Anchor rode length?

Rossynant said:
Ależ proszę; moreover - нет проблемa :D:D
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Sorry, it's "нет проблем", no "a" at the end. Genitive plural, feminine. "No problems", grammatically sort of "none of problems". "проблемa" is nominative case; can't be used with "нет". Russian grammar is a b*tch.
 
>And don't expect the anchor to hold in strong winds, it's the weight of the catenary that holds the boat and rope has little weight.

>>oh dear, here we go...Let's see what the usual answers are:Absolutely true
Totall False

Since it's the weight of the catenary with the anchor as back up that anchors the boat how can it be false, or do think it's something else?
 
Dockhead said:
Sorry, it's "нет проблем", no "a" at the end. Genitive plural, feminine. "No problems", grammatically sort of "none of problems". "проблемa" is nominative case; can't be used with "нет". Russian grammar is a b*tch.
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You don't say... :) Learned this for ages. Compulsory :mad:
Actually I may say why the "a" - On russian square rigger up there in rigging you can hear that a lot ;)
Polish grammar is about the same style, though, so not much problem for me with russian.
But then on Iceland we met an owner of a big trawler - so I was told the story of his first mate, from Poland, who had one answer for every instance something needed taking care of; so those are the only words he knows in Polish: nie ma problema - also grammatically wrong :)

But there is another story to this... http://cdn.memegenerator.net/instances/400x/24999379.jpg
 
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KellysEye said:
Since it's the weight of the catenary with the anchor as back up that anchors the boat how can it be false, or do think it's something else?
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Both calculation and observation show that chain is not in contact with the bottom at around wind force 6 - 7. Catenary is so little to be effectively non-existent at these wind speeds, and above. You could do a lot worse than read the Alain Poireaud book referred to above. When he used to post here he was vehement that nobody should need more than 30 metres of chain, plus rope. His argument is derived from the work of Alain Fraysse (google it) which shows catenary to be of little use in higher wind speeds.

Although not arguing with the principle, there are other reasons than simply holding for using all-chain rodes, so I choose to continue to carry my 60 metres but I do use a long snubber.

If it was only the chain that held the boat there would be little difference in the holding of various anchors, which is clearly not the case.
 
>that chain is not in contact with the bottom at around wind force 6 - 7. Catenary is so little to be effectively non-existent at these wind speeds, and above.

It depends how much chain you carry and put out, we had 290 feet and 2 x 100 feet that we could link to it. Never had to use the extra chain even anchored in a strong gale.

>When he used to post here he was vehement that nobody should need more than 30 metres of chain, plus rope. His argument is derived from the work of Alain Fraysse (google it) which shows catenary to be of little use in higher wind speeds.

I doubt 30 metres of chain and the rest rope would hold in much wind at all. I saw a Moorings boat in Antigua that had that and it dragged when the wind got up to 25 knots. We went over to help him re-anchor. Alain Fraysse is wrong.
 
Well, I have approximately 15 metres of chain (5mm) which doesn't seem very much.
Will consult with the RYA guy at the marina as to whether this will be suitable for what we're going to tackle this Year but I suspect I'll be chain shopping!
 
You will :) As the scope minimum is 5 for modern (Danforth I heard?) gives you max two fathoms.... 3 may be a scope for classic hook, Admiralty. On greater depth this may be less, but not in strong wind.
 
KellysEye said:
I doubt 30 metres of chain and the rest rope would hold in much wind at all. I saw a Moorings boat in Antigua that had that and it dragged when the wind got up to 25 knots. We went over to help him re-anchor. Alain Fraysse is wrong.
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Doesn't prove a thing. I have seen loads of boats on all-chain dragging all over the place, some of them in only a force 4. I have dragged in almost no wind and no tide, when the Fortress I was testing as the bower failed to bed when the wind changed direction. I was on all-chain, inland Holland.

I also know that I can drag 60 metres of 8 mm chain along a boatyard, provided the pull is in a straight line. I doubt very much that I can pull more strongly than a boat at anchor in a blow.

