macd
Well-Known Member
Unless the kedge is small, I think there's nothing mistaken about your (relative) sense of security.
8mm Anchor chain?
- Thread starter Niander
- Start date
Unless the kedge is small, I think there's nothing mistaken about your (relative) sense of security.
NormanS
Well-Known Member
I think I've already asked on this thread, how people manage the rope part of their mixed rodes. So far, nobody has responded. So if you have a mixed rode, do you heave in using the gypsy? Does the rope go down into the locker on its own, or do you have to push it down? Chain stows itself in the chain locker, what happens with rope. Do you have enough room in the chain locker for the greater volume of rope/chain? Or do you heave in the rope by hand, and then somehow get the chain down into the locker.
When using my second anchor, (Fortress), I use a 50m climbing rope with 5m of 11mm chain. For retrieving, I use the windlass warping drum, and hopefully the water is deep enough, so that the anchor breaks out before the chain reaches the drum. Then just pull up by hand.
Earnest searching after truth
When using my second anchor, (Fortress), I use a 50m climbing rope with 5m of 11mm chain. For retrieving, I use the windlass warping drum, and hopefully the water is deep enough, so that the anchor breaks out before the chain reaches the drum. Then just pull up by hand.
Earnest searching after truth
GHA
Well-Known Member
The gypsy I have has a slot in it, very rare but should then16mm octaplait at the end of 60m of chain get used then it sticks nicely in the slot and goes straight down the hawse pipe when getting retrieved, maybe needing a bit of helping hand now and again. There's a sort of wedge bracket which peels it back out of the slot.
vyv_cox
Well-Known Member
My GK29 came with mostly rope and a short length of chain, no windlass. That boat has no chain locker lid, just a hawse pipe. Getting 30 metres or so of rope down it from on deck was a monumental task needing someone below to pull it down. Although once we replaced the rope with chain it remained a two-person job, one in the forecabin to flatten the pile. Another problem was that the rope stank after a few weeks of use, whereas chain didn't. The kids slept in the forecabin in those days and we could ignore their complaints.
The chain is good its a G4 quality (it tests at just a bit over G4 mins), come from Maggi, who make a G7 as well. its marked A4 (as in Aqua 4) so you and whoever buys the yacht subsequently knows exactly what it is. Decent galvanising. Ask for a test cert with the invoice. We have found that getting a shackle to fit is a problem as gal 3/8th inch (imperially made) but nominally 10mm pins shackles say Crosby (safety factor 4.5:1) or better Peerless of Campbell (safety factor 6:1) (all WLL 2t) does not fit the link (from Maggi - fits other metric links??!). Van Beest in Holland I think make equivalent metric shackles but have never seen one (Green Pin) For shackle source try Techni-Lift in UK. CMP are meant to be introducing a 2t 3/8th shackle (its on the Titan website) but never seen one, Black Pin.
Jonathan
Niander
Well-Known Member
Oh, is that what all this was about?
NO connection of course but they look very good even send you out a chain sample to test the fit on your gipsy free...+1
they will certainly get my order ill probably get some rode spliced on by them also and tested shackles[weakest link and all that].
I want ground tackle I can rely on if I ever need it...
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vyv_cox
Well-Known Member
Squeezing the last link endways in a vice opens DIN766 chain enough to insert a Crosby C-link. I assume that the Crosby shackles, links, etc are to a different standard, presumably an Imperial one, just a bit too fat for a metric chain.
I know someone who was charged an additional 10% for Maggi chain with a proof test certificate. I don't know if this was a Maggi stipulation or a bit of enterprise by the chandler.
I know someone who was charged an additional 10% for Maggi chain with a proof test certificate. I don't know if this was a Maggi stipulation or a bit of enterprise by the chandler.
Here in Oz we get a test cert for which there is no charge, you simply need to ask. It covers a Proof Test for the whole batch, or length made - so maybe 1,000m (and of course you might only be buying 50m). Chain is commonly Proof Tested, continuously - but not sure how they do it. Ultimate Break Strength is conducted on as few as 7 links, from that 1,000m. So none of it is very exhaustive - but better than nothing.
If you wanted the specific length you were buying Proof Tested and break tested - I can see that costing!
Vyv, I think you had mentioned previously (and I'd forgotten) that it is possible to squeeze and widen the last link to fit slightly oversize shackle pins and that you thought the squeezing would not have any impact on strength. edit Oddly Australian made metric chain of nominally the same size as Maggi's - does take the Crosby pin?, close edit.
Niander - as you point out Jimmy Green do seem to offer a decent service. I tested, one only, CMP Titan 3/8th inch WLL 1t shackle. The min break load should be 6t, the shackle failed at 8t. This seems plenty strong enough for both 8mm G3 and G4 chain!
