Do I need a Swivel on my Anchor?

[colemj]

Originally Posted by four winds

In the first photo, the threads are sheared off.

Just pointing that out if others are interested. I don't know swivel from shinola.

If you are talking about the first picture that Jon posted of the failed Kong, those are not sheared threads. That swivel is missing 1/2 of its 2-part assembly. The only way for it to fail like this is for the non-loaded assembly screw to back out of its top assembly. This screw should have been set in Loctite as per instructions.

If you read the COX report posted earlier, it discusses the different ways that swivels are connected, and points out the superiority of the Kong-type method of attachment, which does not rely on a threaded screw.

The Kong, Wasi and Ultra swivels are of much higher quality and different design/construction than all the other common cheaper swivels. This is the first Kong I have ever seen or heard fail, and the failure mode appears to be human error. I have never seen or heard of a Wasi or Ultra failure.

Mark

[sailorboy1]

I've never really understood the hate that some appear to have for swivels. It's really pretty simple:

- get the right size to match the strength of the rest of the gear
- install it correctly

If you don't and it breaks, don't blame the swivel.

[estarzinger]

I'm just looking at the Ultra details.

They claim their swivel is "designed to take side load up to the breaking strength of the Swivel".

However, they do not show any particular evidence of testing or test data to support that claim.

They do show a single test certificate for their 10-13mm swivel, which is listed with a 17510kg breaking strength, for an 8000kg 'proof test' (from a turkish test company), which means a straight line, purely static test at (a bit less than) half breaking strength. That is rather a far cry from full breaking strength, dynamic/shock loaded, side loaded tests of their entire product range. It may all be just fine, but the Rocna experience, and the experience with other well built fork designed, causes one to be particularly suspect of unbacked claims like this.

[colemj]

Originally Posted by estarzinger

but the Rocna experience

What was the "Rocna experience"?

Mark

[estarzinger]

Originally Posted by colemj

What was the "Rocna experience"?
Mark

Claimed to have certified test data to support strength claims. Turned out to be mostly either misleading or flat out lies.

[Kenomac]

Originally Posted by estarzinger

I'm just looking at the Ultra details.

They claim their swivel is "designed to take side load up to the breaking strength of the Swivel".

However, they do not show any particular evidence of testing or test data to support that claim.

They do show a single test certificate for their 10-13mm swivel, which is listed with a 17510kg breaking strength, for an 8000kg 'proof test' (from a turkish test company), which means a straight line, purely static test at (a bit less than) half breaking strength. That is rather a far cry from full breaking strength, dynamic/shock loaded, side loaded tests of their entire product range. It may all be just fine, but the Rocna experience, and the experience with other well built fork designed, causes one to be particularly suspect of unbacked claims like this.

Turkey, is not.... China. Lots of nice products coming out of Turkey.

Rocna=China. Ultra=Turkey. Not the same at all.

There are nice, high quality products built outside the USA. Germany, England, Italy, Poland, Japan... Just to name a few, and yes... Turkey.

[colemj]

Originally Posted by estarzinger

Claimed to have certified test data to support strength claims. Turned out to be mostly either misleading or flat out lies.

Thanks - I thought there was a swivel failure incident involving them that I missed.

Mark

[estarzinger]

Originally Posted by Kenomac

Turkey, is not.... China. Lots of nice products coming out of Turkey.

Rocna=China. Ultra=Turkey. Not the same at all.

There are nice, high quality products built outside the USA. Germany, England, Italy, Poland, Japan... Just to name a few, and yes... Turkey.

My point was they do not support their claims.

There are also nice well built products coming out of China. And some crap made in USA, Germany, etc. It's not about country of origin, it's about proper design, specification and testing.

The product may well be terrific, but we can't know because they don't support their claim . . . and personally if your objective is to orient the anchor I believe the twist approach is a much better design solution than the fork direct attach to shank swivel.

[TheThunderbird]

Kong is good to prevent only twisting.

To avoid the anchor coming up upside down, you need a swivel with a DOUBLE JOINT, NOT A SINGLE ONE.

PRICE goes up from 230 to 330eur then

[Jon Eisberg]

Originally Posted by estarzinger

^^ it is interesting that the ultra swivel fork is attached directly to the anchor shank, which is generally viewed as a "no no" (possible side loading on the fork), but it is (I think) the only way to make this sort of swivel flip the anchor.

In my estimation, the design of that and other similar swivels could be improved immeasurably, with a very simple modification...

Instead of using a fork and pin, turn the body into more of a straight toggle, then make the connection to the hook with a bow shackle, running the pin thru the swivel, instead of the shank...

Walking the docks, it's astonishing how many are relying on ground tackle setups that pass a shackle or swivel pin thru the shank... I was just browsing the latest issue of PRACTICAL SAILOR the other day during a quick run to WM, where they did some testing on anchor shackles... Didn't read it in full, but one takeaway from a quick scan was the mention that the overwhelming percentage of shackle failures involve that of the pin, as opposed to the body of the shackle... why anyone would want to subject their pins to any additional or eccentric loads beyond that of a straight pull, is a mystery to me...

Just one more opinion, from a Certified Non-Engineer...

;-)

[Bulawayo]

Originally Posted by nigel1

Just for interest on the subject of swivels

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

Hmmmm......we always use a bow shackle to prevent such an occurance.

[Bulawayo]

Originally Posted by Jon Eisberg

You might want to keep a close eye on that swivel of yours (X-Ray vision might help ;-))... Sure didn't take a hurricane to cause this one to fail...

Not sure it would have made any difference had it been properly affixed to the shank to begin with, either...

Latitude 38 - 'Lectronic Latitude





And to the OP, your new anchor will be identical to mine, which can be manhandled if need be without too much fuss... In that case, Just Say No to Swivels...

;-)

Add a bow shackle at the very least.

[CruisingKitty]

We are not proponents of swivels having seen too many failures. But, if you must choose a swivel to correct orientation of your anchor, the Ultra swivel is the most impressive. It reverts the anchor to the correct orientation well before it hits the bow roller. And it is very well made with no hidden parts.

If you use any other swivel, don't connect it directly to the anchor. Use a piece of chain between the anchor and the swivel to reduce lateral force.

We've written about our experience with swivels here: To Swivel or to Twist, That is The Question

[hoppy]

I'd never used a swivel until I bought a bowsprit with an integrated anchor roller. I found out the hard way that the Ubolt on my anchor would not go through the bowsprits roller.

Luckily the local chandleries had the Kong swivel which seems to be stronger than my grade 70 chain but after seeing that the Ultra swivel is even stronger, I might look at an upgrade

[four winds]

Hey Mark. I'm often confused so to clarify this is the picture to which I referred. Zooming in on the threads it appears that only the base of the threads remain. Looking at the two sunlight reflections they extend across evenly and completely. I see no peaks on the threads. Of course I could be wrong. But a sideloaded failure could have this symptom along with the forks deformation.

Originally Posted by colemj

If you are talking about the first picture that Jon posted of the failed Kong, those are not sheared threads. That swivel is missing 1/2 of its 2-part assembly. The only way for it to fail like this is for the non-loaded assembly screw to back out of its top assembly. This screw should have been set in Loctite as per instructions.

If you read the COX report posted earlier, it discusses the different ways that swivels are connected, and points out the superiority of the Kong-type method of attachment, which does not rely on a threaded screw.

The Kong, Wasi and Ultra swivels are of much higher quality and different design/construction than all the other common cheaper swivels. This is the first Kong I have ever seen or heard fail, and the failure mode appears to be human error. I have never seen or heard of a Wasi or Ultra failure.

Mark