We anchored in Cala Lupe, east Sardinia, for several days in winds up to 45 knots. We were in water depth 2 metres with about 35 metres of chain out. I dived on the anchor up to six times per day to watch what was happening. The whole length of chain was off the bottom for most of the time, so catenary was doing nothing for us. The construction of the rode is immaterial - it's the anchor that does the holding. The elasticity of a length of nylon helps enormously to damp the effects of swell.
 
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My own thoughts on the " chain holds the boat" theory is that the theory is much closer to being false than true. a chain without an anchor attached can be pulled along by a child on the bow.

But I do like to have plenty of chain as it won't chafe, the catenary will keep a much better angle for the anchor than rope, hopefully helping the anchor to dig in better as the wind builds up to the speed that make the catenary almost none existent, and the catenary needs almost infinite force to become totally straight so there is some elasticity at all wind levels - added to of course by a decent length of stretchy line as a snubber.

The one thing that keeps me awake at night is the rope attachment to the chain if in high winds and deeper anchorages - say 20m plus depth for me before we have to start using rope.
 
RupertW said:
My own thoughts on the " chain holds the boat" theory is that the theory is much closer to being false than true. a chain without an anchor attached can be pulled along by a child on the bow.
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Depends how much chain you have out :rolleyes:...

Have you ever tried pulling 5m of chain along wet sand?
 
Murv, please bear in mind in mind that I know almost nothing about anything - but just one more thing...

Before I did it it a few times, anchoring scared the hell out of me. I didn't sleep well, the first few times I did it. In the end, you get more used to it, and you sleep better, until the time I tried to anchor off Southend pier at 2 in the morning, and just could not get the anchor to hold for love nor money, and in the end, tried to get the anchor to foul the mooring buoy. Long story. Don't try that... However:

On one fairly recent occasion I anchored (single-handed, as ever) in an utterly utterly inappropriate place - actually inside the Crouch river, but still with a fair bit of water in between me and the prevailing wind. The lack of sleep generated by my bed going through a vertical 8 foot sine wave wasn't so much the issue, but because my rode is all chain, the battering my hull took from the chain wasn't lots of fun.

In future the solution to this would be to find somewhere better to anchor, but a length of rope would have helped my bow take less of a mashing from the chain also.

Having said that, ending up with stories to tell and hopefully exaggerate about at every opportunity (such as an 8 foot swell on the Crouch river) have always struck me as part of the point of sailing, or at least as reasonable compensation for the terrible night's sleep...
 
Reptile Smile said:
Murv, please bear in mind in mind that I know almost nothing about anything - but just one more thing...

Before I did it it a few times, anchoring scared the hell out of me. I didn't sleep well, the first few times I did it. In the end, you get more used to it, and you sleep better, until the time I tried to anchor off Southend pier at 2 in the morning, and just could not get the anchor to hold for love nor money, and in the end, tried to get the anchor to foul the mooring buoy. Long story. Don't try that... However:

On one fairly recent occasion I anchored (single-handed, as ever) in an utterly utterly inappropriate place - actually inside the Crouch river, but still with a fair bit of water in between me and the prevailing wind. The lack of sleep generated by my bed going through a vertical 8 foot sine wave wasn't so much the issue, but because my rode is all chain, the battering my hull took from the chain wasn't lots of fun.

In future the solution to this would be to find somewhere better to anchor, but a length of rope would have helped my bow take less of a mashing from the chain also.

Having said that, ending up with stories to tell and hopefully exaggerate about at every opportunity (such as an 8 foot swell on the Crouch river) have always struck me as part of the point of sailing, or at least as reasonable compensation for the terrible night's sleep...
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Good points, thank you :) and looking forward to my first 8' swells on the Medway (of which there are many, I'm sure :D )

The instructor recommended I source some additional rope, so it looks as if I'm going to learn the joys of splicing next!
 
Rossynant said:
http://www.sw-marine.co.uk/acatalog/8_strand_multiplait_to_chain_Splice.html
Another anecdote - was told from a boat - being blown on a lee shore, so they let go all the tackle and hoped for the best...
This caught and held. After the exercise some parts of chain were so elongated that for a meter or two it was stiff as the iron bar. But held :)
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:eek:

Thanks for the link, have just bought an app to start practising knots with https://play.google.com/store/apps/details?id=com.animatedknots.knots&hl=en :D
 
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