Downsizing chain

[Nomad Willy]

MathisW wrote;
"Whilst I would tend to agree with you that this could be very efficient in terms of total chain weight that needs to be deployed, it does not appear to be practical for the average sailor to handle."

Indeed.
Over half of the skippers here don't even go out on deck to use their ground tackle.
I'd like to see a CG on the chain to be 10-15' up the rode from the anchor. This should maximize catenary at the anchor shank.

And my model to support it is the Alaska fishermen. I think the fishermen have it right and the Trawler Form skippers have it wrong. The only downside is the extra 200lbs on the bow.

 

[Nomad Willy]

Mark wrote;
"I don't place much reliance on catenary. My boat's three-eights chain stretches pretty straight when there is a two-knot current."

Yes but you could have the same catenary at the anchor w half the chain weight.

 

[markpierce]

I've always worked on the ground tackle from the bow despite having in-pilothouse controls. First, need to tip-over/launch the anchor, and then to fresh-water wash down the chain and anchor when recovering.

 

[psneeld]

Dang....all these years I been anchoring all wrong.

How could something so wrong work so well?

 

[markpierce]

Mark wrote;
"I don't place much reliance on catenary. My boat's three-eights chain stretches pretty straight when there is a two-knot current."

Yes but you could have the same catenary at the anchor w half the chain weight.

No worry. I could easily hand 100 feet more of chain, beyond the 200-feet already, as the boat is slightly bow-light.

 

[Caphenning]

Wondering if anyone here has replaced a larger chain size with a smaller size but more length? I am thinking of replacing the 300’ of BBB 3/8 chain we currently use with 400’ of HT 5/16, and wondering what the difference will be in overall size in the anchor locker. I understand about differences in chain, I have multiple wildcats for the different chain sizes, and have the need for the extra length, but I am pretty maxed out on space in the anchor locker so I want some first hand experience in the differences in overall volume between the two rodes before I place an order.

Personally I would keep the 3/8 for the holding power, and if I needed more scope would soft line behind it. With 300’ of 3/8ths at the anchor end, you could add 100’ of soft line and have better holding than 400’ of 5/16.

 

[Nomad Willy]

MathiasW wrote;
"It seems I have stung here into a nest of folks who are not really interested in looking at new view points and rather are content with what they already believe to know."

Cose.

But many would like to understand what it says in everyday terms.
Also most will get into it a bit and realize their in over their head. I haven't lost interest but I must say I'm not willing to do lots of work for an unknown.
Please don't give up on us. There are many here that are people of science and numbers. They may be reading your link now. But you'll need a little patience to hear their side.

 

[Caphenning]

Or he could put the weight savings into a bigger anchor and probably come out ahead in the long run.

No, if you want better holding, you up the chain weight. It’s chain weight that makes it all work.

 

[rslifkin]

No, if you want better holding, you up the chain weight. It’s chain weight that makes it all work.

Nope. It's been proven that's not the case. Chain has plenty of useful functions, but it doesn't keep you in place. That's the anchor's job. Otherwise we'd just carry a bunch of heavy chain and no anchor...

 

[Caphenning]

Nope. It's been proven that's not the case. Chain has plenty of useful functions, but it doesn't keep you in place. That's the anchor's job. Otherwise we'd just carry a bunch of heavy chain and no anchor...

You can use a an oversized anchor and undersized chain and you will drag. You use an undersized anchor and oversized chain and you will hold in the same conditions. Simple truth, believe it or not as you please.

I used to anchor a 127’ tug with a 530’ barge by hipping up and dropping a few warps of cable on the bottom. That would hold in all but the worst of weather.

 

[rslifkin]

You can use a an oversized anchor and undersized chain and you will drag. You use an undersized anchor and oversized chain and you will hold in the same conditions. Simple truth, believe it or not as you please.

I used to anchor a 127’ tug with a 530’ barge by hipping up and dropping a few warps of cable on the bottom. That would hold in all but the worst of weather.

Anchoring physics don't scale up linearly, so what works on a big ship doesn't on a smaller boat. Smaller boats move far more in gusts and waves, so any reasonable size chain gets pulled pretty much tight at some point. Unless you're in deep water with a lot of chain out. And plenty have anchored with mostly rope and very little chain with plenty of success.

You may believe that chain is what holds you, but at reasonable boat size scale, the math says it's wrong. Yes, adding more chain weight helps, but provided you have other ways to reduce shock loading (snubbers), then the extra holding power of a bigger anchor helps more.

 

[Nomad Willy]

One can anchor w enough chain
And one can anchor w a big enough anchor.

But if you had 300 lbs of anchor and John had 300 lbs of chain I’d be betting on you.

 

[Caphenning]

One can anchor w enough chain
And one can anchor w a big enough anchor.

But if you had 300 lbs of anchor and John had 300 lbs of chain I’d be betting on you.

I’ll take 280lbs of chain and a 20 lb anchor and go up against a 280lb anchor with 20lbs of tackle any day for holding.

 

[rslifkin]

I’ll take 280lbs of chain and a 20 lb anchor and go up against a 280lb anchor with 20lbs of tackle any day for holding.

I'll bet on the 280lb anchor. The small anchor and big chain will be a more comfy ride when conditions aren't that bad yet. But when it gets bad, the bigger anchor has a lot more holding power

 

[Nomad Willy]

280 lbs of chain could probably be found in the chain locker of a 40’ trawler.
I have a problem visualizing a 280lb anchor.

For this contest we’d prolly need Caphennings “Elmore” to even set a 280lb anchor.

rslifkin,
For a 200’ nylon line what could the size be ... over 5/8ths?

 

[Caphenning]

I'll bet on the 280lb anchor. The small anchor and big chain will be a more comfy ride when conditions aren't that bad yet. But when it gets bad, the bigger anchor has a lot more holding power

No it doesn’t, and your tackle will break leaving the anchor behind. The anchor is meant to be the weakest point in your ground tackle, and it’s supposed to be sized to drag before it breaks.

 

[Nomad Willy]

But Caphenning,
This was supposed to be about holding power ... not gear strength.
I’m thinking in terms of gear small/light enough to go on a boat.

Let’s say I use a 45lb anchor. Twice my usual size and nylon line. And another could use 60lbs of chain .. no anchor. That would be a more real world comparison ... do you agree?