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Old 08-01-2012, 18:23   #91
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Originally Posted by Ex-Calif

Please dont mistake inquiry for lack of understanding. Yes I should have stated 10-100x with your measure of hold as the initial x.

Lets say the first system in your example had 400lbs of hold. 10-100x means 4000-40,000lbs of hold.

I might buy 10x but nowhere near 40,000lbs. The chain is only like 5k working load so 100x improvement in holding is impossible.
What has the breaking strength of the chain to do with the holding power of the anchor buried in the seabed? May be you need to explain exactly what you don't understand first because you keep popping up new angles without further adressing my explanations on the previous questions you asked...

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Old 08-01-2012, 19:36   #92
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Quote:
Originally Posted by s/v Jedi

What has the breaking strength of the chain to do with the holding power of the anchor buried in the seabed? May be you need to explain exactly what you don't understand first because you keep popping up new angles without further adressing my explanations on the previous questions you asked...

cheers,
Nick.
I dont think this is difficult at all.

There is a rule of thumb used by you and other experienced cruisers that says swapping chain for anchor weight results in 10-100x increase in holding power.

I dont think that is possible and you seem to change the subject to Dan doesnt understand.

I fully understand your explanation but a 100x improvement in holding is not possible and it is misleading.

There is no new angle. The 10-100x rule of thumb as explained is not valid.

It would be a strange explanation to say the anchor holds 100x better but the chain parted? Of course the chain strength matters.
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Old 08-01-2012, 20:10   #93
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Re: Chain versus rope scope?

Anchoring in coral.

Chain and then rode or all chain?

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Old 08-01-2012, 20:11   #94
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Re: Chain versus rope scope?

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Originally Posted by s/v Jedi View Post
7:1 wt-frak, that is way too much. I might do that in a hurricane. Anchor gear must work 100% at 5:1 scope. If you drag with that, you need a bigger or better anchor, or both.

What is your reason for the nylon?

cheers,
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I lived aboard for 15 years, East Coast, Bahamas, etc, and only had anchor drag once. This was at Fishing Bay, VA. Locals told me in advance it would happen and it did.
Nylon is stretchy. It's the jerking that is uncomfortable when in steep wave patterns. I have a Bruce and CQR with a backup Danforth. All three manufactures recommend a combination rode with 7:1. Just following what I have read. The only problem I have is with the size of line, 3/8" looks too small, so I use 1/2". Go figger...
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Old 08-01-2012, 20:19   #95
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Quote:
Originally Posted by Ex-Calif

I dont think this is difficult at all.

There is a rule of thumb used by you and other experienced cruisers that says swapping chain for anchor weight results in 10-100x increase in holding power.

I dont think that is possible and you seem to change the subject to Dan doesnt understand.

I fully understand your explanation but a 100x improvement in holding is not possible and it is misleading.

There is no new angle. The 10-100x rule of thumb as explained is not valid.

It would be a strange explanation to say the anchor holds 100x better but the chain parted? Of course the chain strength matters.
No Ex, it is your view that is not valid. Because if I would explain this chain strength somehow, you would come back with the windlass that can't pull it or the cleats being ripped from the deck.

When I talk about the anchor holding power, that is what I talk about and not about chain strength.

So let me just try it once more because we can't have Dan not understanding me

Take a string made from ultistrength fiber. It has a WLL of 69 million pounds.

Now, tie a bundle of chain weighing 30 pounds to it and toss it overboard. Measure the holding power. My guestimate is about 10 pounds. Now replace the bundle of chain with a New Zealand made 30 pound Rocna and toss overboard again. Cleat it off and test holding again. The cleat is made from Zyrkonium-reinforced Tiranium with a WLL matching the ultistrength rode. Now, my statement says that the holding can be 100-1,000 pounds, while you state that this is impossible? Because of the chain WLL? Come on lol

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Old 08-01-2012, 20:21   #96
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Quote:
Originally Posted by NorthPacific
Anchoring in coral.

Chain and then rode or all chain?