Jonathan
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vyv_cox
Well-Known Member
I think that one of the videos on chain manufacture shows the standard proof testing, in which every length of around a metre(?) is subjected to a defined load. Presumably if there is any elongation it sounds an alarm or something.
Bradney told me that they proof test sample lengths of 100 metres or so when imported. I think the case I know of from Maggi may have been such a proof test, i.e. the actual length being bought. So as you say, you might expect to pay if this is over and above what is normally provided.
FairweatherDave
Well-Known Member
Been following this thread with interest as I am also about to buy 8mm chain. Obviously I have the Jimmy Green option but closer to home (Solent) I have a reputable chandler with two offerings. The first is calibrated for Lewmar, it is grade 30 and has a rating for Hot dip Galvanising test of 12.7 kn msl 0.6t (supplied by Bainbridge Aqua). The second is for Lofrans, and has a hot dip galvanised test of 19.8 kn msl 1t and is by XM Yachting. They are the same price although the Lewmar is reduced to the same as the Lofrans. I don't have a gypsy so there is no issue. These ratings are confusing me as the measure is not referred to on the Jimmy green site. Anyone care to explain which I should go for. The Lewmar looks shiny but having read up about that I don't think that is an issue.
Storyline
Well-Known Member
Five years ago on so when we got our chain from Jimmy Green I am sure the lady who works in sales said our chain (3/8") came from a foundry in France. Do you happen to know who they might be and have any comments about their chain ?
vyv_cox
Well-Known Member
Five years ago that was correct, manufactured by Benedict Garcia, Realmont, . JG had some concerns about the quality of the chain they supplied and switched to Maggi. When I asked JG for a sample of their current stock to test somebody sent me the French stuff, documentation with it contradicting what it said on their website, specifically that it was Grade 30, not Grade 40. I wrote this up for my YM article, causing JG to be considerably less than pleased and condemning me on their website. .
When you write up an honest but less than complimentary comment you sadly fall of the Xmas card list and seem to be condemned for life. I speak from experience. It seems very short sighted to me, but just shows, we are all human - even corporate bodies!
There are, or were (at least) a couple of chain makers in France, one of which I think is now owned by Pewag but whether they make anchor chain do not know. Someone on this forum had G40 French chain fail, he omitted to say where the chain came from, he rescued the anchor and chain and the broken link. The link had failed at the weld. The chain maker was mortified (his words) and quietly replaced the chain.
I was a bit uncomfortable with the story as I 'extrapolated' and thought that if they had one bad weld then the probably had bad welds in the same production run and there ought to have been some sort of recall (which actually might have occurred) but the story suggesting the chain was quietly replaced implied not. I've never written this up, except now, as I do not know enough of the story and do not want to condemn French chain makers. The story happens to be specifically relevant to this part of the thread.
Chain is usually, always?, Proof Tested and Break Tested in Newtons but maybe Kn. But because most of us do not know, or care, what a Newton is the data is often converted to Kg.
I do not know what the figures 'kn msl' mean.
The 0.6t and 1.0t look like G30 and G40 WLL - and these are simple mathematic calculations. As Vyv has shown much G30 chain is near G40 quality.
The other figures might be Proof Test loads in Kn - these are actual loads to which the chain was loaded and if any deformation was detected the chains should have been rejected. The actual chains could be much better - as there is no break test. My tests are the same as Vyv's - most G30 is near G40 quality most G40 just exceeds min G40 specs. In general therefore G40 is better than G30 but not by much - but again as with Vyv, some G30 is near G30 specs - and there is no way to tell the difference except by testing
But chain failure (and most people have been using G30) is very, very rare.
Fairweather dave appears to have chain on offer with some sort of statistical reassurance. I'd go for the product that seems 'better'. But I'd still ask for the technical details to be provided, on the invoice, as a separate sheet and I'd buy one metre extra and stick it in a cupboard in case of problems.
Much chain is now coming from China and a lot of Chinese chain is of excellent quality. Some is absolute rubbish. It is impossible to tell the difference between the rubbish and good stuff (except for CMP who mark theirs).
Do not buy because the chain is 'shiny'. Its a red herring. Its just zinc on the outside and the zinc will abrade off in the first few days you use it. Old zinc can look dull, new zinc shiny. Sometimes if you dig into a barrel the zinc exposed to air is dull and lower in the barrel, same chain - its shiny.
What is important is the gal thickness - in general - the thicker the gal the longer it will last. If you have access to a decent microscope you can measure gal thickness, 150 microns or more is good, 70 microns is not good.
I do not understand how 2 metric 8mm chains can be calibrated for different windlass/gypsies. The 2 chains are meant to meet the same size specifications and the 2 gypsies are meant to be made to meet those same specifications - and no-one makes chains (that I am aware of) for specific windlass makers.
The longer this thread runs the more uncertainties seem to be exposed!
