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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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These are 8mm, metric 8mm not 5/16" which will be a smidgen higher. The US isn't quite the same as the rest of the world but recently it's started to fall into line quickly. The US has been protecting their manufacturer, as has Aussie, nothing wrong about that but it has left them a little behind the rest of the world.

 

Grade 20 - bust load 2400kg - very low grade - not seen in NZ until China arrived on mass. Good for cray pot but not for the boat carrying it.

Grade 30 - bust load 3200kg - What NZ had as it's only choice for many years until 15 years ago +/-. China makes most of this these days but PWB in Melbourne still do (and it good stuff) as does Pearson Acco in the US which is what they call Grade 30 or BBB.

Grade 40 - bust load 4000kg - Chinas not into this big time yet. Common in the US being called G40 H-T, the HT being High Test not high tensile.

Grade 70 - bust load 7000kg - the world strongest, comes out of the EU mostly made by Maggi Catene SpA. Note: The US G70 is really a G60

 

So your 32kN chain is a Grade 30. Proof load ( the load at whicjh the chain shouldn't change shape) being 16kN or 1600kg. A average (in windage and bow shape) 32ft would expect around 1500kg of horizontal load in 62kts of wind. So in 60 odd knots you are below proof load. I'd be very happy with that on my 32fter. On my 930 I have a Maggi G40 7mm which has a bust of 3000kg, It works fine but if I cruised more I'd go to a 8mm for the ground weight.

 

The other question of course is where it's made. That will dictate how accurate the loads reported on it are and how often you'll replace it. Buy good stuff, it is the smarter option when looking at the lifetime cost. In NZ chinese made will cost you a lot more than the good stuff over time...and in some bizarre cases to buy in the first place. We can sell Chinadian chain (chinese being sold by some as 'Canadian') for less than it costs us to buy the good stuff. For something with next to no labour content it can only be made cheaper buy using low grade materials and leaving out manufacturing process's.

 

Oh and the high grades aren't lighter than a lower grade. No idea where that myth came from but many still believe higher tensile equals lower weight, it doesn't.

 

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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.

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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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Ask away here.

All info is good info and the chances are high you'll ask what someone else wants too as well so 2 birds one stone sort of a thing.

 

 

Those machines, one is a Wafious by the looks the Ferrari of chain making machines, are cool to watch, especially when making 25mm and other big chains. The power to bend the wire that easily is impressive. The normalising one is also a ripper. I watched on in Aussie heat cold 10mm chain to white hot in less than one meter, then plunge it and reheat it. The power in that machine was also large but of the amps type, the power wire feeding it was the size of a thigh.

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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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What Steve said. The 2mts of 14 or 16mm on the end won't do much but it will do a little more than nothing.

 

A 'average windage' 11mt boat would expect to see around 1600kg of horizontal load in 62kts of wind. You'd be below average windage and the same wave action related so the 1600kg would be higher than you would expect to see.

 

As anchored in 60kts isn't common but can happen, even in the H Gulf, we like to work on that number. So with that in mind you want a chain that won't deform below 1600kg, if it does and you have a windy night then it's not going to work in your winch come the morning, a growing issue we have seen over the last few years.

 

So from there we suss the boat at take a stab at the chain it would be OK on. Being a multi weight sensitivity is important so smaller and stronger is better the larger weaker. Being low wooded and windage I'd say a 8mm is a highly viable place to start.

 

Now we need to make sure it's strong enough so back to the 1600kg we go to get a chain or grade with a proof load exceeding that 1600kg. A Grade 30 8mm has a Proof load of 1600kg, coincidently. Proof load is twice the working load, a load at which the chain should not change shape and a load that the chain is taken to prior to leaving the factory. For the purpose of explaining 'Grade' to the punters we can say it's the strength rating of the metal used so higher the grade the stronger it'll be.

 

So we have established the expected load, the base chain starting point and a Grade 30 chain will just meet the required load.

 

Now we suss the boat owner to see if the 8mm, in this case, give them what I call the FGF (feel good factor). By that I mean I have a 1mm dyneema rope here that has a load that would allow both me and Steve to climb Mt Everest on it at the same time BUT our heads would be screaming 'You're fecking joking, get me the feck off this rope NOW!!' i.e. we would have no FGF. No matter what I say, the interweb says or the Labour Party says we are not the ones sleeping on the boat so if those that are don't have the FGF they won't sleep well. After a day or 3 'She' will get real grumpy and the trip will spiral down to 'Just get me home'. So if the FGF means you need 20mm chain where I'd use 8mm, so be it 20mm is the way to go. In many cases the FGF has dictated going up a size, it happened just this morning on a 60 being built, so we say don't be shy is saying 'Up one please'. We actively ask that but most don't.

 

Assuming the boater is OK with the visual and has FGF with that then you can look at the options like grades and steel types. In NZ almost all Grade 30 is made in china, some say Canadian but I can't find a city in Canada called Ningbo nor a Canadian Provence called China so we don't fudge things and simply say china. Some chinese is a lower grade, there is zero reason to go there as that crap is being sold at pretty close to the vastly higher quality Maggi made G40, it's bizarre but happening. There is PWB made Grade 30, that is made in Melbourne and it is good stuff I would use on my own boat. The other option is Maggi AQUA4 or AQUA7, a Grade 40 and Grade 70 respectively. Grade 40 is 33% stronger than Grade 30, Grade 70 is 125% stronger than Grade 30. So if the owner wanted that little bit extra they could go to the Grade 40. The Grade 70 is really for those who subscribe to the US style of anchoring system, MASSIVE anchors connected to the boat by tiny hi tensile chains, a theory most of the world doesn't and personally think is simply silly as you put all your eggs in one basket, the anchor only. Here we tend to balance the system so the chain does a lot of the work as well.

 

Then steel, stainless, plastic or even Titanium. The last one is out as it costs beyond silly. The plastic is out as it's a low load chain so only good in no weather. Stainless is blingy but has its own set of issues steel doesn't have, it also costs a lot. Steel, the choice of most. What you can do if you want some, only a mt or 3 usually, bow bling is add some SS on the end of the steel, we do it more and more.

 

If it's a genuine Bruce then you have a desirable item indeed. They are at the lower end of the holding power spectrum and do released in very sudden spectacular way but they have a very strong following in the cruising fleet, which tells me they have to be at the very least OK. Most of the knock-offs scare me, so much so I have 50 odd here I'm not willing to sell and only give them to clubs to use for race marks and other none life threatening uses. Some are OK but not all of them. Manson make the 'Ray' which is a Bruce style, I'd happily use one of those. 

 

15kg? On the lighter end of the scale but a good technique and throwing lots of chain out behind it sure would help.

 

If you were to replace it these days you'd have to be looking at Supremes, Excels or Sarcas really. The Boss maybe but it is physically HUGE. All 4 are 1st world made out of good metals and have SHHP approvals (the Boss maybe not yet) so a high standard to maintain. And interestingly they are all cheaper than the very heavily marketed anchors out of China that have no approvals and are very cheaply made.

 

So there ya go, that's some of how I spend my day.

 

NOTE: The above has been simplified for ease of understanding, is based on the NZ market and is a little general even if done with a 38ft Warram in mind. It will not apply to boats in Class or MNZ Survey as they are dictated too by a book of requirements that are so very old school they must have been written by a James Cook during his trip down this way a few years back.

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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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