440: Anchor Chain Size and Anchor Size - Lagoon 440

[Adelie]

So if money is not a big deal here then my thought would be to go with:
5/16" G70 hot dipped anchor chain (4700 lb SWL, 1.1lb/ft) and an A140 or 200 Aluminum Spade anchor. There would be a moderate decrease in chain weight despite doubling the length and a slight drop in anchor weight with a marginal increase in working strength.
https://www.spadeanchorusa.com/anchor-sizing-charts.php
https://www.westmarine.com/acco--gra...05_154_001_512

The 3/8" G43 has a safe working load of 5400lb at 1.49lb/ft. Would give you a moderate increase in weight and also in working strength.

1/2" BBB or G30 has SWL of 4500 at 2.8lb/ft

In reality 3/8" G43/HT will be about 10% weaker than BBB and the G70 another 12% weaker still. The safe working load for G43/HT and G70 is 33% of breaking strength instead of 25% as with BBB.

5/16" G70: 14,100lb breaking strength.
3/8" G43/HT: 16,200lb breaking strength
1/2" BBB: 18,000lb

[UFO]

Originally Posted by Adelie

So if money is not a big deal here then my thought would be to go with:
5/16" G70 hot dipped anchor chain (4700 lb SWL, 1.1lb/ft) and an A140 or 200 Aluminum Spade anchor. There would be a moderate decrease in chain weight despite doubling the length and a slight drop in anchor weight with a marginal increase in working strength.
https://www.spadeanchorusa.com/anchor-sizing-charts.php
https://www.westmarine.com/acco--gra...05_154_001_512

The 3/8" G43 has a safe working load of 5400lb at 1.49lb/ft. Would give you a moderate increase in weight and also in working strength.

1/2" BBB or G30 has SWL of 4500 at 2.8lb/ft

In reality 3/8" G43/HT will be about 10% weaker than BBB and the G70 another 12% weaker still. The safe working load for G43/HT and G70 is 33% of breaking strength instead of 25% as with BBB.

5/16" G70: 14,100lb breaking strength.
3/8" G43/HT: 16,200lb breaking strength
1/2" BBB: 18,000lb

The point is not so much about strength, but about the extra holding power the heavier chain gives you at anchor.

[rom]

Originally Posted by UFO

The point is not so much about strength, but about the extra holding power the heavier chain gives you at anchor.

I am glad you get that point right ! Another advantage of 12mm is that you can use a big 90mm wichard snap shackle through a chain link to connect the bridle. https://marine.wichard.com/fiche-A|W...000000-ME.html

[fxykty]

Originally Posted by rom

I am glad you get that point right ! Another advantage of 12mm is that you can use a big 90mm wichard snap shackle through a chain link to connect the bridle. https://marine.wichard.com/fiche-A|W...000000-ME.html

Hmmm, I’ve never seen a snap shackle used as a bridle to chain connection. What keeps it from opening when it drags along the bottom? Or keeps it from bending open when it doesn’t rotate with the chain? That can’t be a good idea.

Use a chain hook, or chain grip shackle, or rolling hitch, or even better a soft shackle.

[rom]

Originally Posted by fxykty

Hmmm, I’ve never seen a snap shackle used as a bridle to chain connection. What keeps it from opening when it drags along the bottom? Or keeps it from bending open when it doesn’t rotate with the chain? That can’t be a good idea.

Use a chain hook, or chain grip shackle, or rolling hitch, or even better a soft shackle.

Well, there is theory (or your idea of theory) and then there is experience. I had a bad experience with Wichard's chain grip where the small pin that holds the chain in the hook eventually bent.https://marine.wichard.com/fiche-A|W...000000-ME.html
The equivalent size snap shackle has a higher working load and has been working flawlessly for me, about 4 years and 1460 anchorages :-) I saw that same snap shackle in use in two different charter companies, the reason is it is super easy to use and reliable.
Soft shackle does not sound like a bad idea, what are you using yourself ?

[rom]

[UFO]

Originally Posted by fxykty

Hmmm, I’ve never seen a snap shackle used as a bridle to chain connection. What keeps it from opening when it drags along the bottom? Or keeps it from bending open when it doesn’t rotate with the chain? That can’t be a good idea.

Use a chain hook, or chain grip shackle, or rolling hitch, or even better a soft shackle.

Soft Shackle

[boom23]

Soft shackle worked great for me.

[MikeFergie]

Look for “sailing impi” on you tube or Instagram. Brent and Ana have had extensive sailing on a Lagoon 440 for over 8 years around the world. All conditions and destinations. I would go with Brents recommendation on your boat

[Bean Counter]

A potential problem with a complicated bridle attachment - that in severe condition if the snap shackle or whatever is being used does get deformed and it is not possible to quickly release in an emergency to allow the anchor to be retrieved. I guess having a big set of bolt cutters on board would solve it. We carried bolt cutters capable of cutting 12mm chain (and big wire cutters).

[boom23]

Originally Posted by Bean Counter

A potential problem with a complicated bridle attachment - that in severe condition if the snap shackle or whatever is being used does get deformed and it is not possible to quickly release in an emergency to allow the anchor to be retrieved. I guess having a big set of bolt cutters on board would solve it. We carried bolt cutters capable of cutting 12mm chain (and big wire cutters).

