I hate to do this...but

noelex said:
There have been a few Fortress anchors bent, including some during anchor tests.
Fortress have always been excellent at replacing these anchors.
It’s a great anchor, but in extreme conditions there is some risk of deformation.
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True. I think Brian Fortress noted one such case above, requiring 3,000# of lateral force to partially bend the shank. Any piece of metal can bend or break, the question is whether the product is built to the standards specified by the engineering brief. Fortress, certainly, Rocna, appears not.
 
noelex said:
There have been a few Fortress anchors bent, including some during anchor tests.
Fortress have always been excellent at replacing these anchors.
It’s a great anchor, but in extreme conditions there is some risk of deformation.
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No doubt, they will remain buried into a sea bottom and sometimes get mangled long after many anchors have broken free and the boat is set adrift.

Also, under a heavy load they do tend to bury very deeply and get stuck on stuff way down below the sea bottom. After a serious blow, owners have told me how difficult it has been to retrieve their anchor, with comments like "it must have been stuck on the core of the earth,".......and once the anchor finally did break loose, it brought up all kinds of things with it: Fossils, dinosaur bones, and one time even a Chinese gardener....although I'm not believing that story! No way!! :D
 
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Look guys, its no use speculating on who knows what or who is the sharpest needle in the haystack, the simple facts are that a 25kg shank , if it was bis80 , has a bending force of only 745kg.

A 450mpa shank, if it was on the same anchor , has a bending force of only 459kg.

Pete Smith, when setting steel specifications, chose the bis80 , or equivalent, for these exact properties and resistance to bending.

Now, one of the features of both the rocna and the manson supreme is that when they set , they stay set, and do not rotate, rather you rotate around it. There is therefore always going to be sideways strain applied to the shank.
If it is to the designer's spec then it will very rarely bend, if it is below his spec then it will become a noodle.
 
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I believe Grant said in a previous posting that he was responsible for examining Rocnas that had bent or failed for some reason.
He may or may not be able to give specifics, I don't know but some idea of how many he has seen would help.
 
Nostrodamus said:
I believe Grant said in a previous posting that he was responsible for examining Rocnas that had bent or failed for some reason.
He may or may not be able to give specifics, I don't know but some idea of how many he has seen would help.
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I am going to have to sit on this one for a short while.

I do have extensive knowledge and data of others including photos.

If they were posted now then I am sure that Bambury would pop a valve and being the spineless wonder that he is would most likely send his monkeys to visit just like he did last time.

Last time that happened my child was very upset and distressed for a long time afterwards and I am NOT prepared to let that happen again.
 
Grant,
No one would ever want to put you or your family in that position so we understand that you cannot post specifics at this time but can you just give a rough estimate for the number of anchors you have seen that are bent or defective.
 
The real danger EXPLAINED.

Quote:
Originally Posted by Ubergeekian

Alternatively if there isn't a problem, either because the material is strong enough (and frankly I wouldn't have thought that 690MPa vs 800Mpa would make much difference) or because there has just been a small rogue batch of bad anchors, reassurance from the designer would help enormously in preserving the reputation of both design and current production.

So, Craig. What's your opinion?


Quote; by congo

I think a lot of you are clearly missing the point, we keep using figures such 690MPa vs 800Mpa and suggestions swaying toward acceptable even if the Rickety anchor is constructed out of the lower there is not much difference, no there is not much difference when you are simply working of figures.

Now you have seen G.K latest post and why, if you don’t want to bend shanks it must be of 800 MPa, understand it is not the difference in figures but the properties of the steel, Bis 80 or 800 MPa has incredible recoil, flexing properties, so 690 MPa is mild steel and has little to no flex or recoil properties, on impact applied to 690 Mpa it will yield well below its rated strength.

On the other hand BIS 80 will take considerable impacts and absorb it through its recoil and flexing properties, so while the mild steel strength is lesser on impact than its given hardness number, bis 80 on impact can actually be higher than its hardness number.So when the going gets tuff, the tuff get going.

This is why the rickety anchor design could be extremely dangerous when subjected to impacting from less than favourable conditions with the wrong type of steel, far more dangerous in gal force conditions, the mild steel will be subject to sever impact and yield instantly and pull out looking very similar to the liquorice Venice anchor .Try redeploying that anchor when it dislodges due to bending.

That my friends is where the danger lies, don’t argue the numbers strength, argue the properties of the steel type.

If the lower grade of steel subject to discussion on the Rickety anchors still held the same properties of bis plate then the numbers game would be more accurate.

My conclusion and it is only mine, the anchors in question with the steel grade discovered are and will be, make no mistake rickety anchors.

You know we have steel experts on this forum that we so desperately need for accurate information and then to put that information to use so as we can all understand, I have rambled on here quite a bit until I could make sense out of it , I hope you can.

If any expert would like to correct me, prove what you are saying, express in such a way we can truly understand the downside, explain the properties of steel, pack the numbers game away if you are going to use them when discussing two very different types of steel in the name of safety. So do we have a problem, Rickety owners could have a dangerous problem.

Rex.

Anchor Right Australia.
 
