Rocna Anchor Failure

[hpeer]

Originally Posted by BugzyCan

I am betting on a thief, they left the shackle so it would not make any sound when removed, and even did it partway back up to confuse the owner.

Buy a new one and forget about it.

Yup. I’ve read on Active Captain of folks having their anchor stolen WHILE ANCHORED. When they brought up the chain the anchor was gone. Here in Guadeloupe IIRC.

Guy says he’s a newbie so give him a break.

If he has a windlass remote control insuppose it’s possible the chain came up without the anchor and he didn’t notice. Maybe he lifts to a mark with out eyeballing the anchor?

Or maybe someone stole the anchor prior to leaving and he didn’t notice?

Or maybe the damn thing just fell off as he says.

BACK TO THE OP

So tell us the story. When was the last time you anchored? Where did you spend your time between then and noticing the anchor missing? Were you on dock? On mooring?

I can see some one pulling a dink under a bow and releasing the anchor. A 20kg Rocna is worth something.

Why put the shackle back? Just to screw with the owner and make him think it fell off?

I believe the OP has a true mystery, and maybe it really did fall off. Or maybe it fell into someone’s hands.

[double u]

observations:
accusing thread title (“failure“)
Aruba-Curacao: rough upwind passage most of the time
expectation of OP of warranty settlement when he can't show product. If a manufacturer would commence such a practice they might as well close down.

[alc]

Hi All,

Thanks for the feedback and Happy Thanksgiving. Sorry for the delay but have been in Klein Curacao the past couple of days and the Internet is really poor.

To answer some of the questions. The anchor was definitely not stolen. We were at anchor in Palm Beach Aruba and we weighed anchor there. The anchor was definitely there because we stowed it in the same fashion as the replacement one in the photos, less the line tying it. We departed for Curacao right then with no other stops. I have a tendency to walk and inspect the boat during the passage, specially in rougher seas, which is when I noticed the anchor missing. It was about 2-3 hours into the passage. The shackle pin, while still completely tightened had the head broken off as well, as you can see in the image. I had replaced the chain in October and didn't use new SS whipping to secure it yet. The image of the anchor is our backup anchor that we installed so that would could anchor in Curacao, it now has a new shackle and is secured with whipping as well.

I honestly did not think Rocna would honor the warranty because most companies don't operate that way. However, Echo-Tec did stand behind a failed product even after the warranty expired by a month and recently sent me a new part at no cost. I guess I was hoping Rocna would be interested in why the their product failed or how I was using the product incorrectly that caused it to fail. I was slightly hoping that I might get some sort of discount since it says it has a lifetime warranty. I was also very curious if this is something that happens to others since I don't ever remember hearing of it before. I know anchors can be lost for various reasons but have not heard of it happening like this.

Finally, is there a better way to secure the anchor in rough seas. Thanks again for all the opinions.

To me it will always be a mystery I guess.

John

[Sailing Drummer]

My guess is still that, 1) you used the wrong type of shackle and 2) you only used 1 shackle, not 2. Both of these issues could cause extreme loading on the the anchor causing it to break.

[KC375]

The broken shackle pin head is an interesting fact. It seems unlikely the shackle and the anchor shank slot fractured on deck. Could the damage have happened before being secured on deck.
The loss of an anchor is not “nothing” but this actually seems very good luck to lose the anchor not the boat. An anchor system that would fail on deck was bond to fail under anchoring load which could have cost the boat.

[hpeer]

Truly interesting story. And especially the broken head on the shackle.

I have HEARD, but do not know, that today much steel is made of recycled product. And that when the product is recycled some “junk” metal can get into the batch and not be detected. I read elsewhere about a big metal shop that was breaking band saw blades because the operator was hitting some exotic bolt that was embedded in the sheet. The foreman, the author, claimed he fired the saw operator on the spot because that is such a common problem that a competent operator would not have wasted the additional blades on a clearly bad bit.

I suppose it’s possible that an otherwise piece of good steel could have some flaw that would allow it to fail at relatively light loads.

I know that seems improbable, and it is. But it’s not impossible. And no manufacturer would have a way to determine that - that I know of.

[Mike OReilly]

You may have detailed this before John, but what kinds of conditions did you face in those first two-three hours? I assume it was pretty bad. And the sheering of the shackle pin head surely is related.

Without a seizing wire it is very possible to have the pin work its way out, especially if there was high motion, which clearly there must have been. The pin appears to be partially backed off in your photo.

Does your roller/holder adequately contain and support a Rocna? It seems to be good with your Delta. A Rocna is shaped differently, of course.

And had you put the Rocna to the test under anchor? I still find it incredible that the slot could fracture with the anchor sitting in a holder if it had previously held in serious anchoring conditions. This suggests a pretty compromised metal structure, and damn lucky it happened on deck.

[hpeer]

Mike,

I can see the shackle pin backing out, I can not see it backing back in.

[JohnGC]

With the shackle pin head snapped off, could the shackle be sprung open with a twisting load? The anchor was a big leaver and the shackle could have simply sprung closed once the anchor had departed for the deep.

John

[SwellGuy]

Originally Posted by zboss

The anchor isn’t a rocna and that shackle isn’t the shackle on that anchor. The anchor was tied off to the boat.

Cmon. Try a little harder.

[s/v Jedi]

The anchor did not fail. It was the missing swivel, the missing 2nd shackle or even the shackle shown has a fractured pin but sprung back in shape after the anchor shank worked out.

Also, like others stated, the wrong type of swivel was used. Use every component galvanized steel or use every component stainless steel, do not mix types.

Also, do not use Wichard HD shackles, not even on stainless chain and anchor. It’s too brittle.

[SwellGuy]

What possible load would have been on the head of the shackle while sitting on deck?

Unless the two failures are able to be related somehow, I’d say we have two failures that each seem wildly unlikely.

Seems more likely that some of the details are mixed up.

[Checkswrecks]

Originally Posted by SwellGuy

What possible load would have been on the head of the shackle while sitting on deck?

Unless the two failures are able to be related somehow, I’d say we have two failures that each seem wildly unlikely.

Seems more likely that some of the details are mixed up.

The anchor itself makes a big hammer in a pounding sea, especially if the shackle is twisted in the slot. You can see the gouge in the fiberglass where the tang of the pin had been hitting, and another worn or beat area closer to the bow on the far side.

John - You might consider adding a way to lock your anchor down both for damage prevention and anti-theft.


Separate part of the discussion - I have seen pins back out and then re-engage but it's usually associated with vibration.

[Sailing Drummer]

I think the load issue happened cyclically while at anchor causing some weakening. While in the roller something happened that was the proverbial last straw. Fortunately, as stated by others, the final result happened while in the roller, not while at anchor.

[a64pilot]

Something apparently broke, the broken swivel is I believe a smoking gun.
However it cost you an anchor, but thankfully it didn’t cost you your boat. I’m thinking of the story of the guy who anchored out at West End Bahamas to check in, to come back later to find no boat, it was never found or hasn’t yet anyway. His anchor may have drug or may have broken.

I’m paranoid, so I basically oversize everything, I went with a Mantus S2 swivel, if you desire a swivel, take a look at one.