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anchor chain question


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I'm looking at new chain. I recall a reasonably recent thread about chain and pros and cons. Question is. ... is 32 kilonewtons a good thing for 8mm anchor chain? Is it rated on that or something else? Cheers.

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That myth will have come about as higher tensile strength can equal a lighter chain for the same given load / break capacity. 

 

I once used a brand spankers g40 maggi 12mm anchor chain to tow a stuck truck out. Was not a clever move as it broke and did considerable damage to the truck. Alongside giving us less than any confidence in the chains ability to hold our yacht afterwards.

 

I did not think that an 8 T tractor on mud could pull that hard!. Now we only buy g80 chain on the farms. A bit safer.

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Seen a 10t digger smash a 16mm anchor chain as well. Shock loads will kill, especially using lower grades not designed for the task in hand. I busted a rope with a break load of 9,000kg trying to pull a car off a beach with my Toymotor Landtractor. That dent in the back doors is the one next to where I missed putting the trailer on one day.

 

But as we don't drop many boats we don't need to worry about shock loads unless you use the silly theory of massive anchors with tiny hi tensile chains. One anchor brand pushes that theory so it makes their anchor look that much better. We do find strange as the anchor designer thinks that theory is for those only wanting to become flotsam and jetsam, we agree with him.

 

Yeap, we tend to think the same about the chain weight thing. More stuff twisted and misconstrued due to people not knowing their product, hardly uncommon these days.

 

Is there a way to get in touch for advice of our anchor setup as it stands?

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We've got a Wharram Tiki 38 thats got 50m of 8mm chain with a small 2m section of heavy stainless at the anchor end, Not sure about it's size but it's gotta be atleast 15mm.

 

We've had our bruce re-galved and will weigh it tonight but it feels around the 15kg mark, I was wondering if you had any ideas on the boat the loadings involved and what system you would recommend if it was a clean start?

 

 

Cheers :)

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Keep an eye on the welds on the stainless, I have seen several cases of serious porosity apearing after a year or 3. I would sugest dropping the SS if it shows signs of deterioration and only using the 8mm galvanised. if you need the weight of the 15mm SS, use galvanised instead, although 2m isn't going to make a lot of difference.

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Thank you very much for taking the time to reply, We're looking at our backup anchor system at the mo and I will be sure to take your advice - Not sure if it is against the rules but do you run a shop? If so what shop?

 

I noticed you left out Rocna from your list of anchors, Is there a reason behind that at all?

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erice, that machine is not just testing. It takes every 11 links and stretches to a set length. It insures the links are at the correct length to meet the specifications and in doing so, the "proof" load checked.
Right after that, the chain is run through an induction heater and heated to red hot, then quenched. This is what then hardens the metal to the tensile strength. The Power required at the speed the chain feeds through is horrendous.
Please note that the chain in that giff hardly changes. There is no deformation to the shape of the link. All the Chinese Chains I have done that too, have all deformed the link. And that deformation is often at loads far below the prrof load stated. The result in the real world is that after a blow and when the boaty hauls the chain back up, the Chain no longer fits the gypsy correctly and it causes both wear and sometimes rideover. In one or two cases we have had people not being able to bring the anchor back to the boat.

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I noticed you left out Rocna from your list of anchors, Is there a reason behind that at all?

It is not just Rocna. But answering that specifically first, there has been a " negative history" with this anchor's build quality, it's marketing and most importantly, it's Importers, that CRA has not wanted to be associated with. That now extends to several other products in that Importers range, including a Chain said to be "engineered in Canada". They have several anchor designs now.

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