Back down with the windlass or the snubber?

[Dockhead]

Originally Posted by thinwater

. . . 3. Chain. Might as well wait for full scope. Except for case #2, there is nothing to be gained. If you use heavy chain, the chain won't lift even at short scope during a light set, so there is no harm. But the chain will lift during a heavy power set, so there is negligible up-side to setting short. . . .

The notion that dragging chain buffers the set is obviously silly on the face of it. How hard is it to drag 100 feet of chain along a beach? Try it. It is a trivial portion of the anchoring load, no more than a few percent. Side to side is a little different. Cattenary matters. But line-pull is trivial. Measure it and check back with us. I have.

Really? With respect, I beg to differ.

All this might be close to true for someone using very light chain in very shallow water. And it might be true if we were setting our anchors at high power settings.

But for those of us trying to delicately work the anchor into the seabed before putting power on it, and especially in deep water and with heavy chain, the catenary of more chain really interferes with the process, as does the friction of more chain on the seabed. Try pulling a table across the room with a length of chain with a lot of catenary in it -- it's really hard, because the catenary damps out the spikes in the force which might overcome the stiction (a force ignored by Thinwater here) of the table legs on the floor. Same thing with anchoring, at least for those with heavy chain in deep water. My anchor rode, for example, weighs 1/3 of a metric tonne.

The fact that the friction of the chain is a small percentage of maximum anchor loads is completely irrelevant -- it is a HIGH percentage -- if there's a lot of chain out -- of the small force required to get the anchor going in. And no one said that we just don't have enough force to set the anchor -- of course not -- the point is how well you can FEEL what is going on. It makes a really big difference in FEEL if you've got a quarter tonne of chain dragging in the seabed ahead of the anchor you're trying to set. Furthermore, chain in the seabed has a lot of STICTION by itself -- see: https://www.orcina.com/SoftwareProdu...ictionData.htm. These forces really interfere with the process of setting the anchor.


Shorten that chain up, if you want to feel what is going on when you're trying to get a set. Unless you are using only small amounts of light chain, in shallow water, like Thinwater does on his catamaran in the Chesapeake, in which case, it probably doesn't make much difference.