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Old 15-07-2005, 22:51   #16
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Good advice...

Good advice, Wheels.

Sometimes when thinking through purchases such as this, you read so many things that you get away from the basics... which you so perfectly brought up.

It's really a matter of how the anchor, chain, seabed, etc... function than any given anchor. Assuming I already have a couple of CQRs, I will probably need something with some major area (flukes) to hold in place in muddy bottoms, right?

You mention the Bruce is really good at that. Does it indeed grab in the "muck" better than a Danforth/Fortress style? Looking at the pure geometry of the Danforth/Fortress, it seems as though they would present more surface area to the muck at a nice angle to really stick in there. The Bruce (to my eye) seems like it might slide in the muck as more and more pressure is applied. Any thoughts to that?


Also, thanks for the advice in sizing the chain. I don't know what the boat has for sizing right now with the CQR, but I'll check on that too.

So basically... what I'm getting is that I really need to have a good variety of anchors to work in many types of bottoms that I will encounter.

Thanks for the input, everyone. I'm weighing out all this carefully.
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Old 16-07-2005, 02:25   #17
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What is your intended use....

The other way of looking at anchors is that whatever you get it may well be wrong anyway.
Don't set your heart on a particular anchor solving your anchoring problems.
You probably got an anchor with your boat. Try using it for a while and see how it works, unless it is obviously wrong. If you like the type you can go bigger or smaller. Or you can try a different type. It all depends on the boat and the bottom type and the depth of water.
Buying an anchor that is too big can ruin your pleasure just as much as an anchor that is too small, not to mention the damage it could do to your back.
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Old 16-07-2005, 03:03   #18
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The most important factor is chain. right size and right length. Length is simply, at least 3 x the depth of water, 5 x in a real blow and no limit in length apart from, you have to store it and get it back onboard again. Chain is more important to the holding power than the anchor is, (providing it is a good name anchor to begin with).
The holding power of an Anchor, is not in it's size. Otherwise, you would need something huge, like a locomotive lying on the bottom. If youn think about it, an anchor, even the 110lb one, has no show of holding a boat on it's own. So weight and size is not the issues as such. It's about the anchor digging in, leaving the bottom as undisterbed as possible. If you want to get all scientific, an anchor is an impedance matching device. It "connects" your chain to the ocean floor. It's ability to hold is much like glue. Scientificly, glue works by the fact that it does not allow air to come between the two stuck surfaces. Now, much like a boat hull stuck to a sand bar, it's that same suction that stops the anchor lifting out. The anchor has dug down deep into the bottom sediment, The bottom remains intacked, and water cannot get in under the anchor to allow it to release. So a suction involving a large area of bottom sediment holds the anchor down, thus holding your chain. So yes a Bruce will hold and hold well, becasue of it's shape. It slices very cleanly and deeply down in the mud and it's shape means it holds a large area of bottom.
The spade anchor, plus a few others have a similar principle, but one that has married together several design aspects.
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Old 16-07-2005, 13:16   #19
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Our boat just rode out Hurricane Dennis on a Bruce designed, Simpson Lawrence Anchor, all chain rode (at a scope of about 6:1), and 10' of nylon 3-strand snubber. Bottom was soft sand. We watched six boats drag past us and they all had set multiple anchors that either fouled or chafed.

This is the anchor that came on the boat so I was prepared to replace it. In several thousand miles of cruising the Gulf of Mexico, however, we have not dragged (except when I was impatient in setting it).

I've read the anchor tests, too, and my gut feeling is that there are too many variables to isolate for the tests to be meaningful at anything other than very coarse intervals.
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Old 17-07-2005, 04:07   #20
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Absolutely Curtis, I have yet to see a good anchor test, especially in any magazine.
And I must say, even tests for a particular product made by that manufacturer, tend to have the odd's in favour.

For any boat to drag, when another can hold in the same conditions, the rules of anchoring have simply not been followed. Especially any that have had a lose of anchor due to chaffing.

