Anchor chain, antifouling

[Tranona]

It's probable I'M the weak link in the system...!

It is hoped ( and not just by myself! ) that I'll go off offshore cruising. That's not an issue, but it is my inshore anchoring I'm concerned about.

Yes, but the offshore cruising sort of implies anchoring in more variable and probably demanding situations unlike my pottering along the South coast. Having said that the relatively large number of people who bought GHs when they were new and sailed off into the wide blue yonder would have been equipped with just a 35lb CQR and maybe 5/16" chain that was the norm at the time. Most (all?) lived to tell the tale.

 

[Neeves]

It's kind of hard to wash the chain when it spends 90% of the time in the sea.

You said you chain was in the sea 90% of the time. That leaves 10% of the time to be actually sailing. 10% of a day is 2 hours, does not leave much time for sailing and even less when you have to leave and enter an anchorage.

Perhaps I was taking you too literally and you were being a bit inaccurate with your 90%.

Apologies

Jonathan

 

[Sea Change]

You said you chain was in the sea 90% of the time. That leaves 10% of the time to be actually sailing. 10% of a day is 2 hours, does not leave much time for sailing and even less when you have to leave and enter an anchorage.

Perhaps I was taking you too literally and you were being a bit inaccurate with your 90%.

Apologies

Jonathan

Yep we don't spend much of the time actually sailing. Quite often a few weeks in one spot. It's hard to actually see much from a moving yacht. Better to go ashore.

 

[Neeves]

Yes, but the offshore cruising sort of implies anchoring in more variable and probably demanding situations unlike my pottering along the South coast. Having said that the relatively large number of people who bought GHs when they were new and sailed off into the wide blue yonder would have been equipped with just a 35lb CQR and maybe 5/16" chain that was the norm at the time. Most (all?) lived to tell the tale.

Briefly I'd suggest:

Find your self a sympathetic galvaniser. I'd suggest you talk to Geoff who was MD at Highland Galvanisers (and use Highland Galvanisers). Discuss you needs. Suggest to him you would like to galvanise G100 x 6mm chain - in the same way Peerless galvanise G70 chain. You will lose about 30% of the G100 chain strength and finish with a G70 (but it will be stronger than Peerless G70 (which, if you look at the specs is only G70 because they fudge the safety factor from 4:1 to 3:1). Peerless do make metric G70 - check their sizing.

You need grit blasted raw chain, it takes the galvanising more easily.

I've been using G100 grit blasted, lightly oiled (diesel) from China. Its good chain and meets a G100 spec (it just has that made in China connotation - unfairly). So you need to find a G100 importer from China and buy the appropriate length.

I do something similar. I've 'managed' 5 or 6 rodes now - I'm just an unpaid QC manager - I'm not involved commercially.

My 'clients' buy from an ex Director of PWB (chain maker in Oz, now owned by Peerless, itself owned by Kito) who has established himself as a supplier of lifting kit from China. I'm galvanising using the Thermal Diffusion Galvanising process (Armorgalv) and you could do the same or similar, instead of HDG. There are Armorgalv operators in Israel, where the process was developed, who have coated anchor chain and there are competitive processes Greencote being but one and who could process your G100 chain. Bodycote in the UK used to operate a TDG process (I think they might be in Bristol). The other and original TDG process was called Sheradizing - there were operators in the UK - I don't know about now (again contact Geoff)

If any of this sparks interest I can expand on the background and help you allay your fears. I can advise how to have the chain tested, free of charge, and I can tell you the TDG process conditions - though if you used one of the 2 Israeli operators they know the conditions.

Jonathan

 

[Neeves]

Yep we don't spend much of the time actually sailing. Quite often a few weeks in one spot. It's hard to actually see much from a moving yacht. Better to go ashore.

Just out of interest - how long, roughly, has you chain been used, at anchor.

