Anchor chain: How rusty is too rusty

[Tranona]

"Yes, 8mm chain is heavier and has more catenary."

Thank you, at last.....

"your claim is just not supportable with any evidence either theoretical or empirical."

Oh dear, I thought we were getting somewhere.


"I am not sure what your pretty picture is designed to show - other than you can draw pretty pictures and post them on here."

It's not my picture nor my explanation. The copyright belongs to Marine Insight:

Marine Insight is a global leader in providing maritime news and training maritime professionals with an expert panel of writers, news reporters, and consultants. The content from Marine Insight is used by global online media, institutes, and Organisations as a reference tool for Maritime and Shipping Industry.​

" I have never seen any research that quantifies this , nor crucially what the difference is between different sizes of chain, Another "everyone knows" kind of belief."

Nor have I. All I have said is that the advantages are there, will be measurable and the prudent yachtsman might want to note the fact. I have never used the term "everybody knows" or even hinted at it. All I have said is that these things are established science.

"I have as instructed googled broken anchor chain and see nothing that is in the least bit relevant to this thread"

Several examples on this thread: Breaking an Anchor Chain - Cruisers & Sailing Forums
Plus some closer to home.

"That is not the real question........"

Aye well, we can all change the question.
I think it's good policy to concentrate on what is said, not what you thought was said, or wish was said, or might be imagined through the veil of your own imagination.

.

Yes, I thought we were.

Never disputed that catenary exists - how could one when it is a fact. What is debatable is its value and whether an increase in size and weight enhances that value. The only other thing we know for certain is that it disappears when the load on the chain is sufficient to straighten the length. Therefore your claim that it is measurably more valuable is not supported by any evidence - only what you believe. You just say it "will be measurable". Big difference between "will be" and "is". Even bigger difference to then actually measure it and quantify its value. Until you devise a way of measuring it and placing a value on it it is just a belief.

Just because the pretty picture is somebody elses' copyright (which you did not acknowledge) does not give it the meaning that you claim. it is just a static picture that shows chain lays on the seabed when the boat is static and there is no load on it. Please explain why you think this is relevant as I can see no explanation - only a picture. Even if there were an explanation from your source that does not mean it is correct, which in the way you are using it is simply wrong.

As for "everybody knows" please read what you wrote in post#23 last but one sentence. You have made a lot of claims about "facts" without any evidence to support them and resort to statements like this one to imply that everybody else agrees with you. NONE of what you have claimed is "established science" - you have quoted no scientific papers, established theories, empirical tests - nothing.

I did indeed read that thread and 2 others from the same forum. The vast majority of posts report never seeing or hearing of chain breaking, and of the small number that do, none have sufficient detail to explain exactly what happened except that most boats were old and chain was old or that failure was a manufacturing defect. The one close to home was a Westerly but there is no detail as to why it failed in circumstance where it should not have failed because it was not strong enough. None of the incidents you have cited make any suggestion that the failure would not have occurred if heavier chain had been used. Given this is your central claim - that chain failure can be avoided by having heavier chain as lighter chain may fail is simply not supported by any evidence - 6mm chain has more than adequate safety margin for the OPs use and there is nothing to suggest that 8mm is "safer".

I am afraid it is you that has imagination - for example why are you imagining people buy chain on the basis that it will still be OK when it rusts away? Nobody else has even suggested this - just your imaginary "argument".

It is indeed good policy to concentrate on what was written and to challenge it when it is not supported by any evidence.

I have no problems with people having beliefs. It is when they make claims that are not supported by facts and empirical evidence I find it difficult to take them seriously. Progress and enhancement of knowledge (and as a consequence hopefully better decisions) come from questioning what is claimed.

 

[Tranona]

I'm intrigued why some on here use chain at all. We have people advocating lighter and lighter chain, - perfectly understandable for those with light displacement boats. We have people stating that chain goes "straight" at quite modest wind strengths.

