Anchor chain: How rusty is too rusty

[lampshuk]

Hi, all. I would welcome the opinion of some of our resident metallurgist/engineering experts.
I have about 30m of 8mm chain of unknown but probably cheap origin. It's been on our Moody 31 since we bought her 10 years ago and I suspect some time before that, too.
We anchor mostly in shallow water around the Solent and nearby. One of the advantages of a shoal draught is getting in close.
This year the encroaching patches of mild rust have merged and become rather more pronounced.

I'm assuming that the first metre or so of chain is a "goner" (but I also understand that while rust can look really bad it has less of an impact on performance than one would think, so would appreciate any input on that score).
That's shown in the first photo.



But what about the less badly rusted parts? (subsequent photos).





If I need to cut off a length of chain I'd plan on attaching a fresh bit that extended the total length. We don't have a winch so I'm not constrained by that, but I'm thinking that one of the 8-pin Osculati C-Links would make sense, sealed with a large hammer and a solid lump of metal as an anvil. Any comments? Choice of shackles seems to be a bit of a minefield.


As always, very grateful for comments and suggestions.

Martin.

 

[Mudisox]

It doesn't look too bad to me.

In consideration of your use of the anchor, and the conditions you are likely to encounter, I wouldn't worry too much.

Find some fine sand and drag the whole chain through a few times to remove the large bits of rust, and then see if the diameter of the chain is greatly reduced. If not, and you want to keep it simple just end for end the whole chain and avoid anchoring in situations when you anchor in force 6+ winds and in exposed places.

 

[fredrussell]

If you have no windlass to size to you’ll probably get away with 6mm chain which is £4 per metre (vs £7 for 8mm). With that in mind I’d replace with 6mm chain for circa £120. If it lasts 10 years that’s not too irksome an outlay. Mainly I’d do it to avoid rust stains on my bows (where my anchor locker drains to) and for a bit of peace of mind on a blowy night in the anchorage. Less graft getting the hook up too.

 

[lampshuk]

Thanks, both. Reassuring, Mudisox. I'll give it a good brushing and make sure I inspect the individual links!
I agree about the rust stains, fredrussell. Drifter's chainlocker drain does have a certain "patina" that would look more at home on a Port of London workboat than a pleasure yacht.

I had considered 6mm chain, but there's something reassuring about the heft of 8mm.
Possibly a false perception.

I can't find 6mm chain for less than £5.33 a meter (30m length from Force4). Do you have a source in mind?
If I wanted to join 6mm to 8mm, to extend my current chain, what would you recommend?

Many thanks,

Martin.

 

[andsarkit]

I can't find 6mm chain for less than £5.33 a meter (30m length from Force4). Do you have a source in mind?
If I wanted to join 6mm to 8mm, to extend my current chain, what would you recommend?

Boat Gear Direct | Titan G40 Calibrated Galvanised Chain

Excellent company

 

[Neeves]

There is an industry standard, chain industry, when you have lost 10% of diameter (whether through corrosion or abrasion) then retire (a better word would be condemn) the chain. As suggested to find out how much steel you have lost - find some clean seabed, drop the chain on the sand and gently reverse - the sand will remove the rust, repeat if not clean. You can similarly drag your chain behind your car - until you reach clean steel - but your roads might be busier than the seabed....??

It may not look 'bad' - bad is such a lovely technical term but you do not know the chain source, you do not know whether the welding might be more susceptible to corrosion than the rest of each link.

New 8mm chain will cost you, apparently, stg210 and will last 10 more years (if you look after it), that's stg20 per year. I'm really not sure why you are asking . If you tell me you will not own the yacht for 10 more years - then when you come to sell her I'd look at your chain and say - 'if the chain is in that state what is there wrong I cannot see' - and I'd walk away.

I'd favour replacement with 6mm chain, 8mm is OTT (so you own a yacht and are questioning an investment in safety of approx Stg100 for a new 30m) - splash out and buy a bit more.

For shackles I might suggest, as CMP has been mentioned - that you buy CMP's Titan Black Pin shackles (as they can be sourced small enough to fit 6mm chain). I do not recommend CMP's Titan Black Pin shackles for larger sizes but prefer Crosby shackles for the larger sizes (so if you buy 8mm chain - source Crosby shackles).
Do not buy Titan yellow pin shackles - they have approx half the strength of the black pin shackles (note the approx).

I don't know Oscalutti's 'C' links - and would not therefore trust them - buy Crosby's 'C' links. Check Vyv Cox's website for chapter and verse. Crosby components can be bought from a variety of sources in the UK, I buy through Tecni (I think based in Bristol).

