Rocna Size

[Exile]

Originally Posted by sailingaway221

Actually the distributors don't care. They sell the anchor, make the profit ... after that point the warranty goes straight to Rocna ..... Also how many anchors do you think have been taken back? Like thousands? Hmmm maybe 3 in total... all of them the guy who did the test....No one else here with a Rocna seems to be running to take it back. I think this whole thread is blown out of proportion..... No one that walks into West marine to buy an anchor cares... If West marine or any other distributor did they would have removed the anchors from sale... but no... still there and still selling...... Sooooo I imagine Rocna is quiet because this has not affected their sales in the slightest. Just my opinion but I think you think they care more than they really do.

I took mine back. That makes 4.

[sailingaway221]

Just one more point... but how do you side load an anchor? The ONLY way to side load an anchor is to wrap it around something and load it up..... if you anchor in coral or rocks you can do this... sand mud... etc.. not possible. If your anchor shaft doesn't bend under side load you probably will rip something off your boat or break the anchor or shackles holding it ...... Think about it... to load up the shaft on your anchor you have 0 scope left.. the chain is going straight to the anchor... usually when you are retrieving or setting the anchor.......... If you have 0 scope left and your anchor is still holding and bent 90 degrees ... 1/ Its a good anchor.... 2/ you're asking for something to break... on the boat or in your gear. I could understand all the concern... but again I say it... if these anchors are holding the boat and not breaking in two ..... They are strong enough for the purpose they are being used.... Has anyone heard or seen a Rocna anchor break and the boat be set adrift?

[marinextreme]

Originally Posted by Cormorant

"fit for purpose"
"no evidence from real-life anchor use"
"meet requirements"

so begins the legalese, the wiggling and the weaseling. . . .

you are dealing with experts in that field

[sailingaway221]

Originally Posted by Exile

I took mine back. That makes 4.

LAst month.. out of two large shops in St. MArtin 17 Rocna anchors were sold..... so imagine how many are sold worldwide and then try and imagine that 4 returned really have impacted anything at all for rocna?

[Delfin]

Originally Posted by sailingaway221

LAst month.. out of two large shops in St. MArtin 17 Rocna anchors were sold..... so imagine how many are sold worldwide and then try and imagine that 4 returned really have impacted anything at all for rocna?

So, 17 people paid more money for a weaker anchor made by people who don't tell the truth when it suits their economic interest. I can see why the folks at Rocna might view this as a victory of some sort, but am hard pressed to understand why anyone else would.

Side loading a 3rd generation anchor is not that difficult since they can get pretty well set. That is why Peter Smith said that the grade of steel required for the Rocna is a much harder grade than the current management bothers to use, knowing that even if caught, they will still have supporters amongst the useful idiot contingent.

The side loads required to bend a thin shank made out of under spec steel is in the hundreds of pounds - a force easily encountered in wind shifts on a deeply buried anchor, and that is perhaps why Manson uses 800 MPa steel and Rocna pretends they do.

[marinextreme]

Originally Posted by sailingaway221

Just one more point... but how do you side load an anchor? The ONLY way to side load an anchor is to wrap it around something and load it up..... if you anchor in coral or rocks you can do this... sand mud... etc.. not possible. If your anchor shaft doesn't bend under side load you probably will rip something off your boat or break the anchor or shackles holding it ...... Think about it... to load up the shaft on your anchor you have 0 scope left.. the chain is going straight to the anchor... usually when you are retrieving or setting the anchor.......... If you have 0 scope left and your anchor is still holding and bent 90 degrees ... 1/ Its a good anchor.... 2/ you're asking for something to break... on the boat or in your gear. I could understand all the concern... but again I say it... if these anchors are holding the boat and not breaking in two ..... They are strong enough for the purpose they are being used.... Has anyone heard or seen a Rocna anchor break and the boat be set adrift?

The side load required to bend the shank on a 33kg using Bisalloy80 steel is only 564kg.

Drop that to a 450 grade and the load is only 317kg

In your passion to defend the anchor you are forgetting the point that the discussion and problem has been about the shanks bending and the probability of the anchor breaking loose from the seabed. It has not been about the shank snapping.

The design, like the manson supreme, has always exhibited exceptional grab and "stickability" to the seabed. They do not rotate and the vessel moves around, they dig in, bury themselves and stay there. The greatest force applied in wind shifts is a lateral load and even if the material is slightly below the rated standard then it is more likely to bend sideways and risk breaking out as the movement of the vessel, after the shank has bent, will alter the setting position and stress on the blade resulting in the anchor pulling out and not resetting.

The geometry of the anchor is critical in the success of the setting ability of this design. According to Smiths even if the shank , when being assembled, is even a few millimeters out of true centre line, the anchor will not work completely successfully and may be difficult to set.

