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Old 30-06-2013, 18:35   #16
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Re: Anchors and chain

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Originally Posted by davecalvert View Post
On a slightly different subject, has anyone had experience using chain links to attach extra lengths of chain together?
I've used one too and have doubled up by lashing small dyneema along the link as others here have suggested. Its not in the water often and I watch it closely but no issues.
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Old 30-06-2013, 18:35   #17
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Re: Anchors and chain

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Originally Posted by Chrisc View Post
3 strand nylon is generally a pain in the bum to handle but I find 8plait almost as easy to stow as chain, so I guess I'll stick with what I have?
You go ahead and anchor on whatever rode makes you happy.

(Don't even think about the fact that most active cruisers are anchoring on all-chain rodes.)

Really.

(After all, Mr. Smith is on your side.)
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Old 30-06-2013, 18:44   #18
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Re: Anchors and chain

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Originally Posted by sabray View Post
Way to mess with my anchor lifestyle smugness.,

I'm all chain big chain heavy chain because well forget math it works. It really does.
Here is why. If I can throw a small one pound stone 30 yards a heavy 6 lb stone 10 yards then the 6 lb stone is more effected by gravity. Forget Cantinery think gravity. This weight effects set at the time I set. Plus it's really heavy and it sinks harder. I know this because its harder to lift. Never mind that. It relays on a snubber that has 2100 lbs breaking strength minus the knot loss makes it around 1300 lbs. I'm worried that my shackle that will fail at 4000 lbs isn't strong enough. Bahhhh with your math.


Yeah, sure! 1/4" HT chain is capable of ripping the bow structures off most boats. And it weighs a lot less than the 5/16" HT that I now carry only because Maxwell did not sell a 1/4" chain gypsy for my windlass
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Old 30-06-2013, 18:59   #19
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Re: Anchors and chain

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Thank you - excellent, reasoned replies.
My interest stems from the fact that I mainly anchor in a depth of 3 - 8m, mainly on sand or mud,(not much coral in NZ) and having now only a 30' yacht with not a great deal of reserve buoyancy, am keen to save weight where I can, especially forward. Currently I have 20m of 8mm chain and then a vast amount of 8 plait nylon, and a similar setup on my secondary anchor.
3 strand nylon is generally a pain in the bum to handle but I find 8plait almost as easy to stow as chain, so I guess I'll stick with what I have?
If those are your depths, then your current gear is probably just fine. The H28 is fine in the bow so carrying weight forward isn't going to help sailing characteristics. With 20m of chain and a 3rd gen anchor like an Excel in 8m of water, you can lay out all the chain and 10m of line and you are good to go in typical conditions.
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Old 30-06-2013, 19:00   #20
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Re: Anchors and chain

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Originally Posted by foggysail View Post
Yeah, sure! 1/4" HT chain is capable of ripping the bow structures off most boats. And it weighs a lot less than the 5/16" HT that I now carry only because Maxwell did not sell a 1/4" chain gypsy for my windlass
I'm probably wrong but once you get to 8mm or 5/16th inch you cannot go any smaller as no-one, Muir, Lewmar makes a gypsy.

Reports of chain breaking, apart from someone buying a chain that is cheap and nasty, are notable by their absence. The complaint about chain is that its heavy (current thread) or loses its galvanising. If you went thinner, from say 12mm to 10mm or 10mm to 8mm would one expect the galvanising to be subject to more wear (and thus have a shorter life?)

Jonathan
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Old 30-06-2013, 19:42   #21
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Re: Anchors and chain

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Originally Posted by JonJo View Post
I'm probably wrong but once you get to 8mm or 5/16th inch you cannot go any smaller as no-one, Muir, Lewmar makes a gypsy.

Reports of chain breaking, apart from someone buying a chain that is cheap and nasty, are notable by their absence. The complaint about chain is that its heavy (current thread) or loses its galvanising. If you went thinner, from say 12mm to 10mm or 10mm to 8mm would one expect the galvanising to be subject to more wear (and thus have a shorter life?)

Jonathan

As you point out, if a gypsy is not made, one is not going to use it. That is why my chain is 5/16"HT.

