Chain Versus Rope Scope ?

[Lagoon4us]

Exactly!

[webejammin]

Very enlightning reading Makes me feel our cat is well set up with enough chain, rope, snubber line, along with a kettle if I need one Now all I need is about 400 ft of line to stearn tie to shore far some locaions in the Pacific North West and I'm sure other locations.

[s/v Jedi]

Originally Posted by avb3

Perhaps the same reason this conclusion was reached? Go towards bottom of page, point 6, Conclusions.

Oh my... Yes, you need a snubber. I am sure that is what they mean with "long chain and short nylon". A snubber:





cheers,
Nick.

[sailorboy1]

Originally Posted by Curmudgeon

On my previous boat I had 30' of chain and then 3-plait nylon rode. The rode would often slip on the windlass and would get jammed in the hawspipe when I was trying to get the anchor up. Very annoying.

I then went to 30' of chain and 8-plait nylon rode, which is more limp than 3-plait. It did not hang up in the hawspipe but it still slipped on the windlass. Often I had to pull the anchor up by hand.

Now I have 200 feet of chain. It never slips, never hangs up and never chafes. A snubber with a chain hook is a minor expense item. I would never go back to nylon rode.

Plus, as others have noted, more weight on the bottom NEVER hurts. It's better to have the weight in the anchor, but weight in the rode helps in most situations.

I also believe in a second anchor. I have a 75 lb Luke stored in the bilge. If heavy winds are forecast, I'll put that down as well.

I agree. My main item in changng to a longer chain is the windass. I'm tired of the rope slipping and having to deal with rope/chain connection.

Far as anchors; last year I got a 60# Manson Surpreme which was 1 size larger than called for for my boat (since considered an 80# instead) and beside the weight I like this anchor because it has a lot of surface area so have a bigger bite on the bottom.

[boatman61]

Originally Posted by cfarrar

Well said, Klem. I'm not selling anchors, but this photo by Peter Smith shows how catenary disappears under high loads. Clearly chain is for other purposes, as you and others explain so aptly.

Ahhhh... the famous ROCNA Bible.....
If my chain was entering the water at that angle I'd be worried... its usually half that under those apparent conditions.... I just Lurve long rodes...

[s/v Jedi]

Originally Posted by boatman61

Ahhhh... the famous ROCNA Bible.....
If my chain was entering the water at that angle I'd be worried... its usually half that under those apparent conditions.... I just Lurve long rodes...

With some anchors you have to. It is mostly the weight of the chain that improves the holding then, not the further reduced angle.

cheers,
Nick.

[noelex 77]

Originally Posted by s/v Jedi

Oh my... Yes, you need a snubber. I am sure that is what they mean with "long chain and short nylon". A snubber:





cheers,
Nick.

Nick splicing Nick. Whats the purpose of the doubled up thinner line connecting the chain hook.

[noelex 77]

Originally Posted by jeremiason

I swam from the bow and followed the rode, after about 75 feet, the chain took a 90 degree turn in the sand and ran to the anchor. In other words, my 37,000 lbs. boat was riding along in 25 knots of wind, using the weight of the chain only. So regardless of what the experts say, at least in this instance the weight of the chain did help.

I dive and look at a lot of anchors. Boats will typically not straighten the chain till 15-25 knots, but any reasonable anchor will have no trouble at much higher windstrengths than this so it does not have much relevance.
I have 13mm chain and rather than help, as others have suggested, its a nusance most of the time because we will still lie to our chain at higher windstrengths. Swinging differently means we sometimes need a bit more anchoring room

[s/v Jedi]

Originally Posted by noelex 77

Nick splicing Nick. Whats the purpose of the doubled up thinner line connecting the chain hook.

Thanks. I actually do these quick with California taper (the lazy method ) because they end up dirty very quickly...

The lashing is Spectra rope and needed because the diameter of nylon I require doesn't fit through the eye of the hook. That is one of he problems that come with using a very strong but small size chain. It brings you to a 3/8" chain hook but the nylon still needs to be matched to boat size and weight.

ciao!
Nick.

