Coaster
Active member
Which seems to sum up much of the posting on this thread.
Rocna Anchors acquired by Canada Metal Pacific
- Thread starter Laura Nineham
- Start date
Which seems to sum up much of the posting on this thread.
Hoolie
Well-known member
What has puzzled me is that this need to paint over cracks is largely self-generated. I know very little about grades of steel - nothing in fact - but it seems highly likely that the difference in production cost between the lower grade now used by Rocna and the higher grade still used by Manson must be pretty well negligible.
Why on earth didn't they just use the specified grade rather than trying to argue the case?
CMP seem to be also in a similar situation, trying to justify a minuscule cost saving in production relative to the premium price for this anchor. Just use better steel and the arguing will cease!
vyv_cox
Well-known member
The UTS of 8 mm DIN 766 chain is 4030 kgf. The 15 kg anchor, which is what I have, would be appropriately matched with this chain. According to the information I have, which I believe originated with Rocna, the bend strength of this anchor is 4185 N (427 kgf) assuming a yield strength of 780 MPa, very optimistic for Bisplate 80. The figure for a shank with yield strength 690 MPa is 3702 N (377 kgf). The only other materials I have figures for have yield strengths of 480 and 450 MPa, for which bend strengths of 2575 N (262 kgf) and 2414 N (246 kgf) are calculated.
ABYC and Sail Magazine data suggests that for a 35 ft boat (as mine, with a 15 kg anchor and 8 mm chain) forces generated for 15, 30 and 42 knots are 116, 408 and 816 kg respectively. Values derived from measured data by Prof John Knox are about three-quarters of these theoretical figures.
Very clearly the bending strength of even the almost impossibly strong shank cannot come anywhere near approaching the tensile strength of the chain that would be used with it. Even with this unlikely anchor the shank might be expected to bend, given sufficient restraint of the flukes, in a wind force of 6 - 7. The 'sub-standard' shank might even bend in a wind of force 4.
vyv_cox
Well-known member
Bisplate 80 was manufactured in Australia and is a sophisticated low-carbon steel. It would have needed to be imported into China, no doubt a difficult and expensive process. The low-grade stuff is an almost bog-standard carbon steel manufactured in China. Using the latter no doubt saved a considerable proportion of the manufacturing costs.
Hoolie
Well-known member
OK - assuming this steel grade is not realistically available in PRC, could they not increase the shank thickness proportionately across the range to achieve the same strength? Again, little increase in production cost I would have thought.
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Keen_Ed
Active member
No, because (as we've been repeatedly told), the thin (& therefore light) shank is necessary to get the weight distribution right.
Delfin
New member
You probably have the same charts I do, which confirm your observations. What is of interest isn't whether the thin shank on the Rocna would bend in a lateral load, whatever steel it was made of, before the anchor chain would break. That would seem obvious even without data. What's interesting is why Mr. Smith would make such a claim, since it's so clearly bogus?
Shanty
Member
Some random thoughts:
I think I saw somewhere in this mention of a 690 grade steel. I wonder if this is closer to the Bisalloy 80 spec?
I wonder whether some of the comments eminating from Rocna or Peter Smith are confusing bending under a lateral load with buckling under an extreme axial load?
The shank under lateral loading is a very thin encastre beam. An I section would be far stronger. I wonder if any attempt has been made to design an I section shank?
I think I saw somewhere in this mention of a 690 grade steel. I wonder if this is closer to the Bisalloy 80 spec?
I wonder whether some of the comments eminating from Rocna or Peter Smith are confusing bending under a lateral load with buckling under an extreme axial load?
The shank under lateral loading is a very thin encastre beam. An I section would be far stronger. I wonder if any attempt has been made to design an I section shank?
Colvic Watson
Well-known member
Genuine CQR's have always had it
Rigger Mortice
N/A
Vyv,
Am I right in my understanding that, as well as making savings in material costs, a lower grade material is also going to be easier and cheaper to machine, weld and galvanise? i.e. a darn sight more profitable for licensee and licensor
Rigger Mortice
N/A
The problem with that is that, if they accept that the higher grade material is needed (as they have always claimed in the past) they are probably worried that they may have even more anchors to replace.
The whole exercise appears to be more to do with damage limitation and profit maximisation than anything else.
