Dropping an anchor and chain whilst making way

[cagey]

What do you think would happen if you’re doing 5kn sailing on any point if you let go 20 metres of chain and anchor, assuming you were in 30 metres of water, again assuming sand or mud bottom what is likely to happen if there is only 15 metres of water, would there be any slowing by chain and anchor through the water, would it stream behind before it hit the bottom and then what, sudden catastrophic stop or hairy roundingup. A what if question.
Ta
K

 

[lpdsn]

I'm sure it must depend upon the type of anchor.

Seriously though you would get some drag from an anchor in the water and if it touched bottom a lot more resistance, with it possibly stopping dead. First action would be to duck in case the boom came across, after which you could go to the bow and check for damage.

 

[awol]

You are reinventing "club hauling". Try it and let us know.

 

[cagey]

You are reinventing "club hauling". Try it and let us know.

Every day is a school day, never heard the expression before and a quick google shows an interesting naval gunnery use but I was curious how much slowing and or disruption the tackle going through the water would have.
When I’m confident of the depth I will give it a go.
K

 

[Mr Cassandra]

We did it on the North West coast of Corfu? by the rock that looks like a submarine It was on a first 345 with two buttons close to the anchor well.One of my daughters pressed the button and we came to a violent stop with no idea what the hell was going on.
Flotilla holiday 1994-5

 

[lpdsn]

When I’m confident of the depth I will give it a go.

Try doing it at slow speed first with the boom not too far off the centre line.

I've done it when the quadrant shattered jamming the helm half over. Would've been doing two knots max but the mainsheet was uncleated and no one left in the cockpit thought to do anything about when I ran forward to drop the anchor.

 

[johnalison]

I reckon the drag through the water and the catenary would take most of the abruptness off the stop. I met somene once whose anchor jumped into the water while they were going through the Alderney Race, taking the whole length of chain with it, still attached. He didn't notice it at the time and it wore a large hole through the toe-rail/side-deck.

 

[zoidberg]

Have done that deliberately, as a 'running moor' in Port Ellen.... in 5 metres of water, beam reach at ~3-4 knots/mainsail only, dropped the anchor with 30m. chain running out. As the anchor ( est. ) hit the bottom, put the tiller half-over and bore away. The chain described, as it ran out, an arc and the CQR dug very firmly into sand as the weight came on progressively. The bows came sharply round, and we stopped, head to wind.

Nothing further was needed, apart from a half-hour anchor watch on deck, then supper and a hot toddie below. It blew hard all night, from the NW, but the beach, the cottages, and the hedges kept us gently bobbing until morning.

 

[Neeves]

Every time you retrieve your anchor you lash it down and as back up add some sort of chain lock, I mean everyone does this as standard practice - so its a very hypothetical question - a bit like asking 'what happens when you hit a rock mid Atlantic'

Jonathan

 

[Lon nan Gruagach]

What do you think would happen if you’re doing 5kn sailing on any point if you let go 20 metres of chain and anchor, assuming you were in 30 metres of water, again assuming sand or mud bottom what is likely to happen if there is only 15 metres of water, would there be any slowing by chain and anchor through the water, would it stream behind before it hit the bottom and then what, sudden catastrophic stop or hairy roundingup. A what if question.
Ta
K

Compare your anchor to a sea anchor, that will give you a good idea of what happens before it hits the bottom, remember though that this is on the bow and, if you are not moving straight forwards it will pull to one side.
Now, 20m chain in 15 m water.. Who here thinks thats enough chain for the anchor to set? Not me.
By far the most likely (no matter how soft the bottom) is that the anchor will skip making the boat lurch slightly, dipping the bow (mebby a tad more than slightly). As you get more chain, or shallower water the lurches will increase to the point of one final full stop. At which point you will spin around to face all your followers (all paying up the bets as to what would happen)

 

[oldharry]

Everybody who knows what they are doing. But not everybody, by any means...

 

[lpdsn]

Now, 20m chain in 15 m water.. Who here thinks thats enough chain for the anchor to set? Not me.

Obviously that's not enough chain if you want the anchor to set. However if you don't then it's bound to snag on something.

 

[cagey]

Now, 20m chain in 15 m water.. Who here thinks thats enough chain for the anchor to set? Not me.
My question was what effect would the chain and anchor have on the boat and then if the depth decreased what would the effect then be, never was it intended to be a scope question, perhaps drudging.
Why don’t people read a question before trying to gain brownie points

 

[Neeves]

I don't think anyone is trying to gain brownie points - it seems a very unlikely scenario only one produced by an owner who does not follow simple and basic rules.

