Is there a Quality Anchor Swivel?

[ErikFinn]

Is this one any good? Average? Below average? Above average?




Universal Anchor Swivel | Stainless Swivel | Suncor Stainless

[Dockhead]

Originally Posted by ErikFinn

Is this one any good? Average? Below average? Above average?




Universal Anchor Swivel | Stainless Swivel | Suncor Stainless

I've never seen one so can't really say.

The simple load bearing bolt in each pair of jaws is not a good design per Vyv Cox. All the ones he tested with this design, failed at that bolt.

However, the jaws look really massive, and that's really good.

I don't know how the swivel mechanism works so can't comment on that.

One big advantage this has over the PowerBall is that the joint flexes 90 degrees, so in a side pull you won't have that fulcrum effect tending to break the swivel neck. And the lever arm is really short. Those are good features.

[a64pilot]

I have a Suncor, it's now on my second anchor, although pretty much un-used, it has already gotten significant rust on it, which surprised me.
It is just as high price as the Mantus, and less than 1/4 the metal, no way could it be nearly as strong, but it is much smaller too so it easily fits through a roller, where the Mantus may not.
The jaws on mine, which was properly sized for a 5/16 chain, barely fits on my Rocna, it had to be forced on.
Weak link may be the pin that holds it together, and of course the jaws themselves, the screws that attach both ends rely only on Loctite to keep them in, they are counter sunk, so other than possibly peening them, only possible locking could be Loctite.


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[leftbrainstuff]

Originally Posted by bobconnie

Tryed all of them almost! never had a swivel hold up yet! I went back to the old way and will continue to use shackles for ever I guess! I trust the screw in pins and wire! I like to sleep !! and Ive had to dive to get my anchor back twice now from broken swivels, never again ! just my 2 cents

How did you attach your swivels?

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[Fuss]

Originally Posted by Dockhead

That rotation doesn't help you at all with a 90 degree pull -- which is the common way to break a shackle or spread the jaws of the anchor attachment -- anchor fouled in rocks. Look at the fulcrum formed by the edge of the socket, and look at the thin neck by which the ball is attached.

Sounds like great advertising copy! I am guessing you sell them.

Have you seen any side loading test data? Kong, for example, publish this for their swivels. If not, then how do you know it's stronger than any given other swivel, or shackle? The inherent advantage of a normal non-swiveling shackle is that it is almost impossible to side load it. But any swivel which is attached with jaws, creates a lever arm which can exert forces to spread open those jaws.

Here's a failed Kong swivel:

Attachment 122206

Which failed despite the much stronger construction (for side loads) than the PowerBall. This should illustrate how difficult it is to engineer a swivel which is adequately strong.

The PowerBall has one other weakness, which I didn't mention -- the loadbearing bolts are not fixed in anyway expcept by "potting" them in silicone. A J42 was lost a few years ago when the bolt fell out of the PowerBall swivel.

That is generally a bad way to do it, a weakness of the PowerBall design not only with respect to the risk of the bolt falling out, but also the strength of the link between the jaws:

Attachment 122207

Cox's commentary:

"The design shown on the left [as used in PowerBall, Ultra, etc.] 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 [Kong] uses forged lugs to carry chain load. The screw only clamps the components together. This design was found to be stronger."

Here's the diagram illustrating the point:

Attachment 122212

From Cox's useful article on his destructive testing of swivels and shackles:

https://coxengineering.sharepoint.co...onnectors.aspx


One simple way to solve this problem, is to not attach the swivel to the anchor at all. Put a couple of shackles and a short length of chain between the anchor and the jaws designed to take the anchor. In the fine print, this is what is actually recommended by WASI for the PowerBall, which begs the question why they made jaws for anchor attachment, and always show the swivel attached directly to the anchor in all their literature. Also in this case, the whole ball is superfluous.

Don't believe it, when someone tells you that any given swivel is "stronger than the chain". In side load, even the strongest swivel on the market, the Kong, is weaker than the chain. If you don't believe me, just ask yourself -- in how many cases of ground tackle failure you know, did the chain break when the swivel remain intact? The answer for most everyone is going to be zero point zero percent. In something approaching 100% of cases of ground tackle failure, it's a broken swivel, or a pin falling out of a shackle, which causes it. If you use a swivel, be sure to know that this is the weak point in your ground tackle, no matter how well you choose and implement the swivel, at least if you attach it directly to the anchor.

A few points about the Wasi Powerball to clear up some misinformation.