Jonathan

 

[Neeves]

Yes, but the offshore cruising sort of implies anchoring in more variable and probably demanding situations unlike my pottering along the South coast. Having said that the relatively large number of people who bought GHs when they were new and sailed off into the wide blue yonder would have been equipped with just a 35lb CQR and maybe 5/16" chain that was the norm at the time. Most (all?) lived to tell the tale.

I'd second all of this.

Thousands have anchored and though some have dragged (including me) no damage was done - we all had luck on our side. In the grand scheme of things very, very few yachts end up on beaches or rocks.

Jonathan

 

[Sea Change]

Just out of interest - how long, roughly, has you chain been used, at anchor.

Jonathan

Something like two years, maybe a little longer.

 

[Neeves]

Something like two years, maybe a little longer.

I did a check, based on owners who are members of YBW and similarly contributors to Cruisers Forum and derived a life of about 4 night years at anchor. This was fairly consistent.

Life is a function of quality and gal thickness. A standard gal thickness is internationally about 70 microns, though some chain coatings are thinner, few are thicker. If you try to achieve a thicker coating the alloy produced (the gal coating) is less tenaciously adhered to the underlying steel and flakes off - so you are stuck with about 70 microns max.

If you have only achieved 2 years - even though my calculations and data are statistically suspect - your chain life is poor - I don't think my data and calculations are out by a factor of 2.

There was a lot of forum activity critisizing Maggi and their gal processes some years ago - it turned out (in my estimation) that people's expectations were too high as many Maggi users were achieving my magic figure of 4 years.

The galvanised alloys, the coating produced, is harder than the underlying steel, G30 or G40. 4 years to wear through 70 microns - crudely that's 20 microns a year, or 1.5 microns every 30 nights/days - expecting much more is unrealistic.

Many people anchor over night and then move, regularly - if you anchor for days on end - you would expect higher wear.

If you anchor in those acidic seabeds you then have two processes, chemical and abrasion + any chemical reaction in your anchor locker (Google 'white rust')

Jonathan

 

[Neeves]

A Rated G80 shackle of 3/8th" size has a WLL of 2t and has been Proof Tested to 4t (this effectively means it has deformed, at most, fractionally). Larger or smaller shackles are proportionately stronger or weaker.

If you can bend a G80 shackle in an application such that it is unusable (you cannot remove or insert the shackle pin) then the shackle is incorrectly applied or the shackle should not have been used in the first place - and another device chosen.

To bend a 3/8th" shackle demands a 4t tension on the shackle, used in a straight line pull - or 2t if loaded at 90 degrees to a straight line pull ie loaded parallel to the pin.

Interestingly the lifting industry does not generally use shackles but uses hammer locks or omega links (both of which are less convenient to use than a shackle). I can only assume that the lack of convenience is replaced by greater versatility and safety of the hammerlock and omega link.

For a 3/8th", Rated, G80 shackle a 2t load, the WLL, is excessive and 4t unthinkable - or the shackle size is incorrectly specified.

I cannot imagine how/why a shackle from Crosby, Yoke, Peerless or Campbell would ever distort, let alone 'break' when used and sized correctly - something else will fail first - the anchor will drag, the bow roller collapse or the chain fail, distort.

(Anchor or rode) Security is cheap.

Interestingly reports of chain failure are historic and I cannot think of anyone mentioning failure for at least 5 years.


There appears to be a technical limit to shackle strength as though there is G100 (or G10) and G120 chain the limit for shackles is G80. G100 components are easy to source - G120 less so.

Jonathan

 

[Neeves]

I'm persuaded of the merits of upsizing the Grade of my anchor chain while downsizing its Size and Weight - as per Jon Neeves' recommendations.

I've been hunting for 6mm or 7mm in Grade 70 or Grade 80 - but galvanised against salt water corrosion. Without much success.

Neither Jimmy Green nor William Hackett nor S3I were able to help. In fact the 'friendly technical team' I phoned at both the latter could merely read out the same words as were on their web pages - which I was already looking at. They couldn't tell me the nature of the 'finish' at all. So yes, 'friendly'.... but 'technical', no.

