Anchor size

[Talbot]

I know that there are lots of recommendations for anchor size available, and also that the weight forward should be minimised, However, it is also clear that cruising is safer with bigger gear. At the moment I have a 20lb danforth type as my main anchor, with a 6Kg delta as a lunch hook. My boat is a 9m cat, and I have upgraded to 3/8 chain - <font color=blue>should I go for the 10Kg delta or the 16Kg delta as the main anchor </font color=blue>- I would then degrade the danforth to supplementary, and shift the light delta down aft as a stern mooring etc.

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[tcm]

What can you haul? I think it is quite feasible to haul the heavier one with even quite a lot of chain, so i'd have that.

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[ChrisE]

I guess it depends upon where you are going to cruise. If you are going transat and beyond then I'd definitely plump for the bigger of the two deltas. If you want to save weight I'd also not go for the traditional all chain rode, I'd have 30m of chain attached to 70m of multiplat.

I'd also take 100m of multiplat as a secondary anchor rode for when you have to lay two anchors in a tight anchorage.

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[Talbot]

I have a 1000w windlass, so should be no problem /forums/images/icons/smile.gif

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[Talbot]

Plan is across to windies, through Panama, and then on to Aus.

I have 30m of chain, with 45m of multiplait at the moment. Had planned on 15m of 3/8" chain and another 45m of multiplait for secondary, and 10m 5/16" chain for stern with 25m of multiplait.

I prefer the heavier chain to a really heavy anchor cause I think it rides a lot better especially in heavy wind.

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[hylas]

Re: Anchor size, not weight!..

Catamarans have more windage than monohull.. For a 9m boat, I will suggest a 14 kg anchor; but for a 9 m Cat, I will rather choose a 16 kg one..
But I will also point out that weight is not the good measurement for selecting an anchor, as holding is both related to the surface area of the anchor, and to the shape of this anchor.. not to the weight..

To give you an example, for my 12m /14 tons boat, my own main anchor is only a 16 kg steel one.. but the 16 kg anchor I use, has more than TWICE the surface area of 30 kg anchors from the competition.. For your boat, the 12 kg model, will give you more holding than a 25 kg standard anchor. (and the 8 kg model will be sufficient..)

Then I have a very good holding and at the same time I can save weight at the bow and the anchor is much more easier to haul..

About the mooring line: 30m of chain attached to 70m of multiplat. 8 mm chain and 14 mm Nylon rope is far enough.. with a rope to chain splice.


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[Talbot]

Re: Anchor size, not weight!..

I was aware of the weight/holding power debate, hence the move to a delta which has much more holding power/weight than a lot of others. I am aware that the fortress has a very vociferous support group, but as I already have a danforth style anchor, I decidedthat an alternative style would be a good thing, as it is also apparent from a lot of the tests and reports that different styles of anchor perform differently in sand/ mud/weed etc. I have nearly convinced myself that I should go for the heavier delta and accept the weight penalty.
In my experience the weight of chain is a big factor for a multihull, which in addition to the larger windage, has a tendency to swing more than a monohull.

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[davidbains]

Re: Anchor size, not weight!..

I've been sailing a 39ft multi for many years and have always used a 35lb CQR with
considerable success. Initially I had only 30ft of 3/8" chain but replaced it with
50ft of 5/16" chain which is kinder to the hands. On a multi I don't see the point
of carrying more than about 50ft of chain since over that the nylon is off the
bottom and the weight saving is considerable.
My second anchor was a 45lb CQR which I occasionally used in a blow but out
of consideration for my back I replaced it with a Fortress which can live in the
focsle without depressing the fine bow. It seems to work well either as main or
second anchor. Very easy to row out or even throw overboard when two are
required. The 45lber is now slid under the Yanmar where it's weight should be
and it will take a storm to get it out again. I also used to carry a small stern
anchor for med bows on mooring. But didn't find this very satisfactory with a
large multi. Any crosswind and the kedge was inadequate. It's gone to a grateful
recipient and I back up to the quay in the unusual circumstances that there's room
for a 25ft wide boat. Always dropping the main anchor much further out than I
used to!!
I would have thought your 16kg bower would be right. On long trips anchoring
becomes the norm.