A curve in the shank will affect the ability of it to set and hold as per the design parameters. The tolerances on the straightness of the shank call for anything greater than a 1mm over 500mm length curve to be straightened or the anchor will be classed as a reject and not fit for purpose.

Does that not show just how critical both the material and the tolerances are to the design?

[sailingaway221]

Originally Posted by marinextreme

The side load required to bend the shank on a 33kg using Bisalloy80 steel is only 564kg.

Drop that to a 450 grade and the load is only 317kg

In your passion to defend the anchor you are forgetting the point that the discussion and problem has been about the shanks bending and the probability of the anchor breaking loose from the seabed. It has not been about the shank snapping.

The design, like the manson supreme, has always exhibited exceptional grab and "stickability" to the seabed. They do not rotate and the vessel moves around, they dig in, bury themselves and stay there. The greatest force applied in wind shifts is a lateral load and even if the material is slightly below the rated standard then it is more likely to bend sideways and risk breaking out as the movement of the vessel, after the shank has bent, will alter the setting position and stress on the blade resulting in the anchor pulling out and not resetting.

The geometry of the anchor is critical in the success of the setting ability of this design. According to Smiths even if the shank , when being assembled, is even a few millimeters out of true centre line, the anchor will not work completely successfully and may be difficult to set.

A curve in the shank will affect the ability of it to set and hold as per the design parameters. The tolerances on the straightness of the shank call for anything greater than a 1mm over 500mm length curve to be straightened or the anchor will be classed as a reject and not fit for purpose.

Does that not show just how critical both the material and the tolerances are to the design?

Grant... to get 300-400 kg load to my anchor using a 7 to one scope and 10 mm chain ... unless I miscalculated .. I would need 67 knots of wind ...... then I would need to pull my anchor sideways without it tripping under 300 plus KG's of load.....? Thats not including the elasticity of my Nylon stretch bridle.... which they say can reduce the loading by up to 20% by the stretch...... soooooooo that would mean I need to get my boat sideways to the anchor in 85 + knots of wind to get anywhere near that loading.

http://northpacificresearch.com/down...d_revealed.pdf

Sorry, but again I stick by my previous post.

I have no doubt that after using my anchor for the last 2 years.. non stop in all sorts of bottoms that the shaft is appropriate for my use ..... to bend it I need to hook it on something or.... be in 87 knots and get sideways to it..... hopefully the only thing that will bend will be the anchor!

[vet222]

Originally Posted by sailingaway221

Grant... to get 300-400 kg load to my anchor using a 7 to one scope and 10 mm chain ... unless I miscalculated .. I would need 67 knots of wind ...... then I would need to pull my anchor sideways without it tripping under 300 plus KG's of load.....? Thats not including the elasticity of my Nylon stretch bridle.... which they say can reduce the loading by up to 20% by the stretch...... soooooooo that would mean I need to get my boat sideways to the anchor in 85 + knots of wind to get anywhere near that loading.

http://northpacificresearch.com/down...d_revealed.pdf

Sorry, but again I stick by my previous post.

I have no doubt that after using my anchor for the last 2 years.. non stop in all sorts of bottoms that the shaft is appropriate for my use ..... to bend it I need to hook it on something or.... be in 87 knots and get sideways to it..... hopefully the only thing that will bend will be the anchor!

The point is though SA221, do you have the goal post shifted Chinese spec and built 'Rocna" or the NZ/Canadian original reputation building, made to spec Rocna to have your confidence and proof in action for 2 years.

It seems I and others may well have been sold a misrepresented goal post shifted product and I not only have the right to know, but my boat and maybe a life may someday depend on this product.

I just want to know what "this" product is that I purchased given it may not be the same as what I was lead to believe I bought.
I want to believe in my Rocna BUT if made substandard to spec as either 1. a mistake........ then Rocna need to make good and give me and others a new one made to original 800MPa spec (which I would prefer) OR 2. a sly profit making rip-off........then Rocna need to be caught out and refund so I can review my purchasing options again. OR 3. is made to spec and this forum is fueling bad vibe, but Rocna need to weigh in pretty soon to defend and restore consumer confidence cos their silence is not helping and they should know the answers NOT be waiting on test results as per their email to me.

I didn't buy the most expensive anchor around to later find the company trying to prove it meets minimum standards that are found in other time honored brands...... I bought my anchor because it reached premium specs and seemed to set a bench mark in spec and performance based on their advertised original. I would feel ok too if mine were an original. I have nothing against made in china but I need confidence that made in china is as advertised.

