Rocna Anchor Failure

[alc]

Hi All,

I wanted to see if others have had the same issue with your Rocna 20 kg anchors failing. While transiting from Aruba to Curacao our anchor broke away from the shackle and chain. The shackle is completely intact on the chain but no anchor is left. I contacted Rocna and was told that without a picture of the actual anchor, which is sitting in 2000 feet of water, there was nothing they would do for me. I was surprised first that it failed after only 3 years and appeared to be in like new condition. I am just glad it happened while we were underway and not at anchor. I always believed Rocna was a good reliable product and shocked that it gave out to begin with but even more surprised that Rocna would not honor the warranty.

I am thinking about replacing it with a Mantus, has anyone had a similar experience with Mantus or could it just be an issue with Rocna. Also, how is the warranty service if we need it?

Thanks to everyone.

Regards,
John

[tkeithlu]

You almost had me on the 2,000 feet, a remarkably deep anchorage. So now, how did you lose it underway? If it looked OK recently, we're not talking about wear, we're talking about a fracture. Keeping to that line of thought, could it have been badly cracked before you got underway, such that a wave or a loose chain might finish the job? Was it galvanized, such that you might not see a crack? Does Rocna use brittle steel? Did you have a high stress anchorage and an all chain rode, given that nylon would stretch enough to minimize shock on the side of the anchor? If I were Rocna, I'd at least be very interested in what happened, because that does not sound good.

I've never heard of ANY anchor fracturing at the shackle, although I guess it must have happened here.

[BigBeakie]

The OP seems to be saying the anchor fell off while underway at sea. If the shackle is intact at the end of the chain with the pin properly moused, that means the anchor shaft slot broke. That , to me, sounds impossible.

So more information is needed, such as, was there a swivel? Was there 2 shackles attaching chain to anchor?


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[Tayana42]

Could there have been two shackles rather than a swivel and one of the shackles failed? Also, was there nothing securing the anchor on the roller other than the shackles and chain?

[CAELESTIS]

Three posts? BS.

[Mike OReilly]

I hope the OP comes back and provides more specific detail. What I think he/she is describing seems well-nigh impossible, even for a cheap or poorly made anchor. I know Rocna went through a period of using lower-spec steel for a short time, but even those builds weren't that fragile.

I've heard of shanks bending, shackles breaking and swivels cracking, but I've never heard of an actual anchor slot fracturing. And for this to happen while the anchor is sitting in its holder -- not even under load -- seems beyond the pale. I suppose it's possible to have a really bad single item come out of the production line, but if it was truly this fragile surely it would have fractured under use first.

Not saying the OP is uttering bs (yet), but something seems pretty odd here.

[carlosproa]

My 15 kg one is so far great! I do not have a swivel.

[NYSail]

Doesn’t sound right...... for it just to fall off you would assume that significant damage occurred at last anchorage that would be noticeable when retrieving. Swivel or another shackle maybe...

[alc]

Hi All,

I have attached some images of how I discovered the chain and shackle when the anchor left. I suspected some sort of stress fracture in the slot and I see that others think it might have been the same. I have also attached an image of how the anchor is stored while we are under way but have added a line to secure the backup anchor.

We are not that experienced, only been sailing for 5,000 nm over the past 18 months so any thoughts are very much appreciated. Is there a better system for the anchor to produce less stress? I was really surprised that this could happen but again really happy it happened underway and not at anchor in the middle of the night.

[JohnGC]

Is the shackle pin still done up tightly? Or is it lose?

[a64pilot]

Any chance at all that someone stole it before you left and you didn’t notice?

[Mike OReilly]

Thanks alc. It's quite the mystery. I still don't understand how a anchor slot could fracture while sitting on deck when it had already withstood anchoring forces already. Unless you've never anchored with it?

The pin on the shackle does appear to be a bit backed off. Any chance it worked itself free with the boat's motion, which then let the anchor loose? Seems unlikely that you wouldn't have notice this, but shackle pins can be accidentally backed off in this way. This is why we seize our critical shackles with SS wire.

Hmmm... looking at your shackle pin, there is no head. How do you tighten/loosen? Is there a screwdriver slot of some sort? I'm not familiar with this type of shackle.

[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.

[NYSail]

I kind of second the stolen anchor theory...... are you sure it was there when you departed. If it fractured off where is the broken part of the shank? Looks like there is a nice slot for it to sit in on deck.

[CassidyNZ]

How many thieves would take the time to reassemble the shackle? I’d wager not a lot. In fact, why would they not just take the shackle as well?

Have to say, when I think of the slotted end of my anchors it’s inconceivable that the anchor would break before the shackle and, unless the person stowing the anchor wound the chain in really tight, how would it fail in a no-load condition on deck? If it was a forging/casting flaw, perhaps it was brought to critical mass the last time it was used and failed with last stressed event (taut chain on the windlass)?

Strange indeed.