Anchor Chain Swivels

[BruceK]

Not sure about letting this dog off the chain,but here goes.

A while back, noting my chain coming up twisted, I bought one of those very smart polished stainless steel swivels,tapered one end to pass easily over the bow roller. Then I googled them.

On the net I saw frightening pics of swivels with the jaws forced apart,and warnings of the risk of failure, possibly reduced by never ever attaching the swivel directly to the shank, but mostly advice that if you have one remove it, right now. The shipwright went quite pale when I mentioned fitting one.

My beautifully polished swivel,a virtual work of art, sits unfitted. The chain still comes up twisted, probably slowing the already leisurely retrieve by the Muir Cheetah winch fitted to my IG 36.

My first new topic, so be kind. Advice on preventing chain twist, on swivels, and associated experiences, most welcome.

Bruce K "Doriana"

 

[Codger2]

Bruce Kops wrote:
My first new topic, so be kind. Advice on preventing chain twist, on swivels, and associated experiences, most welcome.

*Bruce:

I, too, have a beautiful SS swivel that attaches directly to the anchor shank. (20kg SS Force) Both anchor and* swivel look like fine jewelry on my bow.

Since I don't anchor much, they are safe from failing but when I know I'm going to anchor, I carry a Danforth and a Bruce in the lazarette. They are both galvanized as is the shackle I attach them with. Chain twist? No suggestions.


-- Edited by SeaHorse II on Tuesday 15th of November 2011 09:21:03 AM

 

[BruceK]

Thanks Guru. I just checked Nigel Calder`s "Cruising Handbook" (page 400), he never fits a swivel, never had twisting, but says if you use a swivel put a shackle between it and the shank,otherwise the swing of the boat puts "an unfair sideways load on the swivel for which it was not designed".

Bruce K

 

[Marin]

We used a swivel for awhile but after reading Earl Hinz' book "The Complete Book of Anchoring and Mooring" and talking to several very experienced boaters in our part of the marina who have been anchoring in our waters for decades we removed it and threw it in the dumpster. The fewer components in an anchor setup the better, and a swivel in our experience is totally unnecessary. Couple this with the fact that almost every swivel I see on a a boat is either installed backwards or is the type that attaches directly to the shank so can only pivot one way and they can be a recipe for disaster.

We have an all-chain rode and we boat in an area where strong currents and shifting winds can circle a boat around its anchor countless times in the course of a couple of days. Despite this we have never had a twisting or kinking problem with the chain.

There is only one swivel on the market that I think is worth using if one really needs a swivel, but it costs several hundred dollars. As we have never experienced a need for a swivel, we see no point in buying one.




-- Edited by Marin on Monday 14th of November 2011 10:44:33 PM

 

[Nomad Willy]

We've been here before and when Carl sees this he'll prolly belly up to the bar and point out that when the anchor gets really big the swivel is quite handy. There dos'nt seem to be a need for swivels on smaller boats like most of us have and I also consider them a weak link * *.....but one could always use an over sized swivel

 

[BruceK]

Eric, I felt this might be a well ploughed field,but with nothing up now and wanting help, thought I`d raise it. Much appreciating the input so far.

Bruce K


-- Edited by Bruce Kops on Tuesday 15th of November 2011 12:03:20 AM

 

[Marin]

nomadwilly wrote:
.....but one could always use an over sized swivel

But then we'll need oversized chain to get a link large enough to accomodate the swivel.* And that will be way heavy and we'll be chastised for putting too much weight in the bows of our boats

 

[markpierce]

My Coot came with a stainless steel anchor swivel.* A project manager of a local boatyard told me they are subject to fail, and that's best to have a shackle between the swivel and anchor.

 

[Marin]

markpierce wrote:
My Coot came with a stainless steel anchor swivel.* A project manager of a local boatyard told me they are subject to fail, and that's best to have a shackle between the swivel and anchor.

