Anchor chain question.....

[NYSail]

Hello all.... so upgrading my anchor chain. I currently have 3/8bbb which weighs 1.6lbs per foot, a working strength of 2,650 and a cost of $4.70 per foot. G4 is an option with a replacement gypsy and it weighs1.04lbs per foot, has a working strength of 3,900 and a cost of $3.40 per foot.
I currently have 100 ft and want to move up to 250 ft so I’m terms of weight it would be 400lbs vs 260lbs. All around better for cheaper unless I guess one needs the extra chain weight or just want to use less chain and have a greater weight.
Opinions greatly appreciated.... thanks.
Greg

 

[jssailem]

I am guessing a lower bow weight would be preferable even in a 42 ft boat.

The question I have is why do you think you need that much chain? For security you might be better served to increase the size of your anchor than adding more chain. Then add 250 ft of nylon rode.

 

[smokey73]

Is the chain (either one) Chinese made? Not saying all Chinese chain is not up to snuff, but it is worth knowing anyway. Should be cheaper to ship the G4 than the 3/8bb but then again the new gypsy will add to the cost to convert.

I agree with @jssailem on the anchor upgrade if you have not already done that.

 

[Kings Gambit]

Yeah. In what depths do you typically anchor—25 to 30 ft? I do a lot of anchoring here on the west coast in the general range of 20 to 60 ft. At 60 ft my scope is usually about 2:1 @ 150 ft of chain out, nearly all of it. (But the chain is backed by 200 ft of nylon rode which can be veered as needed.) At shallower depths I have more chain scope, of course. That said, it’s not unusual for boats of your size to carry 250 ft or more of chain. Although, I sometimes question the need for the amount of scope I see some boats putting out. At, say, 4:1 scope, 250 ft of chain gets you 60 ft of depth to anchor on all chain. Is that what you are after, or are you going for a 10:1 scope in 25 ft? Do you have an anchoring plan?

 

[thinwater]

I think the OP is on the right track. it comes down to typical water depth. As Kings Gambit implies, you don't need enough chain for the deepest place you will ever anchor, since you can back it with rope, but it is nice to be able to use all-chain >90% of the time. My PDQ has 100 feet of chain, which in the Chesapeake Bay (shallow) is enough to anchor on all chain 99% of the time. More would be a complete waste. But I very seldom anchor in more than 7 feet of water. Though you will generally use less, I like to have enough chain for 7:1 scope even in deep water, in case it really blows, so up to 25 feet (34 feet to WL with 6 feet of tide), 250 feet of chain sounds pretty good. Then add 100 feet or so of rope, for good luck.

Additional length is also very handy when kedging, though typically that will be with a lighter anchor and a very long rope. I once had to kedge 1/4 mile, and two long rodes helped!

 

[Charlie Jones s/v Tehani]

On my 25, I carry 75 feet of Hi Test 1/4 inch chain, backed by 200 feet of nylon. I've cruised the coast from Port Isabelle Texas, to Annapolis Maryland, and 3 months in the Bahamas. Over 12,000 miles. I've so seldom had all the chain out . Had thought about going to 100 feet wjhen I replaced, but just didn't seem worth it

 

[Kings Gambit]

On a recent charter to the San Juan Islands I noted that several of the fleet yachts were equipped to anchor on chain at least on 4:1 scope (e.g. @ 65 ft), the company/owner “policy.” That is, the safety seminar reported that in the SJs, 4:1 anchoring scope is the “standard practice”, so all charter skippers were asked to use 4:1 (minimally), which we did. That was their “anchoring plan.” BTW, we were never anchored in 65 ft, or even near it. Our 34-ft charter carried 300 ft of chain, just for comparison.

 

[thinwater]

This could go on forever:

• How much windage does the boat have? Following ABYC H-40, he can downsize to 5/16" G4, which decreases chain weight and increases the scope requirement.
• How deep is the water (remember to add freeboard and tide)? It turns out that the effectiveness of catenary depends a lot more on the mass of chain in the water than scope.
• How much wind? Some people think 35 knots is a lot. I've been hit with 70-80 knots in squalls a few times over many years, so I figure on that as a worst case. In settled weather I figure on more like 35 knots as the worst case overnight blow I would like to be able to sleep through.
• Waves? Some areas have open roadsteads, other places are full of snug harbors.
• Chafe? Does the bottom contain rocks or coral, or is it 100% sand and mud?
• Is the harbor crowded? Many places you can lay out 300 feet of rode with impunity. Other places you need to keep it really tight and hang fenders over the side, just in case.
• Do you trust rope? Honestly, rope does not cut or fail when it's off the bottom (unless you have serious chafe issues--fix them). But some people just sleep better with all-chain. That's absolutely a real reason and I won't tease them.
• Allowance for trimming. Every 2-5 years or so I cut away either some rope or some chain, depending on wear. I like to be able to do this comfortably. Same with halyards and even sheets.

I've used a lot of different combinations, so I'm not a hardliner.

 

[Kings Gambit]

I think the point is to equip the yacht for the job you intend for it. How much of what kind of chain one should buy, whether this or that, is a question that, in a vacuum, has no good answer. If the only considerations are cheap versus light, then OP has already answered his own question.

 

[shemandr]

I can't think of many, or any, places on LI Sound where you would anchor in 60'. Most places I can think of on LI Sound where it's 60' are far too open for anchoring. Maybe NYSail wants to go cruising but he'll get pretty far with 150' to 200' of chain.