Many people don't use chain or only a short length. The strength of the rode (whether chain or rope) is indeed related in part to displacement of the boat, but more importantly to windage. This determines the load that is placed on the rode and anchor when the wind increases. There is more than enough evidence that the rode (chain or rope) does indeed become straight at relatively low wind speeds. You know this because I have posted in direct response to your same question in the past a link to the Practical Sailor series of experiments on exactly that subject. These are supported by similar tests carried out by Vyv Cox and reported in YM.

Of course you may wish to disbelieve them. If you believe that they do not show an accurate picture then suggest you conduct your own tests and report the results. If you want to understand the point at which chain becomes straight (that is catenary disappears) then drop your anchor in a nice clear spot, put your engine in reverse and see how much power you need to apply to straighten the chain - that is the point at which the anchor stops the boat from moving. Again I have directed you in the past to empirical work that shows the load applied by an engine in reverse required to straighten the chain and thus set the anchor is somewhat similar to that experienced at the "modest wind strengths".

The size of chain required is determined by its strength in relation to the load placed upon it. It is irrelevant whether the boat is light or heavy in relation to its size. The maximum load is determined by the maximum holding power of the anchor. Once you have that figure then you can determine the size of chain (or rope) that will give you an adequate safety margin. All this data is in the public domain so there is no need to rely on past practice, much of which dates from before high holding power anchors and reliable high quality tested chain was available.

 

[penfold]

I'm intrigued why some on here use chain at all. We have people advocating lighter and lighter chain, - perfectly understandable for those with light displacement boats. We have people stating that chain goes "straight" at quite modest wind strengths.
If this is the case, why don't these same people use wire of suitable SWL? Wire would be easy to manage on a "magazine" winch, where the wire would wind into the winch drum. Wire would be lighter than chain capable of handling the same load.
Show your confidence, anchor with wire.

Wire is not inspectable in any meaningful sense, it must be replaced on a time basis, it's vile stuff to handle and likely to form a rats' nest on retrieval.

 

[NormanS]

Wire is not inspectable in any meaningful sense, it must be replaced on a time basis, it's vile stuff to handle and likely to form a rats' nest on retrieval.

Wire is used throughout industry in many safety critical situations. It is nonsense to say that it's not "inspectable".
If you actually read my post, you will see that there is no handling involved. Do you think that the wires on, for example, cranes, "form a rats nest on retrieval"?

 

[NormanS]

Many people don't use chain or only a short length. The strength of the rode (whether chain or rope) is indeed related in part to displacement of the boat, but more importantly to windage. This determines the load that is placed on the rode and anchor when the wind increases. There is more than enough evidence that the rode (chain or rope) does indeed become straight at relatively low wind speeds. You know this because I have posted in direct response to your same question in the past a link to the Practical Sailor series of experiments on exactly that subject. These are supported by similar tests carried out by Vyv Cox and reported in YM.

Of course you may wish to disbelieve them. If you believe that they do not show an accurate picture then suggest you conduct your own tests and report the results. If you want to understand the point at which chain becomes straight (that is catenary disappears) then drop your anchor in a nice clear spot, put your engine in reverse and see how much power you need to apply to straighten the chain - that is the point at which the anchor stops the boat from moving. Again I have directed you in the past to empirical work that shows the load applied by an engine in reverse required to straighten the chain and thus set the anchor is somewhat similar to that experienced at the "modest wind strengths".

The size of chain required is determined by its strength in relation to the load placed upon it. It is irrelevant whether the boat is light or heavy in relation to its size. The maximum load is determined by the maximum holding power of the anchor. Once you have that figure then you can determine the size of chain (or rope) that will give you an adequate safety margin. All this data is in the public domain so there is no need to rely on past practice, much of which dates from before high holding power anchors and reliable high quality tested chain was available.

Interesting that you make no attempt to answer the question that I posed. All your fluff about your belief that chain goes "straight" is neither here nor there. Actually it is a mechanical impossibility, unless the chain is vertical.
All that I'm asking of the believers that weight of chain makes no contribution to safe anchoring is, why don't you use wire?

