Length of anchor chain

claymore

Well-known member
Joined
18 Jun 2001
Messages
10,644
Location
In the far North
Visit site
This must have been covered somewhere before so apologies for that.
I'm swapping my anchor chain this winter. I currently have 40m of 5/16ths chain.
I think I may go up to 10mm (3/8ths) because the 5/16ths seems a bit lightweight.
Just out of interest - what length of chain do you carry?


regards
Claymore
 

gunnarsilins

New member
Joined
16 May 2001
Messages
450
Location
Stockholm/Sweden
www.eilean.se
I had a...

...posting about anchors recently. I was told by several that the 56 m I carry was too short, at least for cruising Scotland and Brittany. 80, or even 100 metres would ideal.
 

MedMan

New member
Joined
24 Feb 2002
Messages
683
Location
UK
teall.name
I have a Trident Voyager 35 that weighs about 6 tons. I carry 60 metres of 10mm (3/8") chain and I would not be without it. However, that much chain does weigh a fair amount and may be too much for your 30 footer.

A long length of chain is particularly useful in the Med when mooring bows to our anchor, stern to the quay as it enables us to drop the anchor well out away from all the others. It also means we do not have to judge our distance off the quay quite so accurately - running short of chain 5 metres from the quay and having to start all over again is a real pain!

Best wishes,

David
 

ccscott49

Active member
Joined
7 Sep 2001
Messages
18,583
Visit site
I have 160' of 5/8" chain on my boat, but she is rather large 57' I dont think I would want anymore than that, unless I went to 1/2" then I would have 200' or even 250', or whatever the same weight was anyway. 5/8" is a bit overkill, even for me. But I'd need a new anchor winch aswell, so it will probably stay that way.
 

heerenleed

New member
Joined
13 Mar 2002
Messages
535
Location
Netherlands
www.heerenleed.com
i carry 95 metres of 10 mm chain on a 60lbs CQR
never let me down so far if well digged in.
i do have an electric windlass, otherwise i would not anchor very often

cheers

Peter a/b SV Heerenleed, Steenbergen, Netherlands
 

Bodach na mara

Well-known member
Joined
21 Aug 2002
Messages
2,698
Location
Western Scotland
Visit site
I had 40 metres in my Renown when I brought it up from Solent. I couldn't anchor safely in Tobermory and had to let go at the bitter end (after tying on a 20 metre length of multiplait.) I bought another 25 metres of 9mm last winter.

I think 5/16" should be enough if the Claymore is a "Marcon Claymore". I looked at one in Kip a few years ago, maybe even yours!

Ken Johnson
 

Aja

Well-known member
Joined
6 Nov 2001
Messages
4,790
Visit site
When I bought my boat it had 20m of 1/4" chain + 30m 1.5" nylon and the previous owner said he never had a problem on the west coast - just went in closer! I've now got 50m of 5/16ths to which I can still add 30m of 1.5" nylon. I sleep at night - even in Tobermory.

I've got a manual Anchorman - wouldn'y fancy hauling anything bigger than what I've got.

Donald
 

webcraft

Well-known member
Joined
8 Jul 2001
Messages
40,185
Location
Cyberspace
www.bluemoment.com
Admittedly I've dragged (a bit) in Tobermory in a 25 footer with 8m chain and 25m plait, but I would have thought 40m chain should be OK - near the shore (trees/rock) you can always anchor in less than 10m and it's pretty sheltered.

25m chain and 25m nylon is generally reckoned to be enough for most places on the W. Coast - but then I sail small boats and 40+ metres of chain would simply be too heavy.

<font color=blue>Nick</font color=blue> -
computer.gif


BlueMoment.Com
<A target="_blank" HREF=http://www.bluemoment.com/>http://www.bluemoment.com/</A>
 

vyv_cox

Well-known member
Joined
16 May 2001
Messages
25,913
Location
France, sailing Aegean Sea.
coxeng.co.uk
55 metres of 8mm chain on Sadler 34. This has always been sufficient on the west coast of UK, Scillies to Tobermory. I have rarely used more than about half of it now that we sail on the east side. I carry quite an assortment of rope warps that could be added if necessary.

