How much chain needed on anchor?

J

JimC

Well-Known Member
Joined
30 Aug 2001
Messages
1,570
Location
Lancashire
Visit site
I know that matters related to anchors have been discussed endlessly on the forum but I've not found a thread that addresses my particular concern. My 31 footer is rather fine forward, and I carry a 10Kg Delta anchor on the bow roller and a rolled-up inflatable and a windlass on the foredeck. I'm restricted in the weight of chain I can carry without giving her a nose-down attitude. I've read that the minimum is the boat's length and this happens to be what I have: 10 metres of 8mm which was on the boat when I bought her. To this I have spliced 70 metres of 14mm octoplait. She wanders round a bit at anchor, which I accept and allow for, but I haven't yet dragged - although yet to experience severely testing conditions. I do worry that the chain length might be marginal and would be glad to hear the forum's views.
 
Jim, would your yacht really trim noticeably down by the bow if you put another 15 m of chain in the forward locker?
If you are worried about this when sailing, then think also of the effect of having say 2 or 3 stocky crew sitting in the cockpit - their weight will be substantially more than the weight of the chain up forward.
OK, the longitudinal inertia will be increased slightly by having extra chain forward (and heavy crew aft), which might increase pitching a wee bit, but I doubt that the effect would be significant.
And if it allows you to sleep better, knowing you have more chain out or available, then that must be a plus?
 
One of my early boats came with 5 m of chain and a rope warp, she was around 30 feet, fin keel skeg rudder built in the mid 70's.

In the 3 years I had her she broke free twice, both times in sand, I suspect this was more due to the anchor type rather than the lack of chain.

We had a few sleepless nights at anchor with high winds and waves but she never failed to hold under these conditions.

Good luck.:)
 
Bajansailor said:
think also of the effect of having say 2 or 3 stocky crew sitting in the cockpit - their weight will be substantially more than the weight of the chain up forward.
Click to expand...
True, but the boat has much more reserve buoyancy aft so weight in the cockpit won't affect her trim like weight in the bows. I am willing to add more chain if necessary - just looking for advice as to how much (if any).
 
JimC said:
I know that matters related to anchors have been discussed endlessly on the forum but I've not found a thread that addresses my particular concern. My 31 footer is rather fine forward, and I carry a 10Kg Delta anchor on the bow roller and a rolled-up inflatable and a windlass on the foredeck. I'm restricted in the weight of chain I can carry without giving her a nose-down attitude. I've read that the minimum is the boat's length and this happens to be what I have: 10 metres of 8mm which was on the boat when I bought her. To this I have spliced 70 metres of 14mm octoplait. She wanders round a bit at anchor, which I accept and allow for, but I haven't yet dragged - although yet to experience severely testing conditions. I do worry that the chain length might be marginal and would be glad to hear the forum's views.
Click to expand...

Jim,
That's pretty much what's recommended. Length of boat in chain plus rope. Size of rope depends on what's easy to handle. 14 mm nylon is very strong. My 30 footer has 8 metres of 10mm chain. I was going to buy 10 meters of 8mm chain when I replaced the chain a couple of weeks ago but the 10 mm chain had a much better looking galvanising and so To keep the weight in the anchor locker the same I used 8m of short link chain.
I sold my fishing vessel a few months ago and we always used the same chain rode combination, even anchoring in 110 metres of water. The full chain thing is very rare here, matter of fact I can't remember seeing one for ages.
 
It also depends on whether you have a windlass.
You should choose to have a length of chain which allows you to bring the chain and anchor aboard by hand when the whole assembly is hanging vertically from the bow.
If you have 30m of 8mm chain, thats about 22kg and plus your 10kg anchor.... gives 32kg ...less a bit for flotation in water.
I reckon thats about as much as the wife could comfortably manage!!!!
 
Last edited:
Do you really need that weight in the bow?

Anchor and chain have no effect on the trim of the boat when deployed, only when not deployed. But when not deployed, there is no need (apart from convenience at the beginning and ending of each anchoring episode) for them to be at the bow. Can you therefore store them elsewhere, moving them forward when needed?

I recall seeing several boats where the chain was kept in a chest just forward of the mast, with the anchor kept on chocks well back on the foredeck. I've even seen a boat with the hawse pipe just forward of the mast, with the chain stored below it in the bilge.

