How much chain..really?

[rslifkin]

Originally Posted by merrydolphin

Interestingly, from a physics, and holding power point of view. What makes chain work is the weight causing a catenary curve so as to give you a shallow angle of pull.

Physics shows that about 77 feet of chain is all you need to get full effect of the catenary, regardless of depth. You also get a lot of chafe protection as this is also the part on the bottom. This is perhaps more important to multi’s Being more weight conscious.
However! I will always opt on my mono for at least 200 feet of chain. One of the problems that concerns me in so many third world type anchorages is that power boats seem to have little problem with passing quite close to an anchored vessel. I know of a number that have had their anchor rode cut or badly damaged by this. And there is the outside chance of chafe on bottom obstructions even with the 77 feet on chain.

So you're saying that with enough wind to put 1000 lbs of pulling force on the chain, 77 feet of chain will maintain useful catenary? Not a chance unless we're talking about using massive stud link chain on a tiny boat.

[thataway41]

We did World wide cruising with 200' and 160' of chain (two different boats) backed with 400' of 3 strand. I believe that most cruisers should be using HT chain (G4) and rope rode appropriate size for the boat. There is a minimum size for "hand"--that is being able to grip the rope--and that is probably 1/2" for most boats, although some smaller can get away with 3/8"

With the current 25' light weight C Dory we use 50' of 1/4" HT chain, and 300' of 8 plait, with a Lewmar 700 Horizontal windlass. We have anchored in up to 100' with this--but I much prefer to stay in the less than 60' range. Our experience is that in winds of over 40 knots that chain will be bar tight. You always want adequate shock absorption. Sudden shock loads can break all chain rodes. I usually use two sizes--one just barely enough, the other one size up. I have broken one of the shock absorbers in over 70 years of cruising. That was when a sudden burst of over 50 knots hit the boat as we were raising sail..preparing to sail off the anchor. There was plenty of safety there: the line which broke was 1/2', the next back up was 5/8" and the main rode was 3/4". We had 3/8 HT chain on a 65,000# boat. Our storm rode was 50' 1/2" HT chain and and 300' of 1" 3 strand rode.

Never leave the boat riding to all chain with a chain stopper or on the windlass.

[pma_foyl]

Originally Posted by NorthernMac

You are correct sir.

Area of operations would be eastern US, Bahamas and possibly US west coast, with the Panama journey being involved if that occurred

If you’re headed to the US west coast 200 feet of chain will be used commonly. I have 300 feet of chain and routinely use 160 to 250 of it.

[SV__Grace]

Judgy, academic discussions annoy me, especially about a topic I care about.

All answers, solutions and opinions depends upon very different boats, lifestyles, comfort levels, and cruising grounds, so it would be most courteous and effective for any OP to specify that when they post, and extra points if they are sincerely posting for themselves, not spouting opinions of others.

It should go without saying in this incredible forum of boaters of all types from all over the world that the needs of a lightweight racer, day or weekend sailor or powerboater are very different from someone in a heavy cruiser who lives on their boat. Those in southern latitudes have very different needs from those in northern latitudes, etc. etc.

So here goes, walking my talk and attempting to provide value here:

We are full time cruisers living on the hook in the PNW where anchorages can be very deep and gales are common. I want/need to be able to anchor in places up to 100' deep and weather gales up to 70 knots. We have a 47' LOA, 20 ton center cockpit ketch with more windage than ideal. We are over 60.

I want to be able to sleep at night knowing my boat is secure. Everything we have is on this boat. I am committed to our safety and the comfort of my wife.

So therefore, I choose to have 500' of 5/16 G43 HT attached to an oversized primary bower that I trust to hold us in deep anchorages in any gale, given decent holding.

I really should have chain a size up, but the HT is within recommended specs for my boat and I pay close attention to the state of my ground tackle. I've weathered gales up to 60 knots without stretching any links that I could see. It helps to use the right size snubber- length and width, to minimize load on the anchor (few boaters seem to do this correctly). 500' of 1/2 inch chain would be unworkable for our boat size and weight. Everything is a compromise.