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Do not anchor in coral, you will not makemuch friends that way and almost anywhere illegal. Use all chain.

ciao!
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Old 08-01-2012, 20:26   #97
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Quote:
Originally Posted by jewel114
I lived aboard for 15 years, East Coast, Bahamas, etc, and only had anchor drag once. This was at Fishing Bay, VA. Locals told me in advance it would happen and it did.
Nylon is stretchy. It's the jerking that is uncomfortable when in steep wave patterns. I have a Bruce and CQR with a backup Danforth. All three manufactures recommend a combination rode with 7:1. Just following what I have read. The only problem I have is with the size of line, 3/8" looks too small, so I use 1/2". Go figger...
The 7:1 is for storm conditions, ie. maximum scope. None of the manufacturers knows anything about anchoring so discard their combination rode stories. All chain with a snubber rules among cruisers today and or good reason: the number of boats getting damaged or even lost due to the rode breaking is reduced dramatically with all-chain rodes.

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Old 08-01-2012, 20:37   #98
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Re: Chain versus rope scope?

Quote:
every pound of weight in the anchor provides 10-100x as much holding as a pound of weight in or on the rode.
This actually makes sense for high winds (when it counts), when the catenary disappears, and there's little-to-no friction between the chain and the bottom. In those conditions the anchor is holding the boat. Adding 50# to the chain is unlikely to add much holding power. Meanwhile, if I trade in my 55 lb anchor for a 105 lb model, I wouldn't be surprised to see an additional 500-5000 lb of holding power. More like 5000 lbs with a good bottom.

I realize I'm taking this rule-of-thumb to the theoretical limit (chain holding power = zero), and that's not exactly fair. Surely, extra weight in the chain must do something. But so far this thread suggests the answer is "not very much."
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Old 08-01-2012, 20:38   #99
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Quote:
Originally Posted by s/v Jedi

No Ex, it is your view that is not valid. Because if I would explain this chain strength somehow, you would come back with the windlass that can't pull it or the cleats being ripped from the deck.

When I talk about the anchor holding power, that is what I talk about and not about chain strength.

So let me just try it once more because we can't have Dan not understanding me

Take a string made from ultistrength fiber. It has a WLL of 69 million pounds.

Now, tie a bundle of chain weighing 30 pounds to it and toss it overboard. Measure the holding power. My guestimate is about 10 pounds. Now replace the bundle of chain with a New Zealand made 30 pound Rocna and toss overboard again. Cleat it off and test holding again. The cleat is made from Zyrkonium-reinforced Tiranium with a WLL matching the ultistrength rode. Now, my statement says that the holding can be 100-1,000 pounds, while you state that this is impossible? Because of the chain WLL? Come on lol

ciao!
Nick.
Quote:
This thread proves how hard it is to do away with all the silly talk about the importance of chain weight. It was 20 years or so ago that Dashew stated something like every pound of weight in the anchor provides 10-100x as much holding as a pound of weight in or on the rode.
I am trying to stay on point and your responses become increasingly dismissive. That's OK. When one tosses out the second quote one could be led to believe that 100x increase in holding is possible when clearly it is not.

Like I said, I dont disagree but you raise the correct point that it may not be appropriate in all cases to blindly add weight to an anchor. It is a system and everything in the system needs to be evaluated. Just adding anchor weight may not solve an anchoring problem.

If your only point is that a bigger anchor is better when nothing else is considered then I guess that is hard to argue with.
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Old 08-01-2012, 20:56   #100
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Re: Chain versus rope scope?

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Originally Posted by jeremiason View Post
We have been fulltime cruisers for about 16 months. During that time we have been on the hook about 60% of the time and so far haven't dragged (Thank you sea gods).

We use all chain rode with a Rocna 55lbs anchor and a 5/8" 12 foot long nylon snubber on our Catalina 47. We routinely anchor at 5 to 1 scope and let out chain in the event of rough seas or heavy winds.

Over the summer, we were in the Sea of Cortez and expereinced two extreme winds events while at anchor. The first was a "Chubasco", which hit us with 55 knot winds for about 20 minutes and then continued for another 2.5 hours at 40 knots. We also expereicened an Elephante, which blew at 40 knots for 13 hours. We have also been on the hook during a number of 25 knot plus blows for extended periods.

During one 25 knot blow along Baja California, I dove the anchor to make sure it was holding ok... What I found was pretty shocking. At the time I was anchored in 30 feet of water with 175 feet of chain out.