 

[vyv_cox]

Interesting that you make no attempt to answer the question that I posed. All your fluff about your belief that chain goes "straight" is neither here nor there. Actually it is a mechanical impossibility, unless the chain is vertical.
All that I'm asking of the believers that weight of chain makes no contribution to safe anchoring is, why don't you use wire?

I have never seen a claim that chain goes 'straight', whenever I have posted on the subject, along with Peter Smith and others, I write 'essentially straight'. There will always be a small amount of sag with the forces that can be generated by a boat on the water but all of the chain will be off the bottom in winds of force 6 or more, and at the end of each yaw in lesser winds.

I have posted photos of this in reality, as has noelex.

I have never anchored on wire as I see little advantage in doing so. But I, and countless others, have anchored on rope in big winds and not suffered for it.

 

[NormanS]

I have never seen a claim that chain goes 'straight', whenever I have posted on the subject, along with Peter Smith and others, I write 'essentially straight'. There will always be a small amount of sag with the forces that can be generated by a boat on the water but all of the chain will be off the bottom in winds of force 6 or more, and at the end of each yaw in lesser winds.

I have posted photos of this in reality, as has noelex.

I have never anchored on wire as I see little advantage in doing so. But I, and countless others, have anchored on rope in big winds and not suffered for it.

I suggest that you read some of the posts written by Tranona, which claim that chain goes "straight".
I am merely searching after truth. I have been in situations where we anchored using wire. Personally, I wouldn't particularly recommend the practice, but I wonder why the proponents of ultra light chain don't.

 

[Neeves]

Interesting that you make no attempt to answer the question that I posed. All your fluff about your belief that chain goes "straight" is neither here nor there. Actually it is a mechanical impossibility, unless the chain is vertical.
All that I'm asking of the believers that weight of chain makes no contribution to safe anchoring is, why don't you use wire?

You don't need to use wire (to have a lighter rode), you can use smaller chain - which I do. Many people use G70 chain, smaller than the size of chain recommended for their yacht. Those who use G70 do so because it is lighter and takes up less room in their locker. Using, a different size of, chain involves minimal new equipment, a smaller gypsy. Changing to wire would mean a wire drum winch - a complete new bit of kit. The whole anchor retrieval system would need to be redesigned. The problem is money - its a whole new ball game.

Classification Societies do not reject use of wire, it can meet requirements. The problem is not 'just' the wire - but the swages.

I've investigated a drum winch since I discovered that I could buy a 4mm high tensile chain. 4mm chain is 'almost' like wire. The torque of a filled drum is slightly more than any torque applied to a chain windlass - there are major technical developments that would need to be resolved to use a drum winch with wire for anchoring of a leisure yacht. Comparing use of wire on a crane used in construction with use of wire on a marine vessel is a bit like comparing chalk and cheese or apples and oranges.

Another issue - if a wire drum winch 'fails' handling wire by hand would be a nightmare (and I have never heard it mentioned). Handling chain by hand is not easy but even 12mm chain could be retrieved on a sheet winch.

Many highly respected international yachts men use, or have used, G70 chain, for the reasons outline above. There is nothing new and novel about it. There is no underlying internet chatter that it is dangerous or unsafe - there is still a lot of ingnorance.

I have looked at chain, of the recommended size, and in strong winds the bit you can see looks straight in fact straighter than some billiard queues in a pub's pool room . Of course its not straight but I'd challenge you to go and prove its not .

Jonathan

 

[Mudisox]

What man amazing set of waffle and personal themes. Read the use and conditions that the original OP needs the chain and anchor for.

 

[NormanS]

What man amazing set of waffle and personal themes. Read the use and conditions that the original OP needs the chain and anchor for.

It's a forum.

