Please help me identify my chain

[braybayoutdoors]

Hi,



I have been thinking of replacing the windlass that came with my boat with an electric since I plan to do a lot of single handing next year and thought it would be a good upgrade. The current windlass is a seized Simpson-Lawrence Seahorse with a S.72 gypsy which the manual tells me supports 4 chain sizes: S-L-0058002 1/4", S-L 0058003 5/16", American BBB 1/4", and Most European 8MM.



I was trying to find out what chain the boat came with to make sure I get a compatible windlass, and found that the chain links have a thickness of 9.8MM, which I think is closer to 3/8" than the supported 5/16"... I didn't notice any stamped information on the chain aside from the manufacturer country Japan and the numbers "38" which might mean 3/8 or 3B. Attached are some photos. I was wondering if anyone has any insight into what chain this is? Its my first keelboat so I haven't had to worry about windlasses and gypsies and chain sizing before... any thoughts are appreciated.


https://imgur.com/a/VHK1eZK




Thanks

[GordMay]

NACM* Welded Steel Chain Specifications
See Sections 6.0 DIMENSIONS (page 5), and 8.0 IDENTIFICATION (page 6):
➥ https://www.nacm.info/specifications...pecifications/

...
8.1.2 - 5/16" (8.4 mm) and larger Grade 30 chain shall be embossed at least with 3, 30 or 300.
8.1.3 - Grade 43 chain shall be embossed at least with 4, 43, or 430.
8.1.4 - Grade 70 chain shall be embossed at least with 7, 70 or 700.
...

* NACM is the North American Chain Manufacturers.
I don’t know what standard Japan uses.

[Orion Jim]

Originally Posted by braybayoutdoors

Hi,



I have been thinking of replacing the windlass that came with my boat with an electric since I plan to do a lot of single handing next year and thought it would be a good upgrade. The current windlass is a seized Simpson-Lawrence Seahorse with a S.72 gypsy which the manual tells me supports 4 chain sizes: S-L-0058002 1/4", S-L 0058003 5/16", American BBB 1/4", and Most European 8MM.



I was trying to find out what chain the boat came with to make sure I get a compatible windlass, and found that the chain links have a thickness of 9.8MM, which I think is closer to 3/8" than the supported 5/16"... I didn't notice any stamped information on the chain aside from the manufacturer country Japan and the numbers "38" which might mean 3/8 or 3B. Attached are some photos. I was wondering if anyone has any insight into what chain this is? Its my first keelboat so I haven't had to worry about windlasses and gypsies and chain sizing before... any thoughts are appreciated.


https://imgur.com/a/VHK1eZK




Thanks

If you have measured accurately that is 3/8” chain. This is how to measure chain https://peerlesschain.com/pleasure/a...test-iso-chain
3/8” chain would be overkill for your Douglas 31.

[MicHughV]

Yep, 3/8" chain seems a tad large (and heavy) for a 31' boat.

[Stu Jackson]

Calder's Cruisers Handbook has a good section with tables as to how to size chain for boats.


Copies and examples are included here:


Anchor System Sizing Tables (Reply #6) & Swivels http://c34.org/bbs/index.php/topic,4....html#msg30400

[braybayoutdoors]

Originally Posted by Orion Jim

If you have measured accurately that is 3/8” chain. This is how to measure chain https://peerlesschain.com/pleasure/a...test-iso-chain
3/8” chain would be overkill for your Douglas 31.

Interesting... thanks everyone for the info! I used good calipers for measuring so it must be 3/8 on an undersized gypsy. Is there any harm to keeping oversized chain? I wasn't planning on buying new chain but maybe I will, I am already getting a new primary anchor and windlass

[Kettlewell]

Interesting... thanks everyone for the info! I used good calipers for measuring so it must be 3/8 on an undersized gypsy.

Careful! If it is truly 3/8" chain it wouldn't fit at all in a 5/16" gypsy, at least in my experience. So, is it possible they put a 3/8" gypsy on? My gut feeling looking at your photos is that it looks like 3/8" chain. Typically most windlasses for a 31-foot boat would be sized for 1/4" or 5/16" chain. If you were starting from scratch and planning some long-distance sailing I would say go for 5/16" G40 (high test) chain, which would be overkill strength-wise but save a lot of weight compared to 3/8". Here's the Seahorse manual: http://slspares.co.uk/pdf/Website%20...orse%20513.pdf

[braybayoutdoors]

Originally Posted by Kettlewell

Careful! If it is truly 3/8" chain it wouldn't fit at all in a 5/16" gypsy, at least in my experience. So, is it possible they put a 3/8" gypsy on? My gut feeling looking at your photos is that it looks like 3/8" chain. Typically most windlasses for a 31-foot boat would be sized for 1/4" or 5/16" chain. If you were starting from scratch and planning some long-distance sailing I would say go for 5/16" G40 (high test) chain, which would be overkill strength-wise but save a lot of weight compared to 3/8". Here's the Seahorse manual: http://slspares.co.uk/pdf/Website%20...orse%20513.pdf

The windlass manual says they offered 3 sizes of gypsy, S.72, S.60, and S.50, only S.60 and S.50 support 3/8 but mine has S.72 written on the side, I agree it seems to fit the chain fine, strange! Though the other gypsies S.60 and S.50 both support both 3/8 and 5/16 according to the manual (http://slspares.co.uk/pdf/Website%20...orse%20513.pdf) so maybe it is a unique design.



