Anchor doesnt hook up

[PaulGooch]

CQR pattern anchor, 20m of 8mm chain and 140m of 14mm rope. 27 foot boat, anchored all day for angling, including a 180° swing with the turn of the tide.

I find depth of water matters for two reason, the first is the obvious one. Say i'm in 150' of water, neap tides i often get away with 2-2.5 times the depth, springs need 3 times the depth. NEVER had to let any more out and i've anchored in strong strong tidal flows.

Second reason depth matters, if i was in 20 feet of water, 40 feet of chain won't hold. 60 feet might if the tidal flow isn't too much. But, let all the chain out and a little rope, you couldn't tow it loose with a tug. I reckon the reason for this lies in Haydn's theory that the chain does most of the work. 20m of chain lying flat on the seabed of gonna take some dragging. Not only that, it's gonna take some lifting, so it's mostly going to stay on the bottom and keep the anchor stock pulling parallel with the bottom.

 

[andyc]

Im thinking that 15ft is a bit inadequate.I really didnt realise how little I had until I ran it along the deck today.Its just too easy to press a button on the flybridge and not realise how much has gone out.
I was going to mark it in 10m intervals!

 

[sarabande]

a chain 15ft long marked at 10m intervals ? Using invisible paint presumably ? Have I missed something ?

 

[PaulGooch]

Im thinking that 15ft is a bit inadequate.I really didnt realise how little I had until I ran it along the deck today.Its just too easy to press a button on the flybridge and not realise how much has gone out.
I was going to mark it in 10m intervals!

I take it you have rope as well Andy ?

 

[hlb]

I'm gonna stick this thread into my golden oldies collection. The thought of this anchor hanging there, looking for something to "Hook up to" has me spell bound.

Advice that a different anchor will do the job, is just as daft.

 

[PaulGooch]

I'm gonna stick this thread into my golden oldies collection. The thought of this anchor hanging there, looking for something to "Hook up to" has me spell bound.

Advice that a different anchor will do the job, is just as daft.

He could always come up close behind you Haydn and hook it on one o them davits

 

[deborahann]

He could always come up close behind you Haydn and hook it on one o them davits

too late, a reversing raggie got the davits first, now being repaired. shh diesel we don't want to be banned

 

[lenseman]

I'm thinking that 15ft is a bit inadequate. . . . . I was going to mark it in 10m intervals!

I bet you didn't use too much paint then?

Just out of interest, I have 90 metres of 12mm chain on my 50 foot, 25 ton ketch with a 60kg CQR hanging off the end of the chain.

I also carry a very large Danforth and a smaller CQR on 10 metres of 8mm + 30 metres of 3-ply as a kedge.

 

[lenseman]

I'm gonna stick this thread into my golden oldies collection. The thought of this anchor hanging there, looking for something to "Hook up to" has me spell bound.

Advice that a different anchor will do the job, is just as daft.

I have given up with a TV license as there is so much comedy on here it beats watching the Goggle-Box any more.

 

[timbartlett]

I may have sussed the problem.
I let it out today and thought, Ill run it up and down the side deck of the boat a few times and then measure it.
I let it out and it didnt even reach the cabin.It turns out it is only 15ft long.....and the boat is 43ft.

Anybody have any recommendations on just how long it should be?Im thinking 50ft.What does the knowledgable community think?

I, too, was wondering whether the anchor was actually reaching the bottom, because that is the only reason I know of why a Delta won't hold. Best anchor in the business -- bar none! (IMHO!)

When it comes to deciding how much chain you want, the size of the boat is almost irrelevant: it is the depth of water that counts.
If you have all chain, you need an absolute minimum of 3 times the depth, plus the distance from the waterline to the chain locker.
If you use rope, you need about twice as much, with about 5m of chain to get some weight down near the anchor.
So if you intend to anchor in depths up to 10m, you need at least 35-40m of chain.
Or you could keep your 15ft on the anchor, and add about 70-80m of rope -- eight-plait nylon is best.

