Question about anchor chain size. 10MM to inches...

[Lowcountry]

Good day, all. I just bought a sailboat in Spain, and I'm importing her to the US. She has an older (but functioning) Vetus Alexander I windlass. The windlass is using 8mm chain, which I feel is too small for a 22,000lb boat. As such, I'd like to increase the chain size to 10mm. I have been able to locate a 10mm chain gypsy for the Alexander I, but I'm uncertain as to what chain to order. Looking at Defender Marine, it seems the closest size would be 3/8", but I don't want to buy a $300 gypsy and then $1,000 worth of 3/8" chain to find that they won't fit together. Anyone else have experience with this that could offer suggestions? Thanks!

[Paul L]

There's at least two 10mm short link anchor chain specs, both are a bit different to imperial 3/8. You can read some of the difference here
https://chainsropesandanchors.co.nz/...ain-Short-Link
Probably need to get in touch with the gypst vendor and see what fits.

[chouliha]

If possible Why not buy 1’ of chain to try in the gypsy first? We have been running 3/8” BBB chain for 32 years in our windlass and recently changed to 10mm Maggi chain with no issues. Din766/A

[groundtackle]

Lowcountry,
I don't personally feel 5/16" or 8mm G40/43 for 22,000lbs is a strength or WLL issue, I'd recommend it.
If you require metric chain in North America, it's available.
Confirming exactly the dimension is critical.
Fun Fact.. measuring chain requires these (3) dimensions. Inside width/ Inside length / diameter of rod.
Chris

[mako]

Originally Posted by Lowcountry

The windlass is using 8mm chain, which I feel is too small for a 22,000lb boat.

Have you received a quotation to switch to G70 chain instead, therefore keeping the 8mm size which is compatible with your windlass as it is?

[S/V Alchemy]

Originally Posted by makobuilders

Have you received a quotation to switch to G70 chain instead, therefore keeping the 8mm size which is compatible with your windlass as it is?

Every chain of a given size seems to require a sample to "field-test" that the particular grade of chain will fit the "standard" gypsy, which is usually based, it seems, on BBB grade.

That said, I prefer a stronger chain to a heavier chain, and G70 is a great grade for that. It's what logging trucks use to secure logs, among other uses/

[Lowcountry]

Thanks for the responses, all. To be honest, I'm not certain that the 8mm chain isn't G70 already. I'll have to wait for the boat to get here before I can determine for sure. Hopefully it is G70 and I won't have to replace it. That would be the best solution.

[Emouchet]

You will need the exact fit gypsy for the type of chain.

A 10mm gyspy will only work with a 10mm metric chain.

Do not expect to fit a 3/8 G4 or BBB chain into the 10mm gypsy. It will look like it fits, until you try to pull up the anchor under windy condition. The 3/8 chain will constantly jump out of the 10mm gipsy.

Trust me, personal costly experience… In my case it was cheaper to replace the gypsy than the 200' of 3/8 G4 chain...

[mako]

G70 is not very common. You want a stronger chain but not necessarily a heavier one. Certainly better off putting an extra 50lbs into the anchor rather than the chain.

[Panacea2183]

Originally Posted by Lowcountry

Good day, all. I just bought a sailboat in Spain, and I'm importing her to the US. She has an older (but functioning) Vetus Alexander I windlass. The windlass is using 8mm chain, which I feel is too small for a 22,000lb boat. As such, I'd like to increase the chain size to 10mm. I have been able to locate a 10mm chain gypsy for the Alexander I, but I'm uncertain as to what chain to order. Looking at Defender Marine, it seems the closest size would be 3/8", but I don't want to buy a $300 gypsy and then $1,000 worth of 3/8" chain to find that they won't fit together. Anyone else have experience with this that could offer suggestions? Thanks!

3/8 will not work in a Vetus 10mm (ask me how I know)
Better off replacing windlass
Vetus parts no longer avaliable.
You will not find DIN chain here in the US. Importing is cost prohibitive due to weight and shipping.
Go with G4 3/8 and a new windlass.
Had a Vetus went through same drill after getting 2 separate shipments of chain
(Assured it would fit) did not skipped every 1-2 feet.
If you’re going to invest in new chain might as well get a package you can get parts for. Long range it will be cheaper.
Good luck
Cheers

[Chuck Hawley]

There's a wealth of information about chain:gypsy compatibilities on the Maxwell windlass site. I know you don't have a Maxwell windlass, but I think the descriptions of the chain may be helpful in determining compatibility.

This is the page, but you'll need to download the spreadsheet at the bottom.

Chuck Hawley

[sailcrazy]

We replaced our chain in Turkey....trust me, you absolutely want to buy a short length and try it in your gypsy before you buy the lot of it! Then about 5 years later in our case, our 28 year-old windlass died, and we needed to replace it. We had a choice of several gypsies,we looked up and studied and measured many, many times, and finally took a guess at the closest one ......link length is by far the most important dimension. It all worked out, and we guessed correctly. But new chain is not cheap! If you do buy new chain, record the brand, principle dimensions, and any data/manufacturer of it, so next time you'll know what you have.

[Tayana42]

I found parts (gypsy) for my Vetus Tiger windlass which is similar to a Lofrans Tigres at Imtra.

Contact Jim Thomas, Product Manager
Imtra Corp.
508-995-7000
www.imtra.com

[Sailorbob8599]

Originally Posted by chouliha

If possible Why not buy 1’ of chain to try in the gypsy first? We have been running 3/8” BBB chain for 32 years in our windlass and recently changed to 10mm Maggi chain with no issues. Din766/A

Better still, do what I did; If you're able to visit the marine store to make your purchase, remove the gipsy & take it with you to find a chain that fits perfectly.

[Dan_K]

I found buying a 3 foot length of chain better because I could place a load on it. The one foot lengths seemed to fit but after buying 60' of 3/8 BBB, and as Emouchet correctly stated, the chain kept jumping out of the gypsy. Tried sample of 10mm 28mm pitch and that was too short (10mm comes in two pitches). Finally found the 10mm 30mm pitch that the gypsy needed (gypsy was only marked with "10", no pitch info). All works great now.