Joining Chain to Anchor

[duncan_ellison]

As a follow up to my recent thread on anchor swivels ....

I have 3/8" BBB chain (ACCO, I think) and I'm trying to attach my 44# Delta with a swivel.

From the previous thread, I now understand that I should use a bow shackle on the anchor itself with the bow part in the anchor hole (although I did a quick poll at the marina this morning and found that 80%+ had the pin though the anchor shank). So I have a big 3 1/2T schackle taking care of this.

Now on to the swivel part. To reduce the number of possible failure modes, I have a good quality US made swivel with an eye on one end and a pin on the other which goes through the chain, like this ... Swivel

My question is will that little stainless cotter really keep the pin in place ?

I realise that aircraft are kept from falling from the sky by clevis pins secured by cotters and that the load is on the clevis pin not the securing pin, but .... I can't help thinking this is a little flimsy considering the junk down below the anchor might get dropped into.

Anyone else use this arrangement ?

Duncan

[Wand]

I wouldn't like that setup either; maybe replace the securing pin with wire and tie it off? You'd sleep better.

[boatman61]

I think you mean.. will that little pin secure your cotter...
If you set it right it'll be fine.. they're what hold your rigging up.. and the manufacturer obviously thinks so...
But.. on the bright side you can check it every time you raise the anchor... much easier than your rigging

Or you could blob some super glue on the other end as backup..

[craigsmith]

I don't know if you took much away from your thread on swivels. That's a very cheap option. The inline strength should be adequate for G30 chain, but the galvanizing will wear quickly. Galvanized swivels are also subject to binding and don't behave as nicely as stainless. Keep a very close eye on the weld at the swivel nut, corrosion of this weld (if the manufacturer stuffed it up, or there is pin-holing which compromises the corrosion protection abilities of the HDG) followed by the nut undoing itself is a common failure mode.

The clevis pin is okay, if a bit agricultural. Just keep an eye on it. Seizing with monel wire would be better.

You're using heavy chain and a relatively inefficient anchor, joined with a very agricultural connection. It'll work just as it did 30, 50, or 70 years ago... but this is 2010 and you have far superior options for all components.

Originally Posted by duncan_ellison

From the previous thread, I now understand that I should use a bow shackle on the anchor itself with the bow part in the anchor hole (although I did a quick poll at the marina this morning and found that 80%+ had the pin though the anchor shank).

That says more about 80% of boaters at your marina than anything about the proper way of doing things. That said, many anchors are poorly designed in this respect and cannot accept the head of a shackle, requiring the use of two in order to achieve the proper size (body to body, with respective pins through the chain and anchor shank). If the head is through the chain, the shackle is undersized and very likely weaker than the chain, particularly if a sensible grade of chain is in use.

When you're talking about swivels, it's not really that critical, but the body of a bow shackle will in theory behave a little better if through the anchor shank, permitting easier articulation with less chance of jamming.

[s/v Jedi]

Make it big and make it strong ! But as can be seen in the photo below, the cotter pin is better replaced with monel wire.

The photo shows shackle and swivel in 3/4" with a 3/8" G.7 chain that has enlarged end-links... and the shank is part of a 176 pound Bruce.

We used 5/8" shackle and swivel before and it held our boat during Hurricane Ivan in Grenada (cat4-5). Afterwards, the swivel was fine but the shackle malformed and had to be cut off the anchor.

I will always be all over craigsmith when this subject comes up There were 300 boats in this bay in Grenada when Ivan passed right over it.. only 4 came out on their own power and it was thanks to this strong & robust nautical (nothing agricultural about it) hardware that we were one of them. Shiny anchors and connectors look nice in marina's but this stuff keeps you safe at anchor!



cheers,
Nick.

[John A]

Because the pin in the shakle never moves, and may be a disimilar metal, in less than a month of everyday use the pin will-be corroded to the shackle and require a hacksaw to seperate.

The pin for the shakle on my swivel screws into the shackle and I always wired the pin so that it wouldn't unscrew. I've never used a shakle that only had a cottor pin to sequre the pin.