 

[NormanS]

You don't need to use wire (to have a lighter rode), you can use smaller chain - which I do. Many people use G70 chain, smaller than the size of chain recommended for their yacht. Those who use G70 do so because it is lighter and takes up less room in their locker. Using, a different size of, chain involves minimal new equipment, a smaller gypsy. Changing to wire would mean a wire drum winch - a complete new bit of kit. The whole anchor retrieval system would need to be redesigned. The problem is money - its a whole new ball game.

Classification Societies do not reject use of wire, it can meet requirements. The problem is not 'just' the wire - but the swages.

I've investigated a drum winch since I discovered that I could buy a 4mm high tensile chain. 4mm chain is 'almost' like wire. The torque of a filled drum is slightly more than any torque applied to a chain windlass - there are major technical developments that would need to be resolved to use a drum winch with wire for anchoring of a leisure yacht. Comparing use of wire on a crane used in construction with use of wire on a marine vessel is a bit like comparing chalk and cheese or apples and oranges.

Another issue - if a wire drum winch 'fails' handling wire by hand would be a nightmare (and I have never heard it mentioned). Handling chain by hand is not easy but even 12mm chain could be retrieved on a sheet winch.

Many highly respected international yachts men use, or have used, G70 chain, for the reasons outline above. There is nothing new and novel about it. There is no underlying internet chatter that it is dangerous or unsafe - there is still a lot of ingnorance.

I have looked at chain, of the recommended size, and in strong winds the bit you can see looks straight in fact straighter than some billiard queues in a pub's pool room . Of course its not straight but I'd challenge you to go and prove its not .

Jonathan

If you are really so hung up about the weight of chain, instead of investigating lighter and lighter chain (4mm ), why not go for an even lighter alternative? Wire? Rope, in all its different materials? Webbing? Is there some benefit in using chain that you don't want to admit to? Please don't come up with stories about billiard cues, chalk and cheese, or apples and oranges.

 

[doug748]

Yes, I thought we were.

Never disputed that catenary exists - how could one when it is a fact. What is debatable is its value and whether an increase in size and weight enhances that value. The only other thing we know for certain is that it disappears when the load on the chain is sufficient to straighten the length. Therefore your claim that it is measurably more valuable is not supported by any evidence - only what you believe. You just say it "will be measurable". Big difference between "will be" and "is". Even bigger difference to then actually measure it and quantify its value. Until you devise a way of measuring it and placing a value on it it is just a belief.

Just because the pretty picture is somebody elses' copyright (which you did not acknowledge) does not give it the meaning that you claim. it is just a static picture that shows chain lays on the seabed when the boat is static and there is no load on it. Please explain why you think this is relevant as I can see no explanation - only a picture. Even if there were an explanation from your source that does not mean it is correct, which in the way you are using it is simply wrong.

As for "everybody knows" please read what you wrote in post#23 last but one sentence. You have made a lot of claims about "facts" without any evidence to support them and resort to statements like this one to imply that everybody else agrees with you. NONE of what you have claimed is "established science" - you have quoted no scientific papers, established theories, empirical tests - nothing.

I did indeed read that thread and 2 others from the same forum. The vast majority of posts report never seeing or hearing of chain breaking, and of the small number that do, none have sufficient detail to explain exactly what happened except that most boats were old and chain was old or that failure was a manufacturing defect. The one close to home was a Westerly but there is no detail as to why it failed in circumstance where it should not have failed because it was not strong enough. None of the incidents you have cited make any suggestion that the failure would not have occurred if heavier chain had been used. Given this is your central claim - that chain failure can be avoided by having heavier chain as lighter chain may fail is simply not supported by any evidence - 6mm chain has more than adequate safety margin for the OPs use and there is nothing to suggest that 8mm is "safer".

I am afraid it is you that has imagination - for example why are you imagining people buy chain on the basis that it will still be OK when it rusts away? Nobody else has even suggested this - just your imaginary "argument".

It is indeed good policy to concentrate on what was written and to challenge it when it is not supported by any evidence.