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[Talbot]

Re: Anchor size, not weight!..

Thanks, I have gone for the 30m of chain because I normally anchor in abt 8-10m, and that means that my windlass can use chain totally, and I dont have to make use of the drum on top of the windlass (dont like the rope/chain gypsys - reckon they are too brutal on the rope) I am installing a 1000w lofrans windlass this winter as my back is not as young as my brain!

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[charles_reed]

Re: Anchor size, not weight!..

With a lightweight boat like a cat I feel your thinking on chain/rope, to keep weight down in the bows, to be very realistic.
I would, however, suggest rather more rode with your 30m of chain because you might find the need, in the Med to anchor in up to 20m.

On anchors - Hylas like many geniuses is fairly obsessive, here about the need for fluke area, whilst he has a point on the importance of fluke area for holding effect I feel that the ability to set is equally important.

So if you look at his Spade it's holding is superb once it's dug in, far better than any of the other, plough-type anchors.
The Fortress also, has unrivalled holding power, but in any current you need to weight it to get it on the bottom as it plays the manta ray about 2m from the bottom.
The Delta, because of its fluke area and superior penetration is probably better than the CQR for a given weight, but is difficult to set unless its landing attitude is fluke down.
In my estimation the Bruce, holding inferior to any of the above but with faster resetting and penetration nearly as good as a Fisherman, is probably the best compromise bower anchor you can use.

Mind you, as with economists, get any two anchoring experts together and you're likely to get three considered opinions.

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[charles_reed]

About the rope/chain gipsy

Providing you use multiplait you'll find little problem with your rode on a combined gipsy.

I agree wholeheartedly about the dual ones - when it comes to changing from drum to chain...

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[hylas]

Re: Anchor size, not weight!..

Hi Charles,

You are absolutely right when you said “whilst he (HYLAS) has a point on the importance of fluke area for holding effect I feel that the ability to set is equally important.” You can have an anchor with a very high holding.. If the anchor doesn’t set, it is absolutely useless..

But I disagree when you say “The Fortress also, has unrivalled holding power” this is a pure MARKETING advantage.. you have to consider that aluminum is roughtly three time lighter than steel.. if you compare for example a 10 kg Danforth anchor with a 10 kg Fortress.. (nearly the same anchor, Danforth in steel – Fortress in aluminium) the holding of the Fortress is about three time the holding of the Danforth.. but then compare the holding of the Danforth and the Fortress of the same SURFACE AREA it is about the same.. NO SECRET..

Now about the term “Unrivalled” You also believe what the Fortress publicity says.. On the recent tests published by Yachting World, the 6.5 kg Fortress gave 370 kg of holding in sand.. The Guardian 5 kg = 250 kg of holding.. and the aluminium 6.5 kg SPADE 650 kg of holding.. did you say “UNRIVALLED”???

Now to dig in, one anchor needs two charateristics: the right penetrating angle (Chisel shape) and weight on the tip. The Spade anchor is the only one to have about 50% of its weight located on the anchor tip.. it has also the reputation to be one of the best anchor to dig in.. including in weed and hard sand..
The Delta has 28% of its weight on the tip.. but unfortunately a wrong penetrating angle..
The Bruce also has a “right penetrating angle” but unfortunately not enough surface area of the fluke related to the total weight..

I would be very pleased to compare my opinions with any anchoring expert.. I’ve spend some time discussing these points with people like Earl Hinz (the anchor “guru” in U.S.A.) and we nearly share the same opinions..




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[Keith]

My experience in the windies was all the anchorages that are in the Doyles guides get packed with boats, consequently being a cat, like me head for the beach, where theres room, after all you only draw about three feet, take advantage of it.......keith

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[charles_reed]

Anchor tests

are rather like expert opinion, for every additional 1 you read your conflicting advice increases geometrically.

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