Jonathan

 

[geem]

Apart from the loss of thickness the rusty chain makes a real mess of the deck. Mine is going the way of yours. Will replace it in a month or so when I get to Martinique.

 

[lampshuk]

Thanks, all. Lots to digest.
Jonathan, I don't see an obviously 6mm-chain compatible Titan on the CMP site.
(not sure what a "Bail" is in this context).

 

[Neeves]

Apart from the loss of thickness the rusty chain makes a real mess of the deck. Mine is going the way of yours. Will replace it in a month or so when I get to Martinique.

I'm talking out of turn

I suspect the Caribbean is an American market and for chain is primarily Imperial, which maybe why you are going to buy new chain (metric?) in Martinique. Both Campbell (I think part of Apex Tools) and Peerless (the US's biggest chain maker, now owned by Kito), both of the US make good chain and both make a G70, if that is of interest. American chain is marked, embossed, usually with both 'USA" and a makers mark 'C7' for instance, Peerless have a variety of marks, or at least more than one but P4 (for G43 ) or P7 for G70. Peerless make metric chain to metric standards, it might be available - no idea - send Campbell or Peerless an email, for Carib stocks. I'm not aware Campbell make metric chain. Both Campbell and Peerless make excellent shackles, 3/8th" of 2t WLL (as good as Crosby). Campbells are called Orange Pin shackles, Peerless are called Peerlift G80 shackles (both are G80 quality as are Crsoby's (G207B ?). You already know that Imperial and Metric chain are not interchangeable. Do not get excited about Imperial G43 - it is often quoted only with its WLL but is sold to a 3:1 safety factor whereas metric G40 (and most metric chain) is sold to a 4:1 safety factor - G43 thus looks really strong but its an arithmetic fudge (it is slightly stronger because its G43 not G40 - the rest is the difference in safety factor).

In case you are tempted - most windlass makers offer both metric and imperial gypsies - but a new gypsy is extortionate. G70 is stronger - so you can down size and the smaller chain may offer savings (and take up less room in your chain locker) but the 'new' gypsy may be the killer (been there. done that).

As I introduced - posting out of turn

Jonathan

 

[Neeves]

Thanks, all. Lots to digest.
Jonathan, I don't see an obviously 6mm-chain compatible Titan on the CMP site.
(not sure what a "Bail" is in this context).
View attachment 156753

You look to be correct.

It looks as though I'm our of date - they used to make a whole range of shackles down to 1/4" (I have some and 3/16th") - it seems that they have stopped making them. Jimmy Green sell some French high strength shackles from Chaineries.....? - but I don't know how small they come.

If CMP make a 6mm anchor chain then it will be un-saleable without matching shackles - find a supplier of CMP Titan 6mm chain and ask for their recommendation for shackles - you cannot sell chain without a shackle - or its useless.

I indicated that I would not recommend their shackles over Crosby. I tested their Black pin shackles and found they did not meet their own spec - they argued and said my test methodology was wrong (and then quietly changed their own specification which matched what I had found). I took it as a quiet win for testing. It seems that since then they may have become less confident of their source and maybe discontinued the smaller shackles. I don't think CMP make the shackles but merchant them from another, Chinese, manufacturer (nothing wrong with that). I've tested a couple of very good Chinese shackles - but I don't know of any retailers.

If you make no progress there are options - you can use hammerlocks or omega links - if this is your fall back and you cannot make any headway - send me a PM and I'll answer on the thread (so everyone can read it ). I suggest a PM in case I am not following the thread actively. Both hammerlocks and omegas are cheap (used in lifting and commonplace, stronger than you need - but not galvanised. But being cheap you can simply chop them off every 6 months and replace with a new one. You might find forum members here who use hammerlocks - they are not exotics

I use a high tensile 6mm chain with omegas (aka berg locks) and/or hammerlocks

Jonathan

 

[geem]

