How Large an Anchor

[IrishmistIII]

I have another question. I have a 44 lb bruce anchor on Irish Mist. It has been on the boat for sometime, but I only used it last summer. It worked great.
I want to get a rocna. They suggest that I need a rocna33 when a rocna 25 would be larger then my bruce. Irish Mist is a 28000 lb Tartan 4600.
What do you think.

[donradcliffe]

Looking at the rocna sizing guide, I think they recommend the 25 for a 46 ft boat which weights 26,400 lbs--thats pretty close to what you have, and a lot more holding power than a 44 pound Bruce.

[eyschulman]

You could be opening a can of worms. There is a lot of diverging opinion on anchor types and size. I think if you use the manufacturer's scale you are ok if you need more security go one up. There is a large body of evidence pointing toward superior performance with lighter shovel shaped DIGGING type anchors such as spade-manson-ronca-ultra etc. This is not to say that other anchors won't work well when properly applied but that newer type pound for pound or significantly lighter will do as well or better..

[hpeer]

Worms indeed....did you miss the fun on the " bigger is better" thread.

I'm on the ridiculous side.

44' steel cutter, 40,000 lbs

Secondary is a spade 66 pounder

Primary is a Mantus 125 pounder

33' steel cutter, 16,000 lbs

Primary is a 44 lb Rocna

Secondary 50 lb fisherman

[eyschulman]

Hpeer you seem to have good taste in anchors and I have no argument with the weight and size. You did oversize your windless to handle the weight and you use a trip line to take the strain off your bow pulpit and windless when breaking loose?

[hpeer]

The 44' sprit had rusted out, so I replaced it. When I did I reinforced it. I also added an eye at the cut water. She already had a big windlass ( falcon?). Trip lines are a good idea, I've run into foul bottom too many times before. Discarded fishing cables, etc.

[paccrest]

I have a Hunter 45 which displaces about 27.000 lbs empty and in cruising form about 30k. I run a Rocna 55. Amazing anchor, never has drug a single time. I wouldn't trade it for world. In general, bigger IS better as long as your windlass or mate can handle pulling it up.

[Jim Cate]

FWIW,

All this worry about whether your windlass can handle the extra 20 oe even 50 pounds of anchor weight... how silly is that? Even a small windlass is rated at a thousand or more pounds of pull. Adding a minor increment to the anchor weight will not bother the windlass at all.

Of course the greatest loads on the windlass come if you use it to break out the anchor when it is well dug in, and the bigger anchor will be harder to break out. The answer to this quandary is to follow the manufacturers advice and use the engine or the vessels buoyancy for that effort.

Cheers,

Jim

[Horror Hotel]

You could go with the Rocna 33 but it wouldn't be to radical to go with the 40.

[Red Sky]

Mines 40', 21,000# dry. 33kg. acts like a bottom magnet. What I find amazing is how fast and at what little scope it will bite into the bottom. We worked as a stake boat for the Americas Cup this past summer and had to anchor in 80' of water on very short scope to maintain position during tidal changes. 2.5 to 1 scope on 100' of chain and 100' of 3-strand. When setting, I could snub the rode just for kicks as soon as the 3-strand started going over the roller and stop the boat. Some days we had 3 knots current with 25 knots of wind and 3' of chop. 32 days on station during the summer and didn't drag once. I bought it to sleep well, I do.