ANCHORING

[Con_Brio]

In the past month I've three times encountered a problem new to me in all the years I've been anchoring. It arises from wind over/across tide. The boat is a Sadler 29, light and easily driven, with a shallow fin and full-length skeg for the rudder. No anchor windlass. The anchor on the bow is a 25lb CQR with 15m chain and the rest rope; backup is a 35lb CQR with an all-chain rode. The 25lb-er has settled into its familiar East coast mud with the boat facing the tide; the wind has then blown the boat over and across the anchor, so that the cable is stretched bar-taut aft along the side. Twice I have found this when I wanted to raise the anchor. I couldn't budge it by hand and think that a windlass would simply have scragged the topsides as the cable came home - even worse with an all-chain rode. Letting out more cable achieved nothing. I tried sailing it out - no go - I tried motoring it out, fearful that the cable was near the prop - no go. Eventually all that heaving induced the anchor to drag and then it was possible, with difficulty, to swing the boat far enough clear to get the anchor up. I have a simple tiller lock which holds the rudder dead centre. Should I instead have lashed the helm hard over to impart a sheer before leaving her to her own devices? Tiller upwind?
The third time it happened was in the dark in an open roadstead - the Small Downs - where we were waiting for a fair tide to go round the N Foreland, and it happened directly after we had bedded the anchor in, before I had even thought about applying a sheer. The boat was leaning hard on the warp; the tidal stream atlas appeared to indicate that the tide would begin to rise before the stream turned; so I was afraid we might drag before she swung. However, after many visits to the foredeck, I found at 2.30 am that she had swung sensibly to the first of the N-going stream and I could get some sleep before riding the stream northwards.
Using two anchors as a routine does not appeal.
I can't think why I haven't encountered the problem before (though I did have the boat in the Med for 9 years, which is part of the answer). Perhaps I have never wanted to get under way in those circumstances before or been concerned about an exposed anchorage just after having spotted the potential problem.
Is imparted sheer the answer? It doesn't help once the problem has arisen.

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[LeonF]

Same thing happened to me in Stangate creek on the Medway in my Sigma 33. Dropped anchor late at night single handed. Woke next morning by a steady thwacking on the hull to find boat had swung at change of tide and mooring warp was taut along the hull and under the boat. So taut that I couldn't let out any more slack. There was also quite a breeze kicking up a chop. Knew I should wait a couple of hours to slack but I was impatient and tried to motor astern. Nothing. Motoring forward suddenly released only to find the bitter end of the warp, neatly frayed. My spare is a light kedge so decided to leave-- it was a nasty grey day anyway--and head for home. Now have a heavier warp and more chain. And the waypoint for a lovely CQR and 10 metres of chain.

<hr width=100% size=1>L.A.R.Ferguson

 

[jbate]

I've not had this, but...
Is the problem caused by the anchor warp floating? when the tension comes off the anchor warp, boat moving over anchor, etc, warp floats up and snags hull?
If so, then you could possibly consider more chain/less warp? Or chain only?
Try using just chain and see if the problem occurs, if not then you have established the cause..
Dunno if this helps.
JB



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[vyv_cox]

I don't think so. Our mooring was often subject to wind against tide and suffered exactly the problem described. That was made of 1/2 inch and 3/4 inch chain. I don't think the situation described is at all unusual in such conditions. The difference is that it's easy to drop a mooring under some tension but not the same thing at all with an anchor warp.

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[Robin]

Wind against tide makes anchoring unpleasant and the boat will try to overun the chain/warp. With all chain there is the possibilty of chafe to the bow from the chain. With warp the usual results are as you describe.