I'm talking out of turn

I suspect the Caribbean is an American market and for chain is primarily Imperial, which maybe why you are going to buy new chain (metric?) in Martinique. Both Campbell (I think part of Apex Tools) and Peerless (the US's biggest chain maker, now owned by Kito), both of the US make good chain and both make a G70, if that is of interest. American chain is marked, embossed, usually with both 'USA" and a makers mark 'C7' for instance, Peerless have a variety of marks, or at least more than one but P4 (for G43 ) or P7 for G70. Peerless make metric chain to metric standards, it might be available - no idea - send Campbell or Peerless an email, for Carib stocks. I'm not aware Campbell make metric chain. Both Campbell and Peerless make excellent shackles, 3/8th" of 2t WLL (as good as Crosby). Campbells are called Orange Pin shackles, Peerless are called Peerlift G80 shackles (both are G80 quality as are Crsoby's (G207B ?). You already know that Imperial and Metric chain are not interchangeable. Do not get excited about Imperial G43 - it is often quoted only with its WLL but is sold to a 3:1 safety factor whereas metric G40 (and most metric chain) is sold to a 4:1 safety factor - G43 thus looks really strong but its an arithmetic fudge (it is slightly stronger because its G43 not G40 - the rest is the difference in safety factor).

In case you are tempted - most windlass makers offer both metric and imperial gypsies - but a new gypsy is extortionate. G70 is stronger - so you can down size and the smaller chain may offer savings (and take up less room in your chain locker) but the 'new' gypsy may be the killer (been there. done that).

As I introduced - posting out of turn

Jonathan

We buy chain in Martinique. It made in France. It's G43 and not expensive. Last 3 to 4 years of constant anchoring/cruising. We don't want G70. Too expensive and nowhere to get it galvanised here when it rusts.

 

[srm]

I used to lay and maintain my own moorings. The critical part to look at with chain, where failure is most likely, is where the links rub against each other. The body of the link can look OK but the hidden contact areas can be worn. As long as the contact areas have plenty of metal clean up the chain and continue using it. I found towing behind the car very effective especially on bends where the chain swings out in a wide arc; but that was on a very quiet, little used, road in the far north of Scotland.

 

[Neeves]

On reflection.

If you go the 6mm route.

When you decide to buy the chain choose shackles that fit the end link at the same time. You should be able to buy a shackle with a WLL slightly better than the chain. Testing of CMPs Yellow Pin shackles indicates they are of good quality and always better then their specification. As long as the shackle is better than the chain and you use it as an enlarged link at the end of your chain then the shackle that joins this enlarged link and the anchor can be much larger (than the one you are using as the end link).

The problem with shackles is that they can lock into the slot in the shank and then be side loaded. A shackle side loaded at 90 degrees loses 50% of its strength - I've tested this, it is correct and most shackle suppliers warn against the problem. The shackle that fits 6mm would not meet this restriction but equally will not be side loaded, because it is not being used to joint anchor 'directly' to the chain.

I advise you take your anchor with you when you buy your chain and you can then play around with shackles so that you get the best fit.

You want a bow shackle at the anchor slot - the shackle at the end of the chain could be a bow or 'D' shackle. I'd use Loctite and mousing wire to secure the small shackle at the end of the chain - as you are not going to change it often, maybe annually.

For some reason the shackles and first few links preferentially corrode - simply chop them off each year. It maybe that the alloyed steel of the anchor shank, the alloyed steel of the shackle accelerates the corrosion of the first few links - not a big issue its only 2-4 links.

Your chain may simply be old but leaving chain in a locker for a long period along with rope is a recipe for corrosion. The rope holds moisture. Wash the chain, and locker, with fresh water every time you rinse down the decks and keep rope and chain separate. Check also that the drain holes in the locker are not blocked, with mud or rope - corrosion needs moisture - remove the moisture and you remove the corrosion.

As Geem says - anchoring frequently will remove the galvanising (and as with your chain wear is fairly even - much of the gal is lost from the long of the links as they sweep the sea bed - tension between links and abrasion is less of an issue - because the links are seldom under much tension. Most people don't actually anchor that much - its the poor conditions in the locker that is commonly the reason for premature death. Crudely chain should last for around 1,300 nights at anchor (4 years plus or minus) - based on chain life reported by those who live on their yachts 365. Your chain looks to have corroded sufficiently to be condemned and it would be a waste of time and money to have it regalvanised (if you can find a galvaniser near you to accept it). Chain size 6mm vs 8mm or quality G30 vs G70 is not much of an influence on chain life (or there is only anecdotal comment) - the quality of the initial galvanising is the key - and you - the consumer cannot measure that but more gal means a longer life. Shiny chain simply means its fresher - not better. Gal dulls with exposure to air. Raw zinc on the surface of the gal soon wears off anyway - its soft but the underlying alloys of Zn and Fe are hard - and the protection you want (not shiny zinc).

You can regalvanise G70 chain without any issues, I've tested for this, as has Peerless - but if you leave the chain to corrode too long you will lose the underlying steel - and then its not worth ragalvanising. Better to regalvanise early.

