Rocna anchors - hard to come by

[CSFenwick]

Well, Easter is getting nearer and I've promised myself a new anchor for the coming season. Set my heart on a Rocna but no one seems to have one - supply problems. Anyone know what's going on or where I might procure a 20kg Rocna at a fair price? /forums/images/graemlins/confused.gif

 

[machurley22]

I have also noticed the dearth of Rocnas and have no real idea what's going on although I believe there have been malicious rumours about the manufacturing being moved to China.

 

[Anonymous]

[ QUOTE ]
I have also noticed the dearth of Rocnas and have no real idea what's going on although I believe there have been malicious rumours about the manufacturing being moved to China.

[/ QUOTE ]I heard that but why is it 'malicious'? The Chinese are some of the best contract manufacturers in the world, today.

 

[claudio]

I agree, Pratt & Whitney, the aircraft engine manufacturers' have a plant in China.
Like everywhere else, you can't generalise. There is a lot of rubbish made in China, also lots of good stuff.
The Chinese can make anything to any price. If you want a Rocna copy cheap, they can do that too.
If Rocna go to a 'proper' enginering company in China, there will be no problems at all with the quality of production.

 

[mawm]

I also had my eye on a Rocna, but the local supplier who sells them recommended a Manson supreme at a much cheaper price - and commented that in their opinion, the Manson was performing better.

I have just sat out 55kn, gusting 65kn, winds with a 25lb supreme on my 9m yacht without moving an inch. whilst many around me were playing musical chairs all night long.

 

[[2574]]

I've just purchased a 20kg Rocna. Mine came from Arthurs Chandlery in Gosport who I think are the (one of?) UK main importing dealer. Speak to Ian Ripper at Arthur's - he's extremely helpful.

http://www.arthurschandlery.co.uk/

rob

 

[vyv_cox]

Mine came from Boyd Boats in Dublin. Delivery was pretty cheap.

 

[Blueboatman]

Now thats a recommendation ! Who would dare to argue with a name like 'Man-Son Supreme'

 

[exapp]

Hello,

Rocna Anchors imported into IRL & UK by Boyd Boats of Dublin. Tel +353 (0)1 2301230. Apparently they have a container with 300 Rocnas in UK customs about to be released on Friday and will ship to stockists on Monday.

http://boydboats.com/boydboats/boydboats_2.html

Regards,

Exapp

 

[lenseman]

[ QUOTE ]
I agree, Pratt & Whitney, the aircraft engine manufacturers' have a plant in China.
Like everywhere else, you can't generalise. There is a lot of rubbish made in China, also lots of good stuff.
The Chinese can make anything to any price. If you want a Rocna copy cheap, they can do that too.
If Rocna go to a 'proper' enginering company in China, there will be no problems at all with the quality of production.

[/ QUOTE ]
You only have to look at the Great Wall of China! Their kit lasts for ages, must be good quality. /forums/images/graemlins/grin.gif

And anyway, most stuff you buy in the shops has a CE mark on it somewhere, I was told it stands for "Chinese Engineered / Engineering" /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif

 

[Scotty_Tradewind]

I'm told mine is on the consignment docking/due to dock.

Manson are supposedly not constructed in the same manner and it's suggested they are therefore not as strong. Anyone know more???

 

[AncoraLatina]

[ QUOTE ]

Manson are supposedly not constructed in the same manner and it's suggested they are therefore not as strong. Anyone know more???

[/ QUOTE ]

First, it is a well known fact that the Rocna is now manufactured in China.

They are small subtle differences between the two models, but both are strong enough to make good anchors;

- Both have a shank in Bisaloy 80 – strong steel alloy - but difficult to weld onto the mild carbon steel plate
- the Rocna now has a cast-iron fluke (blade) and the shank is welded straight onto the top of it with a single weld. That weld (Bisaloy 80 to casting fluke) needs to be done under extremely controlled conditions and should really only be done to lock a component into position rather than to absorb the entire load.

Welding cast iron to plate steel is generally seen as a big no-no.

- On the other hand, the tip of the blade of the Supreme is made of two layers of steel – which can be a weak point – If for some reasons, (slightly bent tip) sea water will penetrate in between the two layers, it will rust and nothing can be done to solve the problem...

- They are other small subtle differences but both are good efficient anchors...

João

 

[vyv_cox]

<<< Manson are supposedly not constructed in the same manner and it's suggested they are therefore not as strong. Anyone know more??? >>>

There was a strong post from Manson here in the past month, strenuously denying someone's suggestion that their anchors were:
a) made in China. Apparently they are all made by themselves in NZ
b) made by any methods other than good practice. The equipment used was listed
c) that the slotted shank was weaker than necessary. They say it is plenty strong enough
d) that slotted shanks are banned in France or elsewhere. They say not so.

As usual, someone else then said that Rocna are not made by themselves, etc.....