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CONGO said:
I think a lot of you are clearly missing the point, we keep using figures such 690MPa vs 800Mpa and suggestions swaying toward acceptable even if the Rickety anchor is constructed out of the lower there is not much difference, no there is not much difference when you are simply working of figures.

Now you have seen G.K latest post and why, if you don’t want to bend shanks it must be of 800 MPa, understand it is not the difference in figures but the properties of the steel, Bis 80 or 800 MPa has incredible recoil, flexing properties, so 690 MPa is mild steel and has little to no flex or recoil properties, on impact applied to 690 Mpa it will yield well below its rated strength.
Rex.

Anchor Right Australia.
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I agree with Rex that discussion of whether a lower grade of steel is "good enough" completely ignores the original engineering of the Rocna. There is a reason why Craig and Peter Smith have made such a big deal about using 800 MPa Quenched and tempered steel, and that is because it is required for normal service given that the shank is so thin. The shank is thin to get the weight distribution loaded to the tip, otherwise the anchors ability to set quickly would be significantly reduced.

The analogy would be if the engineer responsible for determining what tires go on your Lamborghini specified one that would run at 180 mph without spinning apart, but Lamborghini decided to put 140 mph tires on to save money. They would still be black, still round, still work fine right up to the point where they failed. Rocnas made with steel below the grade specified by the designer are defective, period. If you doubt that, ask Peter Smith, or perhaps read what he wrote about the necessity for 800 MPa steel:

"The shank on any anchor is a common failure point, normally bending when a high lateral load is applied (for instance, when the anchor fouls on a submarine obstacle and is jammed). For this reason, the shank on the Rocna is a high tensile quenched and tempered steel, with a grade of around 800 MPa. Its pure resistance to bending is around three times that of mild steel. This adds to the price of the anchor, but compromising this strength is not something we would entertain. " He also explains why Rocna couldn't make an aluminum alloy anchor with the same design for similar reasons:

"We have not produced an alloy version primarily because we feel it would be a compromise on this. The current design would have to be modified substantially in order to facilitate alloy production, and any changes would represent a compromise. For example, an aluminium shank would not be able to possess the same tensile strength as the 800 grade steel we use without being significantly thicker, which would then affect setting performance in hard sea-beds."

Given that other anchors are available, many for less money, with a similar design, similar performance but are made of the materials they are designed to be made with, I am still at a loss why anyone would buy a Rocna, sell a Rocna, or defend their business practices.
 
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Justice May Prevail

What G. king is having to contend with re (monkeys) I can for one fully understand where he is coming from, when I ditched N.Z. the once nice little guy I was dealing with was now texing messages to not just me, but two my children, I have Five, threats of sending Gang members in Australia linked to N.Z. were supposedly going to visit me to get me sorted, I spent many sleepless nights so it still took a toll even though it didn’t eventuate.

For god Sake, how did this happen, all Iwas wanting to do was sell anchors.

Grant Lives in N.Z. what he has done and said he will do, takes real guts and needs to be commended, I would not even comment on the perpetrators of these tactic’s, but there may be justice yet Grant as the guy that took me to very nearly ending my business is doing six and a half years. How good is that.

I wish you all the best, but more importantly keep safe.

Rex.

Anchor Right Australia.
 
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I still need to buy a new anchor which I will do today.
In fairness to Manson and Rocna I wrote to both of them to see what assistance I would get.
For the Rocna I e mailed a well-known UK Chandelry who advertise the said anchor asking if they had a 33kg Rocna in stock and if not when would they have one in. I also asked if they would give me a written guarantee that the specifications and composition were as the Rocna web site. The reply was as follows
“Unfortunately we have sold out of 33kg Rocnas. The UK distributor for Rocna is Marine Factors. Their website http://www.marinefactors.co.uk/ has a list of stockists, so you may be able to track one down there.
On the subject of the specifications of the Rocnas, we have them delivered direct from the factory so we are happy to guarantee they are all made to Rocna’s strict standards. We are aware that there was a small batch from the start of last year (all now sold to the best of our knowledge) which were made of a lower grade of steel, but this is certainly not something you need to worry about if buying new.”

I also e mailed Manson asking what sized anchor I would need for my boat but I did not ask for a written guarantee. Their reply was as follows.

“Hi there ******, thanks for your email and consideration of our Supreme
Anchor.
I would be looking at a 45lb for general anchoring and coastal sailing but,
to be honest if you were going offshore and extended cruising and wanted a
bulletproof anchor then I would be looking at a 60lb Supreme. All Force Four chandleries have our anchors or can get them in or sell them online. Where are you located and I will forward your request to our local agent to sort the details for you on this”.

I am not going to comment on content of the replies as you can make your own mind up but there appears to be one company here which has faith in its product and wants to sell me an anchor and one which wants to send me elsewhere. Which would use choose?
 
One enquiry was to the UK agent, who has performed a neat sidestep by confirming that an anchor it cannot supply will be to spec.

The other was to a non-UK manufacturer that has been helpful in recommending a size, and pointed you in the direction of a local supplier, but has said nothing about spec.

As I don't believe in the 'magic' of the roll bar, personally, I'd be getting in touch with Rex from Sarca, to see if he could load an anchor for you on the pallet he is proposing to send to the UK and also asking Spade what they've got that would grace your noble vessel.
 
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