Fashion and convenience seem to dictate storing anchor and chain at the least buoyant part of the boat where, incidentally, they also encourage pitching.

Is it essential in your case that they be there?

The anchor locker could be used - for example - to store warps and fenders which are almost certainly used more often than your anchor and chain. Doing that would free up space in a cockpit locker where the ground tackle could live until needed. If that sounds impracticable, remember that it's perfectly possible to anchor by the stern then move the rode to the bows when the hook is down and working.
 
Last edited:
Anchor rode

SHUG said:
WHAT!!!!!!!!!!!
Click to expand...

Yes that is correct. Also here on the west coast of Oz all chain is very unusual. The authorities here require you carry an efficient anchor and quote 10 metres of chain with rope as regarded as an efficient anchor rode.

It is strange that there are different habits for boating in UK which are considered vital in UK but are not complied with in other parts of the world. ( like roller reefing jibs)

For my opinion I think a bigger anchor and 10m of chain would give better performance than a smaller anchor and all chain for less weight increase. However in the end it is your sleep and your peace of mind in a field of so many variables when you are anchored. I have quite a lot less than 10m of chain and a danforth but then I don't anchor much. Good luck olewill
 
JimC said:
I know that matters related to anchors have been discussed endlessly on the forum but I've not found a thread that addresses my particular concern. My 31 footer is rather fine forward, and I carry a 10Kg Delta anchor on the bow roller and a rolled-up inflatable and a windlass on the foredeck. I'm restricted in the weight of chain I can carry without giving her a nose-down attitude. I've read that the minimum is the boat's length and this happens to be what I have: 10 metres of 8mm which was on the boat when I bought her. To this I have spliced 70 metres of 14mm octoplait. She wanders round a bit at anchor, which I accept and allow for, but I haven't yet dragged - although yet to experience severely testing conditions. I do worry that the chain length might be marginal and would be glad to hear the forum's views.
Click to expand...
All boats wander around a bit at anchor. 10 m is a good length for most of the UK and you're not going to notice big differences from more chain. If your boat's sailing and misbehaving, try experimenting with various ideas to minimize it, such as putting the rode a little off-center and/or a riding sail.

If you're worried about the anchor not holding, then you need to upgrade it. You say you have a 10 kg Delta. Consider the options of adding 5 kg to your system: a) upgrade to a 15 kg anchor, never mind improving the type (!), or b) adding 5 kg of 8 mm chain = 3.6 meters.

One will improve your anchor system's holding power by 50%, the other will do next to nothing. Take a wild guess.
 
I've mentioned this before, so apologies to any who've seen earlier posts.

For a start, I completely agree re. your concerns about weight, if I carried a lot of chain on my 22, even though she is quite buoyant forward, her performance ( normal not racing ) would be crucified.

That doesn't alter the fact I have to anchor in the same depth of water as larger boats...

I also don't anchor very often, when I do it's usually in secluded shallow spots.

For 'proper' holiday cruise anchoring though, this is my grand plan;

I have a 7.5kg Bruce anchor ( apparently not trendy now but I've always found it brilliant in 32 years ) 6 metres of 1/4 - heavy - chain and 40 metres of 14mm nylon.

I also carry a 7.5kg folding grapnel as a kedge.

I very rarely lie to 2 anchors - if I did I'd have another spade type anchor not the grapnel, but there are good reasons for the grapnel.

For a start, if everything went pear-shaped and I ended up having to anchor on rock, the grapnel has a chance of penetrating weed and holding on a pointy bottom, which the Bruce and any spade I can think of won't.

The rest of the time, i use the grapnel as an 'angel', lowered in folded state halway down the bower warp.

This gives the lower angle of pull and takes the shock out of waves in heavy weather, and also crucially it prevents the anchor warp from fouling around the deep keel as she tends to sail the anchor.

It also allows one to use a shorter than text book rode, if in a confined anchorage in good weather and not leaving the boat.

One quick tip I found re. sailing the anchor, for short stops in good weather I throw a sea anchor drogue over the stern; this prevents getting the warp round the keel, but extends the boats' swinging circle and increases pull on the anchor.