Don't know why this happens with anchors. Why not with boats, sails, or anything else. I cannot think of any other topic where manufacturers and users lambast each others' products to anything like this extent. Still, makes for enjoyable forums, I suppose.

 

[CSFenwick]

Spoke to the nice man at Arthur's and he confirmed that they were expecting a container load to dock today although they won't have them until next week. I asked him to save me a 20kg one as long as he can get it to me before Easter Friday.

He said there'd been no deliveries into Europe since August last year which must have lost Rocna some business. Said he didn't know the reason for sure but speculated that a manufacturing switch to China had taken longer to settle in (to get the quality right) than had been planned for.

I've trawled around various forums and heard from people with both Manson and Rocna. To be honest both groups seem very happy and report startlingly better performance than the likes of the CQR that currently sits on my bow. When I looked at pricing the Manson wasn’t significantly cheaper than the Rocna (£390 versus £415) so my preference was to go for the original assuming I could get hold of one!

 

[Chris_Robb]

If you cannot get a Rocna, go for the Manson Supreme - I have one - superb bit of kit..... I think that they are both as good as each other - but then I haven;t tried the Rocna!

 

[vyv_cox]

Whilst not intending to get into a 'my anchor is better than your anchor' argument, I can't let this misinformation about Rocna pass without comment. Below you can read the actual situation, from the horse's mouth.

Those interested in further debate as to the relative properties of certain designs may like to look here.

%$%$%$%$%$%$%

Firstly, the Rocna is now being produced in a facility in China in addition to those produced in New Zealand and Canada. All three facilities produce to the identical specification, which of course speaks to steel types and grades, welding specs, detailing, and more. Chinese production has been selected both for good future expansion options and to allow a high level of quality to be retained without needing to raise pricing.

One difference we have implemented in China is a migration to casting, which Peter Smith has wanted from day #1, but we have been unable to get quantities high enough to justify the start-up costs involved. Casting the fluke allows us to solve a number of problems to do with fabricating such a shape that is quite geometrically complex. This assists quality control and does permit a few trivial detailing improvements.

The steel used in the fluke is mild steel of a composition meeting the original Rocna specifications; it is certainly not "cast iron"! Welding the shank to the fluke is not a practical issue any more than it is with the fabricated versions, and the weld is not a single pass except on the very small anchors. The shank join is reverse chamfered and adequate passes are made to meet or exceed specs. The shank weld is very strong, and under extreme load we know that either the high tensile shank itself or the fluke tip will fail before the weld lets go.

The shank, usually the failure point when tested to destruction, remains 800 grade high tensile Q&T plate steel.

%$%$%$%$

 

[AncoraLatina]

[ QUOTE ]
I can't let this misinformation about Rocna pass without comment.

[/ QUOTE ]

Is there any welding specialist on this forum who can comment about welding Bisaloy 80 to mild carbon steel??

João

see for example:
http://dme.digdnn.com/zone_files/inspectorate_pdf/safety_alert071.pdf

COMMENTS:
Investigation indicated several points which could have contributed to the cracking and eventual failure :-
1. The bottom half of the stem lock plate is ATSM A-514 Grade AT1(similar to Bisaloy 80 T-1) and the top half is AISI 1018 H R ( mild steel ).

Welding the two together may have created metallurgical problems.

 

[vyv_cox]

I wouldn't call myself a welding specialist, but I have a degree in metallurgy and some experience in the area.

I see no reason for any particular concerns in welding Bisalloy 80 to mild steel. I don't understand the concerns expressed in your link. Bisalloy 80- is a low carbon steel, with low carbon equivalent. It is readily weldable and rarely requires pre- or post-weld heat treatment. Such treatment is commonly applied where the carbon content is moderate or high and there is a risk of development of low ductility phases. In the case of Bisalloy 80, whose carbon content is less than 0.2%, there is minimal risk of the development of martensite.

 

[Anonymous]

Can you shed any light on the Queensland Government Mines Safety Alert? It looks as though they've considered this carefully and say that there may be a metallurgical problem.

Welds can be dodgy. That was the beauty of the Spade design. Forged must be better than cast for this application.

 

[vyv_cox]

I'm not at all sure that this was a measured investigation. The summary, which is all I can find, attributes failure to six possible causes, one of which is 'Welding the two together may have created metallurgical problems'. Not a very convincing analysis to me.

Is the Spade forged? Their literature suggests that it is welded, " SPADE is designed for strength. The shank is designed to be strong yet light, with the classic trapezoidal profile (like a box grinder) being used in our welded models. The shank sockets into the body of the anchor, with a socket supported by double triangulation, giving a rigid and indestructible joint. All our anchors are made of high tensile steels, or high resistance aluminium alloys, and of scantlings designed by a mechanical engineer to be very strong."

The CQR is forged, and possibly the Bruce? Most others that I know are fabricated. There is no reason why a well-designed weld should be any weaker than the rest of the fabrication. Polyethylene hyper compressors and their discharge pipework operating at 3500 bar are welded - a considerably more arduous duty than an anchor.