How much chain..really?

[s/v Moondancer]

World cruisers that survive carry all chain, we spent 1,500 nights at anchor. At times in the Pacific my 330 ft was barely enough. Anchoring in 50+ knots on a rope that could chafe through would not allow my wife and I to sleep the night through! My wife just said I should mention he sleeping pill...the 122lb rochna.

[barnakiel]

Originally Posted by NorthernMac

Doing the weight and balance of my cutter, I need more weight forward, but sail to displacement is a concern,
...

So outside of belt and suspender status, how much chain does one REALLY need for most ops, presume 30-50’ boat?

Also what about dyneema after chain?

Your boat is 30', not 50'. So skip the 50' exercise and concentrate on your boat.


Next think about WHERE YOU anchor.


If you expect to be ever in a dire situation, use all chain or long chain, otherwise OK to use less chain + more rope.


Do not use Spectra. Fat Spectra is very expensive and very slippery. Use something easy to grab - say 3/4 multi-plait polyester (others use nylon, which is nearly the same thing).


an EXAMPLE, from our boat:


Boat 26', 4 tons loaded.
Typical anchorages: Caribbean, 3-20 meters deep.
Chain attached: 30 meters. (planned to become 50 meters - when I find quality chain)

Rope tail: 25 meters.

Chain stored: 30 meters.
Rope stored 100 meters.



Mind again: this boat, these anchorages.


Before hitting offshore big way, our boat did with just 10 meters of chain, smaller anchor and about 30 meters of rope. Again, different anchorages, different rode.



Cheers,
b.

[Tillsbury]

I carry 80m which is a reasonable compromise, I could add rope but haven't needed to ever. 100m would be nice if I were really going off the beaten track, but I haven't found it necessary for the places I go

[Mike OReilly]

I carry 250' chain on the main bower anchor. I have another rode with a further 80' which could be attached if need be.

As other say, it depends on where you cruise, and how you cruise. I'd say it also depends on your boat. If weight in the bow really affects your boat, then the calculus is different than a boat which is unaffected.

For the record, I've had all 250' out on rare occassions, mostly around storm prep. But I routinely deploy 160'-200' feet for standard anchoring. My cruising ground is currently Newfoundland, so yeah, we need it.

[Westcliffe01]

in 92 I went for a sail with my boss and his pregnant wife on what should have been a 3-4 day sail from Mossel Bay to Port Elizabeth. We got out the protected water and off the southern exposed coastline, became becalmed, then a big swell started coming through. Within a few hours we were hit by a SW gale that ended up blowing for 4 days straight. We made it into the lee of Robberg peninsula by GPS in the pitch dark and anchored as close to the beach as we dared.


For the next 3 days we did our best to manage chafe of the anchor rode on the strong point at the bow. I wrapped the rode in a smaller line and sleeved it with some slit water hose that we had on board. The final night, the wind was blowing over 100mph and gusting to 130, swells were huge and moving at 50mph against the ocean current the anchor rode parted. The skipper had a 2nd anchor and had let it down touching the bottom, but without paying out a lot of extra chain. He motored forward, to get into shallower water and smaller waves and inadvertently went fast enough that the second anchor streamed behind and the chain got into the prop, blew the transmission and jammed the rudder.


That turned the "incident" into a full blown sea rescue and we were very lucky indeed to come out of it alive and still in possession of the boat. It took a group of fishermen with dual engined catamaran fishing boats all night to drag us back to the beach against the 100+mph winds and sea. The tow line parted once and the tow boat was swapped for a different one with direct drive props that was known to tow better. When they finally got us back to the beach as dawn was breaking, the fishermen gave us another anchor and couple hundred feet of chain, secured with a D shackle and we felt for the first time that we didnt have to worry about chafe...


So, I agree, crazy storms can come up with no warning and if any of your ground tackle fails you are SOL. It can cost you everything. Today we may have better forecasting than then, but dont cheap out on your ground tackle. There could be times you may need to anchor off bow and stern if a space is too narrow to allow swing. Skip Novak has a series of videos on Youtube about how he anchors his yachts in Antartica where the wind blows like few other places on the planet...

