Anchor chain question.....

Captain Larry-DH · Nov 6, 2020

Hi Greg -
In the Eastern US or Bahamas I can't imagine a situation where you'd need more than ~100' of 5/16 HT chain for your boat, backed by another 150+' of rope rode. Anything else is excessive weight, IMHO. You'd have to decide whether that's worth the cost of changing the gypsy. I have a spare (moderately used) 5/16" HT gypsy from a Lewmar Ocean 1 series windlass, so PM me if interested. I don't know how specialized (fit) those are.

Richard19068 · Nov 6, 2020

Stu Jackson said:
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.

Thanks. That clarifies it. I was just trying to relate it to my experiences sailing in the Salish Sea area and a few times wanting a lot more chain than the boat had. One time had to borrow some from a buddy boat to get down in Princess Louisa inlet.

Even here in So Cal some of the anchorages can be very deep very close to shore. 80 to 100 feet is not unusual.

Captain Larry-DH · Nov 6, 2020

My research and limited experiences on anchor tuning:

Mixed rope/chain is best for most small boats
There is no “rule of thumb” that is right for every boat or anchoring situation.
(The old axiom "one foot per foot of boat length" has no basis)

Decision factors to determine proportion in mixed-rodes:
Abrasion hazards based on bottom type (rocky or coral)
Some chain is desired to resist bottom abrasion and cuts
More/all chain increases catenary
More/all chain reduces swinging, and wandering in still air
More/all chain reduces chance of prop cut or entanglement from passing boats
Weight in the bow reduces boat performance, affects trim, is not desired in the ends of the boat.
More weight in the anchor is more effective to improve holding than more weight in the chain.
All-chain reduces holding power except in very deep anchorages. * See the following reference for the engineering justification for that.

* Reference: Rode - Dynamic Behavior “Tuning an anchor rode” by Alain Fraysse (CAUTION - That page contains a spreadsheet containing Macros. Macros can download malware and compromise the security of your computer. My best advice as a computer guy who is trained in security: Read the web page content but DO NOT OPEN THE SPREADSHEET.

dLj · Nov 6, 2020

NYSail said:
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 weighs 1.04lbs 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

As I understand it, there are two things that chain does for you -

1) add weight to keep the anchor working at the preferred angle when anchored, and
2) to resist wear, especially in rock type bottoms.

@NYSail Your avatar says you are on the north side of Long Island in Long Island Sound.

Where are you sailing to that you feel you may need this change? What are your primary and secondary anchors? What do you feel you are gaining through this change?

I can't really comment unless I understand more about what you have/want to do.

dj

jssailem · Nov 6, 2020

dLj said:
I can't really comment unless I understand more about what you have/want to do.

My point as well

..

Kings Gambit · Nov 6, 2020

OK. You guys got me!! Asleep on the hook, worry free, in [tropical] storm winds? No watch? I like my [regular] sleep? Geeze

. Good luck with all of that.

It's out of my experience realm.

capta · Nov 6, 2020

Stu Jackson said:
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...)

I'd have to disagree with this. I've used all chain or cable on every boat except light weight multihulls. The anchor below (about 300#) was fouled somewhere in the middle of my chain. It was dark and I shudder to think what it would have done to the bow had we been pulling the chain remotely, never mind what it would have done to a line rode over a day or two.

Anchor wrapped in chain, chaguaramas.JPG

dLj · Nov 6, 2020

NYSail said:
Sooooo back to my question, how come the stronger chain is less expensive? I would think in the marine industry they would add a premium. Or again am I missing something??

thanks again

Greg

Stronger chain simply means that the alloy used in making the links is a different grade of steel than the chain with less tensile strength. The differences you have quoted would not even begin to bring up any kind of "red flag" as to the differences in the quality of the chain - as far as the actual links were concerned, they are likely both welded links. My main concerns would be
1) What kind of galvanizing.
2) Grade of chain links.

Looking at the price per foot costs you've quoted, you must be looking at galvanized steel chain as 3/8" stainless is quite a bit more expensive. My main concern with your lesser expensive, higher strength chain is that I'll be willing to wager that it has what is called a mechanically galvanised coating. For anchor chain, I would want expressly hot-dipped galvanized. There are a number of reasons.

The grade of the links deal with the rating of the chain and for anchor chain, I'd not be overly concerned. The main concern for me would be the galvanizing.

So - without second guessing how you want to use your anchoring system - your boat, your choice - I'd be looking carefully at the galvanizing process for each of the two chains. If it's hot dipped galvanized - it will state that explicitly - hot dipped galvanized... Not some euphemism that is trying to market you "high corrosion resistant" or some such marketing crap...

dj

Hello Below · Nov 6, 2020

NYSail said:
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.

NYSail just to clarify, you are comparing 3/8" BBB to 5/16" G4 in your original post correct?

dLj · Nov 6, 2020

Price difference is due to link size. I guess I'm not understanding your question?

5/16" = 0.3125" diameter
3/8" = 0.375" diameter.

17% difference in material - in just steel. Price difference in cost is not far off that at about 27%, but don't forget you've also got a measurable addition in galvanizing material and actual more chain length in the 3/8" links.... Seems like about right on the price differential...

dj

jssailem · Nov 6, 2020

I explored Fisheries Supply and found the same pricing difference. BBB galvanized is more expensive than the g43.
The G43 has a more than double WL about 5400 than the BBB at around 2600.

jssailem · Nov 6, 2020

You will need to factor in the Gypsy cost as BBB and G43 use different gypsy configuration for most windlasses.

Grade 4, 40, and 43 Chain — Rigging Doctor

For a very long time, BBB was considered to be the epitome of perfection when it came to anchor rode. BBB is very strong, galvanized to protect against corrosion, and produced in a calibrated method that allowed it to run smoothly through a windlass. With advances in metallurgy though, BBB became a

www.riggingdoctor.com

Stu Jackson · Nov 6, 2020

NYSail said:
every deep anchorage I’m in most of the boats have primarily all chain out and much more in their lockers. Guess they are as dumb as me.....

NYS, thanks for describing your plans, makes sense.
My only question is: what the heck good is that chain doing in their lockers?
Your boat, your choice.

Richard19068 · Nov 6, 2020

NYSail said:
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.

I think that's your answer right there.

Terry Cox · Nov 6, 2020

Very pleased with the ACCO brand hot dipped galvanized 5/16" G40 chain made in the USA that I've been using in our waters since 2015 that still looks as new. Will never trust off shore Asian made products for the most important boat system. Big difference between galvanized and hot dipped galvanized steel.

Anchor chain question.....

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