A Second Wind for Rocna

[Pete7]

Originally Posted by smackdaddy

(PS - Is that report online anywhere...linky?)

Unlikely to be a legal copy. Practical Boat Owner (PBO) derive some of the magazine income from selling back articles.

Anchors on test. Gear & equipment / Product tests. Download this article.

However, they are easy enough to pay for and download. Used the system a few times in the past.

Pete

[Therapy]

Originally Posted by Bash

I don't think it's as much the result of a witch hunt as it represents resentment at having been lied to.

Much of this discussion began when many of us asked why this otherwise-fabulous anchor cost so much. We were told that it was a matter of materials and workmanship. That reply was given in highly technical terms where the materials were specified. We looked this over and agreed that the argument made sense, and proceeded to purchase the anchor in droves. Then, to our horror, we discovered the big lie.

And now the people who purchased Rocna are angry. The people who bought Manson ancors, probably for considerably less, do not seem as angry. This is understandable. But it should be equally understandable, for those Manson patrons, why the Rocna owners feel that they've been swindled, and that while it has nothing to do with witches, it has everything to do with crooks.

Right!

And after what Dockhead said (now that I have a Manson) I am pissed again.

[smackdaddy]

Originally Posted by Maine Sail

I have the entire set of "behind the scenes" test data including the notes sections from the West Marine / Sail tests. That is probably where Delfin's data comes from too.

A better summary can be seen here where I pose the long winded question one of the testers who was present at that testing.

Feel free to scroll down to the post directly below April 7 @ 12:24.

Bill Springer's Sailboat Stories: Which Anchor Holds Best? 14 Anchors Are Put To The Test

Thanks Maine. I've seen most of this data (and more) on TD's Anchor Wars thread over on SN, which has been the most thorough, extensive, and evenhanded treatment of the debacle I've seen thus far. It's always good to get the bigger picture.

Of course, none of it matters now that Spade is the best anchor in the world. Sorry therapy.

[mikereed100]

Originally Posted by Bash

Much of this discussion began when many of us asked why this otherwise-fabulous anchor cost so much. We were told that it was a matter of materials and workmanship.

I too wonder where the justification for the price is. Here in Thailand you can get a Rocna 33 knockoff for around $300. They are made with ss400 steel, roughly equivalent to what Rocna was using while charging 3x the price.

Mike

[Maine Sail]

Originally Posted by smackdaddy

Of course, none of it matters now that Spade is the best anchor in the world. Sorry therapy.

Sure it is... If my Spade performed better than either my Manson or my Rocna it would be on my bow, it is not... Gotta love anchor tests.... Heck in the Sail mag test the Fortress was really the winner but you'll never catch me using my Fortress as our primary bow anchor unless tide and wind shifts somehow magically stopped happening...

Trust me if I had even an ounce of reason to not use our Rocna it would already be collecting dust. For our cruising waters it and the Manson perform best, then the Spade...

[xymotic]

When you guys say 'spade' are you talking about a Lewmar Delta?

[cat man do]

Originally Posted by xymotic

When you guys say 'spade' are you talking about a Lewmar Delta?

A quick google...

spade anchor - Google Search

[Dockhead]

Originally Posted by smackdaddy

Of course, none of it matters now that Spade is the best anchor in the world. Sorry therapy.

Funny. Now we're causing people to have anchor inferiority complexes, I guess.

The fact that every anchor test shows something different is pretty good proof that there is no best anchor in the world. Either that, or no test has yet been devised which can evaluate anchors to any fine degree.

[TassieBloke]

Wow, I love these anchor threads!

I just wanted to jump in here and maybe help clear up some of the terms that are being used. For those without an engineering background, they all may sound more or less the same. Hope it helps (Wiki is your friend).

Yield Strength: The lowest stress that produces a permanent deformation in a material. In some materials, like aluminium alloys, the point of yielding is difficult to identify, thus it is usually defined as the stress required to cause 0.2% plastic strain. This is called a 0.2% proof stress.

This not to be confused with Tensile Strength.

Tensile Strength: The limit state of tensile stress that leads to tensile failure in the manner of ductile failure (yield as the first stage of that failure, some hardening in the second stage and breakage after a possible "neck" formation) or brittle failure (sudden breaking in two or more pieces at a low stress state). Tensile strength can be quoted as either true stress or engineering stress.

These values are given in MPa, which is force over an area (think flat 20c coin). Yield Strength is the first value to be observed, as this is the initial point where there is permanent deformation, but not fracture. To put it simply, this is the point where the object (think steel bar) will no longer spring back to its original shape, but is nowhere near breaking. Then the second point measured is Tensile Strength, where the object will suffer fracture (think pulling on a carrot until it breaks) 'Normal steel' has a very long yield plateau before fracture, whereas other metals will yield, then fracture almost simultaneously.

So the two terms are not mutually exclusive, as one precedes the other.

Notice that there is no mention of bending. Any bending moment (think lever arm like socket rachet) is referred to in kN/m, not in MPa. Resistance to bending is a function of the section size/shape and material properties (steel, aluminium etc).

Does any of that makes sense?

Cheers,

Bloke

[virginia boy]

[COLOR="Blue"]Here is the response I received to the email I sent the new owners.[/COLOR]

Hi Eric,

Thanks for your email, and we’re delighted to hear your Rocna has been serving you so well.

Regarding production quality, here’s what we can tell you so far:

The incorrect steel alloy was used during a period of time starting in 2010. Canada Metal has reviewed material certificates for the steel used in anchors since that time plus independent lab tests of random sample anchors off retail shelves and found no issue.