They each were quite happy to recommend shiny stainless steel chain, despite my stated equirements.

The concept of 'chocolate teapots' came to mind.....

I forgot

Gunnebo produce a galvanised G80 chain in sizes from 6mm + 10% for aqua culture application. https://www.gunneboindustries.com/Lifting/Products/Aquaculture/Hot-dip-galvanized/Chain-KLZ-HDG/

I suspect they use a G100 alloy but with a wire size plus 10%. Galvanising reduces the tensile strength to a G70 quality which is then beefed up to G80 by using larger wire....

The increased wire size may be the killer - it may not (or it may) fit a standard 6mm gypsy. You would need to try it. Ask for a 400mm length, try it on your gypsy.

The peculiar use of a metric wire size + 10% is not unusual - even if a fudge.

Gunnebo is a Nordic lifting kit company, high reputation and now owned by Crosby - impeccable credentials. If it fits a gypsy I would have no hesitation in using it - but Gunnebo will not be as cheap as using a Chinese feedstock and having a galvaniser coating for you.

G120 is a G100 with a larger wire size (and in one case a square wire section not round).

Jonathan

 

[NormanS]

I hope that Jonathan is not succeeding in putting people off the simple process of anchoring, by blinding them with science.
Boats have been anchoring successfully for years and years without caring about the minutiae of precise details of the construction of the materials normally in use.
Use adequate equipment. Anchor in suitable situations. And relax.

 

[Neeves]

I hope that Jonathan is not succeeding in putting people off the simple process of anchoring, by blinding them with science.
Boats have been anchoring successfully for years and years without caring about the minutiae of precise details of the construction of the materials normally in use.
Use adequate equipment. Anchor in suitable situations. And relax.

See post 46.

 

[Tranona]

I hope that Jonathan is not succeeding in putting people off the simple process of anchoring, by blinding them with science.
Boats have been anchoring successfully for years and years without caring about the minutiae of precise details of the construction of the materials normally in use.
Use adequate equipment. Anchor in suitable situations. And relax.

We should thank all those who use the science that underpins the design and manufacture of adequate effective anchoring equipment that allow us to relax. Your beloved Bruce did not just "happen" but was the result of the application of science resulting in a product sufficiently novel that it was granted a patent.

Nobody is being blinded with science - there are only those who are either unable or unwilling to see.

 

[NormanS]

We should thank all those who use the science that underpins the design and manufacture of adequate effective anchoring equipment that allow us to relax. Your beloved Bruce did not just "happen" but was the result of the application of science resulting in a product sufficiently novel that it was granted a patent.

Nobody is being blinded with science - there are only those who are either unable or unwilling to see.

It concerns me that people may be put off from anchoring by the misconception, regularly aired on this forum, that anchoring is in some way complicated. At no time and in no way have I expressed an opinion that one design of anchor is better than another. Your reference to the make of one of the anchors which I happen to carry aboard is entirely inappropriate.

 

[Sea Change]

It concerns me that people may be put off from anchoring by the misconception, regularly aired on this forum, that anchoring is in some way complicated. At no time and in no way have I expressed an opinion that one design of anchor is better than another. Your reference to the make of one of the anchors which I happen to carry aboard is entirely inappropriate.

Just part of the human tendency to fixate on equipment.
I know musicians who get more excited about what instruments and gear people have than about the sounds coming out of them. And others who just get on with it.

All this talk of high grade chain is moderately interesting. I'm just using what came with the boat. When it's time to replace, maybe I'll consider other options. Although I would certainly keep my 10mm gypsy, who knows whereabouts I will be in the world when it's time to buy the next chain.

 

[Tranona]

It concerns me that people may be put off from anchoring by the misconception, regularly aired on this forum, that anchoring is in some way complicated. At no time and in no way have I expressed an opinion that one design of anchor is better than another. Your reference to the make of one of the anchors which I happen to carry aboard is entirely inappropriate.