[Dockhead]

I think Nick and Craig are both right in this case. I don't think Nick would use G30 chain, big or not. And a Delta anchor is fine if it weighs 176 pounds. But I think the OP could do a lot better in every aspect of his ground tackle.

[Boracay]

For myself, I don't like the thought of a stainless steel split pin in a galvanised swivel. Something might sacrifice itself...

If the cotter was what I had I'd go with a zinc plated split pin (used to hold boat trailer wheels on), and plan on inspecting/replacing often.

I'd also prefer a heavier swivel (the type without cotter pins) joined to chain and anchor using shackles.

I've wired my shackle pins on with galvanised wire. Must have a look and see how they're holding up...

[craigsmith]

Originally Posted by Boracay

For myself, I don't like the thought of a stainless steel split pin in a galvanised swivel. Something might sacrifice itself...

It's fine.

[duncan_ellison]

Nothing like an anchoring question to get the forum going, is there ? ;-)

I've spent more boating dollars in the last few weeks on anchor terminals than food and I'm building up small branch of West Marine here, but I still don't seem to be able to get the correct combination of items to be happy.

Let's see if I leaned anything here :

1) The setup I have is the same as Nick's (even looks like the same brand of swivel) and it serves him well.

2) It's OK to us a stainless cotter pin, just make sure you inspect it regularly. Monel siezing wire would work as well, but somehow I think the pin seems more robust than the wire option.

3) Watch out for corrosion where the pin goes through the chain. Check.

Craig says a stainless swivel is better than a galvanized one as they "don't behave as nicely as stainless". I tend to agree. So .. I had a beautiful stainless swivel in my hands at WM yesterday, good price, really easy articulation, reputable brand (Suncor), actually stamped with a high WLL figure. Then the WM guy comes over and says "wouldn't put that on galvanized chain if I were you". I thought about it for a moment and using the 'it will all corrode away in an instant' arguement above, I put it back on the shelf and went for a no-name galvanized one instead. What's the real story here ?

FWIW, I've been happy with the Delta, it's held up in 35Kn+, but I also have a Spade A100 on the bow ready to go and a Fortress FX-37 in a bag ready to deploy.

If things look like they will get really bad, I plan to deploy all three in a 180 deg pattern.

Seems like anyone without a Rocna is becoming a poor relation, but that's just not going to happen on TALISA, not this season at least.

Duncan

[craigsmith]

I don't disagree with Nick above. The issues I mentioned are hypothetical and not a given for any given example. You don't have the same set-up as Nick, he has an over-sized anchor and high tensile chain. Far more efficient than the alternatives for the same or less weight. His swivel has proven okay, great - yours won't necessarily. Watch like a hawk the weld on the nut. If you see bleeding from it then return the unit. The pin won't cause issues.

There is no issue with dissimilar metals etc, the whole thing is just Chicken Little talk. Even stainless. In theory the zinc of the HDG will sacrifice itself to the exposed stainless steel, by way of galvanic corrosion when immersed, but the effect is so slow that your HDG will need re-doing on account of normal wear and tear long before it has any practical effect. The less the area of stainless and the greater the surrounding area of HDG, the smaller the effect still. It is fine to use mixed metal components, e.g. stainless anchor and HDG chain, let alone a tiny swivel or shackle much less a clevis pin... and even in theory, it is the HDG that goes, the stainless components are protected by it.

[craigsmith]

Originally Posted by duncan_ellison

FWIW, I've been happy with the Delta, it's held up in 35Kn+, but I also have a Spade A100 on the bow ready to go and a Fortress FX-37 in a bag ready to deploy.

P.S. Your Spade, were it not aluminium, is a far superior anchor to your Delta. (The S100 is 20 kg / 44 lb). The alloy ones are really rather unfit-for-purpose in terms of strength and have a habit of folding in half, but not so with the steel ones which happen to be cheaper too. The A100 is worth US$950 new, you have a lot of anchoring equity tied up there... Suggestion: sell the Spade, replace it with a steel version of the same size (or a Rocna of course ), and demote your Delta. Using a Delta when there's a Spade onboard seems rather strange.

