Anchor chain sizing

lupins

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Evening all,

currently in the process of changing out my anchor chain old for new as it has certainly seen better days. I was wondering if someone could kindly shed some light on the sizing. Online, anchor chain seems to be supplied in 6mm,7mm,8mm,10mm,12mm etc.

I’ve taken a set of callipers to my chain and across all lengths of it, it seems to be a set 9mm (see image attached). Does this mean I can get away with an 8mm or 10mm chain or will either wreck the gypsy in the windlass?

Any advice greatly appreciated!
Have a smashing weekend!
 

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Tranona

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The size of your gypsy should be marked on it. That is the starting point. It may well be your chain is 3/8".
 

oldmanofthehills

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You can buy small lengths as samples from jimmy green. Better to risk £5 or whatever than buy a big length and find you have got it wrong. Better still take a small bit of your chain to reputable helpful handlers. Your gypsy may or may not be marked - mine seemed not to be

The critical thing for the gypsy is the length between successive links so it does not ride up, not the thickness of the metal
 

Neeves

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Take your gypsy off, and as suggested the gypsy will be marked with its size. The size may be engraved in the side of one of the plates or on one of the inside facing edges.

Then take your gypsy to the chandler from whom you may buy your chain and wrap a complete length of chain (of the appropriately sized chain) round your gypsy. The size embossed on your gypsy is a good size to start with. This will confirm size.

You must buy the chain that fits the gypsy or buy a new gypsy - they are expensive.

The chain at the bitter end, if it is not corroded is commonly closer to the original size - measure it rather than some of the chain near the anchor.

If when you look at the engraving you cannot understand what is means - post here.

As Tranona mentions you might have imperial chain, but if that is the case your yacht is either American or very old. If its imperial finding chain to match might be difficult but CMP in their Titan range do make imperial chain, for the American market, so sourcing it is not impossible but maybe needs time and a bit of extra money.

When you buy your chain make sure you have a shackle to match both chain and anchor. You need to buy a G209A Crosby shackle, Tecni in the UK can supply. But preferably take your anchor, and gypsy to the chandler and size everything there. Using 2 shackles back to back is not the best way :(. Except in exceptional circumstances - you do not need a swivel.

I would suggest as you progress with your investigations keep posting and we will continue to give advice.

I think Jimmy Green on their website advise how to measure chain. Chain dimensions are nominal and chain wears. Measuring chain, especially if it is old, is not necessarily going to give you an accurate or correct figure, the marks on the gypsy and measuring the bitter end are more useful.

If you look at spread sheets for chain vs vessel size and you think your chain too small or too big - now is the time to change - but you will need that new, expensive gypsy (which may not be available if the windlass is old.

When you have your new chain then is the time to mark it for depth/length marks.

Jonathan
 
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Neeves

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Apologies Graham, but you rightly emphasised the need for a full wrap - which I forgot - and is important.

Taking the gypse off is relatively easy - just read the instruction manual.

J
 

Graham376

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Apologies Graham, but you rightly emphasised the need for a full wrap - which I forgot - and is important.

No you didn't forget - wrap a complete length of chain (of the appropriately sized chain) round your gypsy. :)

I made the mistake one time, bought 10mm DIN instead of ISO because I just tried it in situ, which looked fine. Sometimes jammed when hauling and jumped when dropping. Fortunately managed to obtain the correct gypsy free of charge.
 

Neeves

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No you didn't forget - wrap a complete length of chain (of the appropriately sized chain) round your gypsy. :)

I made the mistake one time, bought 10mm DIN instead of ISO because I just tried it in situ, which looked fine. Sometimes jammed when hauling and jumped when dropping. Fortunately managed to obtain the correct gypsy free of charge.

Free gypsy?? - you got a bargain!

Jonathan
 

lupins

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Take your gypsy off, and as suggested the gypsy will be marked with its size. The size may be engraved in the side of one of the plates or on one of the inside facing edges.

Then take your gypsy to the chandler from whom you may buy your chain and wrap a complete length of chain (of the appropriately sized chain) round your gypsy. The size embossed on your gypsy is a good size to start with. This will confirm size.

You must buy the chain that fits the gypsy or buy a new gypsy - they are expensive.

The chain at the bitter end, if it is not corroded is commonly closer to the original size - measure it rather than some of the chain near the anchor.

If when you look at the engraving you cannot understand what is means - post here.

As Tranona mentions you might have imperial chain, but if that is the case your yacht is either American or very old. If its imperial finding chain to match might be difficult but CMP in their Titan range do make imperial chain, for the American market, so sourcing it is not impossible but maybe needs time and a bit of extra money.

When you buy your chain make sure you have a shackle to match both chain and anchor. You need to buy a G209A Crosby shackle, Tecni in the UK can supply. But preferably take your anchor, and gypsy to the chandler and size everything there. Using 2 shackles back to back is not the best way :(. Except in exceptional circumstances - you do not need a swivel.