One boat I owned came with a system similar to yours, some chain then warp, it sat quietly at anchor, no rumbling chain and no snatch and I became a convert to warp. Next time I anchored however the wind shifted and when the tide turned (about 3am as I recall) the warp was wrapped firmly around the keel and the boat was lying side on to the strong tide with the warp 'singing' under the load. Before I could untangle this mess there was a loud bang and we went walkabout, eventually re-anchoring around a bend in the channel, wind now across the tide, with the kedge. Come daylight we could see that the warp (14mm) had cut through on the back edge of the keel. We were luckily able to recover the main anchor using the folding grapnel anchor we kept for the dinghy, but my liking for warp vanished forever! We replaced the chain/warp very quickly with all chain and never had a problem again. We do use a length of nylon with a rubber snubber to transfer the load from windlass to cleat, this prevents snatching and chain noise and potential chafe damage to the bow but is not long enough to cause the problem you describe.

There you have it, chain all chain and nothing but chain.

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[StephenW]

I had a similar problem recently in Osborne Bay IOW. Anchored up, eventually in the midst of a number of other boats that had arrived later, using a 25lb Danforth, short chain length and then nylon warp. The wind and tide were initially from the same direction (=no problem) then the tide changed and during this turn it appeared that the warp had wrapped itself around the deep fin keel on our 32. As you say, the warp became bar taut and was impossible to pull back up.

The tiller had not been lashed, and we had moved in some very strange ways, so I thought that the whole event could have been avoided by lashing the tiller. Your experience would seem to suggest it wouldn't.

Since we were getting nearer other boats I decided to start the engine despite misgivings about wrapping rope around the prop. By using short bursts on the hard over tiller (to unwind from around the keel as we suspected this as the cause of the problem)we managed to relieve the strain on the rope, which made it slacker and allowed it to be pulled in...much to my relief.

Maybe chain would have avoided this due to its heavier weight, but my guess is that the same could still happen if conditions became stronger

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[jeanne]

We use all chain, but I wonder whether using an anchor angel down the rode would avoid this problem? If we put out a second anchor on nylon rode we nearly always use the weight.

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[davel]

Also had similar problems. I'd thought about replacing warp with chain or, possibly, using a chum in order to keep the warp flatter on the sea bed. It now looks from the experience of others posting above, that this doesn't help.
Options therefore seem to be:
1. use warp to protect the hull but risk chafing through
2. use chain to avoid chafing but suffer damage to the hull
3. run out two anchors
4. don't anchor!

Any others?

Would this be a suitable subject to which the PBO/YM experts should apply their collective wisdom and produce an article?


<hr width=100% size=1>Dave L.

 

[vyv_cox]

5. Sheath the chain in something. On our mooring we used scrap fire hose, always available at your local fire station. Not very convenient for anchor chain but a fender cloth or something similar can sometimes be used.
6. A good alternative is to use a nylon warp snubber hooked to the chain at about three or four metres from the bow roller. Pulling in a little on this and cleating on deck gives some spring to the warp but without the risk that its parting will disconnect the boat from the anchor. It also means that the tensioned part will be nylon, not chain, and hull damage should then be far less.

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[AndrewB]

All chain ... Yes.

My experience too is that this common problem has largely disappeared since I switched to all chain. Not only is chain rarely stretched bar-taut behind by competing wind and tide, but I've never had the dreaded complete wrap around the keel. Nor, with a little care, has the chain ever seriously graunched the hull paint.

On the odd occasion motoring gently backwards has taken the pressure off to aid in raising the anchor, but I wouldn't risk that with rope warp.

The down side is the cost and weight of the chain, which has made a windlass essential.

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[Johnjo]

In wind over tide conditions, when the boat is charginging around, over running the anchor chain,
what works for me at times is a drogue over the stern, couple of buckets do it for me,
might not work for everyone though, but worth a try!

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[Robin]

And put a rubber snubber (like Gondalastik, Plastimo) into the nylon length too, it really does then take out the snatch loads on the anchor and the bow roller. We have 2, the standard one and a heavier one for when it is really bad, we have also used these lines in exposed marina berths to good effect. We used to use a S/S hook to attach it to the chain but the hook straightened (!) in a Vent Solaire one night in S Brittany, so now have some proper cast S/S chain hooks. The lines are long enough so that the chain just rides below the forefoot but cannot reach the keel if wind against tide. That said I also try very hard to avoid wind against tide when selecting an anchorage.