 

[capta]

I do not see any value in stronger chain as it still will never be strong enough to hold your boat if the chain is tight from the anchor to the bow. The catenary working (weight of chain here is the key) with the properly sized anchor is what makes the system work, not the strength of the chain. Your snub line is the safety valve.
I've rarely carried more than 200 feet of chain, which will give near enough to 3:1 in 65 feet, which is pretty deep to anchor in for any length of time.
I would always go for the heavier chain over the strongest and an anchor one size larger than recommended by the manufacturer as my general rule, but that would vary with a few boats. A 125# anchor on 3/8" chain is just silly. A 125# anchor requires between 1/2" and 5/8" chain to make the system function correctly. Because, it is a system, not a bunch of individual parts.

 

[Kings Gambit]

Because, it is a system, not a bunch of individual parts.

 

[JohnShannon]

Somewhere on the internet someone wrote quite a discourse on anchoring. His ultimate point is that when it is super windy your all chain rode will be "bar tight" and provide no shock absorption. With light wind the catenary provides shock absorption but as the wind picks up that goes away just when you need it most. So you need some shock absorption like for instance nylon rope.

 

[Kings Gambit]

Somewhere on the internet someone wrote quite a discourse on anchoring. His ultimate point is that when it is super windy your all chain rode will be "bar tight" and provide no shock absorption. With light wind the catenary provides shock absorption but as the wind picks up that goes away just when you need it most. So you need some shock absorption like for instance nylon rope.

Yeah. But such reports often speak in a vacuum and are irrelevant musings in some actual settings. Shock absorbing? Where is this relevant? Yes. One should attach a nylon snubber that can be stopped off to a cleat and stretch, where its chief function is to protect the windlass from shock loads and other strain, etc. But if you are anchored in a cozy, well-sheltered spot where the sea does not enter, let the wind blow from the shelter direction. The chain comes to “bar tight”, maybe, but where is the “shock” there? True, you still need the snubber but not much for absorbing shock in that setting.

Blind Cove, Shaw Island, Sept. 2020. Scope 4:1 chain in 29 ft. Very secure.

 

[Mark Maulden]

I never have the situation where the windlass takes anchoring loads. In the PNW, I have 100’ of chain and 250’ of rode. Usually, all the chain is out and rode is cleated. If in real shallow waters, a bridle is hooked to the chain with rope and cleated.

 

[capta]

Yeah. But such reports often speak in a vacuum and are irrelevant musings in some actual settings. Shock absorbing? Where is this relevant? Yes. One should attach a nylon snubber that can be stopped off to a cleat and stretch, where its chief function is to protect the windlass from shock loads and other strain, etc. But if you are anchored in a cozy, well-sheltered spot where the sea does not enter, let the wind blow from the shelter direction. The chain comes to “bar tight”, maybe, but where is the “shock” there? True, you still need the snubber but not much for absorbing shock in that setting.
Blind Cove, Shaw Island, Sept. 2020. Scope 4:1 chain in 29 ft. Very secure.

Yu might want to revist the theory of a snub only taking the strain off the windlass If I thought that way, I wouldn't use a 30' snub. Pictures for a thousand words. Not a bit above 10 knots of wind that day.

 

[Kings Gambit]

Clearly not a sheltered cove where the sea does not enter. Try re-reading what I wrote and tell us how yours is an example of an exception.

 

[Stu Jackson]

Because, it is a system, not a bunch of individual parts.

250 feet of chain is nonsense for recreational boats unless they're going to extreme northern or southern latitudes. "Desiring" that amount of chain or even thinking about it indicates a need to learn a lot more about anchoring. Rocna has a good website, and they'vre written, gasp, entire BOOKS about it. NYS, please do some reading. You'll save a ton of $$.

Like this:

Anchor System Sizing Tables (Reply #6) & Swivels Ground Tackle & Anchor System Sizing TABLES & Swivels

Steve’s Anchoring 101

The Rocna. All 20kg of it with 100ft of chain. The rest of the world can debate all they like. When I pull into a place like Bodega Bay at midnight and the fog is so thick I can't see the jetty 50 feet away to make an entrance, I drop my hook in the rolling ocean swells with the surf crashing (Foster says it's like staying in a cheap Best Western beside the highway), and I sleep. And in the morning I have a windlass to pull the beast up and I wouldn't trade it for anything. (I also wouldn't add more chain - this works perfectly in 25 to 30 feet of water - you let all the chain out and you tie off nylon at the preferred scope and don't bother with snubbers and chain hooks and all that stuff...)

 

[Richard19068]

250 feet of chain is nonsense for recreational boats unless they're going to extreme northern or southern latitudes.

Question: Why would extreme latitudes affect how much chain you carry?
And what do you consider extreme?

Thanks.

 

[Stu Jackson]

Question: Why would extreme latitudes affect how much chain you carry?
And what do you consider extreme?

A quality respondent on cf.com has related his trip last year to Greenland, he has a 53 footer. Very deep close to shore, no anchorages as we know them. Needed a lot of rode to just touch bottom and Rocna's website articles discuss just this. Very very deep water needs less scope if you can even find the bottom!
Maybe another way to have said it would be: in reasonably normal anchorages for recreational boating...
Does that help?
I'm sure some folks sailing from WA to Alaska might consider the need, and some folks sailing east from Maine.
Otherwise, in the States, it is usually simply not that deep in anchorages that are used by most folks along the beaten track.

My friend Steve, who I quoted in my last post, sailed from Vancouver BC north to the end of Vancouver Island, then down to Mexico, with his 100 feet of chain as he wrote.

250 feet is ludicrous, unless NYS is going somewhere unusual, and he hasn't said.