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Old 04-03-2007, 21:55   #1
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Chain rode size

Has been discussed here before but I'm after advice specific to my boat. She is 30', fin keel and weighs about 4 1/2 ton. I'm planning on going to all chain rode and my day to day anchor is 35 lb CQR but will be buying a larger storm anchor. Rode will be 100 metres.
Will the advantage of going to 3/8 chain rather than 5/16 be offset by the extra weight up forard? Given that statistically most of the time will be on the hook but she sails beautifully with her weight further aft what would you do?
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Old 04-03-2007, 23:49   #2
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Tuning an Anchor Rode

There is an interesting website at "Tuning an Anchor Rode" that works through many of the variables.
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Old 05-03-2007, 01:59   #3
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Very good site thanks but still doesn't answer my question about the compromise between superior holding over extra weight in the bow. Anyone have any personal experience?
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Old 05-03-2007, 02:04   #4
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A storm anchor assembly, for a 30 footer, should be rigged for about a 1,400 Lb Working Load Limit.
Either 1/4" High Test (2,600# WLL) or 5/16" Proof Coil (1,900# WLL) will exceed the requirements of any likely loads. At 1,300# WLL, even 1/4" P.C. might be acceptable.
Considering the reduced ratings of most shackles, I’d recommend 5/16" chain.
I see no practical advantage to 3/8" chain (and a huge weight penalty), in your case.
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Old 05-03-2007, 16:23   #5
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Arrow

Quote:
Originally Posted by pwederell
Has been discussed here before but I'm after advice specific to my boat. She is 30', fin keel and weighs about 4 1/2 ton. I'm planning on going to all chain rode and my day to day anchor is 35 lb CQR but will be buying a larger storm anchor. Rode will be 100 metres.
Will the advantage of going to 3/8 chain rather than 5/16 be offset by the extra weight up forard? Given that statistically most of the time will be on the hook but she sails beautifully with her weight further aft what would you do?
In essence, it won't make much difference. If you did want to change, it would make a lot of sense to keep the total weight the same by reducing the length of chain. 100m is rather a lot.

In half-decent holding with a decent anchor in bad weather you'll pull the chain tight regardless of how heavy it is.

If you're looking at tweaking your anchor set-up, presumably for a reason, you should be looking at your anchor. Get something decent. That is not another CQR (or copy). Given your location, you have no excuse!

(No reason for anything bigger incidentally, 15Kg is more than enough even for a storm anchor).
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Old 05-03-2007, 16:28   #6
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Thanks Craig, I'm replacing a rope/chain rode with all chain for offshore cruising so will no doubt be in some hairy anchorages from time to time. Yep, I'm saving the pennies for a Rocnar
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Old 10-03-2007, 00:33   #7
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Oh good golly. We do have to have a sit down and chat don't we. Your boat or mine, they are only 50mts odd apart.

10mm or 3/8" on your boat would be pure Grade A lunicy. I'm sorry to put it so bluntly but it would be.

Gord is pretty much on the money with this one, even if using that real old funny measurement system

7mm G3 or if you want the extra meat go 8mm G3. Put 10mm on and I'll put in an application for removal of your Yachting licence, only fizz boat from then on for you

I do know the boat and would have to respectly say, think what your boat will do when surfing down a wave 100 mls north of the Kermadecs (anywhere really) with 100kg in the bow. Ok 99% of the time but keep an seamanship eye on it. Make that 140kg. Be fine as long as watched a fair bit closer when required. Now make that 230kg, the same as 2 1/2 normal size blokes standing there. The surfing now becomes a pure case of trying to stop the impending broach. The weight of 100mts of 7, 8 and 10mm respectivly.

Personally I would (and have done) move the chain aft for any big crossing like that. In a good brezze your boat could get exicting. Chuck in a few good waves and 230kg on the bow...... knowing your boat I'd be making sure I have a clean pair of undies very handy and wetsuit on.

As for being anchored - what would happen to anchor cleat on your fordeck if you hung 2500kg off it and the asociated bits. Now 3200kg. Now 5000kg. 7, 8 and 10mm respectivly and good stuff obviously. Does your anchor hold anything like those numbers, stuck in rocks excepted?

The numbers to ponder on.
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Old 12-03-2007, 01:13   #8
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That's why I love this forum (notwithstanding that I didn't even know I got another reply due to some 'puter glitch). I've always been pretty "industrial" in my approach to sailing due to my commercial fishing & engineering background, big is good.
Craig- was going to have a chat at the boat show but the admiral was chaperoning me in case I spent some money (she was the one that did in the end)
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Old 12-03-2007, 01:23   #9
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If you wanna talk load figures, this has been posted before, but:



'Salright Pete, I wasn't at the show much myself anyway. I'm always at the end of an e-mail.
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Old 12-03-2007, 02:13   #10
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Missed some good sailing weather going to that show. Probably the best we have had all year.
Nice display you had there.
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Old 12-03-2007, 02:21   #11
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On a yacht, any yacht, weight of any sort in the ends is bad full stop, except for one time I can quickly think of. There maybe a couple more, feel free to point them out. Any weight in the bow is bad 100% of the time especially in bad weather.

Ah.. do I hear you say "what about when anchored?". When you are anchored you are just a parked boat of no specific type at that moment in time. You could easily be just a bathtub or the QMII. Motoring it's no so bad but still something to bear in mind. {which bear / bare / or whatever is it? I can never figure it out}

Always a bugger of a question to answer especially as you're at anchored a lot longer than in the open sea but it can be a massive pile more unforgiving and kill you in so many more creative ways.

Do you keep your anchoring system lite weight so you don't kill yourself while at sea or beef it up so you don't kill yourself while at anchor?

Oh... the only time weight is good is when you have the entire crew behind the skipper, hanging off the transom, maybe with the kite up on massive power reach with surfable waves. On the 18 all 3 crew got 23ft out and 6ft behind the rudder on occasions. Usually just hanging on for dear life but the rush was houmungous. I dream for more of those rides.
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