Rocna Anchor Failure

[KC375]

Originally Posted by boatpoker

I believe you have that backwards

I'm not sure you can generalize either way without knowing more about the steel used.
https://www.thebalance.com/thmb/BnUW...00516c9b1d.png

[Discovery 15797]

Originally Posted by boatpoker

I believe you have that backwards

Yes, indeed I do.

Thanks for the correction, unfortunately I cannot edit my mistake now.

[Jimmyhenry]

We have a Rocna 33kg. There is no way the anchor itself could break.
Our previous boat had a Rocna 25 and withstood many a blow. No way that one would break.
Pete

[mark0978]

Originally Posted by double u

whatever metal failed (or didn't), thr OP's common sense certainly did: to claim warranty without being able to show the product or even a foto imho is totally asinine, if he can't see that...

Is there a method on CF to prevent you from seeing toxic people? I'd love to be able block the guy that said this so I don't have to read anything he writes again.

This is the kind of toxicity that is tearing our country apart, I'm just tired of hearing it.

Please tell me there is a button or a feature or something that will let me remove him from my world.

[Bangorang]

From the photo, it looks like a Delta plow, not Rocna. We carried a Rocna 25 about 20k miles in the Pacific as primary on a 42’ catamaran.

My advice: Get a Rocna. Secure it between anchorages with a cam tensioned trailer strap and chain hook, then unload windlass. On blue water passage, bring the anchor aft and secure it in the chain locker, but leave road attached so you can heave it over the cross beam in a hurry. This keeps it from getting slammed around by big seas and brings weight aft.

Also, since your windlass is about 8-10’ from the anchor, you can use a bigger piece of chain (1/2”) between anchor and windlass (8’) and connect that to your rode chain with swivel. This puts another 10-15lbs right on the shank and allows the swivel to articulate.

My $0.02, good luck.

[KC375]

Originally Posted by Bangorang

From the photo, it looks like a Delta plow, not Rocna. ....

Yes I believe the photo with anchor is a Delta.


As the OP said along with the photo " 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."


So I believe the photo is of the back up anchor, now additionally sucured with a bit of string.


I've got to say if the boat motion is capable of braking the anchor shank then I don't think the string will do much.


But then I don't believe the boat motion did break the shank. (Please note that is not the same thing as saying the poster made up his story. It just says I think there is something else going on - shank broke before comming on deck and then shackle worked out or something).

[Jim Cate]

Originally Posted by mark0978

Is there a method on CF to prevent you from seeing toxic people? I'd love to be able block the guy that said this so I don't have to read anything he writes again.

This is the kind of toxicity that is tearing our country apart, I'm just tired of hearing it.

Please tell me there is a button or a feature or something that will let me remove him from my world.

There is indeed an "ignore" function available!

Simply click on the screen name of the poster you wish to ignore. A drop down menu will appear and the last selection on it is "add this poster to your ignore list" or words to that effect.

Et voila! You will not see posts from him again unless they are quoted by some other poster.

Jim

[bcboomer]

Originally Posted by mark0978

Is there a method on CF to prevent you from seeing toxic people? I'd love to be able block the guy that said this so I don't have to read anything he writes again.

This is the kind of toxicity that is tearing our country apart, I'm just tired of hearing it.

Please tell me there is a button or a feature or something that will let me remove him from my world.

Just left click on his name and select "Add *** to your ignore list"

[double u]

Originally Posted by mark0978

Is there a method on CF to prevent you from seeing toxic people? I'd love to be able block the guy that said this so I don't have to read anything he writes again.

This is the kind of toxicity that is tearing our country apart, I'm just tired of hearing it.

Please tell me there is a button or a feature or something that will let me remove him from my world.

My “toxic” zynicism comes from having to deal with this kind of “warranty” claim on the job, &
on topic:
as so far none of us has come up with a real rational explanation I can only conclude that the OP has left some details out, not necessarily intentionally.

[Old fella]

I feel for the OP, that's a lot of money to fall of the boat, the only thing that makes any sense is there must have been a 2nd shackle, and it failed. Best of luck with the next one, cheers Brian .

[GrowleyMonster]

Why would it be on deck during an ocean passage, anyway? At sea, if something is not needed on deck, it should not be on deck. But that is beside the point. It could NOT have worn through undetected with any normal inspection/maintenance regimen. It could NOT have broke in any sort of normal conditions even if it was made of recycled tinfoil. It could not have been used for three years if it was that weak. It could not have been stolen without its absence noticed. How could you not notice that suddenly you have no anchor? Could a second shackle have come unscrewed? Doubtful. Anyone with 5k miles under his keel would by now have learned to mouse his shackles, or use locktite blue, or peen the end threads to prevent it from backing off without applying a fair amount of torque. I agree with others who smell a troll here.

[TabbyCat]

A friend of mine purcahsed a new catamran in France, lifted anchor, and sailed it across the Atantic. When he arrived in the Caribbean, he was quite surprised his beautiful new Rocna was gone, and all that remained was half of the french bullet shaped swivel (you know the brand). So it can definitely happen- a long passge, some rough seas, and the shackle just breaks. I made it a point after hearing his story to never buy one of those pretty stainless steel streamlined bullet shaped shackles - I have a titanium shackle instead.

[chris in SG]

Originally Posted by Uncle Bob

Funny but it has been my understanding that the ideal setup is a bow shackle of the same size as the chain or one size up fitted to the anchor with the pin through the slot and a similarly sized bow shackle fitted to the chain, with its pin through the link, the two shackles providing the best articulation possible for the tackle. As has already been mentioned, all of similar metal.
But then it is always possible that I am misinformed.

Thumbs up for this post - shame nobody acknowledged.

Firstly, Uncle Bob is respectful - no comments like "obviously the guy didn't know what he was doing, etc".

Secondly, I learned a lot! I have always felt uncomfortable with an anchor bow shackle through the anchor slot. It feels wrong because the slot isn't rounded, so you only need a modest amount of mechanical sympathy to be very concerned about the point loading of the rounded shackle on the edges of the slot (see photo). Uncle Bob's method avoids this problem and possibly explains why anchor manufacturers don't bother rounding the slot - because perhaps it IS designed for a shackle pin only. Why is it that most of us don't use two shackles? My guess is that we instinctively feel that shackles are a potential weakness, so increasing the number of shackles will reduce the factor of safety.

[Red Sky]

On my 33 Rocna, 2 shackles, pins in the slot & the chain.

[thinwater]

Note: If you put the pin in the hole the shackle may need to be 2 times as strong (90 degree loading weakens shackle by 50%). That said, if you use two high strength shackles, this should not be a problem. But check the ratings!


The above is for bow shackles. D-shackles, and even worse long-D shackles, need to be further derated. A stainless D shackle is badly underrated if pulled from the side. A slightly elongated version (shown) with the leverage at the end is hilariously under strength. The shackle could easily fail without exceeding the WLL of the chain. Not hard to do, recovering a stuck anchor.



I think this is a common misunderstanding. The bow vs. pin question can be debated, but it can't be a D-shackle and we should understand that any shackle type can be derated by 50% if side loaded.