I have no problems with people having beliefs. It is when they make claims that are not supported by facts and empirical evidence I find it difficult to take them seriously. Progress and enhancement of knowledge (and as a consequence hopefully better decisions) come from questioning what is claimed.

Goodness knows what goes on in your mind, you seem to rattle about looking for people to disagree with on the grounds of your own brand of voodoo science.

You say there is no empirical evidence, but down the years mariners have relied on heavy chain to help anchor setting, most still do - You ignore it.

We know that the use of rope with a chain leader is universal, it helps anchor setting. Empirical evidence - You ignore it


I quote an reasonable external source to outline the almost universally accepted explanation:

"The benefit of this catenary action is that it decreases the initial angle between the seafloor or ocean bed and the anchor rode. "

First you seem not to have read it, then seem to think it is my invention (despite being in italics and quotation marks) then you flounder again 12 hours later:
"Please explain why you think this is relevant as I can see no explanation" Read the above, in bold, italic with quotation marks, taken from my post 29


You say there is no hard data to tell us if the effect is great or small - Your perverse position is: there is no data so we can safely ignore it.


You say the popularity of substantial chain means little in science, I agree. But it does demonstrate how the average boatowner thinks, given a free choice. For years you have been telling us how many people love modern boat design, how many people buy in mast furling, how popular bow thrusters are, how folk have embraced sail drives. - Yet on this occasion - it can be ignored.


You constantly embroider and misrepresent my posts. You tell us that my central claim is:

" - that chain failure can be avoided by having heavier chain"

Lets look at what I actually said:

"* If you neglect a chain you can afford to do it longer and more safely with larger diameter chain"

You increase your safety margin that's all. It's actually irrelevant if the failure mode is by neglect, manufacturing defect, or snatch loads on a fouled anchor.


I have no idea why you rely on flights of fancy, there are good, solid factual reasons for the OP to compromise with 6mm chain. Until it is proven other wise, anchoring performance is not one of them.

.

 

[Neeves]

NormanS

Do you know that wire is lighter for a given unit of strength, please provide the documentation - it might feed my search for knowledge. Webbing loses that volume for length value - you need more space to store it. Again if you know of a manufacturer of webbing winches please offer a link. Dyneema has been considered it is strong - but floats. Find me a wire winch manufacturer that can retreive chain at the same speed as my Maxwell windlass that is as cheap as my Maxwell windlass. These are simply some of the reasons I have not used wire (and webbing).

Peerless, the largest chain maker in America (and possibly the largest outside China) make a galvanised G70 chain. Maggi made and now another Italian chain maker makes a G70 galvanised anchor chain. The American Navy and marines use a galvanised G80 anchor chain. Dashew recommends use of a G70 chain and he equips his expedition yachts with a G70 chain. G70 and G80 is used because it offers an ability to down size chain size, saving weight and space. The off shore oil industry uses high tensile chain for anchor rodes - because it saves weight. Some of out fathers used a mixed rode, because rope is lighter (and they could not afford a windlass). Rope is hardly novel and has been used successfully for decades - lets be a bit more objective - centuries.

Peerless and Maggi make a G70 chain - because there is a market. The US navy use a G80 chain - because they did the research (their chain is lighter and lasts longer - they save billions), Dashew recommends and uses G70 because he tried it and it worked, I believe Starzinger used G70 chain- same reasons - for a given strength its lighter and takes up less room

Instead of being dismissive why not consider why Maggi, Peerless, Dashew and the US Navy have a belief contrary to yours.

Jonathan

 

[NormanS]

NormanS

Do you know that wire is lighter for a given unit of strength, please provide the documentation - it might feed my search for knowledge. Webbing loses that volume for length value - you need more space to store it. Again if you know of a manufacturer of webbing winches please offer a link. Dyneema has been considered it is strong - but floats. Find me a wire winch manufacturer that can retreive chain at the same speed as my Maxwell windlass that is as cheap as my Maxwell windlass. These are simply some of the reasons I have not used wire (and webbing).