Your project manager is right on the money.* A shackle pin (the pin the two halves rotate on) is not made to withstand high side loads.* It is at its maximum strength when the load is lined up with its length.* By fastening a shackle to an anchor in such a a way that the shackle can only pivot back and forth in line with the shank, whenever the boat gets off to the side of the anchor the load will be sideways on the shackle pin.* The farther to the side the boat is, the more toward a right angle the load on the pin will become.* Put enough load on it and the pin will snap where it would have held if the same load had been straight through the pin.

In short, if you're bound and determined to use a shackle the shackle must be free to rotate in all directions relative to anchor shank.* In other words, the shackle must always be able to line up with the anchor rode no matter what angle the rode leaves the shank, not forced to stay in line with the anchor.

Again, take a look at Earl Hinz's book for a great explanation of all this plus illustrations of how to properly attach a shackle to an anchor, plus photogaphs of what can happen when a swivel pin snaps.* There's a right way and a wrong way to attach a shackle to an anchor.* The right way is the only one you can put any faith in.


-- Edited by Marin on Tuesday 15th of November 2011 01:13:37 AM

 

[Marin]

SeaHorse II wrote:

I, too, have a beautiful SS swivel that attaches directly to the anchor shank. (20kg SS Force) Both anchor and* swivel look like fine jewelry on my bow.

*

*Walt--- Based on your attached photo, your swivel is attached incorrectly.* You should have a shackle between the anchor shank and the swivel.* The way you're set up now, the swivel cannot pivot out of line with the shank, so a strong side load could snap the swivel pin.* By which I don't mean the pin that's connecting the legs of the swivel to the anchor but the center in-line pin the two swivel halves rotate on.

Whether you use the anchor much or not, you should change that setup because someday you or somebody else MIGHT have to use the anchor and if the conditions get nasty, you could find yourself disconnected from the anchor because the swivel pin snapped.* Better safe than sorry. If you want to keep the shiny look, use a polished stainless shackle beween the swivel and the anchor.

Or better yet, get rid of the swivel altogehter (the one you have on there is not all that great anyway) and attach the chain directly to the anchor using a nice big shiny shackle.

 

[Tidahapah]

Well guys I have been using a swivel on my anchor chain for about 17 years and wouldn't install an anchor with out one.
Have recently (last 2.5 years) progressed up to a proof tested s/s unit and have not qualms in using it.
I'm hanging a Sarca Excel #8 (40 kg 88 lb) off the end.
As long as your swivel is rated the same as your chain no problem and only positive results with bringing in the anchor and not having it
twisted or flying about comming in to the bow roller.

 

[FF]

No SS underwater for me, the corrosion cracking problems would keep me awake at night.

Hard to believe a boat was anchored so long in one spot that twists in the chain make recovery a problem.

Why not go to deep water once a month ad drop and recover the anchor and chain?

 

[jleonard]

I have a swivel. Is it attached correctly?

*

 

[Peter B]

Hard to see it Jay, but I think it is not shackled direct to the shank, so I think yes. Interesting this subject has come up right now, as I have just had a bit of a saga happen to my anchoring set-up when my anchor winch simply refused to work after working faultlessly the whole 10 yrs I've owned her and goodness knows how long before that. Anyway, I had a stainless high quality swivel installed on my setup, but one shackle removed from the actual shank, and I use it with a sliding Sarca self tripping slotted shank anchor, and had never had any problems. However, one day I decided to reverse (end for end) the chain, and that's when the winch finally refused to work - that was hitch one - then I found the fancy recessed swivel pins had frozen in so tight there was no way I could get them off on the boat. Eventually I had to cut a link with an angle grinder to remove it. In the end to try and get the pins out proved impossible without wrecking them, so now the winch is going again - thank goodness only dirty brushes + a bit of moisture and corrosion - so I am going to re-attach my Sarca without a swivel, and see how it all goes. So, in answer to the opening question - watch this space. Oh, and yeah - never did reverse the chain in the end. It had some dodgy links near the other end, so made the procedure pointless.