A soft shackle solves this problem.

[steve450]

Originally Posted by Adelie

So if money is not a big deal here then my thought would be to go with:
5/16" G70 hot dipped anchor chain (4700 lb SWL, 1.1lb/ft) and an A140 or 200 Aluminum Spade anchor. There would be a moderate decrease in chain weight despite doubling the length and a slight drop in anchor weight with a marginal increase in working strength.
https://www.spadeanchorusa.com/anchor-sizing-charts.php
https://www.westmarine.com/acco--gra...05_154_001_512

The 3/8" G43 has a safe working load of 5400lb at 1.49lb/ft. Would give you a moderate increase in weight and also in working strength.

1/2" BBB or G30 has SWL of 4500 at 2.8lb/ft

In reality 3/8" G43/HT will be about 10% weaker than BBB and the G70 another 12% weaker still. The safe working load for G43/HT and G70 is 33% of breaking strength instead of 25% as with BBB.

5/16" G70: 14,100lb breaking strength.
3/8" G43/HT: 16,200lb breaking strength
1/2" BBB: 18,000lb

You must be insane or stupid to reccomend using 5/16 on a 16-20 ton flybridge catamaran you idea will possible kill some one .i haven’t seen that chain recommened buy any manufacture so how can you disagree with that.most comments are saying use the heavier chain and largest anchor at least 40kg and choose one that has been designed recently not something built for noahs ark.the other thing is the bridal it should be strong enough not to break also are you going to speed the extra money on a rated wichard shackle or one from a hardware shop.your anchor system is the most important item on your boat also if anyone can disprove our systems prove it or come sailing with us

[fxykty]

Originally Posted by steve450

You must be insane or stupid to reccomend using 5/16 on a 16-20 ton flybridge catamaran you idea will possible kill some one .i haven’t seen that chain recommened buy any manufacture so how can you disagree with that.most comments are saying use the heavier chain and largest anchor at least 40kg and choose one that has been designed recently not something built for noahs ark.the other thing is the bridal it should be strong enough not to break also are you going to speed the extra money on a rated wichard shackle or one from a hardware shop.your anchor system is the most important item on your boat also if anyone can disprove our systems prove it or come sailing with us

Take a look at the moderate and ultimate holding power figures of the anchor you’re thinking of, then size your everyday and storm systems accordingly. For anchor and chain and shackles and (if using) swivel and chain stopper should all be sized for the highest working load. You won’t be swapping anchors and ride for storm use, just adding on if desired.

However, bridles, especially for cats, should be sized for everyday use and storm use, as the latter system will be too long and too big for ordinary use. In our case, with a Spade S180 and 1/2” G4 chain, our ultimate working loads are about 3500kg tension according to the ABYC table. Our everyday bridle is 6.5m per leg of 14mm Samson Proset 3 strand with SWL of 1800 kg. That’s plenty for everyday. For storm use we have 12m per leg of 24mm Polyester 8 braid (attached to two cleats each side with a 12mm UHMWPE loop to avoid any chafe issues) with a SWL of 3200kg.

We use a 8mm UHMWPE soft shackle and 10mm Dyneema climbing webbing loop. The SWL of this system is about 3000kg, limited by the webbing loop, though we could thread it through again to double the strength. We originally threaded the soft shackle through the chain but it’s a tight fit and really eats the shackle, so now we use the webbing loop through the chain.

[UFO]

Originally Posted by fxykty

Take a look at the moderate and ultimate holding power figures of the anchor you’re thinking of, then size your everyday and storm systems accordingly. For anchor and chain and shackles and (if using) swivel and chain stopper should all be sized for the highest working load. You won’t be swapping anchors and ride for storm use, just adding on if desired.

However, bridles, especially for cats, should be sized for everyday use and storm use, as the latter system will be too long and too big for ordinary use. In our case, with a Spade S180 and 1/2” G4 chain, our ultimate working loads are about 3500kg tension according to the ABYC table. Our everyday bridle is 6.5m per leg of 14mm Samson Proset 3 strand with SWL of 1800 kg. That’s plenty for everyday. For storm use we have 12m per leg of 24mm Polyester 8 braid (attached to two cleats each side with a 12mm UHMWPE loop to avoid any chafe issues) with a SWL of 3200kg.

We use a 8mm UHMWPE soft shackle and 10mm Dyneema climbing webbing loop. The SWL of this system is about 3000kg, limited by the webbing loop, though we could thread it through again to double the strength. We originally threaded the soft shackle through the chain but it’s a tight fit and really eats the shackle, so now we use the webbing loop through the chain.

Attachment 205064

I like your webbing loop idea - How do they go with abrasion? Is that a Black Diamond loop you are using?

[KP44]

Originally Posted by fxykty

Take a look at the moderate and ultimate holding power figures of the anchor you’re thinking of, then size your everyday and storm systems accordingly. For anchor and chain and shackles and (if using) swivel and chain stopper should all be sized for the highest working load. You won’t be swapping anchors and ride for storm use, just adding on if desired.

Yes. Always use your main anchor when you anchor. Never use a smaller "lunch hook" or any small anchor. Anchor as if an unexpected squall or storm is possible. And always use a capable snubber, bridal, or pendant.