Anchor Chain Question

[Matt sachs]

I have a 50 ft steel Roberts. She will have 2 anchors on the bow. displaces aprox. 17 tonns and has a big wheel house so she will catch the wind more than most, I think.
Im looking at a 400 ft drum of acco 3/8 BBB WLL of 2750 pounds and total weight of 668 pounds for $1,752
compared to 550 ft drum of acco 5/16 G4 WLL 3900 pounds and total weight of 605 pounds for $1,848. There is no shipping charges for either one.

Is this a no brainer, or am I missing something? Im leaning toward the G4.

[skipmac]

Wondering if you might want to go one size larger. I'm looking at exactly the same two options for my 42' Pearson without a pilothouse. From reading on the Pearson424 web site it seems like the other owners are more or less split between 3/8" BBB and 5/16 G4.

Of course you do need to make sure that whichever one you choose works with the gypsy on your windlass.

After much research, reading and agonizing I will go with the 5/16 G4. One consideration. If I recall, BBB and G4 chains are rated differently. I believe BBB chain rated working load limit is a lower percentage of its breaking load than G4 so a slightly higher margin of safety with the BBB.

[Matt sachs]

Thanks, Skip. Im buying windlass' also so Ill just get what fits the chain I end up with. I didn't know the differences in how the WLL was calculated....I do like the idea of having 300 ft on one side and 250 on thre other.

[skipmac]

Correction,

I just checked the specs at 1st Chain Supply and it says that the G40 anchor chain and the BBB the WLL is 1/4 of the breaking strength.

So gave you some wrong information but I certainly recall reading a discussion this issue at some point in my chain research.

[skipmac]

Originally Posted by Matt sachs

I do like the idea of having 300 ft on one side and 250 on thre other.

All chain rode on both anchors is nice but at least for my boat will add a lot of extra weight. I'm planning on about 300' all chain on my primary and maybe 50-100 of chain with nylon on the spare.

Back in the old days always used two anchors but with the new generation I only use one in most situations. I will keep a Fortress rigged at the stern for a kedge and a backup plus another new gen stored below for a backup in case I lose the primary.

[Matt sachs]

I went to the NACM (national association of chain maunfacturing) web site. They put the fail strength of 3/8 G30 (I assume thats BBB) at 10,600 pounds of force, and 5/16 G40 at 11,700. That would put the WLL of BBB at about 26% of breaking strength. The G4 fails at 11,700 so its WLL is 33% of breaking strength. Seems like a pretty good safety margin either way.

[skipmac]

Originally Posted by Matt sachs

I went to the NACM (national association of chain maunfacturing) web site. They put the fail strength of 3/8 G30 (I assume thats BBB) at 10,600 pounds of force, and 5/16 G40 at 11,700. That would put the WLL of BBB at about 26% of breaking strength. The G4 fails at 11,700 so its WLL is 33% of breaking strength. Seems like a pretty good safety margin either way.

This is what I recalled from previous research but if you look at the specs at Gr 40 Windlass Anchor Chain# it says the WLL ratings for BBB and G40 are both 1/4 breaking strength.

But I agree, either way the G40 HT seems the way to go for me. However, with your bigger boat I would think seriously about going one step up to 3/8" G40.

Do you plan to buy from 1st Chain Supply? They were the cheapest I've found and free shipping to a commercial location (you need a forklift to unload the drum).

[Matt sachs]

Originally Posted by skipmac

This is what I recalled from previous research but if you look at the specs at Gr 40 Windlass Anchor Chain# it says the WLL ratings for BBB and G40 are both 1/4 breaking strength.

But I agree, either way the G40 HT seems the way to go for me. However, with your bigger boat I would think seriously about going one step up to 3/8" G40.

Do you plan to buy from 1st Chain Supply? They were the cheapest I've found and free shipping to a commercial location (you need a forklift to unload the drum).

Yes ,1st chain seems to have the best deals. I'll have it delivered here to the office, which is technically a commercial address, and we have a fork lift next door.

[Orion Jim]

I have 5/16 BBB. On your boat I'd definitely go with the 3/8ths.

[skipmac]

Originally Posted by Matt sachs

Yes ,1st chain seems to have the best deals. I'll have it delivered here to the office, which is technically a commercial address, and we have a fork lift next door.

Now that's convenient. Be handy if my neighbor had a fork lift.

[nhschneider]

I'm no expert in anchor/chain requirements but my boat is about the same length and displacement as yours and I use 3/8" hi-test chain. I have been told by people smarter than me that heavier chain helps to keep the anchor set.

My wife is generally very reluctant to spend money for upgrades for our boat EXCEPT when it comes to anchors or anchor chain. She would probably choose 1" bar-reinforced anchor chain if I'd let her.

Fair winds, calm seas and safe anchoring.

[Matt sachs]

Thanks for the input. After sleeping on it, I'll go with 3/8 G4. Why not? Interestingly 400 feet of G40 weighs 52 pounds LESS and is more than twice as strong than 400 ft of 3/8 BBB and only costs $172 more. No brainer.

[thinwater]

a. If you were offered a choice between a knife with good steel and one with lesser steel, which would you chose? The better steel, I would think, even if the blade were thinner. Seems like it would wear longer (higher grade chain).

b. If you were measuring holding power, which would help more, 50 pounds of chain in the locker, or 10 pounds more in the anchor? It's pretty clear that mass in the anchor is the more important factor (I'm not comparing with rope, just between grades).

So why would I buy BBB, other than to save rather few $$? I would by the higher grade chain and the larger anchor. Heck, in shallow water I may not have much of that wonderful heavy chain in the water anyway. Even on short scope, I'm pretty sure the bigger anchor is the better answer.

Mooring chain is different; weight means nothing and corrosion is the enemy. Different discussion.

[Greg4cocokai]

Originally Posted by Matt sachs

Thanks for the input. After sleeping on it, I'll go with 3/8 G4. Why not? Interestingly 400 feet of G40 weighs 52 pounds LESS and is more than twice as strong than 400 ft of 3/8 BBB and only costs $172 more. No brainer.

Exellent Choice! Wish we had 1/2"!

[skipmac]

Originally Posted by thinwater

a. If you were offered a choice between a knife with good steel and one with lesser steel, which would you chose? The better steel, I would think, even if the blade were thinner. Seems like it would wear longer (higher grade chain).

b. If you were measuring holding power, which would help more, 50 pounds of chain in the locker, or 10 pounds more in the anchor? It's pretty clear that mass in the anchor is the more important factor (I'm not comparing with rope, just between grades).

So why would I buy BBB, other than to save rather few $$? I would by the higher grade chain and the larger anchor. Heck, in shallow water I may not have much of that wonderful heavy chain in the water anyway. Even on short scope, I'm pretty sure the bigger anchor is the better answer.

Mooring chain is different; weight means nothing and corrosion is the enemy. Different discussion.

Well not quite as simple as that which is why I spent so much time researching it. For example, one can also get a G70 chain which is even stronger than the G40 However the stronger chains are less forgiving of repeated shock loads and can work harden and get brittle and snap. This can build over time so an older chain that has been through some bad storms and jerks on the rode may have lost a good bit of it's safety margin. In fact I have read recommendations that G70 chain be replaced if it has been highly stressed or the links show any stretching at all.

So BBB from what I understand will stretch more before breaking where the stronger chains tend to fail more suddenly and catastrophically.

My current preference is the G40 chain as the best compromise.