does fitting a shackle direct to the anchors shank interfere with its performance but will snap swivells of regardless of how strong they are, all swivells must be able to articulate to a straight line pull.

Furhter why build strenght into an anchor if the customer is going to fit a weak link. If you can get away withpout a swivell then by all means do so.

Just my opinion.
Regards.
Rex CEO of Anchor Right Australia.

I have no doubts and no questions regarding our chosen equipment, more the point we added a swivel and would not be without one, the anchor sets far quicker in weedy conditions which is very common over here.

My own accreditation, background and experience suffices.

Cheers

[congo]

Hi Lagoon4,

Really sorry if Ihave offended, just commenting on over twenty years of experience, sometimes I suppose one should keep there oppinions to themselves.

My opinion and comments were not aimed percifically at yourself as there are many opinions in this thread, it was for the bennefit of all sharing there experiences, opinions, this is what these forums offer to all, more importantly they supply a host of experience to all new commers in the boating world of whom I do believe would really appereciate it, they are free to believe or not.

There is only one person that has to be happy with your set up and clearly you are, so Iam happy for you.

Regards Rex

[Lagoon4us]

Absolutely none taken, you made me remember the charters last summer in Croatia slamming their anchors into the Cats forebeam.

We were leaving KRKA National Park the wife was dangling the anchor at water level
to clean the mud and weed off, a nearby charterer came over waving at us screaming you've forgotten to raise your anchor totally!!!!

Cheers