True story: we swapped out our chain while on the hard in a boatyard and when it went back into the water it was alarmingly bow down, incredibly and noticeably unbalanced fore and aft with the stern in air. At first I thought we were taking on water and sinking, then I remembered the new chain!

Turns out that the boat wasn't sinking and it wasn't all due to the weight of the new chain. We were upgrading our heating system and had moved everything possible from the stern area to the bow to make room. When we put everything away it was better, but not balanced, so I moved heavy stuff around (all my tools and spares were in the bow which I use as my "workshop") and removed the spare propane tank from the anchor locker and we were back on an "even keel."

[carlwk3c]

Originally Posted by NorthernMac

400’ of chain?

Why?


I am figuring weight and balance, if it doesn’t pull its weight I don’t see a need, that’s a ton of ugg boots for my girl or lots of ammo for me

We carry 300’ of 5/16 G40 HT chain on our PS 34. We are in the Caribbean and there are lots of places off of the islands where might be anchoring in 40-50’
Figure scope for a blow and close to 300’ is just about right. All chain, I’m not worried about rubbing on a rock or coral, though I do avoid those if possible and have only rubbed chain an s coral head once at Great Inagua in the Bahamas.
Prepping now for Tropical Storm (maybe Hurricane) Gonzalo, here in Grenada. Hanging on a good mooring, but the 65# Mantus (storm anchor) is on th Ed end of the 300’ of chain, hanging on the bow roller, ready to go should the mooring fail or if we had to drop the mooring to avoid a dragging boat coming towards us.
More is better when it comes to your ground tackle.

[IanTrail]

We have 50m chain and 50m rope so normally (shallow water, reasonable weather) we are anchored using all chain with a 10m rope bungy.

I discovered that all chain has a security benefit. Some years ago in the Caribbean we met a couple who returned to their anchorage in calm weather to find their boat missing. Later they found it at the quayside. Some fishermen had apparently 'found it drifting' after the anchor rope chaffed, towed it in and were now claiming a substantial salvage reward. Hmmm! Maybe it had a little help drifting in the first place. If it had been on all chain with the windlass switched off, helping it drift away would be much harder.

[Pelagic]

Originally Posted by s/v Jedi

I can understand that one would like to keep the chain rode in two parts so as to store one part further aft and only replace one part at a time.

To the question on how to attach them: there are special couplers that maintain link to link distance. You can find these even at Lowe’s and Tractor Supply. The G70 version as I have here has a gold colored finish, which I spray with cold galvanize from CRC.

Exactly Nick, but there is a technique used to extend chain for deep water anchoring, which I have specified on Super yachts and have a version on my own steel boat that does not require you to carry additional chain.

Assuming you already have 2 anchors with all chain rode already stowed on the bow, with chain sharing a divided chain locker.

In the fore/aft steel division you install a heavy duty chain roller at the bottom of divider (fore and aft) and feed bitter end of secondary anchor chain Athwartships under roller and attach high with a weak link.

Primary anchor's chain' s weak link is tied right beside it as is a joining link as you describe already connected to secondary bitter end and on standby

IF you have no choice but to extend chain for deep water anchor, you:

1. connect the 2 bitter ends
2. Deploy primary anchor and chain
3. Run out secondary anchor till locker is almost empty and remaining chain can run under roller to the other side
4. Unlash weaklink and Slowly pay out primary anchor while retrieving secondary chain to give you the extra needed length.
5. Once anchored, retrieve secondary anchor and secure.

Departure is just a reversal of procedure to get the extra chain on its normal side

[s/v Jedi]

Originally Posted by Pelagic

Exactly Nick, but there is a technique used to extend chain for deep water anchoring, which I have specified on Super yachts and have a version on my own steel boat that does not require you to carry additional chain.

Assuming you already have 2 anchors with all chain rode already stowed on the bow, with chain sharing a divided chain locker.

In the fore/aft steel division you install a heavy duty chain roller at the bottom of divider (fore and aft) and feed bitter end of secondary anchor chain Athwartships under roller and attach high with a weak link.