-They have grub screws to stop the bolts unscrewing. They are not held in place by silicone.

-The Kong is not a stronger construction than the Wasi.

-If you have a genuine bugel then you must use a Wasi Powerball as its part of the design. The connecting hole in the anchor is round not oblong. You cannot use a shackle.

-They do not spread the forks with a side load and you will never find a picture to post disproving this. When connected to a 23mm anchor shank then the shank will bend significantly with a large side load. The Wasi forks will not spread at all.

-There is no hard evidence that a Wasi ever broke...its always a story someone said.

-The Wasi is alot more than 6 years old.

- It has a Germanischer Lloyd certificate


And now a few points on swivels in general to clear up some misinformation.

-There are 2 types of swivels ... good ones and bad ones.
If you look around the boat yard you will see that maybe 80% of all swivels have splayed forks.... These are bad ones.

-Good swivels provide a strong way of connecting the anchor to the chain.

-In your local boatyard there is more chance of finding a good swivel than a good shackle. The boatyard supplied shackle will normally be weaker than the chain.
So good shackles and swivels normally require the sailor to do alot of forward planning and ordering else you are at the mercy of the boatyard solution.

[Dockhead]

Originally Posted by Fuss

A few points about the Wasi Powerball to clear up some misinformation.

-They have grub screws to stop the bolts unscrewing. They are not held in place by silicone.

-The Kong is not a stronger construction than the Wasi.

-If you have a genuine bugel then you must use a Wasi Powerball as its part of the design. The connecting hole in the anchor is round not oblong. You cannot use a shackle.

-They do not spread the forks with a side load and you will never find a picture to post disproving this. When connected to a 23mm anchor shank then the shank will bend significantly with a large side load. The Wasi forks will not spread at all.

-There is no hard evidence that a Wasi ever broke...its always a story someone said.

-The Wasi is alot more than 6 years old.

- It has a Germanischer Lloyd certificate


And now a few points on swivels in general to clear up some misinformation.

-There are 2 types of swivels ... good ones and bad ones.
If you look around the boat yard you will see that maybe 80% of all swivels have splayed forks.... These are bad ones.

-Good swivels provide a strong way of connecting the anchor to the chain.
-In your local boatyard there is more chance of finding a good swivel than a good shackle. The boatyard supplied shackle will normally be weaker than the chain.
So good shackles and swivels normally require the sailor to do alot of forward planning and ordering else you are at the mercy of the boatyard solution.

Again, we hear a naked assertion that the WASI is as strong as the Kong in a side load.

Could we have some facts, please, or is this assertion based on faith and true belief?

The WASI has a longer lever arm, acting on a much thinner structural element, with a sharp fulcrum to boot, so I do not believe this. Maybe if the swivel neck is made of super high strength alloy, it's possible to compensate for the inherent weakness of this construction. But if it's made of the same soft 316 stainless that the rest of the WASI is made of, then it is at least 3x or 4x weaker in a side load, than the Kong. 316 stainless has yield strength of only 290MPa.

[Fuss]

Originally Posted by Dockhead

Again, we hear a naked assertion that the WASI is as strong as the Kong in a side load.

Could we have some facts, please, or is this assertion based on faith and true belief?

The WASI has a longer lever arm, acting on a much thinner structural element, with a sharp fulcrum to boot, so I do not believe this. Maybe if the swivel neck is made of super high strength alloy, it's possible to compensate for the inherent weakness of this construction. But if it's made of the same soft 316 stainless that the rest of the WASI is made of, then it is at least 3x or 4x weaker in a side load, than the Kong. 316 stainless has yield strength of only 290MPa.

I have experience with the Wasi 13mm and bending anchor shanks.
The Wasi does not splay the forks as the anchor shank will bend first.
It is not a naked assertation.

I challenge anyone to post a picture of a Wasi with splayed forks.

Have you ever bent an anchor shank with a Kong or Wasi swivel attached?

If not then I don't understand you comments on this subject.

[Sandero]

Swivels may address some concerns about anchoring. I am not sure why they need to be at the anchor and not a few links or more away from the anchor. it seems to me that they would still perform as needed. But they swivel has to rotate and not the chain. That is the swivel should have low enough friction to allow the chain it connects to not twist tighter. Although twisted chain can be retrieved with a windlass... it ends up as a twisted mess inside the chain locker more often than not. If the twist is "driven" toward the anchor during retrieval... you might be about to remove it by letting the very twisted portion and hang in the water with the anchor free from the bottom... with the anchor's weight driving the untwisting. Maybe.

