Side loading on Ultra Swivel (or swivels in general)

[Steve_C]

I always take great care NOT to jerk, or put side strain on any stuck anchor. My concern is when anchored in storm conditions and a change of direction forces the anchor to re-set and it gets stuck in something that I was unaware of. Especially if this happens in the dead of night.

I was very surprised to see the pictures posted of the Ultra swivel with the broken shank attached, and it certainly speaks well of the strength of the Ultra swivel. But for my own use I wold prefer to avoid the swivel unless I find myself anchoring in situations where I constantly find the chain twisted. Some seem to have no problems with this and of course others in some areas do. If possible, I prefer to keep my anchoring system as simple and robust as possible.

There will inevitably be situations beyond your control that lead to side strain on any setup. Avoid it if at all possible, but be prepared just in case!

[Dockhead]

Originally Posted by Ultra Marine West

. . . I was trying to tell you not to force ULTRA if it gets stuck under a rock, and I am happy to read that you refrain from yanking your anchor on when it gets stuck on something. It is not easy to bend the 318LN Duplex stainless steel shank of the ULTRA Anchor, so unless you use ULTRA Flip Swivel, you will most likely break your shackle or your bow roller or your chain.

Well, this advice is good, but it's not peculiar to any particular anchor -- you can bend any anchor shank if you mistreat it. You will never break even the weakest shackle by pulling sideways on an anchor shank -- the strongest anchor shank will bend before the weakest shackle or crappiest swivel breaks, in a levered sideways pull.

Originally Posted by Ultra Marine West

. . . We should see anchors under rocks as an accident situation so instead of encouraging people to make accidents. I take the shackles don’t take side loads in that category. . .

A correctly installed shackle will have zero side load in such a situation. The pin needs to go through the last chain link, not through the hole in the anchor shank. This is one of several huge advantages of shackles versus swivels attached directly to the anchor. In general, swivels should be separated from the anchor by several links of chain in order to prevent side loading and unnecessary levering of the anchor shank.


But I do agree that an anchor stuck in a rock is an "accident". This is when those of us who sail in warm tropical waters and have diving gear or snorkels are happy that they aren't up where I am, where the water is murky and +3C or +4C most of the year

[ranger58sb]

Originally Posted by DefinitelyMe

Another advocate for no swivel here. Saw two boats with swivel failures and took ours out a few years ago.

Not meaning to pick on you here... so please take this kindly....

But I'll mention this could be an example of what I said above. Could have been crap swivels, could have been improperly mounted, could have been combo of those.... etc.

Without details, reported swivel failures may or may not be useful. And may only add to the general distaste for swivels in general, whether deserved or not.

-Chris

[Jim Cate]

Re chain twisting: I suspect that the big variation in reports of catastrophic chain twisting/hockling may stem from the design of their respective bow roller... the actual roller part of the assembly. I see all too many of these that do not have a groove in the roller to align the chain as it passes over. With a groove, any twists that have developed in the chain stay outside the roller, and the chain lies untwisted between roller and gypsy. Then when the anchor lifts from the bottom, it rotates freely and any twists resolve themselves (outside the roller and well before reaching the gypsy) as the anchor rises.

This has worked for us for all our cruising years.

Jim

[a64pilot]

Mine has that groove, but a tight chain as in retrieving the anchor pretty much ignores the groove.
However the groove is nice to hold the snubber rope in

[Jim Cate]

Originally Posted by a64pilot

Mine has that groove, but a tight chain as in retrieving the anchor pretty much ignores the groove.
However the groove is nice to hold the snubber rope in

That's odd, for ours works quite well at keeping twists outboard. Perhaps something to do with how well the groove fits the chain. Additionally, when I designed the roller I had the narrow groove that holds the vertical link, plus a wider groove or flat that fits the horizontal link. Does your roller have both?

Jim

[s/v Jedi]

The Mantus swivel is sweet but the Ultra swivel is flawed in the way it attaches to the anchor. Like Dockhead wrote: it increases the sideways leverage thus amplifies the possible problems. Not side-loading the anchor is funny to say but not a solution because it happens regardless of what is written here. The way to fix the Ultra swivel is by adding a shackle or even some chain links between anchor and swivel... which introduces more failure points and is not required for the Mantus swivel.

As I wrote before, I have no stick in the fire because I use a galvanized swivel that requires an additional shackle as well. I would need that shackle anyway because my anchor shank is too beefy for any of these shiny swivel thingies

[Muaddib1116]

I want to try to break this down a bit.

Given the same anchor, having a slotted hole that allows a shackle bow to go through it, with the pin in the chain gives the least amount of possible side load, and your limiting factors are the tensile strength of the chain and shackle, and the side load strength of the anchor shank. Add in a Mantus swivel, and the only additional factor is the tensile strength of the swivel.

