Anchor Swivel Really Needed?

[Paul L]

Originally Posted by daletournier

Have a look at a Mantus swivel and explain to me how it is weaker than the chain it's connected to to, seriously, I'd like to know because from what I see it just can't be. What am I missing, please explain.

Here's Mantus comment on working load.

The Strongest Link in Your Chain
The strongest link – Mantus swivel is stronger than its corresponding Grade 40 chain. (WLL is 1/5 UBS)

Integrated shackle design completely eliminates side loading making this the safest swivel on the market.

The pin on the chain side of the swivel is the strength limiting part since the geometry of the chain determines the pin size. Mantus swivel is the first to feature an oblong pin to maximizes the pin strength, with the aid of computer modeling and physical testing we truly created a swivel that is the strongest link.

[groundtackle]

Ranger and others, I really don’t want to start a fight with pics but happy to carefully discuss. Ultra for example is a great anchor but an Excel has some additional features like its cleaner and sharper for exactly the same price in stainless. I’d like to be able to say things like that on this forum without starting fires.
Their swivels are quality a product. Let’s just take the advertised specs on a UFS 08-21 for 5/16” chain. Ultimate breaking load is 12,740lbs and they don’t list WLL. 5/16” G43 UBL is 11700lbs. WLL is 1/3 - 3900lbs as per the required specs. Specs require it to withstand any breakage or deformation for any component of that swivel when side loaded or any odd load of 11699lbs. I don’t have the proof load in front of me for the chain, maybe some else out does. Go for the larger UFS if you like but it’s UBS is 20,400, those are big numbers. The swivel must in my opinion reach or exceed all the RF-271-F specs. I know it won’t do it because I’ve seen them broken on numerous occasions without any chain or shackle deformation. I also bench broke one for fun. Adding short chain in between shank and swivel is a very good idea that helps enormously to achieve the WLL.
A problem I have is seeing the actual testing documentation and procedures, they are strict. Most manufacturers won’t release that information that should be public knowledge. I know Greg and all folks at Mantus well, great bunch of folks. As a result of this thread I’ve requested his documentation today and I’m sure he will release. Any chain manufacturer will also release on request or they basically cannot sell to certain customers. If the numbers are good then I’ll recommend or endorse.
If you have a problem with anchors coming up inverted then check out our Flip Link from Anchor Right Aus. It’s tested and I’ve got the paperwork to show you. Simple, works every time and doesn’t stop the anchor from achieving its maximum diving potential. Bulk at the shank is a factor.
Chris

[groundtackle]

Paul, I rest my case. 5-1
Chris

[boom23]

The Ultra swivel has been RINA tested and certified. The documents are on the Ultra website.

The Ultra swivel (I am using) has a breaking load of almost twice the G40 chain ultimate breaking strength. I understand about side loading failure but anything, even the anchor, can fail with excessive side loading.

The Mantus swivel breaking load exceeds the G40 chain ultimate breaking strength and it looks almost impossible to side load if installed correctly.

I understand that nothing is perfect, and that everything is a compromise. I am sticking with my oversized Ultra anchor and swivel setup and I will keep monitoring the swivel for any signs of stress. If I see anything wrong, I will inform the company and switch to the Mantus swivel.

[groundtackle]

I’m not saying any of this equipment is bad or inferior. I’m just saying it doesn’t meet speciations.
I’m sure it will be just fine.
Chris

[Paul L]

Originally Posted by groundtackle

Paul, I rest my case. 5-1
Chris

Don't get it. They are defining working load as 1/5 breaking strength, is that what you are commenting on? The S2 size for 5/16 to 3/8 chain is ubs21,000 and wll4,300.

[contrail]

I have never used a swivel, over several decades of anchoring. When my anchor comes up inverted, I just let it hang a bit under the surface and back up a couple feet. That has ALWAYS flipped it back, at which point I finish raising it.

[Dockhead]

Originally Posted by contrail

I have never used a swivel, over several decades of anchoring. When my anchor comes up inverted, I just let it hang a bit under the surface and back up a couple feet. That has ALWAYS flipped it back, at which point I finish raising it.

Over several decades of anchoring, my experiences MOSTLY parallel yours.