Most anchor chain is now made in China. As far as I know there are no UK anchor chain makers. Lofrans recently started to sell chain - my guess is it comes from China - no-one would invest in new gear to make and galvanise in Europe. CMP make in China.

Jonathan

 

[Neeves]

I used to lay and maintain my own moorings. The critical part to look at with chain, where failure is most likely, is where the links rub against each other. The body of the link can look OK but the hidden contact areas can be worn. As long as the contact areas have plenty of metal clean up the chain and continue using it. I found towing behind the car very effective especially on bends where the chain swings out in a wide arc; but that was on a very quiet, little used, road in the far north of Scotland.

Most people try to anchor in shelter with a scope sufficient that there is minimal tension in the rode but that the chain sweeps the seabed as the yacht moves. There is wear between the links - but in viewing corroded anchor chain - wear seems pretty even. To measure the wear you need to be measuring cleaned chain, measuring shiny metal.

Moorings are a different issue - and wear is greatest between the links.

Jonathan

 

[doug748]

Thanks, both. Reassuring, Mudisox. I'll give it a good brushing and make sure I inspect the individual links!
I agree about the rust stains, fredrussell. Drifter's chainlocker drain does have a certain "patina" that would look more at home on a Port of London workboat than a pleasure yacht.

I had considered 6mm chain, but there's something reassuring about the heft of 8mm.
Possibly a false perception.

I can't find 6mm chain for less than £5.33 a meter (30m length from Force4). Do you have a source in mind?
If I wanted to join 6mm to 8mm, to extend my current chain, what would you recommend?

Many thanks,

Martin.

The 8mm chain will perform better, no doubt. However you have to remember the weight in the bow and be happy to lug it up each time. Given the possibility of a windlass in the future I would stay with 8mm.

I have used BGD, they are good, as per post 5. Too early to know how well my chain will last but If I bought again I might go for the better galvanised product expensive as it is.

 

[Tranona]

The 8mm chain will perform better, no doubt.

Can you explain what you mean by "perform better"? - and why you have no doubts?

 

[Bouba]

I think it’s one of those questions that if you have to ask then it’s time to change...because that little voice in your head is trying to tell you something....while a picture helps, only by running them through your hands can you get a real feel for the corrosion and how it flakes off

 

[doug748]

Can you explain what you mean by "perform better"? - and why you have no doubts?

I mean it will work better in it's primary role, as an adjunct to the anchor and holding the boat securely in all weathers; whilst remaining reassuringly strong throughout it's life.
I'm assuming that we would all use heavier chain if we did not have to pay for it, to handle it or to carry it on the boat.

In my experience chain does not always rust uniformly. As pointed out above, the internal ends of the links wear and there are often deeper pits. These may be triggered by inclusions in the original material or galvanising faults or harsh treatment, I don't know but I have seen them.
If you lose 2mm from a 8mm chain you have lost perhaps 25% of its strength, from 6mm say 33%.
So
With standard 6mm chain it could be broken by a steady pull of c 1600 lbs
For 8mm chain the figure would be more than double.
I believe you could lose more than 2mm and not notice the problem.

Here is a 1/4 in chain link opened by my boat, similar dimensions to a Moody 31:



The weight of the chain also means it works better in tandem with the anchor. No anchor will set well with a vertical tug, we know this because it's how we universally get them out. The physics tells us the heavier chain will pull horizontally for longer due to it's weight, which is nice when you set the anchor.
It also usefully helps limit the tendency for a boat to sail around it's anchor. Nice in the tight, fair weather anchorages the the OP likes.


We know lampshuc is happy to explore the envelope of useful safe life so, in this regard, I am pretty sure that 8mm chain is wise :

Whilst remaining a good choice if he ever wants to fit a windlass.


Despite being a better choice in the water, it does not mean it is the logical pick for the OP. There are all sorts of reasons for compromise with boats, I pointed out a couple in my last post

 

[Tranona]

I do not know where you get your data from, but it is wildly wrong. Your 1600lbs is just not believable. Basic Grade 40 chain is well over 3 times that. jimmygreen.com/content/217-calibrated-chain-break-load-and-weight-guide You will not break 6mm chain with a boat attached to even the best holding anchor of the size that even the most conservative person might use. It is well over twice the maximum holding of the best 15kg anchor. There is simply no justification for going up to 8mm on "strength". In fact as has been mentioned already in this thread, the weak point in the link between the boat and the anchor is not the chain but the connections, typically the shackle attaching the anchor to the chain.