Jonathan
There are, or were (at least) a couple of chain makers in France, one of which I think is now owned by Pewag but whether they make anchor chain do not know. Someone on this forum had G40 French chain fail, he omitted to say where the chain came from, he rescued the anchor and chain and the broken link. The link had failed at the weld. The chain maker was mortified (his words) and quietly replaced the chain.
I was a bit uncomfortable with the story as I 'extrapolated' and thought that if they had one bad weld then the probably had bad welds in the same production run and there ought to have been some sort of recall (which actually might have occurred) but the story suggesting the chain was quietly replaced implied not. I've never written this up, except now, as I do not know enough of the story and do not want to condemn French chain makers. The story happens to be specifically relevant to this part of the thread.
Chain is usually, always?, Proof Tested and Break Tested in Newtons but maybe Kn. But because most of us do not know, or care, what a Newton is the data is often converted to Kg.
I do not know what the figures 'kn msl' mean.
The 0.6t and 1.0t look like G30 and G40 WLL - and these are simple mathematic calculations. As Vyv has shown much G30 chain is near G40 quality.
The other figures might be Proof Test loads in Kn - these are actual loads to which the chain was loaded and if any deformation was detected the chains should have been rejected. The actual chains could be much better - as there is no break test. My tests are the same as Vyv's - most G30 is near G40 quality most G40 just exceeds min G40 specs. In general therefore G40 is better than G30 but not by much - but again as with Vyv, some G30 is near G30 specs - and there is no way to tell the difference except by testing
But chain failure (and most people have been using G30) is very, very rare.
Fairweather dave appears to have chain on offer with some sort of statistical reassurance. I'd go for the product that seems 'better'. But I'd still ask for the technical details to be provided, on the invoice, as a separate sheet and I'd buy one metre extra and stick it in a cupboard in case of problems.
Much chain is now coming from China and a lot of Chinese chain is of excellent quality. Some is absolute rubbish. It is impossible to tell the difference between the rubbish and good stuff (except for CMP who mark theirs).
Do not buy because the chain is 'shiny'. Its a red herring. Its just zinc on the outside and the zinc will abrade off in the first few days you use it. Old zinc can look dull, new zinc shiny. Sometimes if you dig into a barrel the zinc exposed to air is dull and lower in the barrel, same chain - its shiny.
What is important is the gal thickness - in general - the thicker the gal the longer it will last. If you have access to a decent microscope you can measure gal thickness, 150 microns or more is good, 70 microns is not good.
I do not understand how 2 metric 8mm chains can be calibrated for different windlass/gypsies. The 2 chains are meant to meet the same size specifications and the 2 gypsies are meant to be made to meet those same specifications - and no-one makes chains (that I am aware of) for specific windlass makers.
The longer this thread runs the more uncertainties seem to be exposed!
Jonathan
JumbleDuck
Well-Known Member
msl is probably Maximum Securing Load, which is to securing devices what Safe Working Load is to lifting devices.
The ISO and DIN standards for metric chain differ for 10mm, though not for 8mm. See Vyv's website. Perhaps some windlass makes specify DIN and some ISO across the range, although it only makes a difference with 10mm.
JumbleDuck
There seem to be a whole set of terms to mean:
Working Load Limit
and Minimum Break Load
??
I've just checked the test cert I received from PWB (Oz) for 8mm Grade L (G30)
The Proof Load was 15.9kN
The Break Load was 31.7 kN
The elongation at break was 20%
edit The Americans have spec of min 15% elongation at break for G30, G43 and G70, higher strengths (G80 and up) must have a min elongation of 20% at break, so much for HT chain being brittle! I might add - some chain in America does not meet this min spec, i.e. it is lower. CMP, PWB all exceed the spec. close edit
These are actuals.
I tested the piece I bought, and another piece bought at random, and my results were very close to those of the certificate.
The PWB chain exceeds comfortably min specifications but CMP Grade L, Campbell G30 and Peerless G30 were much better. In fact CMPs Grade L (G30) was almost identical to Maggi's G40. Oz Serafini Grade L was very similar to PWB. I tested 2 lots of unmarked Chinese chain, so no idea where they came from in China, one was rubbish the other the best G30 I tested.
But note, Except that I tested 3 pieces, by accident rather than design, of PWB Grade L (G30) I only tested one x 1m length of each chain, so statistically weak. I wanted to test more of CMP's Grade L, to confirm its consistency - but I'm off their Xmas card list - and one cannot be too emphatic on the basis of one x 1m length
Jonathan
There seem to be a whole set of terms to mean:
Working Load Limit
and Minimum Break Load
??
I've just checked the test cert I received from PWB (Oz) for 8mm Grade L (G30)
The Proof Load was 15.9kN
The Break Load was 31.7 kN
The elongation at break was 20%
edit The Americans have spec of min 15% elongation at break for G30, G43 and G70, higher strengths (G80 and up) must have a min elongation of 20% at break, so much for HT chain being brittle! I might add - some chain in America does not meet this min spec, i.e. it is lower. CMP, PWB all exceed the spec. close edit
These are actuals.