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[Robin]

All chain plus short length of nylon + rubber snubber. Attach to chain and let out enough so that the chain hangs in a slack loop from the bow. The line should be long enough so that the tensioned part of the chain is below the surface just far enough to clear the bow/forefoot if the boat rides forwards, under load from ahead it will be above the surface. Best way to attach it to chain is with a chain hook, most proper chandlers sell them for about £10 as well as rubber mooring snubbers, about £15-£20. The nylon is wound through and around the snubber so the snubber can stretch a selected amounted (vary by number of wraps), if it fails the nylon takes the load, if that fails the chain takes the load, if that fails get outa there!

People used to warp worry about weight of chain especially without a windlass, but you are only lifting the weight of chain equal to the depth, the anchor weight is the same anyway. I never had trouble lifting a 45lb anchor with 8mm chain and didn't bother with the manual windlass which was too slow. We later fitted an electric windlass (oh luxury) when we went to 10mm chain and anchored in deeper water more often. Unless you are a fanatical racer or have a very fine bow, the extra weight forward will be unnoticeable, if you look at similar boats the majority use all chain too, at least in UK waters.

If you use a windlass you must transfer the load from the gypsy to a foredeck cleat or risk damaging the windlass with snatch loads anyway (see windlass manuals) so you might as well do it properly and have a more comfy, quieter night.

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[charles_reed]

I stumbled on the solution.

My boat, despite being on 8mm chain used to over-run her anchor chain and sheer around like a mad thing. Whilst one could protect the hull by various expedients rebuilding the front of the keel became a major task every lift-out.

When I fitted a wind generator on a cockpit gallows she lay like a lamb, head to wind and, even in 3 knots of contrary stream, stopped running over her chain.

Whether this would work with other boats is very dependent on whether they are wind or tide rode - mine definitely tends to being wind ridden.

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[qsiv]

The other, standard, advantage of 6 is that when the tide changes (why does the tide always change at 03:00 when you are anchored?), it insulates you from the noise of the cable resetting.

We dont often suffer (it takes a lot of wind to drive 30 tonnes around), but on previous, smaller, lighter boats a bucket over each quarter usually sufficed to keep us tide rode.

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[DeeGee]

Re: All chain ... Yes.

Isn't the problem that the wind pushes the boat out of line with the current, so her hull then presents as a foil angled to the the current. She then 'sails' forward, restrained by the cable, until she can go no more, and sits there 'straining at the leash' so to speak.

Surely, as this has nothing to do with electronics or modern hull shapes, this must have been around for a long time, and the old salts must have sorted an answer?

Raising the main, or a mizzen if you have one, at the time you want to go, reduces the bow blow-off somewhat, and gives you some room to manoeuvre - possibly?

I haven't figured out how to prevent it - Memo to first mate: find me an old salt. )|:>)x:::====

<hr width=100% size=1>Black Sugar - the sweetest of all

 

[Chris_Robb]

I used to have a Sadler 25 with Chain and mainly warp. It was forever getting the warp between the fin and skeg - which is I supect what is happening to you. I had a quick routine to get out of it. I tied a large fender to the bitter end - and chucked the lot overboard. As soon as the fender appeared clear of the boat, I would motor round and pick up the fender and reanchor.

I then added a very large weight 15ft down from the bows on the warp. This prevented the warp getting between the fin and skeg - never had the problem again.



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[Guest]

when anchored at aldeburgh last year in wind over tide conditions it was necessary to buoy the anchor cable ( 10m chain and 14mm warp) and drop it over board as it was bar taught along and under the hull with the boat lying across the tide. Upon retrieving the cable I discovered it was badly frayed where it had rubbed against the cheeks of the bow roller. Since changing to an all chain anchor cable there has been no problem

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[rickwat]

Glad to hear the drogue works for you. I bought one last year for my cat which often gets blown towards the anchor but havn't tried it yet. On a mooring buoy I have to shorten the line to just under the foredeck but this gives a very bumpy stay. The skill must come in harnessing just enough tide to balance the wind but I'm not that sophisticated so I'll go for a bit of overkill.

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