Another Anchor Thread . . .

[Fuss]

Originally Posted by Pete7

With the quantity you are looking at, I would give them a ring and talk it through with them, they might even have G4, just not advertised . Very helpful over the phone to us, which resulted in me getting my credit card out on the spot. However ours was slightly easier to spec, 30m x 8mm G3.

Pete

Yes, I would agree with Pete7.
I also would like to know the limits for chain as I find this unclear.
If you could post the results of the phone call, that would be interesting.
Maybe even ask them if they have heard of any sailing boats breaking their chain.

[Troubadour52993]

Beth Leonard's Voyager's Handbook has some rule of thumbs for size; 1/8" diameter of rode for every 9 feet of length; BBB chain 1/2 the size of line. So for 50' boat that's about 3/4" line and 3/8" (10mm) chain. She recommends going 1 up from this for bluewater cruisers, so the 10mm G4 chain should be good. Of course, if you have the room, budget, and waterline for 12mm G4 then you may sleep better at night.

[Dockhead]

Originally Posted by Troubadour52993

Beth Leonard's Voyager's Handbook has some rule of thumbs for size; 1/8" diameter of rode for every 9 feet of length; BBB chain 1/2 the size of line. So for 50' boat that's about 3/4" line and 3/8" (10mm) chain. She recommends going 1 up from this for bluewater cruisers, so the 10mm G4 chain should be good. Of course, if you have the room, budget, and waterline for 12mm G4 then you may sleep better at night.

The boat came from her maker with 12mm chain, so I would be reluctant to go down a size. I think that other than strength, there is no benefit to high-strength chain, and I have read that it is more brittle and that it can't be re-galvanized as many times. If the G30 grade is strong enough I would be inclined to go with that, instead of the G40. I do not have the impression that anchor chain is often broken or that the chain is usually the weak link. I have always heard it's the shackles, or obviously the anchor not holding.

But "I heard somewhere" doesn't necessarily make it so -- maybe someone knows better?

[fishwife]

Originally Posted by Dockhead

Looking silly may be a small price to pay.

The first time and every time since that I've encountered a williwaw or storm when I've been anchored, I've blessed my oversized Manson. Where I buying again, I'd go for the Rocna but that's another story.

P.

[Dockhead]

These people: Questions about Anchoring|Offshore Sailboat Voyaging|Attainable Adventure Cruising

use a 55kg Spade on a boat which is almost identical to ours in terms of displacement, beam, length. They argue that over 100 pounds, the holding power of an anchor goes up disproportionately. I don't know why that would be so, but they seem to be knowledgeable.

Arguably they are anchoring in more extreme conditions (high latitudes) than we ever will, but yet another convincing argument that a 121 pound Rocna or Manson would NOT be overkill for our boat.

Fishwife: DO TELL why you would buy Rocna instead of Manson. I am ALL EARS because I am facing that exact choice. I have read an enormous amount on the subject and simply can't get at the truth, through all the emotion and propaganda on the subject.

I was kind of leaning towards the Manson just to be contrary, in view of all the propaganda and even deception by the Rocna-istas. Also I have some impression that the Mansons may be a little better made -- laminated flukes and all of that.

But if you've actually owned a Manson then your opinion will be INVALUABLE. Cheers.

Of course I could just forget both Rocna and Manson and go with Spade. The Spade on our Old Boat was simply brilliant; a quantum leap forward in anchoring for me.

[matrix]

I too would love to hear a 3rd party opinion on that same question...have a Rocna on order but the Manson still tempts me. They are about the same price for the 35# range model of each at West Marine, actually the Rocna is 10% off at the moment which is basically how the choice got made...the threads on the topic are so polemical it's hard to weave through the jungle of arguments...

Great thread by the way!

[fishwife]

I sent a private message to Dockhead about the Manson but basically, the slot on the top of the shaft can cause the anchor to trip and if, as happened with me, a piece of coral happens to jam the shackle in the tripped position, you're in for a few interesting minutes. Otherwise, there's not a lot between them and if you never use the slot on the Manson then you should not have any problems.

P.

[matrix]

Thanks! Makes sense!