I would suggest as you progress with your investigations keep posting and we will continue to give advice.

I think Jimmy Green on their website advise how to measure chain. Chain dimensions are nominal and chain wears. Measuring chain, especially if it is old, is not necessarily going to give you an accurate or correct figure, the marks on the gypsy and measuring the bitter end are more useful.

If you look at spread sheets for chain vs vessel size and you think your chain too small or too big - now is the time to change - but you will need that new, expensive gypsy (which may not be available if the windlass is old.

When you have your new chain then is the time to mark it for depth/length marks.

Jonathan

Thank you very much for the informative and thorough information. I have since gone down to the boat and checked my anchor chain for markings and as you suggested have taken a more thorough look at the anchor windlass. Sadly, I’ve been unable to take the gypsy off however have done some extensive research regarding the windlass model and taken measurements of the anchor chain.

Diameter of chain: 9mm
Link length: 41mm
Link height: 29mm
Length internal loop: 25mm
Height of internal loop: 12mm
Length of 10links end to end (as per Jimmy Green instructions: 266mm

After looking at the chain in greater detail I have noted every couple links or so ‘3B’ stamped into the chain. I understand that this only indicates that it is a grade 30 chain. The windlass model is a Maxwell 800. Online manuals for the Maxwell 800 indicate that it takes a 5/16” chain and that the 800M model takes an 8mm chain. I fear that I may have answered my question and that annoyingly, this may be an American 5/16” chain. The boat is Swedish from 1988 but I understand that Vetus (an American company) bought out Maxwell....this could explain things.

Jimmy Greens websites indicates that 10links of 8mm should be 253mm and that 10links of 5/16” should be between 275mm and 280mm.... I am bang on 266mm, almost halfway between the two!
A stupid question to ask, but is there a possibility that my gypsy will be able to tolerate an 8 mm chain?

Thank you for all the advice so far, looking forward to getting to the bottom of this!
 

Neeves

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Thank you very much for the informative and thorough information. I have since gone down to the boat and checked my anchor chain for markings and as you suggested have taken a more thorough look at the anchor windlass. Sadly, I’ve been unable to take the gypsy off however have done some extensive research regarding the windlass model and taken measurements of the anchor chain.

Diameter of chain: 9mm
Link length: 41mm
Link height: 29mm
Length internal loop: 25mm
Height of internal loop: 12mm
Length of 10links end to end (as per Jimmy Green instructions: 266mm

After looking at the chain in greater detail I have noted every couple links or so ‘3B’ stamped into the chain. I understand that this only indicates that it is a grade 30 chain. The windlass model is a Maxwell 800. Online manuals for the Maxwell 800 indicate that it takes a 5/16” chain and that the 800M model takes an 8mm chain. I fear that I may have answered my question and that annoyingly, this may be an American 5/16” chain. The boat is Swedish from 1988 but I understand that Vetus (an American company) bought out Maxwell....this could explain things.

Jimmy Greens websites indicates that 10links of 8mm should be 253mm and that 10links of 5/16” should be between 275mm and 280mm.... I am bang on 266mm, almost halfway between the two!
A stupid question to ask, but is there a possibility that my gypsy will be able to tolerate an 8 mm chain?

Thank you for all the advice so far, looking forward to getting to the bottom of this!

If its marked 3B it is imperial BBB chain and is a conventional G30. Your windlass thus needs BBB chain to match, which explains why the link size is 9mm. Its not 9mm but the Imperial equivalent. If you search along your chain you should find other marks indicating who made the chain, P for Peerless, A or ACCO for ACCO (now owned by Peerless), C for Campbell etc.

Imperial links are longer than metric links and I think you have a 5/16th" chain - but don't take my word for it!

I'm now out of my depth - as I don't know how you source Imperial chain in the UK. I'm also bemused why you have BBB chain on a UK yacht. CMP, the people who sell Rocna, sell Imperial and Metric chain and they do sell BBB chain - though whether they have stock in the UK - no idea. You may find you need to buy a new Metric gypsy and swap to metric chain. First up contact a CMP distributor, one who sells Rocna, and ask them to investigate if there is any BBB in the UK (assuming you are in the UK?)

Contact Maxwell direct, in NZ, and ask how to take the gypsy off - they have always bent over back wards when I ask for help. If you have problems with contacting them (ie they do not reply for some reason) - let me know and I'll PM an individual email address to you- who will answer. I don't know the Maxwell 800 - and its too late at night for me here to get further embroiled - but tomorrow.....