Peerless, the largest chain maker in America (and possibly the largest outside China) make a galvanised G70 chain. Maggi made and now another Italian chain maker makes a G70 galvanised anchor chain. The American Navy and marines use a galvanised G80 anchor chain. Dashew recommends use of a G70 chain and he equips his expedition yachts with a G70 chain. G70 and G80 is used because it offers an ability to down size chain size, saving weight and space. The off shore oil industry uses high tensile chain for anchor rodes - because it saves weight. Some of out fathers used a mixed rode, because rope is lighter (and they could not afford a windlass). Rope is hardly novel and has been used successfully for decades - lets be a bit more objective - centuries.

Peerless and Maggi make a G70 chain - because there is a market. The US navy use a G80 chain - because they did the research (their chain is lighter and lasts longer - they save billions), Dashew recommends and uses G70 because he tried it and it worked, I believe Starzinger used G70 chain- same reasons - for a given strength its lighter and takes up less room

Instead of being dismissive why not consider why Maggi, Peerless, Dashew and the US Navy have a belief contrary to yours.

Jonathan

I don't really think that you need documentation to know that wire is lighter than chain for a given strength. Just consider how many boats you have seen with chain rigging.
I think you must be mistaking me for someone else. I am not being dismissive. I am seeking answers.

 

[Neeves]

I don't really think that you need documentation to know that wire is lighter than chain for a given strength. Just consider how many boats you have seen with chain rigging.
I think you must be mistaking me for someone else. I am not being dismissive. I am seeking answers.

Please find me a windlass/winch that will retrieve rod rigging or conventional stainless rigging with the same ease as one can retrieve and store chain.

I have always mentioned that the ideal rode is made from piano wire made on the planet Krypton. It would be thin, flexible and strong - Sadly this is unrealistic - but you may have an answer.

Jonathan

 

[NormanS]

Please find me a windlass/winch that will retrieve rod rigging or conventional stainless rigging with the same ease as one can retrieve and store chain.

I have always mentioned that the ideal rode is made from piano wire made on the planet Krypton. It would be thin, flexible and strong - Sadly this is unrealistic - but you may have an answer.

Jonathan

Oh dearie me! When did anyone suggest using rod rigging wire or even conventional rigging wire? That would be ludicrous. There are perfectly good conventional flexible stainless wire constructions that would suit the purpose, without going to planet Krypton. Years ago I sailed a yacht with a wire main halyard. It used a multi strand flexible wire without any problem.

 

[Neeves]

Oh dearie me! When did anyone suggest using rod rigging wire or even conventional rigging wire? That would be ludicrous. There are perfectly good conventional flexible stainless wire constructions that would suit the purpose, without going to planet Krypton. Years ago I sailed a yacht with a wire main halyard. It used a multi strand flexible wire without any problem.

Norman - you must be bored. It must be pleasant to have so much time on your hands. You were the one to mention rigging.

J

 

[Tranona]

Goodness knows what goes on in your mind, you seem to rattle about looking for people to disagree with on the grounds of your own brand of voodoo science.

You say there is no empirical evidence, but down the years mariners have relied on heavy chain to help anchor setting, most still do - You ignore it.

We know that the use of rope with a chain leader is universal, it helps anchor setting. Empirical evidence - You ignore it


I quote an reasonable external source to outline the almost universally accepted explanation:

"The benefit of this catenary action is that it decreases the initial angle between the seafloor or ocean bed and the anchor rode. "

First you seem not to have read it, then seem to think it is my invention (despite being in italics and quotation marks) then you flounder again 12 hours later:
"Please explain why you think this is relevant as I can see no explanation" Read the above, in bold, italic with quotation marks, taken from my post 29


You say there is no hard data to tell us if the effect is great or small - Your perverse position is: there is no data so we can safely ignore it.