[klem]

Regarding chain strength, you want it to be at least as strong as the reasonable holding power of your anchor (there are extreme cases of holding that no chain of reasonable size will take). Anchors like the Rocna and Manson have significant holding power which is great but also pointless if your chain won't be strong enough in a storm situation. If the weakest link in the system is the holding power of your anchor (as it should be), then it will be subject to the breakout force of the anchor. This does not mean that the holding power should be sacrificed, this means that everything else should be even stronger. Also, it means having good shock absorption in the form of a snubber.

The SWL and evening the breaking strength of 12mm G3 chain could be exceeded by the holding power of a Rocna 40 or 55. If you look at the Rocna recommendation (their recommendations are actually quite good if you can see past the marketing), they recommend 11mm G43 chain for the 40kg and 12mm G43 chain for the 55. You can find this in the chart on this page Chain (Rocna Knowledge Base) .

Going to high test chain will not have an effect on weight but will greatly increase strength which never ever hurts. The only problem is that the chain is slightly more brittle so it does not give signs before failure like lower grade chains do but I do not know of anyone ever breaking a properly sized anchor chain.

With a good anchor, chain and snubber, your weak link will become the shackle. Having a large end link installed on the chain will allow you to run a larger load rated shackle.

[Fuss]

Originally Posted by matrix

I too would love to hear a 3rd party opinion on that same question...have a Rocna on order but the Manson still tempts me. They are about the same price for the 35# range model of each at West Marine, actually the Rocna is 10% off at the moment which is basically how the choice got made...the threads on the topic are so polemical it's hard to weave through the jungle of arguments...

Great thread by the way!

Well I dont know for sure but I get the feeling that Rocna, Spade and Manson are all ok.
If it was blowing 60kts and by magic I could instantly swap my Bugel one of the other 3 then it would be ok by me. I'm not saying that the other 3 are better than my Bugel , but I would not expect to drag with them anymore than I would expect to drag with my Bugel.
I would not care which one of these was on my bow roller, I would probably take the one that fits the best with the best price.
I think thats the healthiest way to look at it.

[noelex 77]

Originally Posted by Dockhead

These people: Questions about Anchoring|Offshore Sailboat Voyaging|Attainable Adventure Cruising

use a 55kg Spade on a boat which is almost identical to ours in terms of displacement, beam, length. They argue that over 100 pounds, the holding power of an anchor goes up disproportionately. I don't know why that would be so, but they seem to be knowledgeable.

Arguably they are anchoring in more extreme conditions (high latitudes) than we ever will, but yet another convincing argument that a 121 pound Rocna or Manson would NOT be overkill for our boat.

I have a Rocna 55kg on my 47 foot boat. As my wife says maybe its overkill, but a nice overkill. Draging is no fun.

[Dockhead]

Originally Posted by noelex 77

I have a Rocna 55kg on my 47 foot boat. As my wife says maybe its overkill, but a nice overkill. Draging is no fun.

Do you have a photo of how it looks on your bow?

Does it work with your bow roller ok or did you have to modify it?

Interesting.

[noelex 77]

The boat was originally set up with an 80lb plow. So the Rocna is only one size up from that. The yacht was purpose built to sail a couple around the world so things like cleats are very oversized compared to a normal production boat. The bow roller did not need any modification.

[idpnd]

Yet another anchor thread, but this ones in my range of weight: 25 Mtons, currently there's a 50 kg? CQR on it, don't trust it one bit

[Jim Cate]

Originally Posted by fishwife

I sent a private message to Dockhead about the Manson but basically, the slot on the top of the shaft can cause the anchor to trip and if, as happened with me, a piece of coral happens to jam the shackle in the tripped position, you're in for a few interesting minutes. Otherwise, there's not a lot between them and if you never use the slot on the Manson then you should not have any problems.

P.

G'Day all,

What we do with our 60 lb Manson (46' 9.5 tonne light ship wt) is keep the chain shackled to the "non-slot" hole, and have a shackle in the slot. In areas where fouling is likely, we set an anchor bouy to the shackle in the slot, just in case! Has worked so far...

And Dockhead, FWIW, in 24 years of cruising in the South Pacific, our 85 metres of chain (10 mm L grade... similar to BBB) has been long enough. On Insatiable I we had a bunch of nylon spliced on to the end of the chain, and never used it. Deepest we've ever had to anchor has been 85 feet in French Polynesia, and the 85 metres was adequate. Wouldn't have tried it there under storm condx, though.

Cheers,
Jim and Ann s/v Insatiable II lying Lake Macquarie, NSW, Oz