Anchors for Catamarans

[chrisr]

Originally Posted by BigBeakie

Good move on downsizing chain. We decided to be a pioneer on using a new product, a G100 8mm chain that was galvanized in Newcastle by Armogalv and then break tested. Broke at about 8 Tons and had 25% stretch before failure. I will report on how it stands up in real use, but I expect it to be excellent. There is one user who has used it for over a year and galvanising is like new, so I'm quietly optimistic.

That's a really big anchor, the # 8 Excel. I think it might be a bit over conservative. The Excel truly sets & holds like a rock. You might want to think about having a Fortress for really muddy conditions and as a dual anchor in a V for storm anchoring?


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hey BigBeakie, we are Newcastle based at the moment and been looking to switch fm 10mm to high spex 8mm - just as you have done.
i've found armogalv (at thornton) but where did you get G100 8mm chain prey tell ?

thanks for your help

cheers,

[thinwater]

Originally Posted by LoudMusic

Catamaran you say? Why not carry two?

https://i.imgur.com/Vaphv79.jpg

PDQ 32 LRC, in case anyone cares.

[BigBeakie]

The guys at Thornton were great and did a great job👍

By the way, the galvanising specs were MUCH higher than what we normally get on marine anchor chain from the likes of CMP or Maggi. It was very similar to US Navy specs, about 125 microns of gal.

We had the G100 8mm imported from China after samples were inspected/tested, and after their G80 6mm was used successfully by a full time cruiser for over a year with no corrosion showing.

Unlike other hi test chain from the lifting industry suppliers, the chain came just oiled and not painted, which was a big advantage for Armogalv to do their process.

Once more field user testing is done under tough conditions, the plan is to set up an import and distribution network for Australia.


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[chrisr]

Originally Posted by BigBeakie

The guys at Thornton were great and did a great job👍

By the way, the galvanising specs were MUCH higher than what we normally get on marine anchor chain from the likes of CMP or Maggi. It was very similar to US Navy specs, about 125 microns of gal.

We had the G100 8mm imported from China after samples were inspected/tested, and after their G80 6mm was used successfully by a full time cruiser for over a year with no corrosion showing.

Unlike other hi test chain from the lifting industry suppliers, the chain came just oiled and not painted, which was a big advantage for Armogalv to do their process.

Once more field user testing is done under tough conditions, the plan is to set up an import and distribution network for Australia.


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ok, gotcha - thanks

unless you are going to have this up & running within the next month or 2 we'll have to look at other options as really cannot wait longer

might have a talk to armogalv about galvanising some other h/t chain

cheers,

[BigBeakie]

Sorry, it definitely won't be available that quickly. Perhaps you can source hitensile that is painted, and then strip it?

But it's certainly worth going with Armorgalv. Get them to spec up the coating thickness beyond the 30 to 40 micron that normal marine chain has. It will last much longer.


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[noelex 77]

Let us know how the Armorgalv process holds up. I think it shows a lot of promise, particularly for those using thinner G70 or above chain.

The thinner, lighter chain moves around on the seabed more so abrasion of the galvanising becomes significant, especially for those anchoring in harder substrates. In addition, the heat from conventional hot dip galvanising reduces the strength of high tensile steels.

As I understand, the Armorgalv process is more abrasion resistant and can applied with lower temperatures so should be especially beneficial in reducing the lower lifespan seen with thinner high test chain. However, there have been some reports that despite these advantages the overall life of Armorgalv coated anchor chain is less than conventional hot dip galvanising. I understand that there are technical problems applying the coating as thick as hot dip galvanising.

Anyway, it is early days for this process and there are very few real life reports. The frequent replacement or re-coating of anchor chain is a nuisance for people that anchor out the majority of the time so a better process would be welcome.

[CaptRehab]

I have not seen the Sarca Excel for sale in Grenada or Martinique, but I have found the Rocna, Spade, and Vulcan. The Vulcan looks a lot like the Spade. Does anyone have experience with this anchor? It might fit better in the tight space I have next to the port bow

[chrisr]

Originally Posted by BigBeakie

Sorry, it definitely won't be available that quickly. Perhaps you can source hitensile that is painted, and then strip it?

But it's certainly worth going with Armorgalv. Get them to spec up the coating thickness beyond the 30 to 40 micron that normal marine chain has. It will last much longer.


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thanks

one thing i need to look at is whether nickel coated chain such as this

https://www.nobles.com.au/en-au/prod...grade-70-chain

can be galvanised ? any idea ?

cheers,

[BigBeakie]

Noelex,

There was some "bad" Armorgalv chain in Oz that did not give the normally expected corrosion protection of Armorgalv, but that was a few years ago and was a batch production issue. I discussed that with Armorgalv. A known QC problem that was fixed.

On our G100 8mm chain, the before and after break testing had about a 15% break strength reduction from the Armorgalving process, but considering the very high break strength of the naked G100 chain, it is still a winner compared to G70. Also significantly less expensive.

I've seen photos of the Armorgalv G80 6mm after 18 months of daily use on a liveaboard Lightwave cat that anchors out, and it looks the same as my new chain but just a bit more polished looking from the contact with the sand bittom. No corrosion whatsoever. Seems very promising indeed.


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[BigBeakie]

Chrisr,

Whats the break strength of that chain?

You should discuss with Armorgalv the suitability for their process re the existing coating/ surface treatment. If I were you, I'd get them to do a 3 meter length and then have it break tested to make sure it retains break and stretch characteristics. Don't use brittle chain.


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[BigBeakie]

Chrisr,

Another thought. You'll also need to decide which way to go for the shackles, to match the superior break strength of the chain. No sense getting stronger chain and then creating a weak link by using crap shackles. The Crosby G209A shackle is what we used in 5/8" size and that has rated WLL of 5 tons. Its pin wont go through the 8mm chain so you can either use a larger last link welded on before the galvanising (making sure it's as strong or stronger than the bare chain), or you can use Omega links which is what we used so that we can cut off the chain end links if we ever need to, for example if there is abrasion damage to end of chain. The Omega links can be Armogalved when the chain is done.


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[LoudMusic]

Originally Posted by CaptRehab

What size Rockna? 25kg?

I believe that is correct. Though it might be a 33kg. Can't remember off the top of my head.

[MikeFergie]

I fitted a Rocna 25kg to my Leopard 40 3 years ago and have 80m of 10 mm chain. Very happy with it.

[chrisr]

Originally Posted by BigBeakie

Chrisr,

Whats the break strength of that chain?

You should discuss with Armorgalv the suitability for their process re the existing coating/ surface treatment. If I were you, I'd get them to do a 3 meter length and then have it break tested to make sure it retains break and stretch characteristics. Don't use brittle chain.


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according to nobles the 'lashing capacity' is 3.8mt. i haven't checked yet but i interpret this as swl, so break strength is likely to be x 2 ie 7.6mt

as said, i haven't actually checked this yet...

cheers,

[DockDoc]

33kg rocna on 100 meters all chain rode, 8 meter bridle.. Back up is 25kg rocna stowed in chain locker. I wanted a spadem as back up, but I was in St Maarteen and they did not have one.

The 33kg Rocna is 'oversized' for our 42 foot lagoon and sometimes needs a nudge when dropped to get off the roller, but we have never drug anchor. Highest sustained winds on anchor 55 knots buried in good sandy bottom, 10:1 scope out for that blow.

I think the mantus, spade and rocna all do very well.