If you're limited to a round hole (let's still assume the same hypothetical anchor), then you can either use a shackle, with the bow through the chain and the pin through the anchor shank, or a swivel like the Ultra swivel that has a fork with a pin through the shank.

In either case, you have two concerns when applying a side load to the shank. The first is a prying force that will force the shackle bow or swivel fork open and release the anchor. The other is that both the shackle and the swivel increase the effective length of the shank and increase a side load's ability to bend/break the anchor shank.

In the case of the shackle, I suspect the greater risk, in general, is prying the shackle bow apart. The shackle is not really designed for this type of load and the shackle only adds an inch or two to the effective shank length. Perhaps there are shackle styles that have very robust pin securement systems that can resist this type of prying force. I'm not sure I would trust the type that just threads into one side of the bow.

The Ultra swivel is probably the other way around. It appears that the fork, with the reinforcing arch, is quite robust. So the increased risk appears to be adding quite a few inches to the effective anchor shank length. How much this compromises the designed lateral strength of any given anchors shank, I don't know. But it seems likely that what Ultra Marine West is saying is pertinent, that in that scenario the anchor shank becomes the weakest link, and that given the proper caution that you should be exercising normally, then it shouldn't pose much of a problem. And that in order to exert a side load that will cause the system to fail, it is likely you would have been doing so anyways, with or without a swivel.

With these systems, proper anchor practices can protect you from a lot, but you are still subject to random things like a hard 180 degree anchor reset that happens to jam the anchor under a rock midway. But these events can also damage an anchor with just a shackle or a Mantus swivel.

I'm not sure I have a point to make, maybe it's just that it seems like the best thing to do is find the biggest anchor that works for you and get the biggest and strongest of everything that will fit.

[CarlF]

Well at least we've moved on to comparing swivels rather than just saying "all swivels are bad". It's like saying all anchors are bad because your CQR wouldn't set once 20 years ago

I have an Ultra swivel bought before the Mantus was available. The Mantus is a great design. I sometimes ask myself which I would buy today.

Jedi's right that the Ultra design extends the lever arm on the shank - but I'm not sure the extra 2" length is enough to make a real world difference in whether the anchor shank breaks or not. Especially if the anchor is stuck under a rock.

It clearly doesn't make the swivel fail. My Ultra swivel has a listed breaking strength of 36,200lbs (side load or straight load) - well above the 27,600lb breaking strength of my G43 1/2" chain.

If I was worried, the answer would be a bigger anchor with a thicker shank - but there's always going to be some part of the anchor system that breaks first.

I do like the Ultra's "flipping nub" which always brings the anchor onto the roller in the right direction. So I'd probably buy the Ultra again.

[Ultra Marine West]

Originally Posted by Dockhead

Well, this advice is good, but it's not peculiar to any particular anchor -- you can bend any anchor shank if you mistreat it. You will never break even the weakest shackle by pulling sideways on an anchor shank -- the strongest anchor shank will bend before the weakest shackle or crappiest swivel breaks, in a levered sideways pull.





A correctly installed shackle will have zero side load in such a situation. The pin needs to go through the last chain link, not through the hole in the anchor shank. This is one of several huge advantages of shackles versus swivels attached directly to the anchor. In general, swivels should be separated from the anchor by several links of chain in order to prevent side loading and unnecessary levering of the anchor shank.


But I do agree that an anchor stuck in a rock is an "accident". This is when those of us who sail in warm tropical waters and have diving gear or snorkels are happy that they aren't up where I am, where the water is murky and +3C or +4C most of the year

Once again, in maritime, there is no side load terminology for anchors and swivels. Llyods don’t test the side loads of the anchors and the swivels because the only way the sideload takes place if the anchor gets stuck under rocks—however, neither anchors nor swivels designed to work under big rocks.

The shackle is a general solution to connect links while the ULTRA Flip Swivel specifically designed to connect ULTRA Anchor to the chains. So it is very unlikely that this general solution would perform overall better than our specific design.

Our primary motivation was to come up with a connection more reliable than the chain attached. As per the below picture, people were losing their ULTRA Anchors due to these weak connections. (That anchor in that picture stayed more than four years in the sea till a diver finds it by chance. It is one of the first ULTRA Anchors we made.) That is why we had to offer a connection more reliable than the chain because there are very low-quality cheap connections in the market that would fail even under normal use and conditions with straight forces. The old generation anchors or the new generation ones with roll bar can never dig in and create high holding powers as ULTRA Anchor does so they wouldn’t feel the weaknesses of these connections in that setup. However, once you use the ULTRA with such a weak connector, it would break it even under extreme straight pulls.

After we started selling the ULTRA Swivel late 2005, the only complaint we were getting from some customers was the upside-down anchor recoveries. Even though the ULTRA is a self-righting anchor with its hallow shank and lead-filled tip, it would also come to some bow rollers upside down. We found out that stronger windlasses pull it fast, so the ULTRA starts turning. Still, that speed doesn’t give it enough time to turn totally, or the chain grooves on the rollers were catching the shank from the opposite side, and they were causing that upside-down anchor recovery issue.