But this all works great -- until it doesn't. Some years ago I had a 121 pound Rocna which would NOT come up the right way, no matter what I did with it. It seemed to me that it was just balanced to come up backwards, or something. I soon added the jumbo Kong swivel, which STILL did not induce the anchor to come up the right way, but at least I could turn it around with a boathook. But the swivel was so large that it snagged in the bow roller


All this was such a faff that after a couple of years of messing with it, I changed the anchor to a Spade, which does not require a swivel, like previous anchors (Delta, CQR, Bruce, etc.). I believe balance has a lot to do with it.


I don't understand why we insist on side loading our swivels. Surely nothing good can come from that, even if the swivel is strong enough. I bent the shank of my Rocna with the Kong swivel -- it adds leverage.


There is no reason in the world to mount the swivel directly on the anchor, that I can see, other than the convenience of not having to arrange the extra short link of chain and shackle. This seems like pure laziness to me. Once you've taken the trouble to do it right, and get the swivel off the end of the anchor, then the swivel is much less challenged from an engineering point of view (and stops challenging the anchor shank), so this is already not a big deal.


The Mantus swivel has this feature built in, and seems to me to be a totally superior approach. The Kong swivel is OK, proof tested, made by a respectable engineering firm from the mountaineering sector (and not in a garage in Turkey), but requires the extra length of chain plus shackle (interesting that Kong provide side loading strength data, I guess winking at people mounting them directly to the anchor, while pro forma instructing people not to do that ). I do not at all like the WASI/Ultra design with the skinny neck and narrow angle of motion to the ball joint. What in the world is the purpose of that? It doesn't move enough to provide an actual articulation at the ball joint, but will be hugely stressed at the limit of motion, plus the whole thing is so long that it will significantly increase leverage on the anchor shaft. It looks singularly ill-conceived to my eyes.



ALL JMHO -- carry on.

[Kenomac]

Originally Posted by groundtackle

Kenomac, I’m at the Seattle boat show E820 if you’d like to talk about it in person.
I’d like to properly post with my viewpoint but just don’t have time at the moment.
Vancouver boat show is next.
It’s a very interesting subject that we should all learn a little more about.
Check out RF-271-F for all chain specs. Everything I do is typically based around G43 chain or whatever chain you happen to use. If it meets or exceeds those WLL, proof and ultimate breaking strengths then I’m satisfied to endorse. If it doesn’t I will tell you.
Ask me a question in detail and find the answer if even to educate myself.
Chris

Why would I fly to Seattle to discuss this matter in person, especially since we've been using the Ultra swivel for over 7 years without even a minor issue? I don't believe you have the photographic proof of failure you claim to have regarding the Ultra swivel. Please post it if you do have it or stop making your claims of failure.

[ranger58sb]

Originally Posted by groundtackle

Their [Excel?] swivels are quality a product. Let’s just take the advertised specs on a UFS 08-21 for 5/16” chain. Ultimate breaking load is 12,740lbs and they don’t list WLL. 5/16” G43 UBL is 11700lbs. WLL is 1/3 - 3900lbs as per the required specs. Specs require it to withstand any breakage or deformation for any component of that swivel when side loaded or any odd load of 11699lbs. I don’t have the proof load in front of me for the chain, maybe some else out does. Go for the larger UFS if you like but it’s UBS is 20,400, those are big numbers. The swivel must in my opinion reach or exceed all the RF-271-F specs. I know it won’t do it because I’ve seen them broken on numerous occasions without any chain or shackle deformation. I also bench broke one for fun.

If you have a problem with anchors coming up inverted then check out our Flip Link from Anchor Right Aus. It’s tested and I’ve got the paperwork to show you. Simple, works every time and doesn’t stop the anchor from achieving its maximum diving potential. Bulk at the shank is a factor.

This is about Excel's UFS-08-21 swivel? It doesn't meet RF-271-F specs? You've seen them broken, you broke one?

What ARE RF-271-F specs? (Google isn't helping me on that one...)

Thanks for the Flip Link tip; can't say the swivel we use fixes the orientation all the time, but at least it lets me more easily rotate the anchor manually (as Dockhead also said).

