Two Anchor Swivels

[Anders]

Kong specifies a SWL at 90° of 2000kgf for the 8 - 12mm swivel but anyone using 12mm chain would be better off with the 12 -14mm swivel.
With my 8mm chain and three links of 10mm chain I'm very confident that the swivel will be the last thing to break.

[noelex 77]

Originally Posted by Anders

Kong specifies a SWL at 90° of 2000kgf for the 8 - 12mm swivel but anyone using 12mm chain would be better off with the 12 -14mm swivel.
With my 8mm chain and three links of 10mm chain I'm very confident that the swivel will be the last thing to break.

With three links of chain you are very safe with a good quality swivel like the Kong .

Check that the swivel, chain and the extra shackle cannot jam or lock in place with different directions of pull.

Finally, I would suggest using the same 8mm chain rather than 10mm for the three links. Bulk on the anchor chain connection does impact on anchor performance. There is already extra hardware with the swivel.

The anchor has to bury to achieve its maximum holding power and that means the chain and any connection near the anchor also has to be forced below the substrate.

[Anders]

Originally Posted by noelex 77

With three links of chain you are very safe with a good quality swivel like the Kong .

Check that the swivel, chain and the extra shackle cannot jam or lock in place with different directions of pull.

Finally, I would suggest using the same 8mm chain rather than 10mm for the three links. Bulk on the anchor chain connection does impact on anchor performance. There is already extra hardware with the swivel.

The anchor has to bury to achieve its maximum holding power and that means the chain and any connection near the anchor also has to be forced below the substrate.

Reason for the 10mm chain is to be able to use a bigger shackle. They also have a reduction in strength when sideloaded. I should probably run the numbers again since I need some more mooring shackles. By the time my 15kg Rocna has buried itself up to where the swivel is I'm not to bothered about if the chain has a tiny bit more resistance.

[noelex 77]

It is reassuring to see that you are considering the strength of each of the components .

If you have G30 or G40 chain you should be able to find a shackle that fits 8mm chain and is not the weak link even with side loading.

The Crosby G-209A is one of the best shackles. The dimensions and SWL are shown in the table below. The SWL for side loading is 70% at 45° and 50% at 90° of the table values.

[Anders]

It's G30. Extra strength never hurts but 8mm chain on a 30' 4.5t should be strong enough.

[mikereed100]

What does a swivel actually accomplish? In a situation where the boat is spinning around the anchor, the anchor should just reposition if there is any tension on it. To me they just seem an unnecessary weak point. I am open to being educated, but, having lived at anchor and cruised for over 40 years, I just can't conceive of any need for one.

[Goodxcharly]

My comments below:

- Get rid of the swivel. I just see them as a weak link.

- keep the rest

- anchor-shackle-chain-shackle-thimble or knot-rode

- My 2 bits.

[gulfislandfred]

Stainless steel anchors, swivels, etc with cause electrolysis that destroys the galvanized coating on your steel anchors, chain swivels, etc.


Even a bit of stainless tie wire on an anchor shackle will cause electrolysis. Use plastic zip ties or real monel tie wire.



When you walk down a dock, look at the anchor gear on the bows of the boats.
Most of the boats with SS swivels will have rust on the first foot or two of the galvanized chain.


I have heard rumours of a SS alloy used in some swivels that is electrically neutral, but I haven't seen it yet.


An all galvanized anchor system will last for a long time.

[Bluechart]

When I purchased my 2nd boat, it came with a SS Bruce & SS swivel.
At that time I’d been teaching sailing on SF Bay for 5 years (40’ boats), experienced and studied anchors/ground tackle, and advised my adult students. (I’ve been sailing for ~50 years.) My #1 concern for anchoring- was staying put.
I removed my Bruce and swivel, and replaced with a galvanized Rocna and Crosby shackle.
(My insurance policy at the time specifically excluded losses resulting from failed SS swivels.)
One look at an Anchor Load Test chart, and I’d think you’d swap out that Bruce. I know many owners who swear by their Bruce anchors, but not me when it comes to my boat and family!
In my opinion, the rode should be continuous, one length of chain, spliced to one length of nylon rope, tied to the boat. Else, each “attachment/swivel/removable link” are weak spots.
Here is a link to anchor test chart for soft and hard sand. (There are similar tests/charts for mud.). https://www.petersmith.net.nz/boat-a...ce-testing.php

[nofacey]

For 6 mo…..keep it all the same, figure out what you like/don’t like. The Bruce just might work for your boat/area…..Rocna have their weaknesses too.

Long term, make your call on the anchor, shackle, 3-4 links chain, a decent rated swivel (I like being able to easily straighten out anchor), and as much chain as you can afford to carry….300ft if you’re going offshore. If you’re going with less chain, splice in 3strand rope rode to get you to 300ft overall….hopefully your windlass has a chain/rope gypsy. All components need to be rated higher than your main chain.

