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Old 25-10-2013, 09:14   #301
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Re: It's True! The Mantus 65-lb. hooks first time, everytime.

Quote:
Originally Posted by Dockhead View Post
I think I understand his point -- I think he means that it would be rare for the force to be exactly 90 degrees, so the shackle will slide up in many cases and reduce the leverage, protecting the anchor shank.
0 to 90 degrees it has no force to slide. A shackle pulled at 90 degrees with a high force has a fair bit of friction so in practice it's not going to move till over 90 degrees.

Quote:
Originally Posted by Dockhead View Post

I guess it wouldn't help you if the force were being applied at 80 degree, for example, but in many cases it would help.
I don't agree the shackle will move in the case of 80-90 degrees, but even if we accept this as accurate:

Sin 80 = 0.98 it's not worth quibbling over a 2% reduction.

Quote:
Originally Posted by Dockhead View Post
I wonder if much data has been accumulated about people using the Manson Supreme with its similar "rock slot".
The Manson Supreme has two attachment points. A conventional one and a slot (unlike the Super Sarca which only has the slot). I know of no one who uses the slot in the Manson Supreme when anchoring overnight when there is a possibility of a change of pull.
I would be surprised if anyone would support the use of the Rock slot on the Manson supreme under the above conditions.

Quote:
Originally Posted by Dockhead View Post
It's not obvious to me that the shackle sliding around in the slot would trip out the anchor
When the anchor is being pulled from the forward end of the rock slot (where Rex wants the force measured) it will trip out. This in fact what it designed to do. The pull is no longer at the end of the shank.
The argument is that after it trips out and turns around, the shackle will slide down the slot and the anchor will reset. There are too many "ifs" for most cruising sailors.

There has been countless discussion of this on CF and I cannot remember a single voice of support suggesting the Manson Rock slot is suitable for overnight anchoring where there is the possibility of a change of pull.

The unsuitability of the rock slot for normal overnight anchoring is not a Craig Smith invention, but an (almost) universally held belief among cruising sailors.
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Old 25-10-2013, 09:19   #302
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Re: It's True! The Mantus 65-lb. hooks first time, everytime.

A few of the anchor experts, who I tried to reach, ignored my last post because I was civil. OK let me be more blunt.
You guys are rude.
I would not buy an anchor from most of you, or trust your opinion because you cannot get your point across without being aggressive and rude.
All your analysis and numbers don't mean squat unless I feel you had my interests at heart when you designed your anchor and then manufactured it. And getting a few articles in PS makes an expert?
Welcome to the real world.
Rude people don't sell anchors to me.
Now I realize I am just an obscure sailor in a little cubby hole in the Pacific. But I have friends, and they have friends etc. We vote in a quiet way, with our wallets. Rude people don't sell anchors to them either. You ignore us at your own peril.
So please fell free to continue you catty, demeaning comments to each other.
But know there's a huge silent audience out there. And they are not judging your smarty pants replies to each other.
They are judging you.
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Old 25-10-2013, 09:28   #303
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Re: It's True! The Mantus 65-lb. hooks first time, everytime.

Quote:
Originally Posted by Dockhead View Post
As to shank strength -- I rather agree with Mark that the case for strong shanks being of critical importance to safety is somewhat questionable.
To clarify my position, I think strong shanks are of critical importance. They must be strong enough to not bend during any type of side loading before the anchor appropriately rotates around to provide an in-line load again. Under all conditions.

Again, I do not expect my anchor shaft to ever bend under any anchoring conditions whatsoever where the fluke is not caught fast by rock, coral, sunken wreckage, etc. The anchor should be designed to either rotate into proper linear load orientation or bury deeply enough to use the substrate itself for increased shank strength.

I just don't know how strong it needs to be to satisfy that requirement.

I don't have a problem with shanks bending because the anchor is lodged fast in rocks. That is just bad luck or poor anchoring choice. These things happen, and I don't even think they need to be warrantied against. I don't see the reason for pissing matches around whether one can pull the bow to the water or under the water before a shaft bends when yanking an a stuck anchor.

Mark
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Old 25-10-2013, 10:24   #304
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Posted in wrong forum

Quote:
Originally Posted by colemj

To clarify my position, I think strong shanks are of critical importance. They must be strong enough to not bend during any type of side loading before the anchor appropriately rotates around to provide an in-line load again. Under all conditions.

Again, I do not expect my anchor shaft to ever bend under any anchoring conditions whatsoever where the fluke is not caught fast by rock, coral, sunken wreckage, etc. The anchor should be designed to either rotate into proper linear load orientation or bury deeply enough to use the substrate itself for increased shank strength.

I just don't know how strong it needs to be to satisfy that requirement.

I don't have a problem with shanks bending because the anchor is lodged fast in rocks. That is just bad luck or poor anchoring choice. These things happen, and I don't even think they need to be warrantied against. I don't see the reason for pissing matches around whether one can pull the bow to the water or under the water before a shaft bends when yanking an a stuck anchor.

Mark
Thanks for the clarification. This is actually what I believe, and I expressed myself badly.

How strong does a shank need to be to resist bending in "normal" conditions? No one knows, I suspect. Maybe every anchor made, even one made out of "cornflakes", meets this criterion. An anchor wedged firmly in rocks, and subject to a snatch load, will bend even if it is made out of kryptonite.

But as I said, in the absence of any decent data, I would err on the side of strength.
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