[noelex 77]

Originally Posted by s/v Jedi

Thanks. I actually do these quick with California taper (the lazy method ) because they end up dirty very quickly...

The lashing is Spectra rope and needed because the diameter of nylon I require doesn't fit through the eye of the hook. That is one of he problems that come with using a very strong but small size chain. It brings you to a 3/8" chain hook but the nylon still needs to be matched to boat size and weight..

Thanks. I have gone through a period of snapping snubbers (and they make a frightening bang when they go) so I am intersted in other peoples set up.

[Ex-Calif]

Originally Posted by s/v Jedi

This thread proves how hard it is to do away with all the silly talk about the importance of chain weight. It was 20 years or so ago that Dashew stated something like every pound of weight in the anchor provides 10-100x as much holding as a pound of weight in or on the rode.

Amd still I see guys tying killets and what have you to their hefty chains which all is attached to a silly little anchor.

cheers,
Nick.

Not saying if Dashew is right or wrong but a range of 10-100x doesn't sound like much science as guesswork...

So if extrapolating the statement 1 pound of anchor can equal 100 lbs of chain?

Anchoring is a system dependent on boat, bottom and ambient conditions. Citing one rule of thumb or another leads to traps and dark corners.

Big anchor, big chain, long scope all good... It's when you have to start compromising that the decisions come in.

[s/v Jedi]

Originally Posted by Ex-Calif

Not saying if Dashew is right or wrong but a range of 10-100x doesn't sound like much science as guesswork...

So if extrapolating the statement 1 pound of anchor can equal 100 lbs of chain?

yes it does. It's why the device is called an anchor: it anchors itself in the seabed, thus multiplying the holding power of just the weight. A chain can get a bit of grip on some seabeds but nothing like an anchor.

The range is due to size range... A pound difference on my 176 pound anchor isn't as much as a pound on a 30 pound anchor.

cio!
Nick.

[Cheechako]

It's amazing really how much wind it takes to put a big strain on the chain. While in the Tobago cays in my 42 catamaran, we had a spell of steady 35 knot winds with some gusts higher. In that location there was absolutely no seas, but no wind protection either. We were in about 15 feet of water and i had the usual 75+ feet or so of all chain rode out. White sand bottom. I decided to skorkel down and look at the anchor. To my surprise, the chain had quite a catenary in it... it seem very tight up on the bow of the boat, but below water it had a big curve and didnt even pull out of the sand for maybe 12-15 feet in front of the anchor! It's the waves if you have them, that cause the problems....

[Ex-Calif]

Originally Posted by s/v Jedi

yes it does. It's why the device is called an anchor: it anchors itself in the seabed, thus multiplying the holding power of just the weight. A chain can get a bit of grip on some seabeds but nothing like an anchor.

The range is due to size range... A pound difference on my 176 pound anchor isn't as much as a pound on a 30 pound anchor.

cio!
Nick.

It is still not science...

I go from 30 lb anchor to 31 pound anchor and throw away 100 lbs of chain? I think not...

Rules of thumb are guesses by their very nature...

[s/v Jedi]

Originally Posted by Cheechako

It's amazing really how much wind it takes to put a big strain on the chain. While in the Tobago cays in my 42 catamaran, we had a spell of steady 35 knot winds with some gusts higher. In that location there was absolutely no seas, but no wind protection either. We were in about 15 feet of water and i had the usual 75+ feet or so of all chain rode out. White sand bottom. I decided to skorkel down and look at the anchor. To my surprise, the chain had quite a catenary in it... it seem very tight up on the bow of the boat, but below water it had a big curve and didnt even pull out of the sand for maybe 12-15 feet in front of the anchor! It's the waves if you have them, that cause the problems....

I was just gonna post about the waves and then read your last sentence The waves do 2 things: they lift a bit of chain up and remove the slack by pushing your boat a bit further back so that the next piece of chain can be lifted. It makes the chain loose it's grip of he seabed.

p.s. Everybody has 35-knot spells in the Grenadines. At some point you even ome and go during them

ciao!
Nick.