Originally Posted by groundtackle

I’m not saying any of this equipment is bad or inferior. I’m just saying it doesn’t meet speciations.

Can't tell who you were replying to, which company/swivel you meant?

-Chris

[groundtackle]

https://www.navfac.navy.mil/content/...s/RR-C-271.pdf
Ranger and others, Sorry I’m on the road without my resources and gave the incorrect cert designation so here is the link to RR-C-271-F for chains / shackles. You can find WLL and UB of whatever flavour chain you use. I simply choose to match all the components to the WLL. The UFS 08-21 was related to the ultra.
Paul, the WLL of 3/8” G43 is in there.
Kenomac, flying here was just a funny but many folk have come to visit us and in Vancouver next week. It’s just easier to discuss all of these issues in person. The entire anchoring system has many factors. I enjoy sharing my experiences and hope I can help anyone to have more fun and stay safe at a reasonable cost.
I will not post other manufacturers deficiencies pics online. That’s just not fair play as their are two sides to every story. I would hope if we ever have a failure with our product the customer would give us the opportunity to correct the matter first. When we get back to the anchor chateau I may entertain a PM with you to discuss it further. Check out the link above for test procedures and if you feel confident your hardware meets or exceeds then all is good.
Chris

[groundtackle]

Sorry again, on the road with crappy wifi. That is for shackles but for chain specs
Try nacm.info.
If any of my maths are wrong please correct me.
Chris

[Dockhead]

Originally Posted by groundtackle

. . . .I will not post other manufacturers deficiencies pics online. That’s just not fair play as their are two sides to every story. . . .

Well, you don't mind saying that they all break, and that you have a box full of broken ones in your shop, and that none of them meet spec, but then -- you shrink from backing up these assertions with any kind of facts, because presenting facts would not be "fair play"




This guy, Viv Cox, is an engineer who does not manufacture anchors or anything, so no conflict of interest. He tested destructively a number of swivels and other connectors:



Connectors – Cox Engineering


His test results are a little hard to read, because he doesn't show the rated strength of the swivels, but it seems that all of the name brand swivels held up to their rated strength.




My own opinion is that swivels should never be attached to the anchor, unless they are designed to avoid levering the end of the anchor shank and side loading the swivel, like the Mantus one is.


Viv likes the Kong (and uses one himself), and even more, a New Zealand knockoff of the Kong, which is even stronger, but Kong swivels fail by spreading their jaws, if you attach them to the anchor contrary to the instructions.

[ranger58sb]

Originally Posted by groundtackle

If you have a problem with anchors coming up inverted then check out our Flip Link from Anchor Right Aus. It’s tested and I’ve got the paperwork to show you. Simple, works every time and doesn’t stop the anchor from achieving its maximum diving potential. Bulk at the shank is a factor.

Originally Posted by ranger42c

Thanks for the Flip Link tip; can't say the swivel we use fixes the orientation all the time, but at least it lets me more easily rotate the anchor manually (as Dockhead also said).

Chris, is there a video somewhere showing how the Flip Link works?

I don't find one on the SARCA site or through a general search...

-Chris

[groundtackle]

Dockhead, I am familiar with cox’s testing and he is a smart fellah. I’m not hiding at all, I’m just not in a situation with my reference library, pics etc. I concur straight pulls are how these these items are tested and a short leader will ensure those same conclusions will represented when in field. The way certain manufacturers advertise their swivels is installed fork to shank and just don’t believe they can meet UBS and that’s where I’ve seen the damage. The little anti backwards retrieval tab will not even come close when anchor is locked into the bottom and rode pulls 180 deg from its normally loaded angles.
Vryhoff anchor manuals is one resource ( available online) shows the do’s and don’ts when rigging large equipment and lifting. This info is scaleable down to our itty bitty relative vessels. I rig it right, follow specs and demand documentation because I must. We do some large anchors / gear and have no choice.
Please let me technically discuss these topics without retaliation, it benefits all of us. I’m not saying don’t use certain products, just use them properly.

Ranger, that ‘Flip Link’ is a very simple solution that solves many problems and meets my specs. I’ll attempt to take a series of pics from our boat show display and post them. Sending vids may not happen, I still own cassette tapes.
Chris