What Weight anchor?

Re: 120ft .... weight ????

Approximate weights per metre from an old Plastimo catalogue.
Galvanised calibrated short link chain

6mm - 0.9kg
7mm - 1.1kg
8mm - 1.45kg
10mm - 2.35kg
12mm - 3.17kg
14mm - 4.4kg

steve
 
Re: 120ft .... weight ????

Ta ... saved me trawling net .....

But isn't it funny .... that chain is mostly given imperial size ... 3/8, 1/2, 3/4 etc. - and dear old Plastimo uses mm ......

so my 120ft = 36.6m ...... it's 3/8 chain short link .... (lets take 8mm ......) so that is ... about 53 - 55 kgs total ....
 
Re: 120ft .... weight ????

Using Nylon as it has lots of stretch, which it has when used above it's Safe Working Load. At SWL it's got the same as Polyester which is a lot better for anchoring on unless using a Auto rope to chain winch. Same strength as wet nylon, same elasticity as nylon at SWL and far superior abrasion resistance. No brainer really.

BIG anchors are great IF you have the power to set them. See it often, huge anchors which the boat has no show of setting. Just have to sit and wait for the storm to set it... Yeah thats a good idea.... not.

What wrong with a reasonable sized good anchor in front of a nicely matched rode?

Think 'system' or 'matched set' not individual items.
 
Come again ???????

Reason for nylon is sink ..... any rope that floats is definitely not suitable item for anchoring.

Second to rely on flukes digging in - or setting as it's normally referred - is relying on one factor when you can be safer by relying on 2 ... set and weight.

Three - a heavy anchor will have inertia and its weight to help it set ... well before heavy weather starts to drag it ... which I'm sorry IMHO would happen with a lightweight.

I agree totally "System" .... but am against minimum set-ups ... and especially when allied to rope rodes ...

Dare I repeat that I have seen various rope rode systems drag ... but my all chain heavy plough has always held .... I regard my anchor set-up as a safe "System" ... with a reasonable margin built in. I do have the luxury of a windlass on the foredeck ... but actually have never used it yet ... >>

For all those who have seen this before ... please turn away now ......

29-7-99020.jpg


I rest my case m'lud !
 
The discussions about an all chain rode versus a rode composed of chain in combination with a rope keep going on. In my opinion the disadvantage of an all-chain rode is that when the forces exerted upon the ship increase and therefore the forces via the chain upon the anchor increase, the chain becomes taut and then what. The system at that moment lacks elasticity and the forces exerted on the anchor will increase all of a sudden disproportionally and may cause it to break out. In a combination-rode the rope gives the system the necessary elasticity and the sudden increases in force upon the anchor are much less, making it less likely to break out. IOW the chain-rope system can accomodate the fluctuation in force much better than an all-chain rode. Under "normal" conditions that is seldom important, because the forces acting upon the ship will seldom reach such a level that the chain becomes taut, but it is exactly under very adverse conditions that this advantage of the chain-rope system will show up.
 
If you have as much chain as you can carry then it'll always be better than a chain/rope combination of the same length. I think what's important is to be able to add rope to the chain rather than it being attached at some horribly inaccessible point.

I also have a lot of sympathy for the idea of attaching a weight to the chain at least two or three times the water depth from the boat end, and using a spare anchor as weight feels like it would do no harm and might even help the holding. Haven't tried it though - I've tended to lay out a second anchor at an angle to the first when I've been worried about conditions - though only in tideless waters.
 
SBC I think you were think Polyprop is a nasty floating anchor rope. Polyester sinks just like Nylon.

Sure a heavy anchor will help setting as long as you have the power to move it. Make the anchor too big and then the lack of setting power will become an issue.