[Dockhead]

Originally Posted by duncan_ellison

Nothing like an anchoring question to get the forum going, is there ? ;-)

I've spent more boating dollars in the last few weeks on anchor terminals than food and I'm building up small branch of West Marine here, but I still don't seem to be able to get the correct combination of items to be happy.

Let's see if I leaned anything here :

1) The setup I have is the same as Nick's (even looks like the same brand of swivel) and it serves him well.

2) It's OK to us a stainless cotter pin, just make sure you inspect it regularly. Monel siezing wire would work as well, but somehow I think the pin seems more robust than the wire option.

3) Watch out for corrosion where the pin goes through the chain. Check.

Craig says a stainless swivel is better than a galvanized one as they "don't behave as nicely as stainless". I tend to agree. So .. I had a beautiful stainless swivel in my hands at WM yesterday, good price, really easy articulation, reputable brand (Suncor), actually stamped with a high WLL figure. Then the WM guy comes over and says "wouldn't put that on galvanized chain if I were you". I thought about it for a moment and using the 'it will all corrode away in an instant' arguement above, I put it back on the shelf and went for a no-name galvanized one instead. What's the real story here ?

FWIW, I've been happy with the Delta, it's held up in 35Kn+, but I also have a Spade A100 on the bow ready to go and a Fortress FX-37 in a bag ready to deploy.

If things look like they will get really bad, I plan to deploy all three in a 180 deg pattern.

Seems like anyone without a Rocna is becoming a poor relation, but that's just not going to happen on TALISA, not this season at least.

Duncan

My comments, for whatever they're worth:

1. Your setup is NOT the same as Nick's if it is not sized the way Nick has got his sized. An anchor will be effective if it is either very large or a very good design. Preferably both. But after a certain size anchor design stops mattering so much -- just look at the anchors on big ships.

2. You don't need a Rocna to avoid being a poor relation. Spade and Manson seem to be equal. I've owned both Spade and Rocna and notice no difference between them, but an enormous difference between them and everything else I have used (CQR, Delta, Bruce). I would bet you have noticed a big difference between your Spade and your Delta. I have a Delta 25kg, a Rocna 55kg, and a big Fortress on my boat. The Delta was what came with the boat from the yard and it is inadequate in any but the best holding and calmest conditions (the drawbacks of its design are exacerbated by its being far too small for my 24 ton boat).

3. Stainless steel shackles and swivels do not corrode rapidly against galvanized despite the dissimilar metals. I don't know why but it is a fact. Stainless operates much more smoothly, itself also a safety factor.

4. Your swivel is nearly always going to be the weak point in your ground tackle. I use an enormous and enormously expensive (something over $300) stainless Kong swivel on my ground tackle. I don't like the idea of having any swivel at all, but on my current setup I had no choice -- no other way to get the anchor stowed. The Kong is supposed to be the strongest, and has another advantage in that it has a very smooth shape with nothing to catch in your bow roller cheeks.

[JamuJoe]

I use a quality stainless swivel between my 3/8" G4 Chain and my 70 lb Delta. It works as it should and has presented no corrosion at the interface. I am completely satisfied with my Delta. It sets beautifully and holds fast just as an anchor should. I generally dive my anchor, unless depth prohibits, and very few are the times that I've not been satisfied with the initial set of the Delta. Cruising the Mesoamerican Reef off of Belize presents the most challenging anchoring conditions that I've ever encountered, and I've seen many boats struggle to get a set and/or ultimately drag, as I did with the original CQR on my boat. I sleep well with my Delta on bottom.

[mrohr]

Regarding use of SS shackle:I may be wrong here,but it is my understanding that SS shackles will work harden over time esp. when exposed to heavy alternating loads as in an exposed anchorage, while mild steel will deform before catastrophic failure.
I doubt if a little overkill is harmful and all parts of your system should have your total confidence and are readily aviable for inspection every time it comes up. I like to sleep.