Production will continue in China, with complete quality control oversight by Canada Metal professionals who are employed at our wholly owned ISO-9001-2008 Certified Company (Ningbo Jia Da Specialty Metals Ltd) which is located in Ningbo, China.

We are confident that with our oversight the China plant will produce a high quality, high performance, and cost effective anchor.

Canada Metal was fully aware of the challenges that faced the Rocna brand well in advance of our taking on the Rocna license, brand, and product. During the due diligence process we reassured ourselves that the Rocna product was of sound design and provided exceptional utility.

Even before signing the final documents Canada Metal enlisted the services of a very experienced marine engineer to supervise the transition of the manufacturing quality control process to those professionals who are employed at our wholly owned ISO-9001-2008 Certified Company (Ningbo Jia Da Specialty Metals Ltd) which is located in Ningbo, China.

This transition of QC management will be complete within the next couple of weeks and will ensure that all Rocna products will meet the exacting design standards.

Refer to the statement from Canada Metal on the Rocna website for more details.
CMP Memo to Rocna Customers re Brand Confidence » Rocna Anchors <http://rocna.com/news/cmp-memo-to-rocna-customers-re-brand-confidence>

We certainly hope you will continue to use a Rocna, but if you have any further questions, please don’t hesitate to let us know.

Kind regards,
Tina

[estarzinger]

Originally Posted by Maine Sail

... Gotta love anchor tests.... ...

Originally Posted by Dockhead

. . . The fact that every anchor test shows something different is pretty good proof that there is no best anchor in the world. Either that, or no test has yet been devised which can evaluate anchors to any fine degree.

Yup.

If you read the PBO test carefully, you will note (in a sidebar labeled 'normalization') they had a large variation (+-40%) in results between pulls (not surprising because the bottom is inconsistent), which they then aggravated by their 'normalization procedure (dividing the results of one single pull by the result of another) so that their ending efficiency measure has a statistical confidence interval of about +-80%!

The magazine made the careful and correct (but not to startling) conclusion that for holding in medium hard sand the anchors could be divided into three groups: 'excellent' spade, manson and rocna; 'good' delta, and 'poor' cqr and bruce. Given the very high measurement variation no more precise conclusion/statement than that could/should be made from the data.

It should also be noted that these tests were done at 'infinite' scope, which obscures the important fact that some designs perform better than others at actual real world scope. And that relatively small anchors were tested and there are different scaling effects.

I have personally talked with the people who conducted most of the recent anchor tests and most believe the actual performance of the manson and rocna are indistinguishable (not surprising given the very similar designs) and the spade is somewhat different (better in some situations and worse in others) but in the same overall category.

As many of you know, my personal opinion is that ultimate holding power per lb in medium sand is not the single most important criteria by which to judge/select an anchor - it just happens to be the easiest to test. How many of you pick your car by max straight line speed per lb?

[smackdaddy]

Originally Posted by Dockhead

The fact that every anchor test shows something different is pretty good proof that there is no best anchor in the world.

Don't tell that to Fortress. You have seen their marketing slogan, right?

Google this: the world's best anchor

What do you think about that claim Delf?

[Dockhead]

Originally Posted by smackdaddy

Don't tell that to Fortress. You have seen their marketing slogan, right?

Google this: the world's best anchor

What do you think about that claim Delf?

Indeed, Fortress is an interesting case. I had a long offline discussion with the guy who sells them in Florida. He argues passionately that the Fortress is not just the ideal kedge (as most of us use them), but is also perfectly suitable as a main bower.

I always heard that they break out in a tide or wind shift; so never sleep to them. And so I never have. But I have used them as kedges for decades -- they are incomparably good in that role. Easy to handle, and bite like a piranah.

I wonder if anyone actually uses them as a bower?

[Bash]

Originally Posted by xymotic

When you guys say 'spade' are you talking about a Lewmar Delta?

Nooooooooooooooooo!

[Delfin]

Originally Posted by smackdaddy

Don't tell that to Fortress. You have seen their marketing slogan, right?

Google this: the world's best anchor

What do you think about that claim Delf?

I suppose it goes to engineering compromises. A submerged D9 Cat is probably the ultimate in holding power, but not the easiest to stow on the bow. I have a Guardian made by Fortress as an auxiliary anchor but haven't used it in 25 years so can't comment other than to say that all designs are compromises, so none is perfect. Rocna had a fine hybrid design derived from the Bugel and Spade but had to compromise between cost and the reputation they promoted and found a solution. Just compromise normal business ethics and manufacture an anchor out of mild steel and pretend it was hi tensile. When that didn't work out so well, they found another compromise which is to spend a little more on marketing while saving cost on steel, and communicate a new definition of what is appropriate steel for their design by callinging 620 steel strong enough. Probably is for many situations, probably isn't for others.

The best anchor has so many variables any claim to the best has to be viewed as conditional to the circumstances of use. I don't much like scoop anchors because in the size I need, I'm not interested in dealing with a bushel of PNW mud when I raise it. For smaller sizes, they might be ideal. I wish the Sarca Excel was more readily available as it looks an intriguing design that has less environmental impact than others, while still seemingly having superior holding power.

When we take off south, I may end up with a 250# Manson Ray to replace my 176# Claw since when you get over 150# or so, setting isn't an issue with the Bruce type design and it becomes the closest thing to a stowable D9 Cat I can think of.