As far as anchor setting and holding is concerned the only role of the rode (whether it is chain or rope) is applying the load to the anchor. Its weight and size is irrelevant provided it is strong enough. Most of the tests of anchor holding power use rope to exert the pull. You never see any suggestion that chain will improve the holding power of your anchor. To put some figures on this, a typical smallish yacht like the OPs, mine and yours may be able to exert between 250-300kgs of pull in reverse, which is roughly equivalent to the pull in 25-30knots of wind. Ultimate holding power on a good anchor for this size boat is around 1000kgs (and remember the chain can withstand over twice that).

I do not understand your comment about vertical pull that you imply occurs with rope but not chain. This simply does not happen. By definition when a boat is applying load to an anchor the angle is the same whether the rode is chain or rope and the effect on the anchor will ,be the same. The only benefit of chain in the way it reacts with the anchor is that it forms a catenary which dampens the effect of movement of the boat on the anchor. However this disappears at around 25knots of wind and the chain becomes straight, just as it does with a similar load being applied to set the anchor by using the engine in reverse. There is a small difference in catenary between a heavier 8mm and a 6mm chain, but doubt you would notice it in practice.

I think you would be considered very unobservant if you did not notice a 2mm loss in thickness of your chain. I doubt there is any noticeable loss in strength of the OPs chain, which being 8mm is well over 4 times the maximum load his boat could ever put on it. Note that he anchors in shallow water in the Solent, and I guess in relatively benign conditions. I doubt the load from that type of anchoring approaches even 10% of the breaking load of his chain.

Personally I prefer all chain rodes for 2 reasons. First and important even if you are considering rope, is abrasion resistance for the short length that rests on the seabed in most anchoring situations (ie below 25knots of wind ) and particularly so in tidal or changeable wind situations when the chain moves around on the seabed. Secondly with a well set up windlass and anchor locker, retrieval is seamless and much easier to control.

My Bavaria came with a 10kg Delta and 50m 8mm chain. It really only needed 6mm for the reasons given above, but not worth changing and of course no more difficult to handle. My GH (which has much the same displacement, but less windage) has 6mm chain and now a 10kg Epsilon and a Lofrans Kobra windlass. For connections I have Kong swivel plus 3 links of 8mm which overcomes the shackle limitations. This decision was made after researching all the available tests and reliable data. In reality I shall never anchor in situations that would stress this set up - indeed I might just as easily kept the old 35lb CQR copy which previous owners over the last 45 years or so seem to have been happy with.

I note the OP does not have a windlass, so there really is no argument for keeping 8mm chain if he does decide to change it. Why have something that is way over sized and offers no benefits that weighs more, costs more and is a PITA to handle?

 

[Neeves]

I do not know where you get your data from, but it is wildly wrong. Your 1600lbs is just not believable. Basic Grade 40 chain is well over 3 times that. jimmygreen.com/content/217-calibrated-chain-break-load-and-weight-guide You will not break 6mm chain with a boat attached to even the best holding anchor of the size that even the most conservative person might use. It is well over twice the maximum holding of the best 15kg anchor. There is simply no justification for going up to 8mm on "strength". In fact as has been mentioned already in this thread, the weak point in the link between the boat and the anchor is not the chain but the connections, typically the shackle attaching the anchor to the chain.

As far as anchor setting and holding is concerned the only role of the rode (whether it is chain or rope) is applying the load to the anchor. Its weight and size is irrelevant provided it is strong enough. Most of the tests of anchor holding power use rope to exert the pull. You never see any suggestion that chain will improve the holding power of your anchor. To put some figures on this, a typical smallish yacht like the OPs, mine and yours may be able to exert between 250-300kgs of pull in reverse, which is roughly equivalent to the pull in 25-30knots of wind. Ultimate holding power on a good anchor for this size boat is around 1000kgs (and remember the chain can withstand over twice that).

I do not understand your comment about vertical pull that you imply occurs with rope but not chain. This simply does not happen. By definition when a boat is applying load to an anchor the angle is the same whether the rode is chain or rope and the effect on the anchor will ,be the same. The only benefit of chain in the way it reacts with the anchor is that it forms a catenary which dampens the effect of movement of the boat on the anchor. However this disappears at around 25knots of wind and the chain becomes straight, just as it does with a similar load being applied to set the anchor by using the engine in reverse. There is a small difference in catenary between a heavier 8mm and a 6mm chain, but doubt you would notice it in practice.

