Why does the anchor shackle Kink like this?

"imagine many subjects that will spur more heated debate than anchoring or anchoring systems. "

Single Vs Twin?

Gas Vs Diesel?

Jeez, why am I always being confused with Marin? Guess I'll have to keep my comments shorter - that might help.
And Tom, (see I remember who you are), you still did not ansewer my question.* If not using mild steel, or aluminium, or 316 stainless, what the heck grade of metal will you use which is obtainable to us mere mortal, non-metallurgical types...?

-- Edited by Peter B on Saturday 9th of October 2010 09:13:49 PM

PeterB -- Any chain or rigging supply store of note can get you an alloy shackle. Or go to the 1st Chain Supply store website and order it. All the specs are on their website listed on charts for any chain or shackle you may need for choosing the right stuff from your local store. Of note, your gypsy will govern the chain and the chain dictate the shackle pin size.

-- Edited by sunchaser on Sunday 10th of October 2010 09:42:46 AM

Marin* I'm so sorry for attributing Peter's confusions to you. I must be more careful ---- now for that Sunday honey do list while ogling Brett's girlfriend on NFL Today. Do you think she was passed over by Tiger?

Sorry, but you're asking the wrong guy. My interest in football (US football) is on the list just below my interest in banana slugs.* So when it comes to team sports, I'm the wrong person to ask about anything.

I enjoy a game of baseball although I don't go out of my way to watch one, and I find football (the rest of the world's football aka soccer) intriguing although I have almost zero understanding of the rules. I think cricket is proably a lot of fun to play, but it seems absolute death to have to watch it.* I used to run camera on televised basketball games at the college level and that was fun--- I enjoyed both the game and the challenge of running camera on one..* Pro-basketball has turned into a sort of prison sport judging by most of the players, so the NBA leaves me cold.

To me any game where you have special teams for everything including taking a pee is not a game.* I think players need to play the whole game, not just some super-specialized aspect of it. So for that reason alone I don't even really regard US football as being a sport.

Man I just love having a swivel in my anchor chain.
Just as the anchor is about to enter the bow roller it gives a nice little twist and over she goes right side up every time.
Never have an anchor and chain with out one.
Over size anchor, oversize chain and the swivel will be ok, weakest link maybe but still stronger than required.
benn

I have thought about a swivel on Volunteer.. but I had not seen one in person that I thought was up to the task until I got a tour on Delfin, they have by far the coolest.. massive Stainless steel swivel I have ever seen.* The last time the Bruce ( dont even think about giving me crap over my Bruce ) came up backwards and smacked the hull when it flipped has convinced me to give a swivel a try........now if I can just remember the brand!
HOLLYWOOD

Larry M wrote:

*

Here's the picture of the swivel failure.

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FWIW this is a KONG swivel, manufactured in Italy. Just found this out in the process of looking up something else.

*

hollywood8118 wrote:

they have by far the coolest.. massive Stainless steel swivel I have ever seen.

Click to expand...

Here is the best anchor swivel I have seen.* It's called a WASI Powerball http://www.swisstech-america.com/powerball.html** I have no experience with this unit but of all the swivels I have seen illustrated this is the only one that actually makes sense to me because there is no swivel pin in its design.* They are hellaciously expensive but if someone held a gun to my head and said I'd have to put a swivel in our anchor rode or they'd pull the trigger, this is the only one I'd go with.

Is this what you were thinking of?



-- Edited by Marin on Sunday 10th of October 2010 10:05:16 PM

I wonder why approved by Lloyds of Germany and not Lloyds of London.

Benn

Some have suggested here that a swivel is a weak link in the anchor rode. *I suppose that depends on the equipment. *If you are fond of installing undersized or substandard equipment, I suppose it might be true. *Use the right equipment, and the comment would not be true. *I use 1/2" G4 chain and a SunCor swivel with 3/4" pins and a 25,000 pound breaking point. *Weak link? *Not so much. *Here's a link to the swivel I use, which cost around $200.

http://www.suncorstainless.com/anchor/S0190-00.jpg

Delfin wrote:

I use 1/2" G4 chain and a SunCor swivel with 3/4" pins and a 25,000 pound breaking point.

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Install it incorrectly, however, in such a way that it cannot pivot to line up with the rode no matter which way the rode is angling in to the anchor and I'll guarantee you that the sideload shear strength of the swivel pin is a lot less than 25,000 pounds.* By which I mean the pin or stud that the two halves rotate around, not the horizontal pins at each end that fasten to the anchor and rode.* That center swivel pin is the weak component in every swivel if it's subjected to side loads except the WASI Powerball, which doesn't have a swivel pin.


-- Edited by Marin on Monday 11th of October 2010 10:59:15 PM

Marin, if you look at the design in the link you'll see there is no side swivel, so your point is incorrect.* The only loads possible are parallel to the line of the rode, which is why this is the design I chose to solve the problem the original poster described.

This whole thread is a puzzle for me.

An anchor with the proper sized shackel will hold Da Boat thru the night.