Finally - new gypsies are expensive, very. It maybe more sensible for you to regalvanise your existing chain. Define where you are located and someone may be able to point you toward a local galvaniser - who will process chain. Highland Galvanisers in Cumbernauld would be a good bet - but maybe too far away. But extend the thread to include regalvanising

Jonathan
 

lupins

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If its marked 3B it is imperial BBB chain and is a conventional G30. Your windlass thus needs BBB chain to match, which explains why the link size is 9mm. Its not 9mm but the Imperial equivalent. If you search along your chain you should find other marks indicating who made the chain, P for Peerless, A or ACCO for ACCO (now owned by Peerless), C for Campbell etc.

Imperial links are longer than metric links and I think you have a 5/16th" chain - but don't take my word for it!

I'm now out of my depth - as I don't know how you source Imperial chain in the UK. I'm also bemused why you have BBB chain on a UK yacht. CMP, the people who sell Rocna, sell Imperial and Metric chain and they do sell BBB chain - though whether they have stock in the UK - no idea. You may find you need to buy a new Metric gypsy and swap to metric chain. First up contact a CMP distributor, one who sells Rocna, and ask them to investigate if there is any BBB in the UK (assuming you are in the UK?)

Contact Maxwell direct, in NZ, and ask how to take the gypsy off - they have always bent over back wards when I ask for help. If you have problems with contacting them (ie they do not reply for some reason) - let me know and I'll PM an individual email address to you- who will answer. I don't know the Maxwell 800 - and its too late at night for me here to get further embroiled - but tomorrow.....

Finally - new gypsies are expensive, very. It maybe more sensible for you to regalvanise your existing chain. Define where you are located and someone may be able to point you toward a local galvaniser - who will process chain. Highland Galvanisers in Cumbernauld would be a good bet - but maybe too far away. But extend the thread to include regalvanising

Jonathan
Thanks once again for the informative response Jonathan. I have since contacted Maxwell in New Zealand and managed to get some answers regarding the tolerances of their gypsy on the Freedom models. Unfortunately, they no longer manufacture the freedom series however I’ve been led to believe that the new models they replaced the freedom series with are able to take both an 8mm chain and a 5/16 chain. Apparently the gypsy from these models is interchangeable with the Maxwell model which I currently own. Annoyingly, my gypsy is made to tolerate a 5/16 chain, however, having spoken with some chaps at boat gear direct, they seem to believe that as my chain dimensions sit randomly between both 5/16 and 8mm that its worth a shot with a sample of 8mm chain. Worst case scenario, get a new gypsy which maxwell can source. Best case, the gypsy will take the 8mm chain without spitting it out or riding. I wonder what your thoughts are on this plan?

Thank you so much for the advice and help so far.
 

Neeves

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Maxwell are pretty good with customer support. My understanding is the support is 24 hour 365 - because their customer base is 24 hr 365. Certainly when I had a query they answered during the very late evening.

I'm sorry but the best way to test for fit is to do it! Good chandlers would have a device to which they can fit most gypsies and then run chain through your gypsy - we have one, only, that I know of in Sydney - not much use to you :(. The next best thing is to take your gypsy and try it on various chains, the chandler can then offer available hands. Havig enough to wrap round the gypsy is the next option - but usually the chandler want you to buy the length of chain. Hoping it fits - sometimes does not work.

I have never seen BBB but understand its an old specification. Nothing wrong with that but my exposure to Imperial links is that they are longer than the equivalent metric links - so a 5/16th" link is longer than 8mm link, but might be more similar to a 10mm link but the links are also wider. I'm suspicious that you could fit an Imperial chain to a metric gypsy, or vice versa, but maybe the gypsy is more forgiving.

If you were to be forced to buy a new gypsy - then is the time to consider if you might benefit from a higher grade, G70. It may not cost much different, because you will use a small size of link. Because you use smaller chain it is less weight in the bow, and uses less power to retrieve. You will lose catenary effect and will need to use a decent snubber, which is undoubtedly a nuisance for some - but the snubber will work as wind strength increases but unless you have infinite chain then chain tends to lose the advantages of catenary at about 30 knots.

Much of your issues depend on your location and where you will sail. If you are within America's orbit, many Pacific Islands, Caribbean etc then Imperial chain is not an issue. If you are in Europe and sail in Europe then metric is the obvious answer. Note Australia and NZ bizarrely have their own chain specification but also have conventional metric chain - really confusing.

If you wanted thoughts on the G70 route - I'd start a separate thread. Expect a lot of incorrect but erudite negative comment on not making catenary available to your self - luddites and people without open minds live here :(

But you next step is to take the gypsy to the chandler to identify what is possible (and check the price of gypsies - that might cool your enthusiasm to change :(

Finally - when you solve the dilemmas - let us know what you decide - your decision will be useful to us all - as you are not alone with your problems or some of your problems.

Where ever you are

Take care, stay safe

Jonathan
 
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