I think you would be considered very unobservant if you did not notice a 2mm loss in thickness of your chain. I doubt there is any noticeable loss in strength of the OPs chain, which being 8mm is well over 4 times the maximum load his boat could ever put on it. Note that he anchors in shallow water in the Solent, and I guess in relatively benign conditions. I doubt the load from that type of anchoring approaches even 10% of the breaking load of his chain.

Personally I prefer all chain rodes for 2 reasons. First and important even if you are considering rope, is abrasion resistance for the short length that rests on the seabed in most anchoring situations (ie below 25knots of wind ) and particularly so in tidal or changeable wind situations when the chain moves around on the seabed. Secondly with a well set up windlass and anchor locker, retrieval is seamless and much easier to control.

My Bavaria came with a 10kg Delta and 50m 8mm chain. It really only needed 6mm for the reasons given above, but not worth changing and of course no more difficult to handle. My GH (which has much the same displacement, but less windage) has 6mm chain and now a 10kg Epsilon and a Lofrans Kobra windlass. For connections I have Kong swivel plus 3 links of 8mm which overcomes the shackle limitations. This decision was made after researching all the available tests and reliable data. In reality I shall never anchor in situations that would stress this set up - indeed I might just as easily kept the old 35lb CQR copy which previous owners over the last 45 years or so seem to have been happy with.

I note the OP does not have a windlass, so there really is no argument for keeping 8mm chain if he does decide to change it. Why have something that is way over sized and offers no benefits that weighs more, costs more and is a PITA to handle?

Neatly said.

I may have missed it another post - but why the 3 links of 8mm at the anchor end of the rode? Maybe I should re-phrase that - why use an extra 3 links which simply necessitates an extra shackle, when you could have achieved the same effect with one less.

Your way, I think, needs a shackle sized for the 6mm chain, then another shackle bigger to fit the 3 x 8mm links - you then have another shackle between the 3 x 8mm links and the shank. I'd simply use a shackle suited for the 6mm chain then a shackle to fit the anchor. Buy decent shackles, mouse and Loctite them and the shackles will be as safe as is possible.

This is our 6mm chain, its a 15kg Excel anchor and I have used an Omega link (as an enlarged end link on the 6mm chain) and a 3/8th" 2t WLL shackle to join omega to the anchor. Our cat is a bit bigger than the yachts discussed here but the chain has the same actual strength as the 8mm chain it replaced. The Omega and shackle are both stronger than the chain.


I've used cable ties to better secure the shackle pin - but then I am constantly testing new ideas for anchor to chain attachment.

Imagine if you will that the Boomerangs are the shank of an anchor. As on our anchor with the middle Boomerang I have used an Omega (which would join to the chain) and a Peerlift G80 3/8" shackle. At the other end of the same Boomerang I have simply joined the Boomerang to the anchor chain with a hammerlock.


Most components from the lifting industry are factorially better than simple shackles that we all use but only are available painted. The paint is fairly robust but does wear. The components, hammerlocks and omegas are cheap (cheaper than shackles). I have my components galvanised, that's why they are all 'gal grey' but you could use them painted. Chat up your galvaniser and for 6 cans of beer he may include the few items you want galvanised.



We are using a 15kg anchor, we might be using small chain, 6mm for a 7t yacht, but we still need the hold of a good anchor. For the yachts in this thread, smaller, you should really not need a 15kg anchor and you might find that you can join 6mm chain to the anchor directly using a hammer lock.

A word of caution - like good shackles G80 or G100 components from the lifting industry need a bit of grunt (or an angle grinder) to remove them - if they become rusty. You will not want to remove them on deck - work on the connectors on a pontoon or pier. Omega links and hammerlocks are specifically made for the chain for which they are sold - so the opening on the 6mm omega accepts 6mm chain, only, -you need the shackle as the 6mm slot is far to small for your anchor shank. Because the components are cheap and have a finite life span - when you work out your combinations buy 2 of each component - then you have the spares.

I test representative samples of all my components - for our own safety and because I'm recommending their use to others. Use G100 components and you will have connectors better than the shackles you buy in most chandlers (which at best will be G80).

My suggestions are focussed at this thread where 6mm chain will be overly strong (but you cannot source anything smaller). The same would apply for 8mm or 10mm chain. I would recommend that anyone downsizing chain from say 8mm to 6mm but wanting to keep the same strength, so using a G70 x 6mm also incorporate a snubber. Less necessary, for its elasticity, on a 30' yacht - but will increase comfort. Use the search function on YBW to research snubbers and then start a new thread with any outstanding queries.


Jonathan