Now regarding wear and shorter life, that may be but not many use their chain or for that matter often enough to have worry. And yes, there are some that anchor every day of the year but from my experience, they are the unusual ones.

But no need to philosophize over the merits and potential problems, if you want 1/4" chain, you're going to pull that anchor by hand. I expect my 5/16" chain to last for the rest of my boating years and then somebody else can worry about it.
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Old 30-06-2013, 19:44   #22
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Re: Anchors and chain

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Originally Posted by Sam Plan B View Post
Does anyone know of a US source for 10mm DIN chain. I have a Goiot windlass and don't want to change the wildcat.
Vetus.
They used to be in Baltimore.
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Old 30-06-2013, 20:52   #23
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Re: Anchors and chain

The link posted by the OP is really nothing new. Over a half century ago Eric Hiscock wrote the almost same information(minus the computer generated figures) and gave all the same reasons for all chain with a snubber. Cantenary has limited benefits, but you will almost never hear of someone sawing through their chain on a coral head, or chafe from a lousy chock. I only drug (well almost) my Contessa 26 once in Turtle Bay Mexico with 10 to 1 scope out, all chain. It was shallow and the waves were coming over the bow. Every big wave set me back a foot or so, and sounded like it was going to rip the windlass out of the deck. I remembered reading about snubbers, and tied one on, and stopped the dragging and the horrible noise. My next 2 boats I had chain and nylon, and never slept as well as when on all chain._____Grant
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Old 30-06-2013, 22:05   #24
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Re: Anchors and chain

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Originally Posted by Bash View Post
You go ahead and anchor on whatever rode makes you happy.

(Don't even think about the fact that most active cruisers are anchoring on all-chain rodes.)

Really.

(After all, Mr. Smith is on your side.)
You need to refer to my original post.
I am not on Mr. Smith's side, nor he on mine. As I stated I asked for opinions on his article, mainly because I had considered his propositions well before he ever put pen to paper.
To clarify, I have a mixed rode on my boat because that's what she came with - my last vessel was all chain.
To repeat, I will experiment and in all probability go to an all chain rode. If I do, it will be because I've satisfied myself that its the best for my circumstance and not because 'its what everybody does.'
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Old 30-06-2013, 23:39   #25
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Re: Anchors and chain

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Originally Posted by gjordan View Post
The link posted by the OP is really nothing new. Over a half century ago Eric Hiscock wrote the almost same information(minus the computer generated figures) and gave all the same reasons for all chain with a snubber. Cantenary has limited benefits, but you will almost never hear of someone sawing through their chain on a coral head, or chafe from a lousy chock. I only drug (well almost) my Contessa 26 once in Turtle Bay Mexico with 10 to 1 scope out, all chain. It was shallow and the waves were coming over the bow. Every big wave set me back a foot or so, and sounded like it was going to rip the windlass out of the deck. I remembered reading about snubbers, and tied one on, and stopped the dragging and the horrible noise. My next 2 boats I had chain and nylon, and never slept as well as when on all chain._____Grant
What time of the year was that? The place was flat as a mill pond when I was there.
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Old 01-07-2013, 00:53   #26
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Re: Anchors and chain

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Originally Posted by Chrisc View Post
However, what I was hoping for was a critique of the math and science behind his rationale, not gut feeling. .
The article is well written, the maths is sound, and the theoretical conclusions match the practical observations.
The idea of reducing the weight in the rode is not new, or unique to this article. The same ideas have been pushed by Steve Dashew and others. (Who have no commercial interest in anchor sales)

My only criticism is that there insufficient emphasis placed on poor chafe resistance of rope and the difficulties of boats with mixed rodes sharing anchorages with those using all chain.

Unfortunately many anchorages worldwide have hazards that will abrade rope. This eliminates, or at least greatly restricts its use and is why most cruising boats go with all chain rode. For the cruising sailor that restricts their anchoring to areas where there is a clear snag free bottom, rope remains an option, but there is always some lingering doubt that some isolated debris, or trash on the bottom will cut through the rode.

