What size chain are people using for their cats

[Ostinato]

Frankly I am in the middle of a steep learning curve on chain. My boat is a 12m (40ft) cruising cat in Turkey and I need to replace my chain.

To date I have been unable to find galvanized HT metric chain there that will fit any of the Lofrans gypsies. I can get Din 766 chain in 8mm (5/16 BBB) but the rating for this chain is considerably less than what is recommended at sites like Forces.

So my question is what size chain are people really using for their cats? And relatedly has anyone had any failures in high winds?

[2Hulls]

Acco G4 in 3/8 inch size. The metric equivalent would be 10mm. When I bought my boat it had 10mm and I have since replaced the chain with 3/8. The same gypsy works well with each.

Dave

[Ostinato]

Thanks Dave - What size cat do you have?

[2Hulls]

Catana 471, which is 47 feet. The weight is the more important variable, but everyone lies about this, so best to be conservative.

Originally Posted by Ostinato

I can get Din 766 chain in 8mm (5/16 BBB) but the rating for this chain is considerably less than what is recommended at sites like Forces.

I think you're correct to be wary of the 5/16 BBB in 8mm. Grade 43, called G4 or HT in 5/16 or 8mm seems about right - it has about twice the working load of BBB.

Good luck,
Dave

[kas_1611]

If your windlass gypsy can take 10mm without modification then you could safely upgrade to that but if like mine you need to strip the windlass and replace the gypsy then you might want to stick to 8mm.

The BBB rating you have is basic, standard stuff and not the best stuff out there. It is perfectly strong enough for average conditions but if you are concerned about stronger winds plus the increased strain due to the windage of a cat then look for G40, G43HT or G70. Safe Working Loads and Minimum Breaking Loads for these below:

BBB 8mm SWL 750 kg MBL 3000 kg
G 40 8 mm SWL 1000 kg MBL 4000 kg
G 43 HT 8mm SWL 1300 kg MBL 4000 kg
G 70 8 mm SWL 1400 kg MBL 7000 kg

Or there are stainless options:
G 50 SS 8 mm SWL 1700 kg MBL 5100 kg
G 55 has a SWL of 2500kg (German manufactured)

and G60 Duplex 8 mm SWL 3200 kg MBL 6400 kg

lastly there is German made CROMOX NAUTIC chain with a SWL that (should) cover upto 100kts of wind for my 40ft monohull (I don't have the actual kgs).

The advantages of SS and Duplex (and Cromox) is the chain is less likely to pile up in the locker and get blocked up so you can keep all chain instead of having to go chain and rode.

Hope that all helps

Keiron

[Ostinato]

Kas - are using SS chain now? I have been reluctant consider this because of the crevice corrosion issue and the difficulty in keeping well inspected not to mention cost.

[kas_1611]

Originally Posted by Ostinato

Kas - are using SS chain now? I have been reluctant consider this because of the crevice corrosion issue and the difficulty in keeping well inspected not to mention cost.

No I too have BBB chain (well as far as I can tell) so have been looking into all options myself for an anchor and chain upgrade. As my windlass has an 8mm specific gypsy and I'm loath to have to change everything I have wanted to seak out all 8mm alternatives.

Currently my choice would probably be 50m of 8mm G70 galvanised with 50m of 16mm anchorplait rode spliced on to this but I have to admit I was considering the Stainless option as well as my anchor locker is a pig to access as it is not deck accessed.

Keiron

[hpeer]

Here is a link to the current stampings / compatibility for some Lofrans windlass'.

There are two types of 10mm chain. 28mm (DIN 766) and 30mm (P30). Although I have heard DIN applied to both types.

28mm takes the same gypsie as 3/8BBB.

30mm is the same as 3/8 G40.

Or so I think. But I find this thing damn confusing.

http://www.imtra.com/collateral/docu...heel_chart.pdf

[Ostinato]

It is extremely confusing. I actually own two Lofrans gypsies. One is rated DIN 766 but also *3/8* (276f). With a DIN rating it should take some type of European chain but so far I haven't been able to find out what yet.

One thing for sure if you are in North America then you need to ck out the cost of Lofrans gypsies from Canadian suppliers - about 1/2 the cost of US.

[hpeer]

Originally Posted by Ostinato

It is extremely confusing. I actually own two Lofrans gypsies. One is rated DIN 766 but also *3/8* (276f). With a DIN rating it should take some type of European chain but so far I haven't been able to find out what yet.

One thing for sure if you are in North America then you need to ck out the cost of Lofrans gypsies from Canadian suppliers - about 1/2 the cost of US.

If it's DIN 766 it should take 28mm chain. Go to first chain supply and you can order a sample of chain for $10, shipping included. Order some 3/8" BBB and some 3/8" B4. BBB = 28mm. G4 = 30mm.

Chain, Chain Supplies, Binder Chains, Lifting Slings and Hooks

What Canadian supplier did you have in mind, if I might ask?

I've been thinking of swapping gypsies, but it's damned expensive. I'd like to consider an alternative.

[seandepagnier]

I use 10mm chain on my 4 ton bristol 27

[tomfl]

Maybe a little OT but a previous post mentioned using all chain and no rode. I was always under the impression that using a rode in adverse conditions was a good idea due to the ability of rope to provide shock absorbing ability and the ability to be cut quickly if necessary. This would mean the breaking point of the rope would be a consideration.

Sent from my SM-G900V using Cruisers Sailing Forum mobile app

[kas_1611]

Originally Posted by tomfl

Maybe a little OT but a previous post mentioned using all chain and no rode. I was always under the impression that using a rode in adverse conditions was a good idea due to the ability of rope to provide shock absorbing ability and the ability to be cut quickly if necessary. This would mean the breaking point of the rope would be a consideration.

Sent from my SM-G900V using Cruisers Sailing Forum mobile app

That's what your snubber and bitter end are for :-)

[mark_morwood]

We have 3/8" G40 on a Catana 48. If I was doing it again, I'd probably go with 8mm G70. I could get more chain for the same weight.

As mentioned above, just because a chain is the same size, e.g. 8mm, it doesn't mean it has the same pitch (length of link). The pitch is critical to the windlass gypsy sizing. So changing from 8mm BBB to another 8mm chain may require a new gypsy.

For an informative and detailed article on chain for anchoring and one company's opinions see Chain (Rocna Knowledge Base)

Mark.

[Bulawayo]

Hi, ourcat is 45ft and in cruising mode is around 25,000 lb (per the travel lift). It was around 2000 lb more than I estimated. Remember your profile also affects loadings - a cat like a Lagoon or the newer R&C's snatch at anchor a lot more than the sleeker profiles.
We use 10mm chain.
Practical sailor published an article about the risks of using S/S chain as it can fail without warning. Galvanised chain usually distorts before failing.