 

[Larry M]

I*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 ~150 feet.* So that says the boat could rotate/twist 75 times without the*chain kinking?*

*When we retrieve our anchor, the bow roller pretty much straitens out the twists on the way up.

 

[Peter B]

As I said above, I will be comparing directly the same anchor and chain previously with swivel, and now without, so I will pick up any significant difference quite quickly I think. I doubt it will make any real difference on retrieval with kinking occurring, as you say Larry. What I will notice is if it has any negative effect on it coming up onto the roller assembly aligned the correct way, because up to now, 4 times out of 5 it was aligned right, and I had no need to go forward and twist the fluke around to point towards the bow. If I find I have to do this more frequently, or even if I find it much harder to make that correcting twist, then I think I will have proven that with my set-up anyway, the swivel is better - as long as it is a suitably generous size & type. Pity I had to wreck the one I had to get it off, especially as in the end I did not need to, as I did not reverse the chain in the end. At least I now know the pins would never have undone themselves. But it is a sacrificial act putting on one of these recessed pin types it appears.

 

[Keith]

This is why you put anti-sieze compounds on shackles, etc. I use Tef-Gel. I do use galvanized swivels. They do their job in the last couple of feet of chain being winched aboard. The anchor will spin and settle onto the roller perfectly.

 

[Codger2]

Marin wrote:
Or better yet, get rid of the swivel altogether (the one you have on there is not all that great anyway) and attach the chain directly to the anchor using a nice big shiny shackle.

*Of course you are correct with your comments about my jewelry set up & I fully intend to fall in line with your above statement.(s)

 

[Marin]

Tidahapah wrote:
....only positive results with bringing in the anchor and not having it twisted or flying about comming in to the bow roller.

We've never experienced this, either with the Bruce or the current Rocna, both of which we use/used without a shackle except for a few months after acquiring the boat.* While the anchor doesn't always come up to the pulpit aligned for stowage, a simple twist of the anchor chain between the fore and aft pulpit rollers takes care of that.*

But we've never had an anchor twist or fly about in any manner whatsoever on our all-chain rode as it came up.* And when I was determining whether or not to keep*the swivel we bought along with the Bruce after acquiring the boat, everyon e I asked who doesn't use a swivel about anchor twisting, kinking, or spinning, said they had never experienced this either.

Maybe it's an Australian thing, you know, since everyhing rotates backwards down there and is trying to fall up.

 

[skipperdude]

If your bow roller is equipped with a central groove to guide the chain during retrieval, the chain will untwist itself as it comes aboard.

You can facilitate this by letting the anchor hang from the bow for a few moments after it rises from the seafloor,giving the chain time to untwist itself.

This works for me .

SD

 

[Nomad Willy]

Dude,

You took my post away. Yes and even if it turns on the bow roller it can't turn on the gypsy unless you manually do it. Also regarding Larry M's comment it's assuming that the 75 rotations will be all in the same direction. And as the Dude points out there's lots of time for the anchor to return the way it left on the way up. Re Walts swivel It may have the clearence to rotate on the anchor shank slot and avoid the side load all together. Thus not being a weak link at all. Just say'in.

 

[Delfin]

My roller has a groove, but the anchor still seems to come up bass ackwards about 40% of the time. *The swivel I have is*made of 17 4 PH cast stainless and is*rated at 25,000# with 3/4" pins . *I called the company (Suncor) and asked if the rating was side load or straight pull and they said side load, so I haven't worried too much about it. *Additionally, the yield strength of 17 4 PH is greater than that of the anchor shank so I see it as an extension of, and not a weak link of the shank. *It is a much cleaner installation than shackles and allows me to twist the anchor around with a boat hook when it does come up wrong.

 

[BruceK]

Thanks for all the input, you guys were busy while (most) Aussies slept. I`m using my ss. swivel as a paperweight at present.