If the rode is twisted SO WHAT????


Sure the "proper" swivel might work , but to what gain?

The loss could easily be the vessel, the gain is???

What am I missing?

FF, if you look at the picture sent with the inital post, you can see that the twisting has created sideloading on the shackle so that the strength is likely reduced, perhaps by a great deal.* I guess there is no point in avoiding this unless not losing your freaking boat has merit.

With a 25,000 # breaking strength, this particular swivel I mentioned would be the last thing on my boat that breaks.

Finally, if you're tied up at the dock all the time, you won't encounter the problem that many people have of needing to swing an anchor 180 degrees with a boat hook so you can bring it home without running it onto the roller unside down.* Having a swivel makes turning 175# of metal around a bit easier.

Delfin wrote:

Marin, if you look at the design in the link you'll see there is no side swivel, so your point is incorrect.* The only loads possible are parallel to the line of the rode, which is why this is the design I chose to solve the problem the original poster described.

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The design of this swivel has the built-in flaw that Earl Hinz talks about in his book.* The top half swivels against the bottom half using a stud or a pin as the "axle."* But no matter which end you attach to the anchor the swivel will only be able to rotate back and forth in line with the anchor shank.* Unless you attach it correctly with a shackle which will then allow the swivel to "aim" in any direction* relative to the anchor shank.*

But most people--- and I've seen a lot of anchor swivels of the type you have*in our marina--- attach the swivel directly to the anchor.* This prevents it from pivoting to the side.* So if your boat gets off to the side of the anchor, the swivel cannot pivot around to point at it which means the load is not straight through the swivel, which is where your 25,000 pounds of strength is, but is put sideways on the swivel.* The pin or stud that allows the top of the swivel to swivel is designed to take high loads straight through it--- it is not designed to take high shear loads.*

So your boat is pulling*sideways*like mad on the end of the swivel that's attached to the rode while the other end of the swivel is forced to stay lined up with the anchor shank.* All*the load has be held by the "axle" the two halves of the swivel rotate on, but that axle is only strong when the load is going straight down through it.* By connecting the swivel directly to the anchor, the boater is forcing the load to be put sideways on that "axle" every time the boat moves off-line from the anchor shank.

If you've connected your swivel to the anchor with a shackle, then there is no problem--- the entire*swivel can always rotate to line up with the rode and the load no matter where the boat is*in relation to the anchor.* But if you've done what most boaters seem to do with these things, which is attach the swivel directly to the anchor, then you have set up the potential for a swivel failure.* Hinz has photos in his book of a large yacht that is sittting high and dry on a beach due to the failure of a swivel that was attached directly to the anchor in such a way that it could not pivot sideways to stay lined up with the rode.* This put a high side load on the swivel pin or "axle," the pin snapped or sheared, and the boat ended up high and dry on the beach.* Had the swivel been attached to the anchor with a shackle, no side load would have been put on the swivel "axle" and the boat would have stayed put, assuming the anchor didn't drag.


-- Edited by Marin on Tuesday 12th of October 2010 11:56:36 AM

Delfin wrote:

FF, if you look at the picture sent with the inital post, you can see that the twisting has created sideloading on the shackle so that the strength is likely reduced, perhaps by a great deal.

Click to expand...

If chain "twisting" causes a swivel to break then what is the purpose of a swivel in the first place?* If this is true you make an even better case for not having a swivel than anyone else in this discussion has so far.* A swivel's whole purpose and*design*is to allow the top half of the swivel to swivel relative to the bottom half--- hence the clever name--- when the chain starts to twist.

The reason the swivel in the illustration broke is crystal clear--- excessive side loads were put on it because it could not pivot sideways to line up with the boat and the load.* This is a common and potentially boat-losing mistake made on 90 percent of the boats I see with swivels of this type because the owner connects the "legs" of the swivel directly to the anchor.* It certainly looks nicer than putting a shackle between them, but they've set up the formula for failure by omitting the shackle.

*


-- Edited by Marin on Tuesday 12th of October 2010 12:05:50 PM

Marin, the 25,000#, according to SunCor is the side load breaking strength.* Straight pull would be greater, so again, this is a non issue since the chain would break (9,600 #) or the front of the boat pull off before the swivel goes.* Again, if you put undersized equipment on your boat, you'll have a problem.* If you don't, you won't, with all respect to Mr. Hinz.

Charles, you make the case well.* While people are worried about the strength of the swivel, they lose sight of the reduction in chain strength when its twisted.* The safest situation is as you suggest.* An OVERSIZE swivel that is a strong, not weak point in the system, preventing a kinked chain from becoming the weak point.

This thread got me thinking.* Not always a good thing.

I just measured 2 feet of 3/8" G4 HT, about 20 links.* I then twisted it to see what happens.* I easily twisted the chain 1 complete revolution with no kinking.* If I had to say what is the average amount of road we put out when anchoring it would be ~120 feet.* So that says the boat could rotate/twist 60 times without the*chain kinking?* Does this make any sense?