 

[Wiggo]

8mm chain, and lots of it! (We have 70m on a 12m boat). Mark the chain at 2m then every 4m. All you do is let out to the first mark and you know the anchor is wet, then let out 1 mark for every metre you're anchored in and you automatically have 4 x depth. Simples.

 

[guernseyman]

I may have sussed the problem.
I let it out today and thought, Ill run it up and down the side deck of the boat a few times and then measure it.
I let it out and it didnt even reach the cabin.It turns out it is only 15ft long.....and the boat is 43ft.

Anybody have any recommendations on just how long it should be?Im thinking 50ft.What does the knowledgable community think?

15 feet!

You shouldn't have put to sea, let alone tried to anchor.

I think you said some time ago it was fitted by the manufacturer? Well If I was you I'd check the hose clips on the skin fittings and everything else that could go wrong.

That length of chain didn't happen by accident, so it's unlikely to be an isolated incident.

 

[wetspot]

15 foot?

think youself lucky you got that much

I only got 8 foot on my 2556 when I imported it from the States!!

 

[photodog]

43 foot boat... I would say 60 meters of all chain.

Youve got a lot of windage... 5 to 1 in 10 meters is usefull.

watch the chain size to ensure that it matches your windlass.

We have a 32 foot boat... and 50 meters.

I would like more!

 

[andyc]

It did hold a couple of times, but most of the time we just drifted.It used to really piss me off.
I am just relieved its not me.

 

[hlb]

It did hold a couple of times, but most of the time we just drifted.It used to really piss me off.
I am just relieved its not me.

Umm. I'm afraid it is you. You should know the depth of water and how much chain you've let out. Just dangling a bit over the front, is not an option.

 

[Plomong]

My boat came with 20m chain plus 28m of rope. We regularly anchor in 24m depth, chart datum. That becomes 28+ metres at high water, to which we should add another meter from water to bow. So 48m warp would be woefully inadequate -- multiplying 29 by 3 gives 87m as a minimum recommended scope for that depth.

We now have 70m chain plus 50m rope (and another 50 lurking in the locker), which is quite adequate for the depth of that anchorage. In anything up to F5 or so that is sufficient. Above F5 we are in port anyway !!!!

 

[timbartlett]

Is it worth pointing out (or will I just be accused of pedantry?) that all these X x depth rules (including the one I mentioned) are not really "rules" at all?

They are pretty crude guidelines.

After all, if you had a ten tonne anchor to hold a dinghy, you would only need enough rope to stop the dinghy being dragged under as the tide rose! At the other extreme, if you had a battleship with a 1kg anchor, it wouldn't make any difference how much chain you put out.

In between, there is an infinite range of possibilities. But the point is that for most relatively normal boat/anchor/chain combinations you need a lot more chain than the depth of water. And for boat.anchor/rope combinations you need even more!

Rules that are based on boat length are just plain illogical -- (you could anchor a 100footer in Poole harbour with less chain than it takes to anchor a 15 footer off St Helier!)

 

[BrendanS]

At the other extreme, if you had a battleship with a 1kg anchor, it wouldn't make any difference how much chain you put out.

Really, you don't think 5 miles of heavy chain would make a difference? Most really big ships probably rely more on the weight of chain, than the anchor itself.

 

[timbartlett]

Really, you don't think 5 miles of heavy chain would make a difference? Most really big ships probably rely more on the weight of chain, than the anchor itself.

And I thought I was supposed to be the pedant !
How would you attach a heavy chain to such a piddling anchor?
And why would you bother with the anchor?

I wasn't actually suggesting any of these as practical options: I was merely trying to suggest that just because you have put out 2.9 x the depth of water instead of 12 times the square root of the depth of water (or any other formula anyone cares to come up with) does not mean that your anchor will definitely hold (or not).

Incidentally, the formulae which I learned years ago for warships included different multipliers for whether the chain was made of wrought iron or forged steel chain, because one is denser than the other -- but I still think incalculables such as the holding ground and windage make more difference than any of these things!