So again, to have YOUR degree of confidence, which Rocna do you believe you have ...... Original made spec OR a Questionable?

[captain58sailin]

Bottom line you are paying for something that you are not getting. Regardless of the spec. tolerances, if I am paying the bill, I expect to receive what I have paid for and if I did not; then there is a problem. I don't see the shades of gray in this instance.

[Delfin]

Originally Posted by sailingaway221

Grant... to get 300-400 kg load to my anchor using a 7 to one scope and 10 mm chain ... unless I miscalculated .. I would need 67 knots of wind ...... then I would need to pull my anchor sideways without it tripping under 300 plus KG's of load.....? Thats not including the elasticity of my Nylon stretch bridle.... which they say can reduce the loading by up to 20% by the stretch...... soooooooo that would mean I need to get my boat sideways to the anchor in 85 + knots of wind to get anywhere near that loading.

http://northpacificresearch.com/down...d_revealed.pdf

Sorry, but again I stick by my previous post.

I have no doubt that after using my anchor for the last 2 years.. non stop in all sorts of bottoms that the shaft is appropriate for my use ..... to bend it I need to hook it on something or.... be in 87 knots and get sideways to it..... hopefully the only thing that will bend will be the anchor!

The very informative link you posted from Ocean Navigator indicates in table 1 that a 30' boat in a 15 knot wind puts 58# of force on the anchor. Let's assume your 33' would add a couple of pounds of force. Since this force is coming from the wind pressure on the hull of the sailboat telegraphed through the rode of the test vessels, increasing the wind speed increases the wind force. At 25 knots, the force is 200#. At 40 knots, the force is 457 pounds, and if you actually have to sit out a blow at 55 knots, you'll put around 900 pounds of force on your anchor. At your theoretical wind speed of 87 knots you'd be dealing with over 1500#. It is true that the length of chain rode out, or nylon rode out will affect the calculation, but when it really starts to blow, fudge factors disappear and surges will be placed on the anchor. At that point, my guess is that your support of Rocna will diminish somewhat, and you might even wonder why you paid so much for an anchor only 2/3 as strong as better built alternatives.

[Shawn67]

And that is just talking about the static loading from the wind. Throw in some waves and the dynamic loading will increase dramatically.

Suncoast Marine (the NA Rocna distributor) has a chart saying a 30' boat in 30 knot winds has 700 pounds of dynamic force on an anchor, that is already nearing the bending point of the anchor. At 42knots they are talking 1400 pounds of force and 2800 at 60knots.

Shawn

[marinextreme]

YouTube - ‪bent rocna‬‏

Now this is a 6kg/13lb "fisherman" model that the shank is rated to 200kg force before bending.

It is recommended to fit the following boats sizes:

16ft up to 5ton
20ft up to 4ton
23ft up to 2ton
26ft up to 1ton

you can find it here http://www.rocna.com/product-range/sizing-guides/

It was bent by pushing 1 leg down on it by someone weighing 75kg

[Agility]

I had a 33KG bend last year. They suggested going to a 40KG because the shank is wider, which I did. The shank bent the first time it was used but I wasn't on the boat and the conditions were pretty strong.

[downunder]

Originally Posted by Agility

I had a 33KG bend last year. They suggested going to a 40KG because the shank is wider, which I did. The shank bent the first time it was used but I wasn't on the boat and the conditions were pretty strong.

That's not good and it seems there might be more problems around about to surface.

Did Rocna refund the value of the 33 towards a 40?

[Dockhead]

Originally Posted by Delfin

The very informative link you posted from Ocean Navigator indicates in table 1 that a 30' boat in a 15 knot wind puts 58# of force on the anchor. Let's assume your 33' would add a couple of pounds of force. Since this force is coming from the wind pressure on the hull of the sailboat telegraphed through the rode of the test vessels, increasing the wind speed increases the wind force. At 25 knots, the force is 200#. At 40 knots, the force is 457 pounds, and if you actually have to sit out a blow at 55 knots, you'll put around 900 pounds of force on your anchor. At your theoretical wind speed of 87 knots you'd be dealing with over 1500#. It is true that the length of chain rode out, or nylon rode out will affect the calculation, but when it really starts to blow, fudge factors disappear and surges will be placed on the anchor. At that point, my guess is that your support of Rocna will diminish somewhat, and you might even wonder why you paid so much for an anchor only 2/3 as strong as better built alternatives.

That's right. In a big storm you will be sailing around at anchor and putting huge snatch loads on your whole ground tackle. Read the accounts of people who rode out hurricanes at anchor.

If I paid for an anchor which is supposed to be suitable for riding out a hurricane at anchor, then I am not very happy for it to turn out to be something different, even if I never end up riding out a hurricane at anchor.