You say the popularity of substantial chain means little in science, I agree. But it does demonstrate how the average boatowner thinks, given a free choice. For years you have been telling us how many people love modern boat design, how many people buy in mast furling, how popular bow thrusters are, how folk have embraced sail drives. - Yet on this occasion - it can be ignored.


You constantly embroider and misrepresent my posts. You tell us that my central claim is:

" - that chain failure can be avoided by having heavier chain"

Lets look at what I actually said:

"* If you neglect a chain you can afford to do it longer and more safely with larger diameter chain"

You increase your safety margin that's all. It's actually irrelevant if the failure mode is by neglect, manufacturing defect, or snatch loads on a fouled anchor.


I have no idea why you rely on flights of fancy, there are good, solid factual reasons for the OP to compromise with 6mm chain. Until it is proven other wise, anchoring performance is not one of them.

.

Well guess you will never understand if you refuse to read and learn from the extensive published data and just rely on what people have always done.

Nothing I have written or referred to can be remotely considered a flight of fancy. It is all documented and in the public domain.

Your claim that heavier chain helps better setting is simply not true. What sets anchors is the load applied not the weight of the chain. Watch any of the videos of anchors setting and you will see the chain lifting from the bottom before it moves the anchor. The angle of pull is determined by the scope - that is the more rode out in relation to the depth the lower the angle of pull. I read what that source of the diagram said and the diagram proves nothing and the sketchy explanation is just wrong. All it says is what it says - nothing about aiding setting of the anchor. That is your invention.

I did not say that the popularity of substantial chain means little in science. What I said is that science and empirical data based on it does not support the need for heavy chain. The use of heavy chain (and heavy anchors) long predates any serious scientific work and is embedded by for example the unchanged recommendations from various sources. The work on anchors and anchor design over the last 20 years has disproved most of the long held views on the subject.

I have never said to ignore catenary. All I have said is that there is no data that measures what it does nor what the difference is between different weights of chain in use. How can you make a rational decision about buying heavier chain than necessary if you don't know what additional benefit it brings?

I do not know why you continue to talk about the loss of strength due to corrosion as a reason for buying heavier chain. Why would any one do that? The safety margin of chain, even 6mm is far greater than any boat of the size the OP has could ever generate. That is a fact, and even a 50% loss in strength would still exceed the load the boat could apply.

Your last sentence does not make any sense. There is no need to compromise with 6mm chain. It is more than adequate in terms of strength. It will set his anchor in exactly the same way as heavier chain using the same scope. If you have difficulty with this then read the data on which it is based and the testing work that has been carried out to demonstrate this is so.

 

[penfold]

Wire is used throughout industry in many safety critical situations. It is nonsense to say that it's not "inspectable".
If you actually read my post, you will see that there is no handling involved. Do you think that the wires on, for example, cranes, "form a rats nest on retrieval"?

You raised the subject of wire for no apparent reason; if you want the lightest possible rode use Dyneema like anyone else would.

 

[Macka1706]

Our 38' cat is 7t and has the windage of a Bav 45. We sail to Tasmania, you may have heard of the 'Roaring Forties' ? and have been using 6mm chain for over a decade.

This is a picture of 50m of 8mm chain, the top 2 drums and 75m of 6mm chain the lower two drums. Now I don't know 31' yachts that well - but I am sure the chain/anchor lockers are small and I know which size of chain would best fit a small locker (the difference in weight would be reflected in sailing performance - but that is a bit subjective.... and a different discussion.
View attachment 156840
The 'technology' behind catenary can be replaced with elasticity, or a snubber. I know which is cheaper and lighter, especially if you have a 31' yacht.

I think every credible windlass maker makes a windlass focused at 8mm chain but has a 6mm or 10mm gypsy that will fit (and vice versa). When we down sized from 8mm to 6mm in consultation with Maxwell we opted for a windlass nominally designed for a yacht for which 8mm would nominated (because the tension, or loads), would be for our size of cat) but chose a 6mm gypsy and 1,000 watt motor.