My boat experiences the twisting thing on the mooring as well... the boats relationship to the mooring is driven by tides, winds and wakes. This results too often in the two mooring painters wrapping around the mooring ball and getting themselves tightly knotted/wrapped. This is mostly caused by a lack of wind... which would typically cause the boat to pull against the mooring not dance around it. I am looking for a solution to this problem. Suggestions please!

[Dockhead]

Originally Posted by Sandero

Swivels may address some concerns about anchoring. I am not sure why they need to be at the anchor and not a few links or more away from the anchor. it seems to me that they would still perform as needed. But they swivel has to rotate and not the chain. That is the swivel should have low enough friction to allow the chain it connects to not twist tighter. Although twisted chain can be retrieved with a windlass... it ends up as a twisted mess inside the chain locker more often than not. If the twist is "driven" toward the anchor during retrieval... you might be about to remove it by letting the very twisted portion and hang in the water with the anchor free from the bottom... with the anchor's weight driving the untwisting. Maybe.

My boat experiences the twisting thing on the mooring as well... the boats relationship to the mooring is driven by tides, winds and wakes. This results too often in the two mooring painters wrapping around the mooring ball and getting themselves tightly knotted/wrapped. This is mostly caused by a lack of wind... which would typically cause the boat to pull against the mooring not dance around it. I am looking for a solution to this problem. Suggestions please!

If you put a few links of chain and a shackle between the anchor and your swivel, then you eliminate the side loading problem. In fact that is what WASI suggest doing in the fine print. I guess it's the best approach if it works on your boat.

The reason why people usually don't do this, is because the swivel is expected to perform as an anchor connector as well as a swivel. People often have a problem getting a properly sized shackle through their bow rollers.

Certainly I had this problem. I was able to solve it on my boat only by going to Wichard socket head shackles which don't have the protruding pin.

If you're going to have a few links of chain between a swivel and your anchor, then most of the swivels on the market are not really ideal for this, because one end of them is designed as an anchor connector.

[Dockhead]

Originally Posted by Fuss

I have experience with the Wasi 13mm and bending anchor shanks.
The Wasi does not splay the forks as the anchor shank will bend first.
It is not a naked assertation.

I challenge anyone to post a picture of a Wasi with splayed forks.

Have you ever bent an anchor shank with a Kong or Wasi swivel attached?

If not then I don't understand you comments on this subject.

You make it sound like bending anchor shafts is a good thing. It's certainly not a good thing. The risk of this happening is increased when you use a swivel like the WASI which makes a long lever arm to the end of the anchor shaft. It's like using a crow bar on the anchor shaft. It's an awfully expensive way to protect a poorly designed swivel from breaking. The Kong is better in this regard but not by much. The Mantus is completely superior with regard to this particular problem, because it will not lever the anchor shaft at all.

To say that the WASI is stronger in a side pull, you would need to show some facts. What you've seen and heard are only anecdotes. Kong publishes safe working loads for a side pull. That's an example of a fact.

Basic engineering principles such as lever arms and fulcrums say that the WASI, with a big lever arm acting on a skinny neck, with a fulcrum provided as if specially for beaking it, will be weak in a side pull. I would be open to change my mind about the strength in a side pull if someone would provide some actual facts contradicting the apparent engineering qualities of the device. Rather than anecdotes infused by faith and belief.

But strength in a side pull is only one of several problems with this swivel. I would certainly not have one on my boat. But then as I've said, I wouldn't have any swivel at all if I could possibly avoid it.

[leftbrainstuff]

Originally Posted by Spade Anchor

Have not seen any Kong data if you have some please send it to me or post it. I posted this picture earlier. As far as I know this is the only published data regarding braking strength for Wasi Powerball Swivel.

It's worth pointing out that the Wasi Powerball swivel has been on the market for over 6 years. I have seen many pictures of failed Kongs (one on this thread) and not one of a Wasi Powerball swivel. 0 returns or complaints in the past 4 years that we have been selling them. That is an awesome track record.

How many in use? What configurations? That is the type of data needed to validate your statement. Sales figures are not useful engineering data points.

I have a Wasi, unused, left onboard by the previous owner of our Liberty 458 with an 88# Rocna.

Without good empirical data it's not going to replace our current swivel. It's a very pretty piece of kit though. I've only seen swivels on boats that hardly ever anchor. My sample size is tiny and probably irrelevant.