I am expecting a few posts on evident overkill on the chain front. It has been suggested many times that more than about 20 metres of chain is superfluous and that the remainder is better in heavy nylon. I can accept the theory of this but the practicalities are that if a group of yachts on all-chain warps is joined by one on predominantly rope, chaos ensues. Boats on mostly rope tend to wander about a lot, lying first to wind, then to tide, at frequent intervals, whereas all-chain promotes far less movement.
 

claymore

Well-known member
Joined
18 Jun 2001
Messages
10,644
Location
In the far North
Visit site
Yes to that - particularly in small anchorages - Eigg, Gometra North Harbour, Tinkers and Bull Hole, a crowded Puilldobhran - I tend to pick up visitor moorings in Tobermory because it is so deep and there must be all sorts of clutter on the seabed. Doesn't seem to stop the West Highland Fleet though.

regards
Claymore
 

vyv_cox

Well-known member
Joined
16 May 2001
Messages
25,913
Location
France, sailing Aegean Sea.
coxeng.co.uk
A group of us was on the visitor moorings in Tobermory about 10 years ago, when the West Highland fleet arrived. True to form thay all dumped their underweight anchors, on rope warp, over the side and headed ashore for the celebrations in their marquee. At about 10 p.m a substantial easterly blew up and I have never seen such chaos. Many of the yachts were rafted together, apparently on a single anchor in some cases, and they dragged rapidly towards the town. Owners, largely somewhat under the weather, returned aboard to try to sort themselves out, and many opted to cut their warps due to the severe entanglement. As these boats mostly had no second anchor, for weight saving, they were forced to motor all night. There was a good deal of damage and we all spent a couple of hours fending off unmanned vessels. The divers did very well out of it the next day.
 

heerenleed

New member
Joined
13 Mar 2002
Messages
535
Location
Netherlands
www.heerenleed.com
no down switch

morning Claymore,
it is an old fashioned but recently overhauled SL, and it has a clutch to completely loosen the gypsy. The anchor can then fall freely, unless you use the clutch as a brake. Works well enough for me.

regards



Peter a/b SV Heerenleed, Steenbergen, Netherlands
 

claymore

Well-known member
Joined
18 Jun 2001
Messages
10,644
Location
In the far North
Visit site
Re: no down switch

Thanks Peter
I think thats what I'll do - I normally lay the chain out on deck before anchoring anyway - to the red 15m mark at least, then check the sounder to see what we have beneath us in the desired spot.

regards
Claymore
 

billmacfarlane

Active member
Joined
16 May 2001
Messages
1,722
Location
Brighton
Visit site
I carry exactly the same as Vyv , 55m of 8mm chain on a Bruce anchor. The boat is 11m long. I also carry a 2m , 4m and 6m piece of chain to moor up to buoys in heavy weather and also to shackle on my backup anchor ( Fortress ) in tandem with the main anchor.
 

hylas

New member
Joined
6 Nov 2002
Messages
275
Location
Canaries Islands
Visit site
Re:the Right solution...

Should I give my own opinion about chain??.. I perfectly know that some people will disagree.. but..

The main and ONLY advantage of the chain is that it is the only and perfect mean to avoid shaffing of the anchoring rode on agressive sea beds...

Except this point, chain has all disadvantages..:
Stored in the bow chain locker, it ad an heavy weight where it should not be
- Chain is working on the opposite it should work:
o with light wind, it give a perfect horizontal pull to the anchor and the best holding
o with moderate wind, its weight and catenary effect give a perfect shock absorbing effect.
o As the wind build up, the chain will become more straight (and this with as few as 25/30 knots of wind) then the pulling angle will increase and as a consequence, the holding of the anchor will decrease.
o When the shock absorbing effect will be necessary, the "bar tight" chain will not give it any more..

If there will be some waves entering the mooring place, the resulting shocks will be then directly transfered to the anchor, which then has more chance to break free.. and more serious, the chain is subject to high "picks" of pulling force and has very high risks of breaking..

Which lenght of chain??

During the last seven and half months, I spent 129 days moored (out of 228) into 61 different moorings. The mean water height has been 6.50 metres and the scope 5/1. The total lenght of the mooring line was about 30 meters for which 23.5 metres has been lying on the bottom (30 - 6.50 m)
Therefor, I believe a lenght of about 25 meters will be perfect.. If the water height is less, then you will be anchoring with an all chain line.. if the wind build up.. you will give more lenght but the wind will push the boat and the rope line will not shafe on the bottom..

Which length of anchoring rode??