The principals of the article are still very relevant to someone using all chain rode. Considerable weight savings can be made by reducing the size of the chain and using G7 hi tensile chain. Roughly the strength of this is equivalent to the next size up normal chain.
Many, including me, would argue that reducing the weight of the rode and putting this weight towards a larger anchor will give greater security. I think the article argues this case much more elegantly than I can.
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Old 01-07-2013, 03:37   #27
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Re: Anchors and chain

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Originally Posted by noelex 77 View Post
The article is well written, the maths is sound, and the theoretical conclusions match the practical observations.
Agree with the conclusion, catinary doesn't help much when you really need it. But I can't seem to recreate the very first graph.

After a quick glance at the page there didn't seem to be any formulas mentioned - anyone find anything on the links?

Anyway, using y=a.cosh(x/a) catenary equation I came up with this...

https://www.desmos.com/calculator/ftkwsrjsae

which (almost anyway) agrees with the sag if you put the figures in here..
Cable Sag Error (Catenary Curve Effect) Calculator

This is with steel weighing 87% in seawater and 12mm chain being 3.3Kg/M
Doesn't look like the graph on the site though...
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Old 01-07-2013, 03:41   #28
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Re: Anchors and chain

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Originally Posted by Delfin View Post

The basic issue is that a snub line stretches. If it stretches 5 feet in gusts, then the shock force placed on the anchor and gear is approximately 1/5 what it would be without the snub line.
Where did you get that figure from? Would be interesting to see how it was calculated.

Ta
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Old 01-07-2013, 06:28   #29
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Re: Anchors and chain

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Where did you get that figure from? Would be interesting to see how it was calculated.

Ta
It's from a Marine Safety white paper on dynamic loads on a rode. The formula is D (in tons)*100 *V2/d. It is shown as "a general formula", but in essence demonstrates that if the snatch load of a rode is dissipated over a distance, that distance is the critical factor in determining the peak load. If a snub line dissipates the force over 5 feet, the instantaneous peak force is 1/5th what it would be if the distance is 1 foot.

The formula isn't meaningful in imaginary circumstances of instantaneous stopping of the vessel where d = .000000000000000001 feet and f becomes a Hiroshima level energy release, but it is useful for real world calculations, and demonstrates why all chain rode without a snubber in high winds can generate monstrous forces on the gear. I think Alan Fraysee's calcs can be used to generate the same results....
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Old 01-07-2013, 06:35   #30
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Re: Anchors and chain

I think that your anchor is the most important, and chafe protection of snubbers or nylon rode second. You can have the best math to calculate your rode but if it does not get hold of the bottom what do you have? i would just use the recommendations of anchor company's on rode to match your anchor.

my 39ft boat came with a 45 pound cqr and some how survived with this anchor for 5 years before i owned it, i could not get it to get a hold on most bottoms (sand, weed, coral and rocks. mud yes) and i could rip it out in full reverse unless i got lucky and it hooked something solid. Then i would worry if the wind changed direction because the odds are it would not set again. in st martin i spent three days trying to anchor in the same spot, i double my anchors cqr and danforth in series still could not get it to hold in full reverse, it just dragged slowly at best,

on the 4th day i when to the store and read what manson (supreme) recommended, i started there then i picked up the next biggest sizes until i could not manage by hand, that was my size (2 sizes bigger than recommended) to try, i took it out and it grabbed first time the next three times. i got hit by two boats in the middle of the night after my new tackle when the wind picked up by different boats that dragged and guess what the both had "CQR" and guess what they both told me "i had out nearly huge scope, i cant belive it dragged" one had all chain and the other had nearly all 3 strand nylon. I had 5-1 all chain with snubber 60 pound manson supreme no drag.

so 4 full days of testing in a very hard to anchor bottom I found that a good design and heavy tackle was far superior from real world testing.

in 18 months of living on the anchor no drag at all (wind never exceeded 50knots that i know of) mostly chain and snubber. but i have let out all 60m of chain and the 80% of the depth of 3 strand nylon spliced on the the end of the chain in deep water and windy conditions.

in my reading of failed tackle after cyclones they almost all failed by chafe at the point of contact on the vessel. if your anchor is good enough to hold the bottom with good scope. you cannot do math on the bottom quality or the heat and chafe caused by large motion. But i would be interested if someone does have a formula?

My three days of testing was after months of trying to get a good hold with bad tackle, so i like share this story in hope to save other people the sleepless nights i had.
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