Primary anchor's chain' s weak link is tied right beside it as is a joining link as you describe already connected to secondary bitter end and on standby

IF you have no choice but to extend chain for deep water anchor, you:

1. connect the 2 bitter ends
2. Deploy primary anchor and chain
3. Run out secondary anchor till locker is almost empty and remaining chain can run under roller to the other side
4. Unlash weaklink and Slowly pay out primary anchor while retrieving secondary chain to give you the extra needed length.
5. Once anchored, retrieve secondary anchor and secure.

Departure is just a reversal of procedure to get the extra chain on its normal side

Yes but our anchor is so big that even alone it barely fits on the bow, so no 2nd anchor here. My secondary is currently a Fortress with rope rode and 30’ chain leader, all stowed away.

[Skipper John]

I have cruised my 31' 5 ton sailboat in the Pacfic NW for over 40 years with 25 ft of chain and 300 ft of 1/2" 3 strand nylon line. Most Anchorage here is 50 ft or less on mud/sand bottom. Never had a problem due to lack of chain plus it does less damage to the bottom when you swing. I see boats with up to 100 ft of chain out in 20 ft of water. Duh! OK if a gale blows thru but that is unusual here and most anchoages don't get much swell. I usually set 3 to 1 in with a 15 kg Rocna unless it blows up then I let out line.
I have to admit that this is a pretty benign cruising area. One of the best anywhere.

[jjjacq]

Originally Posted by NorthernMac

...
Also what about dyneema after chain?

dyneema has no elasticity so it's not really a good idea. Nylon or polypropylene is ok.

[Perfect Ride]

We run with between 80 to 100 meters chain with another 100 meter of rode for world cruising. 99% of the time we are all chain. Though when we need the rode I am very happy we have it, as typically those times find me more exhausted with conditions less than ideal.

[Hermia II]

The Cruising area is important. I chartered in the Caribbean with a Swan 42 (12 tons) for a year in the 80's with no chain at all. A hefty CQR and 50m Marlow Multiplait was o'kay. I always anchored on a sand bottom in 10m of water or less. But the swing was wide which could be a problem in congested anchorages which is not uncommon.

These days I sail a Swan 57 (24 tons) and use a Bruce (30kg, which is light) and 80 mtrs of ½" chain. It works perfectly (I love Bruce).
It really comes down to where you sail and how well you'd like to sleep at night.
When things are really shitty, engine is dead, starter motor is burned etc. your anchor is your best friend. It's good to have a really strong friend.

Dyneema is not a good choice, you need an elastic rode and Nylon will be much less costly.

If the weight is a problem (and I admit having had that thought) either go down to a lighter chain (you need to change the capstan) or go for say 20m of chain and splice in 100m of rode to it. But watch out for chafe, that will be an issue.

[rslifkin]

Dyneema will work fine, just treat it like chain and use a snubber.

[Pelagic]

Originally Posted by s/v Jedi

Yes but our anchor is so big that even alone it barely fits on the bow, so no 2nd anchor here. My secondary is currently a Fortress with rope rode and 30’ chain leader, all stowed away.

Yes, each boat is different so there is no one solution.
Luckily I can hold 2 anchors staggered on a long bow spirit with the Fwd one as Primary.
100m of 12-13mm on primary
80m of 12-13 on secondary.

My Chain locker is big and quite far back as chain drops in via windlass to a slippery ramp that takes it even further aft.

The 100m Chain locker is only 2/3rds full when stowed, so no need to lay Chain.

Presently 2 CQRs but expecting a new #13 Sarca Excel on next container from Brisbane in August.

[Aerides]

Chain is about avoiding abrasion. It's weight does virtually nothing, ultimately, but dampen shock loads as it pulls bar tight. (If it has any slack to begin with.) *Nylon* rode will do a lot of dampening, and increase what the anchor system can ultimately hold significantly, by absorbing shock loads. (As does a nylon snubber.) Dyneema would be bad in that regard as it doesn't stretch. I've been considering a combo of chain for the bottom, nylon rode for shock absorption, and *possibly* some Dyneema for extension in very deep anchoring.