Without going through the tedious process of calculating comparitive loads, stresses and failure modes one characteristic is clearly visible.

The chain component of our ground tackle is always able to align such that bending loads are removed. The chain links are loaded purely in double shear and axial tension. Each link is also loaded internally without any first order bending stress. This is the beauty and elegance of well engineered chains.

Any swivel which is loaded in bending is of great concern. Not just in terms of static load but more importantly in terms of fatigue. The swivel attachment via a short length of chain is a more desirable configuration.

Any miners law analysis, which includes the metalurgical, crack propagation and true stresses over time, will highlight how allowable bending stresses fall over time.

Static destructive testing only provides part of the picture. To truly understand the failure modes and true performance of components loaded in bending we need to conduct fatigue tests.

What is clear without any fatigue test data is that the failure stresses will be much lower than the static test data or calculations. Perhaps as low as 20% of the static calculation of stress using any of the simple calculations. (Often the case with rotating elements)

My hypothesis would be failure at or near maximum bending stress at approximately 40% of the calculated static stress value. It would be interesting to conduct some FEA analysis prior to physical fatigue tests. Physical tests would also require statistical validation. One fatigue test of each configuration is not sufficient. It will be very expensive.



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[leftbrainstuff]

Originally Posted by Dockhead

Again, we hear a naked assertion that the WASI is as strong as the Kong in a side load.

Could we have some facts, please, or is this assertion based on faith and true belief?

The WASI has a longer lever arm, acting on a much thinner structural element, with a sharp fulcrum to boot, so I do not believe this. Maybe if the swivel neck is made of super high strength alloy, it's possible to compensate for the inherent weakness of this construction. But if it's made of the same soft 316 stainless that the rest of the WASI is made of, then it is at least 3x or 4x weaker in a side load, than the Kong. 316 stainless has yield strength of only 290MPa.

Exotic materials are not going to provide a significant benefit in this situation.

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[Dockhead]

Originally Posted by leftbrainstuff

. . .

Without going through the tedious process of calculating comparitive loads, stresses and failure modes one characteristic is clearly visible.

The chain component of our ground tackle is always able to align such that bending loads are removed. The chain links are loaded purely in shear and axial tension. Each link is also loaded internally without any first order bending stress. This is the beauty and elegance of well engineered chains.

Any swivel which is loaded in bending is of great concern. Not just in terms of static load but more importantly in terms of fatigue.

Any miners law analysis, which includes the metalurgical, crack propagation and true stresses over time, will highlight how allowable bending stresses fall over time.. . .

A much more sophisticated analysis than what I was able to express.

The human eye, which feels structures and how they work, can perceive a great deal about what is weak and what is strong, but this puts real meat on those bones.

To summarize in layman's terms: you don't want long sticky-outy bits subject to getting levered, in a system like your ground tackle. Especially if the sticky-outy bit getting levered is skinny, and is made of soft crevice-corrosion prone 316 stainless. It's just wrong.

[leftbrainstuff]

Originally Posted by Dockhead

A much more sophisticated analysis than what I was able to express.

The human eye, which feels structures and how they work, can perceive a great deal about what is weak and what is strong, but this puts real meat on those bones.

To summarize in layman's terms: you don't want long sticky-outy bits subject to getting levered, in a system like your ground tackle. Especially if the sticky-outy bit getting levered is skinny, and is made of soft crevice-corrosion prone 316 stainless. It's just wrong.

+1

Sticky out bit is a great layman's term.

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[NewMoon]

Originally Posted by ErikFinn

Is this one any good? Average? Below average? Above average?




Universal Anchor Swivel | Stainless Swivel | Suncor Stainless

Our boat is 26' and 11,000 lb, 10kg Rocna, 42' 1/4" HT chain, 300' 1/2" three-strand nylon.

I installed one of these Suncor Universals two years ago, to address the rope and chain twist I experienced with my new Rocna anchor - the old Bruce never did that (despite the twisting, I still love my Rocna).

It does look and feel sturdy, considerably better than any other swivel I had seen before. The Kong swivel I had years ago started to bend from side loading, so I removed it.

The Suncor Universal has shown no sign of degradation through two summers of anchoring in SE Alaska. And it markedly reduced the twisting. Still, it makes me a bit nervous.

So, I have just received a new Mantus swivel. From the web site it looked like a good design, and in person it definitely seems very robust and trustworthy. It is big! Will be installing it shortly.