I've got on well with the above set-up on my Anderson 22 lift keel cruiser-racer for the last 32 years, going around Chichester-Falmouth and Channel Isles to N.Brittany.

I'll say again though, I completely agree with the OP's concerns about weight carried - another reason I'm keen on the grapnel as an angel, it's multi-purpose; no way am I going to cart around just a weight blob to use as an angel !
 
Last edited:
Twister_Ken said:
Fashion and convenience seem to dictate storing anchor and chain at the least buoyant part of the boat where, incidentally, they also encourage pitching.
Click to expand...

Could you explain that bit? I would have thought that putting mass away from the axis of movement would increase the moment of inertia and discourage pitching, but perhaps I am missing something obvious ...
 
Ubergeekian said:
Could you explain that bit? I would have thought that putting mass away from the axis of movement would increase the moment of inertia and discourage pitching, but perhaps I am missing something obvious ...
Click to expand...

You're partially right - it does increase the moment of inertia but, once a pitching movement has started, it increases and then sustains the pitching. Think a long pendulum vs a short one.

That's why race boats go to great lengths to keep weight out of the ends of the boat (including the mast).
 
Twister_Ken said:
You're partially right - it does increase the moment of inertia but, once a pitching movement has started, it increases and then sustains the pitching. Think a long pendulum vs a short one.
Click to expand...

Thanks. A sort of resonance effect, then?

That's why race boats go to great lengths to keep weight out of the ends of the boat (including the mast).
Click to expand...

They tend to have taller masts, thought, don't they, which will have the same effect. I suppose it's a matter of balancing aerofoil efficiency with pitching problems.

I've taken the mast down on the Jouster (no reasonable offer refused) while she was afloat a couple of times ... it's astonishing how much less comfortable things are without that nice big lump of moment of inertia ...
 
Thanks to everyone who has contributed their advice & opinions. Having studied all the posts the conclusion I've reached is that my length of chain is sufficient and, if I am able to add a little more weight, this would be better invested in a heavier anchor than a few yards more chain.

Twister Ken: I can see the sense in your idea of stowing the anchor & chain aft where the hull has more reserve buoyancy and bringing it forward only when needed but.... I visualise my yacht with blown-out sails and failed motor being driven onto a rocky lee shore. Last hope is the anchor, I just don't see myself clawing my way forward over the heaving deck clutching anchor chain & warp to my bosom. Neither would I fancy anchoring stern-on to the seas which are breaking - I'm in the surf by now. I can see some mileage in the idea, perhaps one could secure the bitter end fwd and lead the rode aft outside the stanchions, but for now I'll leave it's development to those with a less pessimistic imagination and a better sense of balance.
 
There is one other factor which has not been discussed: in areas where a strong tidal stream turns 180deg quite rapidly a rope rode can in some wind conditions and with a bilge-keeler in particular, become trapped between the keels. Not only is this a real pain to untangle, but I was once horrified to find the octoplait warp rode nearly cut through where it had rubbed on the keel. Since then I have always used all chain whenever possible.

Vic
 
JimC said:
Twister Ken: I can see the sense in your idea of stowing the anchor & chain aft where the hull has more reserve buoyancy and bringing it forward only when needed but.... [...] I just don't see myself clawing my way forward over the heaving deck clutching anchor chain & warp to my bosom.
Click to expand...

I'd agree with that - storing the whole kaboodle somewhere aft and manhandling it forward when needed doesn't seem practical on all but the smallest of boats. However, if a proper chain locker can be arranged, complete with navel pipe, somewhere further back than the extreme point of the bow, I think it would be of benefit. In practice this is probably something that has to be designed in from the start, or come as part of a fairly major interior refit, so I realise it isn't all that relevant to your question.

I have seen pictures of a boat which had a navel pipe cut in the side deck just athwart the mast, and the chain locker converted from the bottom part of the standard 70s-layout hanging locker opposite the heads. That's certainly well back from the bow, but I don't know if the boat remained on an even keel afterwards :-)

Pete
 
You must log in or register to reply here.

Other threads that may be of interest

Y
Quick Aries 1000 anchor windless noisy
Replies
0
Views
97
yotter
Y

Share this page

Top