Larry/Lena
Hobo KK42
La Paz,*BCS*

FF* Here is what you are missing - a well constructed swivel allows big heavy anchors to efficiently and properly enter the "hawse pipe" and lay down as intended with no damage to the hull and no monkeying around with chain and anchor. Works for me. A properly sized shackle likley would too, but as I walk the docks and see all the high end vessels with big gouges on their bow and under their anchor ----. You can still find reference that*a 5th wheel trailer will not work as good as a bumper hitch too.

-- Edited by sunchaser on Tuesday 12th of October 2010 12:33:40 PM

Larry M wrote:

So that says the boat could rotate/twist 60 times without the*chain kinking?* Does this make any sense?

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Since every boater I know personally who anchors a lot has no use for a swivel in their rode, and we don't use a swivel, and given that the waters we anchor in are constantly moving our boats around our anchors, and I've not heard anyone I know who uses an all-chain rode ever say they've had a problem with an anchor rode twisting or kinking when they retrieved the anchor, I would say that what you wrote makes all sorts of sense.

The notion of being able to rotate an anchor more easily with a swivel so it doesn't ding the boat makes sense.** But when we had a swivel in our rode it made no difference to this whatsoever--- the anchor still came up any way it wanted to. In fact the swivel seemed to make it easier for the anchor to rotate around and whack the bow.* We eliminated the swivel for the reasons I've outlined earlier, but I've also noticed that without it the anchor is far less likely to rotate around as it comes up.* It may not be oriented correctly, but it doesn't swivel around as much when it's in the air.* This was true with the Bruce as well as with our current Rocna.

So strictly from my own point of view with regards to our boat, I see no value whatsoever in having a swivel, no matter how oversized or strong it might be.

*


-- Edited by Marin on Tuesday 12th of October 2010 12:40:19 PM

Marin wrote:

...* --- the anchor still came up any way it wanted to. In fact the swivel seemed to make it easier for the anchor to rotate around and whack the bow.* We eliminated the swivel for the reasons I've outlined earlier, but I've also noticed that without it the anchor is far less likely to rotate around as it comes up.* It may not be oriented correctly, but it doesn't swivel around as much when it's in the air.* This was true with the Bruce as well as with our current Rocna.


-- Edited by Marin on Tuesday 12th of October 2010 12:40:19 PM

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I dislike it when an anchor makes an unanticipated motion that can damage*the boat or me.* That's why I don't like anchors with moving parts.* (Being pinched twice*by a Danforth was too much.)

*

I've watched these threads through the years regarding swivels.* This is the way I look at it...* If the anchor is set in the substrate and the other end of the chain is set across the rollers and onto the windlass, how can it twist at all?* This is assuming an all-chain rode.* So why is it that I should need a swivel?* Another reason for an all-chain rode?* I don't see a reason for a swivel.* Unless I was in the business of selling them!

Ray

Giggitoni wrote:

I've watched these threads through the years regarding swivels.* This is the way I look at it...* If the anchor is set in the substrate and the other end of the chain is set across the rollers and onto the windlass, how can it twist at all?

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The concern is that as the boat "circles" the anchor--- which it can and does up here but perhaps not in other waters with a lower or no tide range and minimal to no current changes--- the chain can be dragged around in one or more circles which can roll it over multiple times as this happens.* Even if there is little or no load on the anchor, the boats up here still move around a lot and drag their chains around on the bottom after them.*

This is the main reason behind the increasing tendency to close some waters in this area*up to 30 feet deep for anchoring because as the boats move around their anchors the dragging chains plow up the eelgrass beds which are essential habitats for crabs, small shrimp, and salmon fingerlings.

*

I just saw something interesting on the news. They showed the thing they're going to bring the Chilean miners up in and it clearly had a swivel attached. It was one of those barrel like swivels. I can see the possible need for it there but any twist that is in the chain from a wandering boat in the wind and tide should easily get unwound in 100' (or so) of chain on the way up. I don't think anybody needs a swivel on an anchor rode.

Wonderful Eric.* I'll remove mine, and you can crew.* You can also be in charge of leaning over the bow, and turning 175# of steel with an 8' boat hook so it'll line up with the hawse pipe.* Big relief for me, I can tell you, what with you handling this instead of a nasty swivel making it easy.

So, I started this thread with a photograph. Had no idea so many comments would result.
After one of you all suggested that the anchor might spin on the way down I mentioned this to my wife who runs the winch. She said "sure *the anchor spins as it goes down". *I guess I should have asked her sooner.



I like this as probable cause.

No, the problem is dumping the chain on top of the anchor, allowing it to kink.* Back down on it once you hit bottom, and your problems will be largely solved.

I think we are usually moving astern even before the anchor hits bottom.

nomadwilly wrote:

They showed the thing they're going to bring the Chilean miners up in and it clearly had a swivel attached. It was one of those barrel like swivels. I can see the possible need for it there.....

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Plus anything hanging from a crane or suspended vertically like this is going to have the load on the swivel going straight through it, which is when a swivel is at its strongest.

*