Anchor Rode Failure

[Bob Bradley]

I hit the reefs off Watch Hill yesterday in search of togs. The incoming tide was still running around couple knots when we anchored up. We were only in 25FOW or so, so I put out my 50' of chain, and about 10' more of my new 5/8" rope. The stiff SW wind off our stbd aft quarter made for a slightly obnoxious roll, but we set up anyway and were into fish quickly, releasing a few shorts and one barely legal keeper. After 15 minutes or so, we heard a fairly loud bang up forward, and the boat started drifting with the tide. I thought that the anchor had come free, as I can hear it when it pops off a rock sometimes. When it became clear that it was not resetting itself, I went to investigate. Here's what I found...

20161016_111411.jpg20161016_111342.jpg

I couldn't believe my eyes. This is virtually brand new 5/8" anchor line that I installed this past spring when I replaced my windlass and went from all chain to a chain/rope combo with a new Delta anchor. I have anchored a total of 3 times with it. The rope parted right at the roller on my davit. There are no sharp edges there, and the roller turns freely. There is some surface rust, caused by years of my old all chain rode dragging across the stainless steel, on the top face of the davit, about a foot aft of the roller, and I can see that it did scuff the rope a bit as the boat rocked in the waves. But, that's not where it parted. It parted right at the roller. And, it parted after just 15 minutes at anchor on the third time I've ever used it.

Needless to say I'm pursuing it with the vendor.

[finatic]

Bummer! Could it have gotten wedged between the roller and the davit?

[Pascal]

Anchoring with different current and wind usually cause the boat to lay at an angle to the rode. Looks like it was the case here and the line chatted on the edge of the SS plates. Kind of hard to see in the picture but looks like there is a gap and the line can jump over if the boat is at an angle to the rode.

That s why I prefer all chain or at least enough chain to cover 95% of my typical anchoring scenario (100' or so)

[Bob Bradley]

No, the gap is only about 3/16" at the most. And, I was only anchored 15 minutes when it parted. I can't imagine it could have possibly worn thru in that time.

[racclarkson@gmail.com]

Well I thought this was interesting because my first impression of your picture is that the line looked like some of the fibers showed signs of melting.

http://www.petersmith.net.nz/boat-an...right-rode.pdf

[Bob Bradley]

Interesting article. In my case, I only had about 10' of rope out beyond my 50' of chain. We did have some "sailing" going on, as the incoming tide was flowing due west, and we had a fairly stiff SW wind. The current was in control of our position, thanks to the weight, draft, and keel of our 43C, but the wind was putting us at a 45* angle to our rode. I know this without having observed the anchor rode, as our fishing lines were going off the aft stbd quarter at about a 45* angle. Current was not terribly strong, as I was holding bottom in 20fow with just a 4oz sinker while using 65# solid braid line. Given that the current and wind were somewhat opposite one another, I cannot believe that we were generating anywhere near enough stress on the line to cause it to part.

And yet...

[SEVEN]

I was recently going to switch out my 300 feet of chain for 100 foot of chain and the rest 3/4 line. You just change my mind. Sorry it happened to you.

[racclarkson@gmail.com]

What I take away is this: Your 50' of chain and 10' of line were spreading the load over....well, 10' of line.

[SeaEric]

What I take away is this: Your 50' of chain and 10' of line were spreading the load over....well, 10' of line.

Yes. The chain has no "give". The line took all of the strain. It will be interesting to hear what the vendor has to say.

[Bob Bradley]

Yea, I drew the same conclusion. That said, IMHO, brand new 5/8 nylon, being used for the third time, should not snap after 15 minutes of modest load.