Circumnavigated, anchored lots is a very wide range of conditions - used a big CQR (!) and didn’t die. Don’t just bow to anchor fads if what you have works.

[MJH]

Originally Posted by Charlie

Hi All:

Just bought a new boat in Ireland. A ten hour flight away. The previous owner had the boat for 10 + years and never anchored. Good thing as well since his anchor gear consisted of : 1) SS Bruce Anchor, 2) SS swivel, 3) About a meter of SS 3/8 chain, 4) a very cheap, non welded, and rusted chain link, and Finally 4) 30 meters of galvanized 3/8" chain. The 30 meters of chain is in good nick. I am thinking of putting another SS swivel to connect the SS to the Galvanized. The layout of the tackle is such that the second swivel will never touch the windlass. Two problems that I see are 1) It does fail the KISS principle and 2)It adds a second failure point. I am okay with these as the SS does look better going into the anchor locker.

Are there any other problems that anyone can see with the setup that I am envisioning?

My second option would be to remove the SS chain and go directly to the galvanized.

I would get rid of all s.s. gear. Buy/install vertical windlass if boat does not have one (you don't say). Buy/install new properly sized galvanized anchor, shackle, and chain (300'). Completed, you will be able to anchor anywhere with confidence.

Good Luck.

[Cynara]

How many anchors do you have. Make sure you have at least twp

[Dockhead]

Originally Posted by noelex 77

It is reassuring to see that you are considering the strength of each of the components .

If you have G30 or G40 chain you should be able to find a shackle that fits 8mm chain and is not the weak link even with side loading.

The Crosby G-209A is one of the best shackles. The dimensions and SWL are shown in the table below. The SWL for side loading is 70% at 45° and 50% at 90° of the table values.

The lovely Crosby shackles are not generally available in Europe.

I finally found equivalent good shackles here:

https://www.stfeurope.com/manilles-g...-6mm_cr_4033kg

They are made by Chaineries Limousines, are Grade 70, hella strong, and not expensive.

STF Europe is where I bought my new anchor chain last year; the chain also came from Chaineries Limousine and I am very pleased with it, including with the price, less than €1500 for 100 meters of G40 12mm. I was amazed at the price, as at the time I was buying structural steel for building for €6500 per tonne in large quantities; this was cheaper than that, and even today that chain is only €16 per meter. 100m of 12mm chain is 330 kg; a third of a tonne.



The chain was shipped to me in Denmark for under €100 and arrived in two days. You can also get Grade 70 chain from them if you want that.

[Charlie]

Thanks for all the comments. A lot of food for thought. I am going to pick up a few of the Crosby shackles. I will need to find out exactly what size the existing chain is whether ot is 3/8 or 8mm.

Dockhead thanks for the info on the chain. I will need to buy a new gypsy should I change to the G30 chain but the weight savings would be dramatic.

As of now I will do the following: 1) Attach one meter of SS chain to the anchor with a Crosby shackle, 2) change out the location of the swivel (By the looks of it the swivel is a Kong.) To the end of the one meter length of SS chain. 3) I am going to add 70 meters of 5/8" octoplait spliced into the chain.

I am comfortable with a Bruce anchor. After using it for three months I will make a decision as to whether I need new anchor or not.

[Dockhead]

Originally Posted by mikereed100

What does a swivel actually accomplish? In a situation where the boat is spinning around the anchor, the anchor should just reposition if there is any tension on it. To me they just seem an unnecessary weak point. I am open to being educated, but, having lived at anchor and cruised for over 40 years, I just can't conceive of any need for one.

I generally agree, but there was one situation where I did feel I need a swivel -- FWIW.


That was when I was using a 121 pound Rocna anchor. This type of anchor has no ballast, and has a hoop adding weight to the wrong side of the anchor. In my usage at least, it tended to come up upside down, and stay that way, making it hard to get into the roller. No amount of adjusting the chain -- turning it in the gypsy, etc. -- helped.


Eventually I added a Kong swivel so that I could turn the anchor with a boathook before the final pull into the roller.


This worked but was a real PITA.


I eventually went back to a ballasted, hoopless anchor -- a Spade like what I had been using on the previous boat since the late 90's. This anchor is balanced properly with lead ballast and doesn't need a swivel.


I'm now using a stainless Ultra -- very similar to the Spade, also with lead ballast, but even better balanced. I now sometimes raise the anchor from the cockpit without even being able to see it until the shank comes through the roller, but never a problem.


I would not think that one would need a swivel with a Bruce. I never owned a Bruce but used them on charter boats, and in my experience they were fine without a swivel.