Not sure where you get the idea there is a misconception that anchoring is complicated. There is however a view that it is not simplistic as some seem to think. That is what "science" explores and seeks to explain, but perhaps come up with better solutions.

I was merely giving an example of how science has provided you with a better product so that you can relax after you have used it to anchor your boat so completely appropriate.

 

[Neeves]

If you find the idea complicated that a Rated G80 shackle, as opposed to any other shackle, is a 'science' then I think there are other issues. Rated G80 shackles cost, in the grand scheme of things, peanuts. There should be no discussion - they are almost bullet proof - use them.

The trouble is people ignore the advice and some, only a few, pay the price.

If one person reads 'my science' and follows the advice - I'd be that little bit happier. If everyone did it 'hope springs eternal' I would not need to bother.

My recent comments on high tensile chain are in direct response to a member's comment or query. I had downsized my chain - I have direct experience - it would be silly to be a member of this forum and not share.

There is nothing complicated about a G80 shackle nor lighter high tensile chain.


10 - 15...20 years ago - people did not use snubbers for the advantages of textile (rope) elasticity. Now they are almost common place. Whether people use snubbers because of the science, because it is fashionable - I don't care - its just nice to read them being used.

You have never really extolled the virtues of your bent link. Maybe people do not know you made your own, decades ago. I have promoted the concept, regularly, people have made their own, others have bought (to my 'scientific' design). You could have filled that gap (in science) - but chose not to do so - my Boomerang fills the gap you left - and it must be useful as I see Boomerangs on yachts and I know 2 manufacturers make 'exactly' to my design. You made a swivel for a Bahamian moor - I suspect no-one knows of your work but there is a need (or you would not have developed your design) - people would value your ideas - why not share.

I would never encourage anyone to complain about information provided on a forum. Yacht electrics are science and constant source of threads - do you want to criticise the people who provide the answers or volunteer updates on 'science' - like Lithium. Geem sat down and described in full detail with images in an earlier thread on his Lithium build - if you find the link its a masterpiece. You don't need any other information. I don't think he wasted his time. I don't think his posts, and others on Lithium, merit criticism.

Science, learning - repetition engenders converts. Sometimes the science is wrong (think of bigger is better) - slowly 'bigger is better' has proven wrong and people start to see the light.

I just worry as to why more people don't volunteer their knowledge.

Jonathan

 

[NormanS]

Jonathan, I am merely a humble yachtsman. I have no interest in making a living by writing articles in yachty magazines.
However, while you criticise me for not "sharing", you somehow know that I have made "bent links" and swivels. I wonder how you know about them, unless I have shared.
Re 'bigger is better', I am one of those old fashioned yachtsman who, when it's blowing a gale, has never thought, "Oh I wish my anchor and chain were lighter". There is room for more than one school of thought.
You have or had a light displacement catamaran, where every unnecessary weight had to be avoided. I have a relatively heavier displacement monohull, in which the weight of spares, tools, and stores far outweigh the weight of my considerable ground tackle. Our situations are markedly different. I have no interest in persuading or encouraging others to copy me. Each to their own.

 

[Refueler]

I wonder how many people enjoy a thread and then get turned off by long winded techy stuff ?

I think most people are content to decide xx kg anchor of xxxx design ... with xxx metres of chain / rope rode based on observation and TBH - whats available at the chandlers. Finally of course who's handling it and stowage.

Buying reputable is of course accepted - I hope no-one goes to local garden Hardware shop and uses chain / shackles from there .. at least not for longterm use !! I have been guilty of using as a temp measure before replacing with good.

I read a lot here about galvanised this and galvanised that - but just to drift off from anchors and chain ... to moorings and gear :

Stainless Steel is a no-no of course .. but galvanised is not only form you can use for mooring setups .... Black Iron is another ...

Just commenting !!