Modern anchors

[rotrax]

I have to agree with Snooks. Zinc is reasonably ductile and will readily accept deformation of a steel substrate. In one of my previous jobs I used to perform bend tests on galvanised sheet, which consisted of bending it double in the jaws of a vice. If the zinc detached from the steel the sheets were rejected.

Closer to home, this photo shows destructive testing of Grade 30 galvanised chain. No zinc was detached, despite considerable deformation of the links.

You are probably correct. FYI he was a delivery skipper and it was not his boat. Cheap chain aside, the loads must have been significant to deform the chain but the anchor held.THATS what I was asking about!

 

[estarzinger]

BUT the anchor held. What conclusion can we draw from this?

Probably that the anchor/chain was stuck in/under some rocks.

Often in rocks, the chain itself is caught under/around rocks and take almost all the load and the anchor is just sitting there pretty much unloaded.

 

[RichardS]

Iit depends a lot on the depth. When anchored in really strong wind, I always prefer at least 10m. If you are anchored in any less, in a strong wind, yes you will practically straighten your chain, and will probably get better results with part chain / part nylon. I have all chain, so prefer deeper water if it's going to blow.

Just my thoughts but it is probably the angle ultimately subtended at the anchor shank which is more important than whether the chain is approaching a straight pull.

Provided there is sufficient chain out to ensure the angle of straight pull is less than that required to break the anchor free, I suspect that the depth of water is largely irrelevant (ignoring the shock absorbing effect of a longer scope).

Richard

 

[KellysEye]

>Modern anchoring theory says the weight of the chain does very little.

Where on earth did you get that from? It's crazy, so I'm intrigued.

>posted photos of his father's boat lying to a huge scope of chain, 100 metres IIRC, in a big blow in Patagonia

I am very surprised he was using only one anchor. I've never met a long distance boat without three or more.

 

[vyv_cox]

>Modern anchoring theory says the weight of the chain does very little.

Where on earth did you get that from? It's crazy, so I'm intrigued.

>posted photos of his father's boat lying to a huge scope of chain, 100 metres IIRC, in a big blow in Patagonia

I am very surprised he was using only one anchor. I've never met a long distance boat without three or more.

Ah, but it was a Rocna

 

[Twister_Ken]

Ah, but it was a Rocna

I like the 'was'!