I had to borrow a anchor from a mate a few weekends back as I had forgotten I'd taken the anchor off to clean the locker (seriously poor prep for the weekend I know, very naughty). All he had was a 45lb plow. I have a lightish (2200kg all up) 32ft racer with a high thrust 9.9hp outboard. No way could I get the anchor to set using the boat, simply not enuff horsepower. As some 'drinkies' were going to happen and a possible front coming thru that nite, I decided to dive and dig a hole by hand and drop the anchor into it, just in case. My usual main (racing) anchor is a alloy new generation wieghing 4.5kg. Always sets and holds like hell. My cruising anchor is a 10kg steel new generation from another stable. Always sets and hold like hell.

A fact of boating is Rope/chain combo rodes can drag just as all chain rodes can drag. I think some of the rope/chain combo issues you have up there is short lengths of chain. I see often Nth hempisphere posters talking 1/2 the length of the boat of chain then rope. Way to short to be effective for much except a bit of chafe resistance. Down here the minimum anyone runs is 1 1/2 to 2 time the boat length of chain and then rope.

Increase your chain length 50% and the catenary load doubles i.e smallish length increases does wonders to holding ability.

What seems to becoming the norm and what I also like is the Auto rope to chain winches which allows you to run, say a 35fter, 30mts of chain and then rope. This allows for all chain anchoring overnite and the ability to anchor deep during the day for a fish or whatever. If you do anchor deep overnite it is not such an issue as the deeper you anchor the better the rode works so the rope behind is not a problem, assuming no coral or similar.

There is nothing wrong with putting, say, all 10mm chain onto a 40lb anchor on your 30fter as long as you have the power to set it and realise it will seriously effect the boats sailing ability. If you go to much overboard it could have a seriously dangerous effect. Sure if you're a pure cruiser with plenty of time it would not be a problem. I just like to have the nice balance between anchoring and boat performance.

My 32fter uses a 4.5 or 10 kg anchor onto 15mts of 7mm chain to a 12mm polyester warp. Been anchored overnite thru 40 odd knots, sleep right thru it very soundly. The anchor system does not effect the boats performance.

Its all about the balance. A poorly matched anchor system using all chain can easily be out performed by a well balanced rope/chain combo rode. The oppersite also applies.

Don't forget your snubber. /forums/images/graemlins/smile.gif /forums/images/graemlins/smile.gif

As for RECUSANT2 question, not knowing what rode you have behind it does not help but assuming an average one I'd look at a 40-45lb plow type and/or a new generation in the 15kg area. Tweek up or down a bit depending on rode behind. I'm guessing a Danforth pattern as a 'just in case' spare, which I'd make as big as I could store. If you're a pure cruisier and not to worried about loseing a tad of boat performance I may go up one size on the main anchor.

What is it about anchoring that gets everyone so excited? me included /forums/images/graemlins/smile.gif /forums/images/graemlins/smile.gif
 
GMac raises a good point here about setting the anchor. It's been a concern of mine also with just a little 8HP engine that doesn't have loads of reverse thrust. When most of our sailing was in blue water charter yachts, I used to snorkle over the anchor and was too often surprised it was still lying on its side in spite of apparently holding with loads of chain and a 20-30HP Volvo or the like digging it in. In the murky waters of the Bristol Channel I can't see what's happening, so have to go by feel, chain rumble and experience of what happens when the tide/wind picks up. I do however have reasons to suspect that with 25-30m of chain out on a 25lbs CQR, I don't have the power to dig in on a hard bottom until the weather or tide does it for me. When switching to the lighter Delta, it seems to hold a lot quicker...maybe it's because I am able to dig this in with the engine?? It's a forgotten factor I think when discussing anchor weights, chain or chain/rope, etc. I also believe it's the whole system that matters and it has to be matched to the boat (not only length, but weight, beam and windage) and engine power as well as bottom. I'm still inclined to follow the route of various anchor types of moderate weight to accomodate various bottoms, and have a good length of chain (35-40m) extendable by nylon for deeper waters / more extreme conditions. I don't think any one answer fits all. Other forumites expressing an opinion here are neither right nor wrong. They are doing what works for them...same as I am...and I'm constantly experimenting and learning.
 
Re: 120ft .... weight ????

bluedragon has it right.
Many many horses doing many many courses. Not one system fits all.
 
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