20m of chain, 15m of water - you simply don't know what is down there - the anchor might catch something immovable, tree, rock, wreck - you will stop dead, you might damage the bow roller. You will suffer a moment of panic, your wife will never forgive you. There is no catenary effect, or so little as to be irrelevant. The anchor might simply slide through the mud (and if you are silly enough not to lash of the anchor - maybe you will not notice). So what might happen - everything or nothing.

A more likely scenario is you are inaattentive enough not to lash you anchor, the clutch slips in 200m of water and all your chain deploys - until it is stopped by the bitter end (assuming you secured it). One scenario is - your windlass is inadequate to retrieve all the chain and anchor - so test it before you lose both chain and anchor - it has happened.

Learn to secure the anchor - the situation and any like it will never occur.

Jonathan

 

[pandos]

Probably not the answers to your exact question, I sailed into a marina one day proud as punch having just moored alongside on my own without any hassel and at the first attempt in a tightish spot... just walking towards bar when a fellow asked " I am only new to this sailing business so excuse my maybe stupid question....why do you have your anchor hanging in the water as you motpr along" my chain had slipped through a shackle and was about 6m below the surface.... I did not notice.

motoring down a river at night with too many obstructions for auto pilot and several small sailboats and dingies about I had an immediate need for the loo (food poisoning ). Put engine in neutral. Run to bow. layout 10m of clain on deck tie off to cleat through anchor over board run to cockpit, boat does handbrake turn, bow goes close to under, trip to loo..... retrieving anchor was fun, was almost un movable had to tie off and drag /jerk it out ...

In summary, without contact with the seabed I think little noteable difference on 35ft heavy yacht..

 

[cagey]

I don't think anyone is trying to gain brownie points - it seems a very unlikely scenario only one produced by an owner who does not follow simple and basic rules.

20m of chain, 15m of water - you simply don't know what is down there - the anchor might catch something immovable, tree, rock, wreck - you will stop dead, you might damage the bow roller. You will suffer a moment of panic, your wife will never forgive you. There is no catenary effect, or so little as to be irrelevant. The anchor might simply slide through the mud (and if you are silly enough not to lash of the anchor - maybe you will not notice). So what might happen - everything or nothing.

A more likely scenario is you are inaattentive enough not to lash you anchor, the clutch slips in 200m of water and all your chain deploys - until it is stopped by the bitter end (assuming you secured it). One scenario is - your windlass is inadequate to retrieve all the chain and anchor - so test it before you lose both chain and anchor - it has happened.

Learn to secure the anchor - the situation and any like it will never occur.

Jonathan[/QUOTE
Mr Neeve I know you have an anal fascination with all things with anchor in the subject but you obviously haven’t read the question or any of my subsequent answers. I am after an answer to the question of how an anchor and chain behave when lowered whilst a yacht is making way I am not after a lesson in seamanship in this instance. If you don’t know the answer, then please don’t interfere with my pursuit of knowledge. Some of the answers and anecdotes have been fascinating, whereas yours and one other have been an abysmal waste of time.

 

[elton]

I made last ditch efforts to save myself while being driven onto Boulby rocks, by throwing an anchor, chain and warp (?) over the stern, and wrapping it round cleats. The anchor bedded or caught in rocks as I did this; the rope in my hands broke six fingers, and that was that. Goodbye boat, hello helicopter

 

[Neeves]

Cagey,


Good luck with your search for knowledge(?)

Your testy responses do not engender much desire to help you. I have lowered an anchor under way - to wash it and chain, but this scenario is not clear from your opening post (and my answer would contain anal detail in which you would possibly(?) not be interested).

Jonathan

 

[noelex]

What do you think would happen if you’re doing 5kn sailing on any point if you let go 20 metres of chain and anchor, assuming you were in 30 metres of water

I once sailed a 40 foot yacht (not mine) in an emergency situation with the anchor and about 60m of chain deployed in perhaps 100m of water.

Surprisingly, it sailed quite well and serious trouble was averted.

I have no idea if this was typical and I have no desire to deliberately repeat this experience, but it suggests that if the anchor is not touching the bottom and you are prepared to accept a few scratches on the bow, it is possible to manoeuvre with the anchor down without too many problems even under sail. You would obviously only do this in an emergency situation.

 

[Iliade]

I did it with about 40m of chain in about 50m of confined water when my water inlet blocked: Being windlassless I was almost unable to recover the chain...

My anchor chains are always secured through the bow roller so no hull damage likely if deliberately deployed. However, in heavy weather, I have had the hook washed off the deck complete with the bucket containing rode & chain (yes it had all been tied down), and it passed over the guardrail. The change in boat motion was not discernible so it may have been there a little while before it was spotted. No damage ensued but it was a mare to recover.

I have anchored a quarter tonner many times by lobbing the anchor off to the side while still making way. It results in something of a handbrake turn and does help to set the anchor in light wind when no engine is available to to so the modern way.