But I agree with you; if they stop playing games and use the original spec. steel the Rocna name would be re-established
iain789
Active member
Lord, do you lot never get fed up with writing the same thing over and over again? The record's cracked and the needle stuck in a groove! Give us all peace - please?
GrantKing
New member
800mpa
The original NZ manufacturer who is still in litigation against Rocna/Holdfast/Bambury for recovery of $100k of unpaid stock supplied in 2009 still has a stock holding of some 500 anchors made to the original specifications.
He has been prevented from selling them to mitigate his losses by an injunction in the courts put on him by Bambury.
The legal delays and changes of story by Bambury in his defence claims will no doubt come to an end sooner rather than later not that their defendant Company will be wound up and out of business shortly.
The original NZ manufacturer who is still in litigation against Rocna/Holdfast/Bambury for recovery of $100k of unpaid stock supplied in 2009 still has a stock holding of some 500 anchors made to the original specifications.
He has been prevented from selling them to mitigate his losses by an injunction in the courts put on him by Bambury.
The legal delays and changes of story by Bambury in his defence claims will no doubt come to an end sooner rather than later not that their defendant Company will be wound up and out of business shortly.
Pye_End
Well-known member
Post 201 would indicate that CM are not liable, and that any 'damage limitation' is limited to Holdfast. If the Craig's did not rubber stamp certain lower grade materials then cannot imagine there being any reason why they should not tell it like it is.
Hoolie
Well-known member
This is news to me - what a can of worms it's all turning out to be. I hope, for their sake, CMP are fully aware of these background issues.
GrantKing
New member
due diligence
Isn't that what "due diligence" is all about.
But then all information, correct information, has to be revealed during that process as well.
Yes, they are aware of it, just as Smiths were aware of it, Bambury certainly aware of it, but do think that the full extent of it would have been revealed during the sale process?
The claim by CNC in NZ and other claims against them would have been glossed over as a minor distraction and nothing for CMP to worry about as they would not be claims against CMP but remain against the sacrifical company, Holdfast, in NZ.
They have a lot to learn.
Isn't that what "due diligence" is all about.
But then all information, correct information, has to be revealed during that process as well.
Yes, they are aware of it, just as Smiths were aware of it, Bambury certainly aware of it, but do think that the full extent of it would have been revealed during the sale process?
The claim by CNC in NZ and other claims against them would have been glossed over as a minor distraction and nothing for CMP to worry about as they would not be claims against CMP but remain against the sacrifical company, Holdfast, in NZ.
They have a lot to learn.
Hoolie
Well-known member
Indeed ... ... ...
But I can't imagine CMP would take on the financial liabilities of the existing licencee. However the legacy in goodwill/illwill may well be incalculable and turn out to be a veritable mill-stone.
But I can't imagine CMP would take on the financial liabilities of the existing licencee. However the legacy in goodwill/illwill may well be incalculable and turn out to be a veritable mill-stone.
maxi77
Active member
If I was in a marketing role at CMP I would be very concerned about any litigation which may impact on the brand. CMP are investing in what appears to be an already tainted brand. On that basis they need to restore the brand image pretty fast or the income stream they need to provide a return on their investment may never get them to a break even point.
Bosun Higgs
N/A
Galvanising cost would be the same, machining cost the same, welding might be slightly different but I couldnt see that being much different.
Biggest cost saving would be doing everything in China. Cheap labour, no H&S, no environments stuff etc etc,
Bosun Higgs
N/A
Thanks for that Vyv - I was too lazy to work it all out myself.
However looking at your figures, which make it clear that the original correct spec NZ anchors would bend way before the chain gave way, also suggests that all other common anchors would bend well before the chain would break. Even if the force necessary to bend the shank of XYZ brand anchor was double that of a correctly made NZ Rocna at 800kgf it would only be 20% of chain breaking load and equivalent to the force on your boat in 40kn wind.However, that assumes the blades dont move first, and thats the real question about the Rocna and for that matter the Manson and Spade. If they are dug into a bottom, will the shank bend and then rotate the blade out or will the blades move in the ground and keep the straight line pull.
It also assumes that the boat fixing at the end of the chain has a similar strength to the chain, something I doubt on most AWBs.