I am planning some long distance cruising to the Bahamas from the Great Lakes next year and will be solo at times. I am kitting the boat out, replacing the CQR with something more modern and trying to find a reasonably priced electric windlass. I will definitely consider your chain suggestion if I chose to replace/repurpose the existing chain, thank you, overkill is preferred!

[desodave]

Originally Posted by Kettlewell

Careful! If it is truly 3/8" chain it wouldn't fit at all in a 5/16" gypsy, at least in my experience. So, is it possible they put a 3/8" gypsy on? My gut feeling looking at your photos is that it looks like 3/8" chain. Typically most windlasses for a 31-foot boat would be sized for 1/4" or 5/16" chain. If you were starting from scratch and planning some long-distance sailing I would say go for 5/16" G40 (high test) chain, which would be overkill strength-wise but save a lot of weight compared to 3/8". Here's the Seahorse manual: http://slspares.co.uk/pdf/Website%20...orse%20513.pdf

Not sure how much chain that you have but, if you're already thinking about replacing the windlass and anchor, why not replace the chain too ? The gypsy on any new windlass will only handle specific sizes of chain not any, old "oversized" chain. I have 5/16 G4 chain on a 42' boat that weighs

twice as much as yours, so imo the 3/8 is bigger and heavier than you need. Invest in a bigger anchor and smaller chain, especially if you're going to a new windlass. If you're sticking with a "seized" windlass, the 5/16 will be a lot easier to hand bomb in the meantime.

I took my gypsy into the chandlery when I bought new chain for my old boat (my old S/L windlass was working) to ensure that the new chain fit it. I suspected what size the gypsy was but wasn't going to buy 150ft of new chain on a maybe. I had an indeterminate, probably 3/8 chain on the old boat ... similar to your situation. It too took 5/16 which was nicely confirmed when I went to the chandlery.

[Secondshift]

What Desodave said.

And the link with numbers in your photo appears to me to be a “connecting link”

It looks like a couple crush rivets on it.

Here’s a link to one made by seafit as an example.

https://www.westmarine.com/seafit-connecting-link-3-8inch-chain-size-2750lb.-swl-135715.html

Best Luck with your plans.

[sleepy]

i am also leaving the great lakes detroit area contact me maybe we can talk

john

[thomm225]

That chain and shackle look similar to the old chain (and shackle) I had on my 27' boat.

The PO had a newer chain and shackle onboard so I finally replaced it, but used that old one for many years

[davefromoregon]

Contact your windlass vendor. They will help you answer the question. I ended up doing it last summer and it short circuited the whole question.

[hpeer]

You need to measure the chain accurately. Not simply diameter but length also.

AND well used chain can wear in the contact points between links. I have had chain wear to the point it would not work in the gypsy.

My suggestion is to completely measure 5 links of chain near the boat end, less wear. Then average the measurements. Then you should have a good idea of initial chain dimensions.

[JPA Cate]

Originally Posted by braybayoutdoors

Interesting... thanks everyone for the info! I used good calipers for measuring so it must be 3/8 on an undersized gypsy. Is there any harm to keeping oversized chain? I wasn't planning on buying new chain but maybe I will, I am already getting a new primary anchor and windlass

Since you want to keep your current chain, when you get your new windlass, you want a gypsy you know will work with your chain. Undo the old chain from the boat end, and drape the chain over the existing windlass. The chain links should lie sort of swallowed up in the gypsy, the links nestled in. If they do, then the old gypsy is the correct size for the chain. Therefore, the new gypsy needs to be that size. It is worth testing the new gypsy when it arrives, also, to be sure it will work. Then re-connect the bitter end.

You may have to work with the new windlass folks, and you may have to get a different gypsy for it. Someone above mentioned the length of links varies, and indeed they do. That's why we cut off a foot of chain to take to the windlass store and tried it in a number of 3/8 gypsies till we got a good fit. (Over time, one finds uses for little bits of chain. Quite helpful against chafe when tying up to high chafe surfaces. also makes a good weight for a short series drogue to keep the dinghy from surfing into the mother boat when towing downwind in steep seas. Yes, bad practice, but....)


Ann