Just a tip, for those that may not know, I use a bridle at the bow. A pair of good nylon rope with chain hooks at one end of each. They take hold of the chain at just about water level and each comes around the outside of the bow to a good solid Bollard on each side. The chain between those ropes and the winch takes no load at all. Two things occur. Any shock is taken in the stretch of the nylon bridle. The boat no longer swings wildly all around it's mooring in gusts and tends to stay straight on to the wind.
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Old 17-07-2005, 13:02   #21
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Nice...

Quote:
Alan Wheeler once whispered in the wind:

Just a tip, for those that may not know, I use a bridle at the bow. A pair of good nylon rope with chain hooks at one end of each. They take hold of the chain at just about water level and each comes around the outside of the bow to a good solid Bollard on each side. The chain between those ropes and the winch takes no load at all. Two things occur. Any shock is taken in the stretch of the nylon bridle. The boat no longer swings wildly all around it's mooring in gusts and tends to stay straight on to the wind.
Nice! I'll probably emulate that setup. It makes a lot of sense from a loading/geometry standpoint.
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Old 17-07-2005, 14:46   #22
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Nice instructions for making a nylon snubber at Bosun Supplies

I used their recipe and have been very happy. The only variation is that I run the snubber on top of the deck and through an unused roller on the bow, rather than outside of everything. I think this reduces the opportunity for chafe.
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Old 17-07-2005, 21:00   #23
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That picture is exactly it Curtis. I don't get any chafe, as the only part touches is where the rope goes through the upstand to the bollard, where a piece of hose is attached to take the wear.
That picture is great. I show's how the tensions keep the boat nose on.
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Old 18-07-2005, 00:18   #24
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There can be other problems with a big anchor.../

http://www.trawlerlife.com/video/drop_anchor.mpg
Ouch!!!!
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Old 18-07-2005, 10:50   #25
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I prefer much longer anchor bridle (snubber) lines than pictured (Bosun Supplies), and oft-noted in use.
I would recommend that the “standard” snubber be 50 - 75' long, and one size smaller than the appropriate rope rode. I deploy a length about equal (or slightly more than) the water depth, and coil the excess on deck. The longer & smaller diameter bridle line provides much more shock absorption (elasticity) than will a shorter & stouter rope.
In storm situations, I use a second snubber (deployed shorter), with a diameter equal to the storm rode.
As with all rope, effective anti-chaffing gear is essential.
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Old 18-07-2005, 20:51   #26
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I've noticed that the design pictured, with the two eyes in a vee, seems to have more elasticity than the direct single line variety. Seems like one leg of the vee absorbs shocks placed on the other leg. This may allow for a shorter snubber to have more give.

I also really like the load spread between two cleats.

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Old 18-07-2005, 21:00   #27
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Firstly, my snub length is probably 16ft. It's a good 8ft just to the water line at my bow.
Yes Curtis, the system absorbs shock well. Firstly, if one line is stretched taught, the other line comes in to play and add's to the strength. Then should both lines come real taught, the chain comes tight. My thinking, is the ropes should be able to stretch, but not break so as the chain becomes the final leg in the whole bridle. So the strain is taken over 3 points on the boat and not one or two.
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Old 19-07-2005, 01:42   #28
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My snubber is the "V" as described above but at no time does the third leg [the chain] ever become taunt.

I prefer to keep the load totally off the windless. The line I use for the snubber is New Englands Mega Braid which is a 12 strand line which has the stretch of 3 strand but the strength of double braid. I use 3/4 inch which has a breaking strength of over 13,000 lbs. It's interesting stuff.
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Old 19-07-2005, 05:40   #29
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At the risk of a public flogging for causing the thread to drift, what is the best way of attaching the snubber if the rode consists of some chain and some nylon rope rode. For that matter is there even any real advantage in this situation as far as the shock loading goes?

With apologies and thanks

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Old 19-07-2005, 06:57   #30
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No need to apologise, only dumb question is the one not asked.
No not easy to attach to rope. Although, you could bring the rope rode around to the bollard (if you have one on each side) and then attach another rope to it and pull it back to the other bridle, so as the short ropes join to the rode, is centre to the bow, so as you make a bridle. If that made sense. Unless somone has a better idea, I suggest a fishermans knot, so as the short rope doesn't slip along the rode.
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