[DefinitelyMe]

You should be fine with 100' in your intended area. For the SP we carried 300' and had it all out frequently enough that I wouldn't have wanted any less. In many areas chain-rope mixed rhode is not desirable due to coral, rocks or other obstructions.

[Andreas W]

Depends on what you can stow on your boat, and the type of sailing you do. I use 100 meters chain on my main anchor, a Bruce. Then I have a Fortress anchor with 90 meters road plus 10 meters chain.
I have a 43 ft steel monohull with a big chain locker, so no problem to put all away safely.

[slug]

Originally Posted by NorthernMac

So I see posts for boats for sale, and folks talking about operations who have miles of chain

But really why?

I get it’s less likely to be compromised by a rock, but 200’ of chain? Weight/cost to benefit?

What’s the average depth, 7 scope, how much chain does one really need?

Doing the weight and balance of my cutter, I need more weight forward, but sail to displacement is a concern, if I could have less chain and have a water maker and AC/heatpump that seems like a better deal.

So outside of belt and suspender status, how much chain does one REALLY need for most ops, presume 30-50’ boat?

Also what about dyneema after chain?

It not uncommon to anchor in 25-30 metres of water

100 meters of chain is needed

You could add a rope tail but it’s a hassle

Go full chain

If chain stack, storage space and weight is an issue its Better to go one diameter smaller and use high spec grade 70 chain

[noelex 77]

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 also have 400 feet of chain, although we call it 120m .

This would be way overkill for the cruising grounds mentioned, but in some parts of the world it is nice to have the option of anchoring in deep water with the chafe protection of all chain.

For most long distance cruising boats 80-100m is a more sensible compromise. If you are only cruising a limited geographical area that is shallow you can reduce this significantly.

Both our boat and Jedi’s are designed to store the chain further back than is normal, reducing the weight in the bow and permitting the more generous weight of chain without compromising sailing performance unduly.

[chrisr]

as has been said many times already : it depends where you are and where you go

if your local area is fairly shallow and good holding, then maybe you don't need so much...or if not, you'll need more.

if you travel a lot, you need to gear up for the worse anchoring scenario likley

in our part of the world (east coast australia), we find 80m chain pretty much covers all possibilities

NB : i share your concern about weight so recently swapped our 10mm chain for high tensile 8mm. stronger and a fair bit lighter...

cheers,

[s/v Jedi]

It has all been mentioned above so this is just a recap; to handle the bulk and weight of 400’ of chain there are two options that really make a difference. We use both:

1. Reduce the size of the chain. Our boat requires 1/2” high tensile G4 chain. 400’ of that is a huge heavy pile. Instead we went down in size to 3/8” and upgraded the material to G7 in order to keep the strength up.
Some of the weight savings is put back where it belongs: into the anchor itself.

2. Bring the chain locker back, away from the bow. For self stowing chain you need a narrow and high chain locker. Think of something shaped like a 12” diameter PVC pipe. To make it big enough for 400’ of chain, it needs to be higher than what is possible all the way forward at the bow. So bring it back, with the windlass right above it on deck. See the picture on how Jedi deals with the chain on deck. Also note the chain stopper halfway. Saved us in a hurricane

[JebLostInSpace]

Many good points already mentioned about chain requirements in different situations, but one important consideration in my mind has not been raised.

Chain is used on anchors not only for it's strength and resistance to snags, cuts, and chafe, but also for its weight

The reason that 7:1 scope is often quoted as good practice is because that length ensures that the angle of force applied to the anchor shank on the sea floor is close enough to horizontal to cause the anchor to dig into the ground more deeply instead of being pried out. When resting at anchor, the chain/rode should make a deep curved shape - dropping nearly vertically from the bow of the boat and arcing to horizontal at the end attached to the anchor.

The heavier the material used for your anchor line, the more this curved shape will be encouraged. Using heavy chain actually allows you to achieve this shape with a much smaller scope. In calm conditions, I routinely put out 3:1 or 4:1 scope to reduce how much room I need to swing, and I am still able to back down hard on these anchors with the engine. In rougher conditions I of course put out more scope, but the weight of the chain is absolutely a benefit to the safety of anchoring.