I swam from the bow and followed the rode, after about 75 feet, the chain took a 90 degree turn in the sand and ran to the anchor. In other words, my 37,000 lbs. boat was riding along in 25 knots of wind, using the weight of the chain only. So regardless of what the experts say, at least in this instance the weight of the chain did help.

Look the fact is, chain lasts longer, won't caffe, provides more weight for cantanary and with a proper windless is easier to handle...

In my humble opinion, if your boat can handle the weight... Chain is the way to go.
Look at Karen and Jims Excellent Adventure photos taken around Christmas day south Lapaz. Maybe boat size? A Dana is about 9k lbs.
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Old 08-01-2012, 21:20   #101
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Quote:
Originally Posted by Ex-Calif

I am trying to stay on point and your responses become increasingly dismissive. That's OK. When one tosses out the second quote one could be led to believe that 100x increase in holding is possible when clearly it is not.

Like I said, I dont disagree but you raise the correct point that it may not be appropriate in all cases to blindly add weight to an anchor. It is a system and everything in the system needs to be evaluated. Just adding anchor weight may not solve an anchoring problem.

If your only point is that a bigger anchor is better when nothing else is considered then I guess that is hard to argue with.
See how you completely ignore everything I wrote in my post and start with another angle where I would doubt ppropriateness to blindly add weight to anchors. Which has nothing to do with anything I just wrote. And I never said anything like that.

Why don't you reply to my post and explain where I go wronh with my math that shows holding improved 100x ?

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Old 08-01-2012, 21:24   #102
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Re: Chain versus rope scope?

I know Im an Old Commercial fisherman from the PNW, but I still like chain and cable, lol, if I can't have that type of winch (drumstyle) give me all chain, not for the weight so much but for the ease of retriveing chain with 90% of the Yacht style windleses(SPL?) are equiped with pretty good chain dogs. on my last vessel I had on the west coast had 300ft of BIG chain and 500ft of 1in cable and a 150lb Danforth lunch hook. and a 300 lb Danforth windy hook. never drug ever. of course we had a lot of mud bottoms out west and big winds.Out here in the gulf I use a delta with a danforth second hook worked so far both with 100ft of chain and 300 ft if 1 in nylon. Bob and Connie Ps last vessel 80ft steel
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Old 08-01-2012, 21:30   #103
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Re: Chain versus rope scope?

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Do not anchor in coral, you will not makemuch friends that way and almost anywhere illegal. Use all chain.

ciao!
Nick.
Sorry you guys seem to be in the middle of WW 3 here Just reading up on those in the SP now, and they often find themselves with anchors wrapped around coral heads. Wondering if chain less likely to chafe. Seems logical.

Apparently many of the island lagoons are studied with coral heads, Boats swing or drag when the wind gets up on the predominately sand bottom.
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Old 08-01-2012, 21:44   #104
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Quote:
Originally Posted by NorthPacific

Sorry you guys seem to be in the middle of WW 3 here Just reading up on those in the SP now, and they often find themselves with anchors wrapped around coral heads. Wondering if chain less likely to chafe. Seems logical.

Apparently many of the island lagoons are studied with coral heads, Boats swing or drag when the wind gets up on the predominately sand bottom.
Here is an area Nick and I can totally agree on. Coral is extremely fragile. There are many many many dive sites all over Asia destroyed by anchoring and diving.

Please take care around coral reefs! Choose the sandy bits and definitely dont tie off on coral heads.
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Old 08-01-2012, 21:53   #105
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Originally Posted by s/v Jedi

See how you completely ignore everything I wrote in my post and start with another angle where I would doubt ppropriateness to blindly add weight to anchors. Which has nothing to do with anything I just wrote. And I never said anything like that.

Why don't you reply to my post and explain where I go wronh with my math that shows holding improved 100x ?

ciao!
Nick.
Uhhhh. 1000/10=100 - your math is correct.

But if you are going to boil your rule of thumb to comparing 30 poinds of chain to a 30 pound anchor? What is the point of that. Your post about changing the chain and increasing the anchor weight made lots of sense. I doubted that the holding power of that modification increases holding power by 100x.

Apparently that makes you mad.
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