Anchor Chain thickness 35ft Cat?

[Franziska]

Hi,

anyone can recommend what size galvanised chain I need minimum for my 35ft (=10.70m) Mira cruising cat?

She weights in at about 8000lbs (=4000kg) max.

Thanks,

Franziska

[kas_1611]

Franziska,

I replaced my old chain on my 40ft Bavaria (8000kg / 11,500kg displacement) mono recently with 60m of G70 8mm which has an MBL of 7000kg and a SWL of 1400kg, which when pared to a modern new generation anchor (we have a 33kg Rocna Vulcan) should be good for winds of 60kts.

Hope that helps

Keiron

[Franziska]

Hmm. Thanks, but a mono is different weight & windage wise.

All the literature I have on hand gives info on Monos only :-(

Maybe someone else can be multi specific?
What size do the production 35-40ft cats have?

Thanks.


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[Franziska]

The Tobago seems to have 10mm as standard.

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[thinwater]

1/4" G43 is pretty standard on PDQ 32 (8000 pounds) and Gemini (9000 pounds) cats. Use a nylon bridle at least 20' long and the forces are never that great. Heavy chain in the bow of a catamaran is silly.

A conservative person might chose 5/16" (8mm). 1/4" G70 would make more sense.

A lot of boats out there and no failures that I am aware of. This also meets the ABYC table for 40', which is roughly equivalent to a 32-34' catamaran of that weight.

I just posted some preliminary data (it will change as more points are averaged in) on anchor loads for an upcoming magazine article on my blog, below.

[Franziska]

Great answer. Thanks. Will see what I can get here. Lighter is better in my case, I have no windlass.... (for now).

I lean towards 25m of 8mm and a long dyneema rode with nylon bridle.
No coral around here.

[Cuttyhunk]

My 36' EndeavourCat has 5/16" G4 chain. About 10,000 lbs displacement.


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[belizesailor]

I run 5/16" G4 chain. 35' Cat. Build spec about 11K...shudder to think what she weighs in full cruising mode.

[colemj]

We have used 8mm G4 on a 40' 18,000lb catamaran for 12yrs full time anchoring.

Mark

[Franziska]

Great 5/16" =8mm it is then. Thanks to all!

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[Cavalier MK2]

Originally Posted by Franziska

Great answer. Thanks. Will see what I can get here. Lighter is better in my case, I have no windlass.... (for now).

I lean towards 25m of 8mm and a long dyneema rode with nylon bridle.
No coral around here.

HeyFranziska, glad to see you got another boat. A boat length of chain is plenty, Chris White thinks 25' is enough. Certainly nothing heavier than 5/16, for your boat I'd use 1/4. I'd skip the dyneema rode and use nylon 3 strand. It will be far better for shock loads than the nylon bridle only and can be quickly spliced if a section is ever chaffed.

[Franziska]

Hi Chris, not quite as sporty as Aquaris, but a bit more roomy and better as a liveaboard boat.
Thanks for the thoughts on the chain setup!

By the way what Diameter has the Nylon in this case?

Cheerio Franziska

[thinwater]

Originally Posted by Franziska

Great answer. Thanks. Will see what I can get here. Lighter is better in my case, I have no windlass.... (for now).

I lean towards 25m of 8mm and a long dyneema rode with nylon bridle.
No coral around here.

Dyneema is probably a HUGE mistake. I've been doing some testing for a magazine article, and the complete lack of either stretch or catenary put it in a category all by itself. Huge impact loads.

The second reason is that while hauling on rope is work and hauling on chain is bad, hauling on Dyneema is practically impossible (small and slippery).

Yes, the nylon bridle could compensate, but it won't help with reason #2.

How deep is the expected water? Backing the 8mm with 1/2-5/8" (12-14mm?) nylon is probably much better.

---

I just looked at the design. No bridge deck cabin? 1/4" G43 is going to be PLEANTY with that little windage. Put in a small vertical windlass and just go all chain (as much as you use on a regular basis--I have 100' of chain, and that covers me 98% of the time). A MUCH better set-up for that boat.

[Franziska]

Mine has a bridgedeck.

Ladyrover.jimdo.com

Was considering Dyneema for chafe resistance after chain.

Backed with Nylon for stretch.

Handling is an interesting point as well as cleating off, which Dyneema would not like.

All chain and windlass is currently no option (Budget).

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[belizesailor]

Gotta agree with the negatives on Dyneema...great stuff for rigging etc, but I don't think anchor rode is a good application.