Holding is in direct relation with the pulling lenght of the rode.. (or better, the pulling angle).
Generaly speaking, with a scope of 4/1 you will have about 55 % of the maximum holding of the anchor, with a scope of 6/1 about 70 % with a scope of 8/1: 80 % and with 10/1 about 85 % the maximum. - 100 % holding will be achieved with an horizontal rode or a "Infinite/ 1" scope.
Increasing the scope will be efficient up to 10/1 - With more than 10/1, a large increase of the scope will only give a negligeable increase of the holding... Therefor, the total lenght of the mooring line has to be adapted in relation with the conditions you are expecting to meet and should be about ten times the water height you will have to anchor in.. (I suggest 100 meters)

What to use with the chain??

Natural fibers are no longer used.. out of "Chemical" fibers, the one which has the best elasticity (shock absorbing effect) is polyamide (Nylon, Perlon, Enkalon...).. as the breaking strenght of the 10 mm chain is 5 tons, a 16 mm polyamide line will be well adapted.. (5.6 tons) Don't oversize the rope.. Yes you will increase the strenght but at the same time you will decrease the elasticity.. and "Elasticity" is the secret..

You have the choice of three strands rope or eight strands rope (also called "square line") Eight strands rope is better..

How to connect rope to Chain??

Remember: A CHAIN HAS THE RESISTANCE OF ITS WEAKEST LINK...

a) With an "eye" splice over a thimble and then a shackle on the chain..
ALWAYS use a shackle one size biger than the chain.. and secure the pin with a monel wire.
This is a perfectly safe solution but the eye splice will have difficulties to go throuh the bow roller.. will no pass the windlass gipsy and will never go through the deck pipe...

b) with a rope to chain splice..
Two ways: the wrong one and the right one..
a) NEVER splice the rope over the rope after a "U" turn into the last chain link.. you will loose about half of the rope resistance
b) Make a direct rope to chain splice. This is quite easy to do.. when you know how!!!.. Unfortunately it is not possible to make drawings on this forum, but leave me your E.mail address and I will send you free and personnally, all necessary explanations..

I can spend hours or even days talking about this subject.. giving you looonnnggg mathematical formulas, and if necessary to convince poeple, I will.. This is a complex and highly technical subject and I'm not planning to write pages about it on this forum....

Last point, I'm currently in the LAS PALMAS (Canaria) harbor covering the A.R.C. event.. I had the curiosity to check the mooring line of those boats which will cross the ocean and spend plenty of time anchored in the Caribean.. I was affraid to realise than more than half the float has a dangerous mooring line.. (Not talking about inadequate anchors) Main points are:
A too small, rusted and not secured shackle
The use of "beautifull stainless steel anchor connector" The most common one has an axe drilled to put a "security " screw on the opposite side.. although this is a wonderfull idea to avoid unscrewing of the axe.. the hole in the middle of the axe decrease the strenght. - For a 5 tons chain resistance, this connector has only three tons of resistance.. check yours!!!.
Swivels.. theory is perfect, but under loads, swivels doesn't work.. but more than that, it is important to check their breaking strenght.. ?Not only with a "on line" pull but also with a side way pull..
Connecting links.. they have a breaking strenght of only few hundreds of kilo.. NEVER use them on a mooring line.

What to use to connect the anchor and and the chain??

a shackle is perfect.. as before, always one size bigger than the chain..and secure the pin..
the simplest and perfect way is to use a toggle.. the same you use for your rigging.. and again one size bigger than the chain (12 mm for 10 mm chain)

Well.. anymore question?? :0)

Fair winds and peacefull anchorages..
 

claymore

Well-known member
Joined
18 Jun 2001
Messages
10,644
Location
In the far North
Visit site
Re:the Right solution...

Thanks for that - it makes my initial post seem a little unresearched. I am not going to use chain and warp - just chain. My boat lives in the west coast of Scotland where there are a variety depths to anchorages. I always tend to err on the side of caution and so if anchoring overnight will normally put down 4 or even five times the length of chain to max depth if I can. This practice has proved successful and I haven't had any major problems with dragging.
In truth what prompted myoriginal post was the fact that the boat is out of the water now and it is common practice in the yard to bring all the chain out of boats and store it on a pallet on the gound beneath the bow. I have 40m of chain and having a wander around other boats, I seem to have a bit less than anyone else!
Thanks again for your reply.
If you are covering the ARC rally would you go and find Jon Fitzgerald and say hello from me?

regards
Claymore
 
Top