So we worked on our design and added that bridge and nub to make it the ULTRA Flip Swivel. ULTRA Flip Swivel is the only product still today, which is a swivel and a flipping device at the same time.

We around 95% sell our anchor and swivel together, and we didn’t have any complaints from users neither from the anchor performance nor from the swivel performance since 2011. Instead, we have hundreds of happy customer testimonials. So that should tell us something.

[Ultra Marine West]

Originally Posted by Muaddib1116

I want to try to break this down a bit.

Given the same anchor, having a slotted hole that allows a shackle bow to go through it, with the pin in the chain gives the least amount of possible side load, and your limiting factors are the tensile strength of the chain and shackle, and the side load strength of the anchor shank. Add in a Mantus swivel, and the only additional factor is the tensile strength of the swivel.

If you're limited to a round hole (let's still assume the same hypothetical anchor), then you can either use a shackle, with the bow through the chain and the pin through the anchor shank, or a swivel like the Ultra swivel that has a fork with a pin through the shank.

In either case, you have two concerns when applying a side load to the shank. The first is a prying force that will force the shackle bow or swivel fork open and release the anchor. The other is that both the shackle and the swivel increase the effective length of the shank and increase a side load's ability to bend/break the anchor shank.

In the case of the shackle, I suspect the greater risk, in general, is prying the shackle bow apart. The shackle is not really designed for this type of load and the shackle only adds an inch or two to the effective shank length. Perhaps there are shackle styles that have very robust pin securement systems that can resist this type of prying force. I'm not sure I would trust the type that just threads into one side of the bow.

The Ultra swivel is probably the other way around. It appears that the fork, with the reinforcing arch, is quite robust. So the increased risk appears to be adding quite a few inches to the effective anchor shank length. How much this compromises the designed lateral strength of any given anchors shank, I don't know. But it seems likely that what Ultra Marine West is saying is pertinent, that in that scenario the anchor shank becomes the weakest link, and that given the proper caution that you should be exercising normally, then it shouldn't pose much of a problem. And that in order to exert a side load that will cause the system to fail, it is likely you would have been doing so anyways, with or without a swivel.

With these systems, proper anchor practices can protect you from a lot, but you are still subject to random things like a hard 180 degree anchor reset that happens to jam the anchor under a rock midway. But these events can also damage an anchor with just a shackle or a Mantus swivel.

I'm not sure I have a point to make, maybe it's just that it seems like the best thing to do is find the biggest anchor that works for you and get the biggest and strongest of everything that will fit.

After the ULTRA Anchor, we had to come up with something extraordinary with our anchor swivel design, as well.

Even though some of you say that our design is “flawed” and try to fix it while no user complains quite the contrary, it is the world's most advanced anchor swivel design.

-It is more reliable than the chain connected.
-It allows 30-degree rotation with complete 360-degree swivel.
-It assists in recovering the anchor right side up into the bow roller with its unique flipping nub and rear bridge.
- Hexagonal head locking bolts prevent the need for additional grub screws to secure the swivel pin.
- It fits the most variety of boats with its slim point design.
-“Muaddi1116” this last one is actually for you who wants to use the biggest strongest of everything. The revolutionary chain pin system let’s one size bigger ULTRA Flip Swivel attached to one size smaller chain WITHOUT a decrease in its breaking load. See the below picture.

So all anchor swivels are not the same. You have the ULTRA Flip Swivel option, too.

[slug]

I don’t see the information stated on your Swivel description

What is the rated Breaking load when lateral force is applied ?

What is the safe working load of the swivel ?

[Ultra Marine West]

Originally Posted by slug

I don’t see the information stated on your Swivel description

What is the rated Breaking load when lateral force is applied ?

What is the safe working load of the swivel ?

We use the breaking strength only because we see different companies use different safety factors (SF) when they calculate the safe working loads (SWL).
There is no lateral/sideload terminology for the swivels, so we don’t use it. But for your information, the lateral breaking loads match with their pulling loads.
The breaking strength of each swivel stamped to the rear, as you see in the below picture. Here with this link you can reach our Ultra Flip Swivel Selection Table https://www.ultramarinewest.com/site...07.06.2016.pdf

These listed breaking strengths confirmed by the RINA, as well. Here with this link you can check their original test certificates https://www.ultramarinewest.com/site...ertificate.pdf

[slug]

I can see the break load ,

Safe working load includes lateral loading

I dont see SWL

[Ultra Marine West]

Originally Posted by slug

I can see the break load ,

Safe working load includes lateral loading

I dont see SWL

I answered that above. Safe working load does not include lateral loading. It is ideally the maximum load the product works without deformation.