"Nigel Calder`s Cruising Handbook" has a diagram showing a conventional galvanized swivel fitted using shackles, see p400.

I might try stopping retrieve and hanging the anchor a while to see if that helps the chain twist.I don`t have a groove in the bow roller though,it`s just a wide flat roller with raised ends.

Bruce K "Doriana"

 

[Bendit]

I installed a swivel a couple of years ago to stop the chain kinking at about 40 metres. It helped for a while but now the kinks are back. I have tried dropping in deep water and retrieving but it doesn't cure the problem. The only way I have found is to lay the chain out on the marina and manually turn it to get rid of the kinks. This seems to fix it for a year or so.

After what I've read here, I think I'll remove the swivel.

 

[Nomad Willy]

Jeff,

I'm guessing your anchor rotates as it comes up. How else could it possibly twist up the chain? Is there a way to raise the anchor slowly?*Perhaps*another anchor woul'nt rotate as it comes up. Just think'in.

Eric

 

[BruceK]

Eric, If our retrieve was any slower I`d be timing it with a calendar instead of a watch, I doubt the cause is fast retrieval. Twist is visible between roller and windlass gypsy.

Based on the posts I use my ss. swivel as a paperweight but I`d still welcome a solution. Running it out might be worth a try.

BruceK

 

[Marin]

BruceK wrote:
Twist is visible between roller and windlass gypsy.

Is there any chance there is a mis-alignment between the pulpit roller and the chain wildcat on the windlass?* I would think that a misalignment great enough to cause the chain to twist and kink would be really obvious but you never know.

 

[FF]

"Is there any chance there is a mis-alignment between the pulpit roller and the chain wildcat on the windlass?'

There will frequently be a grove machined in the roller that keeps the chain from twisting

The deck fitting , that actually holds the boat while anchored will do the same thing , if the groove is missing on the bow roller.

If neither is present , shoot the surveyor.

 

[Nomad Willy]

The bottom line is that the gypsy will only pull up the chain the way it went down. Even if you shoot the surveyor.*But Bruce if you have twist between the bow roller and the gypsy a very strong twisting force must be present.......not likely to be caused by an anchor coming up very slowly. I have an anchor w a capstan and it is not aligned at exactly a right angle to the bow roller. My nylon anchor line pulls over to one side of the drum quite strongly. Since you can actually see a twist there that is extremely unlikely to be generated from forces from below I propose that the relationship between the bow roller and the gypsy is causing the twist. If the bow roller has no grove there will be a 90 degree twist in the rode between the bow roller and the gypsy because of the way the chain will lie on the bow roller. Get a new bow roller that has the grove that will align the chain to the gypsy. Perhaps your bow roller is for line and not chain. I have a bow roller w the groove and use mostly nylon line haha.

Eric


-- Edited by nomadwilly on Thursday 12th of January 2012 12:21:50 PM

 

[Marin]

FF wrote:

There will frequently be a grove machined in the roller that keeps the chain from twisting

The deck fitting , that actually holds the boat while anchored will do the same thing , if the groove is missing on the bow roller.

If neither is present , shoot the surveyor.

Grand Banks boats--- at least all the ones I've paid any attention to in this respect--- simply have flat rollers on the pulpit.* They have rims to keep the chain on the roller, but there is no groove machined into them.*

As to what the rode is held by, some people let the windlass take the strain, some people use a chain grab and short line cleated to the top of the windlass, and some (like us) use a snubber that's cleated to one or two deck cleats with the chain slacked off between the windlass and the snubber's chain grab.* None of these methods play any role in whether or not the chain can twist.

And, I should add, we don't use a swivel and we have never experienced a kink or twist of any kind in our rode.* If the boat has circled the anchor enough times to cause the chain to lie over itself, it all comes out as soon as the anchor is off the bottom.


-- Edited by Marin on Thursday 12th of January 2012 01:20:36 PM