Anchor chain length

[lezzer-g]

Hi All

I have few questions about anchors and chains I'm hopeing somebody on this forum could help me with.

At the moment my 25 ft sports cruiser has 21m of chain attached to the anchor, and I am mored in Cardiff Marina so my boating is in the Bristol channel, also my anchor is driving by an electric winch.
My questions are:

Is this enough chain or should I attach more for average ancorage say for a spot of fishing in the channel?

What is the best way to mark up the chain so that I know how much chain I've put down?

Thank you in advance for any help you can give me.

 

[activesail]

The general rule of thumb for suitable anchor chain lengths is to allow 3 metres of chain per metre of depth.

Therefore 21 metres will allow you to theoretically anchor in 7 metres. Given this rule of thumb, it is usual to mark the chain at three metre lengths.

Given the strong tidal strengths in the Bristol Channel it may be prudent to allow more chain for the depth in which you anchor. Also bear in mind the tidal range on the day.

I hope this helps..

 

[sarabande]

what's the diameter of the chain link pls ? That will give you the weight of the chain.

More importantly, though, what anchor are you using ?

I suspect that if it is a new generation one, then unless you choose to anchor in a particularly fast and nasty bit, say off one of the headlands in Devon, then 21 m of 8mm chain, plus a rope extension, should be OK.

 

[lezzer-g]

what's the diameter of the chain link pls ? That will give you the weight of the chain.

More importantly, though, what anchor are you using ?

I suspect that if it is a new generation one, then unless you choose to anchor in a particularly fast and nasty bit, say off one of the headlands in Devon, then 21 m of 8mm chain, plus a rope extension, should be OK.

The anchor is a Danforth style atached to what I think is 8mm, chain it came with the boat, I bought the boat from Poole so I assume it was good enough for the solent therfore good enough for the Bristol Channel.

I was going to paint the chain at intervals any idea what would be the best paint to use?

 

[sarabande]

The Brissle Channel is a little bit stronger than Poole

The chain will weigh about 30 kg, so if the Danforth has a nice sharp point you should be OK. Make up a chum of about 5kg from scrap, rather than buying more/different chain if you have any doubt. You will need to get the chain down to the ground, so a reasonably long warp (perhaps 10mm octoplait from Jacques Le Vert in Beer) would be a useful buy.

http://www.jimmygreen.co.uk/yacht-ropes-rigging/anchor-warps/anchorplait-anchor-warps



Paint. I have yet to come across any paint that sticks well to galvanised chain. Even Hammerite wears off as the links are very abrasive when the chain is being stored.

I mean to give an acid etch primer a chance one day.

 

[lezzer-g]

Thank you Sarabande for your reply I will get a warp just to be on the safe side I think.
Not sure how to mark up the chain now though oh! well can't have everything.

 

[Alcyone]

I'd agree about taking a rope as well - you can always pay that out if the chain is not enough. We carry 50m 8mm chain, but we do anchor overnight, and I'm maybe a bit cautious.

We use chain markers. Tried paint, waste of time.

http://www.kylechandlers.co.uk/showcategory.asp?CategoryID=7577

No affiliation to that chandlers, btw, first one I could Google.

 

[lezzer-g]

Thanks for the chain marker idea I'll have a look in the chandlers next time I'm at the marine village. I see what your saying about the warp but only ever intend to anchor up for an hour or so anyway but you can't be too carefull.

 

[Allan]

However you choose to mark your chain, my favourite colour scheme is red, yellow, green, brown, blue, pink, black. Easy to remenber but can be confuse the ladies.
Allan

 

[Alcyone]

However you choose to mark your chain, my favourite colour scheme is red, yellow, green, brown, blue, pink, black. Easy to remenber but can be confuse the ladies.
Allan

Or, for the colour blind among us, brown, yellow, brown, brown, blue pink black.

 

[Anwen]

Chain Markers

Has anyone else tried cable ties? - put them on to the chain at the appropriate points and snip the tails off.

 

[Coaster]

Has anyone else tried cable ties?

Yes. But it's not always easy to see the ties when the chain is rattling out, especially in low light.

Any suggestions for making the ties more visible? Increase number or size? Change ties' colour?

 

[sarabande]

I hate cable ties; sharp hand-tearing edges where you have snipped them off.

If you don't like paint, then thin line, coloured possibly, with a system of knots in them. The line conforms well to going over gypsies and being tumbled down the chain pipe.

You should be able to estimate distance between markers at 5 meter intervals by eye, so perhaps 1 knot at 5 m, 2 at 10, etc. If it's really dark you can then feel the distance. If you don't like the idea of knots, then put line in adjacent links to indicate a multiple of your basic distance.

There are small diameter lines which are almost fluorescent
http://www.springfields.co.uk/camping/accessories/?id=5271&largeimg=1

 

[Bosun Higgs]

Was out anchoring this week with a spring tide and a rise of 12m. We draw 2m so with a safety of 1m, I would need a depth of 15 m if I were to anchor over both high and low water not moving inbetween. Even on 3:1 ( and many people advise much more) that implies a minimum chain of 45m.

In fact I have 40m plus rope.

 

[lancelot]

Anchor Chain

Has anyone else tried cable ties? - put them on to the chain at the appropriate points and snip the tails off.

Good idea. I have coloured string on mine, not sure how long it will last. I will look for different coloured cable ties for next time.

BTW the new radar is looking the business, John. I knew I would be jealous.
Fair winds,
Lancelot

 

[activesail]

Was out anchoring this week with a spring tide and a rise of 12m. We draw 2m so with a safety of 1m, I would need a depth of 15 m if I were to anchor over both high and low water not moving inbetween. Even on 3:1 ( and many people advise much more) that implies a minimum chain of 45m.

In fact I have 40m plus rope.

Extending the chain with 5:1 length of rope is effective.

I should imagine, one would have to watch the yachts scope though as the tide drops.

Anchoring in an area, like the Bristol Channel is bound to problematic.

 

[mrbloto]

Extending the chain with 5:1 length of rope is effective.

I should imagine, one would have to watch the yachts scope though as the tide drops.

Anchoring in an area, like the Bristol Channel is bound to problematic.

a fishing boat anchored off sully island a few years ago in 60 ft off water as the tide dropped they were holed and the boat sunk the people in the boat had drifted up towards newport in there life jackets and were picked up by a boat just come out off newport. they said it must havew been a periscope??you have the wolves out by there when you have lot off rope out just be aware off where you anchor at low tide.

 

[Mymobo]

We anchor around cold knapp alot, last boat had 15 meter
chain and 50 meter of rope. New boat 10 meter chain and 50 meter
of rope. But this is for a few hours only.

If you have a sports cruiser and load it with chain in the anchor locker you will have balance problems.