I'm disappointed that having made 12,000 posts, so an active member, you have not read any of my posts on anchoring - most people are overly critical of my single minded postings - you are quite unusual?

I have not repeated Tranona's evidence - but agree with his posts.

He has a much better handle on the English language than I - but then I've been in Australia for 25 years now - and standards slip and I, apparently, have become verbose . - to the point of tedium.

Jonathan

Hey.
My 32 fter had a bulkhead welded in with stiffeners to strengthen deck for Staysail (Cutter Halyard) I had a 1in Divider Marine ply fore and aft. Port side had 6mm x 100m. with 100m 20mm Nylon splices on behind for day and short term Pick use.
Stbd side had a 82lb Admiralty pick with 120mtrs of 8mm SHort(triple b) chain and a deck box for the Nylon.

Well. Maybe soft was the wrong word but H/T Treatment was gone. around 8 galvanisers I know must be wrong too. They all said the same thing when I was regalving over the 70 ish yrs I've been sailing. AND stretching some chains (Mainly lifting heavy loads) Most just get tank to temp. Load. rattle it around then lift it to drain.
Personally, I just bought Triple b Short,galv. Hammerlocks and shackles to suit. Made up several 8ish foot 30mm Nylon snubbers with clear hose over top metre.for stemhead wear. Never had a problem anywhere I went. (42fter I made 40mm Snubbers).
We used H/T Single chains and and wire strops for heavy lifting with the cranes
Nobody I know ever had any problem with triple b chain of correct links for their boat in ANY conditions. and living in Townsville. Douglas and Darwin for 50 plus yrs. We swung to a few good breezes (Cyclones).

Anchoring is a mix of light and/or heavy single pick.
econdly, heavy shackle 40ish ft chain and second pick on front of. Dropped and set first.
third. Two picks dropped 45 to 60deg part .
Two for'ard and one at stern to hold bow into sets/wind if differing lengths on twin pick drop don't work.
Then the three way anchor set on the one riser with swivel, if leaving boat for a while.
Lots of differing ways. MOST of the old school ways do hold. Always have a decent swivel on head of stock on pick.
ALL Picks. Have fun hey.

Basically most nowadays are after "lightness" in their boats. and keep boat + equipment on board to a mi,imum. ME. My 32 ft 8 1/2 ton. and 42ft 17ton were just right. Any seas, as much crap onboard as i want. I enjoy the sailing of, NOT the getting there. The next time I go past a port/anchorage and keep sailing, won't be the first.

.

.

Absolute rubbish

Gunnebo, now owned by Crosby, make a G80 galvanised chain for fish farming.

Peerless make a G70 galvanised chain (from a G43 feedstock).

Maggi make a G70 galvanised chain, now made by a different Italian chain maker whose name I forget.

Crosby, Peerless, Campbell and others. make galvanised G80- shackles

I took a 6mm G80 chain, had it galvanised, had it tested by an independent test facility - it has the strength of the chain, 8mm G30, it replaced.

The US Navy and Marines use galvanised high tensile chains for tie downs and anchor chains because being HT they can use smaller chain but of the same strength as larger 'soft steel' chain.

Like the tie downs for the military vehicles on this hovercraft.
View attachment 156833

All galvanised and not soft steel.

You can then takes these products when they have worn the gal off (as long as you do not leave it too long) and regalvanise and retain the exact same strength.

You need to start with a HT steel - and yes - you will lose strength but with care and sensible choices you will not end up with 'soft steel'. If you were a chain maker, as opposed to me, you would know the optimum Quench and Temper schedule of the alloy steel and be able to optimise the galvanising process for strength.

I worked with a galvaniser for about 6 months to get as close to optimising my rode as possible and have made a number of rodes since (and galvanised hammer locks, shackles, omega links and chain hooks (and had them independently tested).

Technology moves on

Jonathan