I tested the piece I bought, and another piece bought at random, and my results were very close to those of the certificate.
The PWB chain exceeds comfortably min specifications but CMP Grade L, Campbell G30 and Peerless G30 were much better. In fact CMPs Grade L (G30) was almost identical to Maggi's G40. Oz Serafini Grade L was very similar to PWB. I tested 2 lots of unmarked Chinese chain, so no idea where they came from in China, one was rubbish the other the best G30 I tested.
But note, Except that I tested 3 pieces, by accident rather than design, of PWB Grade L (G30) I only tested one x 1m length of each chain, so statistically weak. I wanted to test more of CMP's Grade L, to confirm its consistency - but I'm off their Xmas card list - and one cannot be too emphatic on the basis of one x 1m length
Jonathan
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Storyline
Well-Known Member
Knew it was stupid to ask about my chain as now I am less than ecstatic that it is not Grade 40.
As it is a bit oversized for the boat I am not overly concerned but will not mention it to swmbo as she tends to fret about such things
First signs of rust and new gypsy and 8mm will be ordered (this will enable us to carry another 30m for a similar weight (guessing) - I reckon 100m will cover most eventualities !
Edit: ps, forgot to say, thanks for the answer Vyv
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FairweatherDave
Well-Known Member
In my googling I have now learnt that MSL stands for Maximum Securing Load, (full marks JD) which is 50% of breaking strength, and kN stands for kilo Newtons (but some might have known that here already). (MSL could also stand for Moisture sensitivity level but somehow perhaps not here
And I have just spoken to the chandlery who called me back and admitted infact their website needed updating. They only supply one type of 8mm chain which is grade 30 and rated at 29 kN and it comes from China via William Hacket. The chandler is happy to get a copy of the certification for me too so I think I am sorted. Not that I was the OP but thanks to the contributors on the thread, really useful .
And I have just spoken to the chandlery who called me back and admitted infact their website needed updating. They only supply one type of 8mm chain which is grade 30 and rated at 29 kN and it comes from China via William Hacket. The chandler is happy to get a copy of the certification for me too so I think I am sorted. Not that I was the OP but thanks to the contributors on the thread, really useful .
vyv_cox
Well-Known Member
I understand that there have been recent changes in the UK chain market. William Hackett now own Bradney Chain, http://williamhackett.co.uk/news/acquisition_of_bradney_chain_and_engineering I don't know whether the Bradney name continues. When I did the work for my YM article a few years ago both companies supplied Grade 40 but that is no longer the case, they only offered Grade 30 the last time I looked. The smaller sizes are all imported from China and achieved well into Grade 40 strengths when I tested them.
My theory as to the strength of Chinese chain is that the steel composition for Grade 30 is very mild, low carbon and no alloying elements. This may well be quite difficult to come by in China, whereas Grade 40 is a typical constructional steel composition, probably widely available at lower cost in China. My guess is that they use a better grade but call it Grade 30. Jonathan's experience of very poor stuff from China shows that there are still problems but buying via the big importers should bypass the questionable ones.
I have had some correspondence with Rigmasters in Southampton. They have carried out their own testing, which produced findings very similar to mine. They import Grade 30 from Rudong in China, supply MOD and several big boatyards, and tell me that their prices are very competitive.
My theory as to the strength of Chinese chain is that the steel composition for Grade 30 is very mild, low carbon and no alloying elements. This may well be quite difficult to come by in China, whereas Grade 40 is a typical constructional steel composition, probably widely available at lower cost in China. My guess is that they use a better grade but call it Grade 30. Jonathan's experience of very poor stuff from China shows that there are still problems but buying via the big importers should bypass the questionable ones.
I have had some correspondence with Rigmasters in Southampton. They have carried out their own testing, which produced findings very similar to mine. They import Grade 30 from Rudong in China, supply MOD and several big boatyards, and tell me that their prices are very competitive.
FairweatherDave
Well-Known Member
For the sake of accuracy, I just got an e mail back from William Bracket re. their 8mm calibrated chain....
"We sell approx. 20,000m per year of this chain and at least 90% of that total would be for the Calibrated Anchor Chain Market without issue. The loadings are as follows,
Proof Load: 15.9kN (M.S.L.)
Min. Break Load: 31.8kN"
Thanks for your comments Vyv. Helpful.
"We sell approx. 20,000m per year of this chain and at least 90% of that total would be for the Calibrated Anchor Chain Market without issue. The loadings are as follows,
Proof Load: 15.9kN (M.S.L.)
Min. Break Load: 31.8kN"
Thanks for your comments Vyv. Helpful.