The weight of the chain also provides a damping effect during gusts. A large part of the force of a gust pushing your boat backwards is consumed in lifting the weight of chain up as your rode gets stretched closer to a straight line. By the time the boat's backward motion is checked, much of the force from the gust is spent, and you reduce the shock applied to your boat and make the ride much more comfortable.

What this means for you is maybe not straightforward. Your primary concern is the weight of the chain, but I'm arguing that you want as much weight in the chain as you can "afford" to maximize safety. I like the previous suggestion of moving your chain locker aft so that you can "afford" more weight without sacrificing so much performance.

And of course, knowing what kind of depths you will anchor in helps a ton with this decision. If you will always anchor in less than 20 feet of water, you can get 7:1 scope of chain for 140 feet (plus a factor for your freeboard of course). Top this with some rope rode for when the wind gets really scary, and I'd be plenty comfortable.

Personally, I inherited a measly 80 feet of chain topped with 160 feet of rope from my boat's PO. It only took one incident of dragging with all my chain out to convince me to make that upgrade...

[Breaking Waves]

quit honestly for the OP's boat and cruising plans . . . he could use 5 or 10m of chain and be perfectly absolutely fine.

I'd use a typically oversized cruisers anchor, which would still not be huge given this small a boat (perhaps 12kgs).

I would not use dynema rode - you want the rode to have some shock absorbing capacity (and dyneema is unnecessarily expensive). There would be valid debate about nylon vs polyester with points on both sides - I personally would go nylon for this boat and cruising plan.

Setting up a 15-20m world cruising tank for all oceans all conditions is a rather different exercise with diferent requirements (although having been there/done that I think 100m is just fine for that mission).

[s/v Jedi]

Originally Posted by JebLostInSpace

Many good points already mentioned about chain requirements in different situations, but one important consideration in my mind has not been raised.

Chain is used on anchors not only for it's strength and resistance to snags, cuts, and chafe, but also for its weight

The reason that 7:1 scope is often quoted as good practice is because that length ensures that the angle of force applied to the anchor shank on the sea floor is close enough to horizontal to cause the anchor to dig into the ground more deeply instead of being pried out. When resting at anchor, the chain/rode should make a deep curved shape - dropping nearly vertically from the bow of the boat and arcing to horizontal at the end attached to the anchor.

The heavier the material used for your anchor line, the more this curved shape will be encouraged. Using heavy chain actually allows you to achieve this shape with a much smaller scope. In calm conditions, I routinely put out 3:1 or 4:1 scope to reduce how much room I need to swing, and I am still able to back down hard on these anchors with the engine. In rougher conditions I of course put out more scope, but the weight of the chain is absolutely a benefit to the safety of anchoring.

The weight of the chain also provides a damping effect during gusts. A large part of the force of a gust pushing your boat backwards is consumed in lifting the weight of chain up as your rode gets stretched closer to a straight line. By the time the boat's backward motion is checked, much of the force from the gust is spent, and you reduce the shock applied to your boat and make the ride much more comfortable.

What this means for you is maybe not straightforward. Your primary concern is the weight of the chain, but I'm arguing that you want as much weight in the chain as you can "afford" to maximize safety. I like the previous suggestion of moving your chain locker aft so that you can "afford" more weight without sacrificing so much performance.

And of course, knowing what kind of depths you will anchor in helps a ton with this decision. If you will always anchor in less than 20 feet of water, you can get 7:1 scope of chain for 140 feet (plus a factor for your freeboard of course). Top this with some rope rode for when the wind gets really scary, and I'd be plenty comfortable.

Personally, I inherited a measly 80 feet of chain topped with 160 feet of rope from my boat's PO. It only took one incident of dragging with all my chain out to convince me to make that upgrade...

I’m sorry but that has been debunked many, many times already. There are dozens of threads with math at rocket scientist level to show that the weight needs to be in the anchor, not in the chain.

[JebLostInSpace]

Oh for real? Well now I feel like a fool. Can you send a link so I can educate myself? I've been buying into the (apparently) myth for forever! This is like that time I finally realized "purposely" was a real word and not just a super common misspelling of "purposefully"