Conachair
Guest
Well it won't be straight, no. A straight catenary is impossible in the real world. But when conditions get really bad the chain won't be touching the bottom. It will point pretty much at the anchor.
Anchor chain is 50m enough?
- Thread starter Seven Spades
- Start date
Well it won't be straight, no. A straight catenary is impossible in the real world. But when conditions get really bad the chain won't be touching the bottom. It will point pretty much at the anchor.
Poignard
Well-known member
You could have also added that if there was an infinite tension on the chain then the chain would be straight!
I wouldn't have added that either.
Conachair
Guest
Rigger Mortice
N/A
Fine, but let's get back to the real world.
Poignard
Well-known member
I agree 100%.
Let's do that, and let's forget about pseudo science and continue to choose our ground tackle based on our own experience or, where that is insufficient, on the experience of those whose opinions we respect.
Rigger Mortice
N/A
Exactly.
The question is, is the "science" produced by Rocna valid or simply marketing blurb?
The question is, is the "science" produced by Rocna valid or simply marketing blurb?
Poignard
Well-known member
I don't know - I haven't read it. But my experience of life and salesmen suggests the latter
Scotty_Tradewind
Well-known member
I don't know - I haven't read it. But my experience of life and salesmen suggests the latter
Have you tested a modern anchor to experience the difference between that and your CQR?
I suggest you do. In fact if my Twister doesn't sell early in the season, I'll lend you my 10kg Rocna for a while to judge for yourself and perhaps you may just modify some of your feelings against modern anchors and their salesmen.
www.sailingscotty.com
Poignard
Well-known member
Have you tested a modern anchor to experience the difference between that and your CQR?
I suggest you do. In fact if my Twister doesn't sell early in the season, I'll lend you my 10kg Rocna for a while to judge for yourself and perhaps you may just modify some of your feelings against modern anchors and their salesmen.
www.sailingscotty.com
That's a generous offer but what difference might I experience? All I'd be doing is swapping a CQR that works for a Rocna that works.
Conachair
Guest
It's valid. Doesn't matter if the chain is tied to an anchor, an island or a very large teacup, if it doesn't drag when you need the catinery most with large forces on the boat it won't be there, the chain will not be touching the bottom but pointing pretty much at the teacup or anchor.
Another site explains it here - http://alain.fraysse.free.fr/sail/rode/static/static.htm
and a some spreadsheets to play around with - http://alain.fraysse.free.fr/sail/rode/synthesis/synt.htm
Rigger Mortice
N/A
Thanks for those links. I'll have a good look at them later, but on the face of it they seem to be more comprehensive than the blurb which Rocna is attempting to pass off.
However, the fact that, in the extreme, a chain will lift off the bottom is not in dispute......it's pretty obvious really. What I am querying is the stuff which Rocna is coming out with to explain the obvious, also the follow up waffle and, most importantly the conclusions. Basically they are using mickey mouse science to justify the assertion that we all dump our existing tackle and go out and buy a larger anchor (by which they obviously mean a Rocna). If you then ask them to support their assertions all they do is provide lots of links to their own pseudo science.
It's a bit like asking a Jehovah's witness to prove that the Bible is fact. All he will do is quote the Bible at you!
Why do I get concerned about it? Simply because Rocna are continually using this forum to push their own commercial interests and supporting their arguements with twaddle.
However, the fact that, in the extreme, a chain will lift off the bottom is not in dispute......it's pretty obvious really. What I am querying is the stuff which Rocna is coming out with to explain the obvious, also the follow up waffle and, most importantly the conclusions. Basically they are using mickey mouse science to justify the assertion that we all dump our existing tackle and go out and buy a larger anchor (by which they obviously mean a Rocna). If you then ask them to support their assertions all they do is provide lots of links to their own pseudo science.
It's a bit like asking a Jehovah's witness to prove that the Bible is fact. All he will do is quote the Bible at you!
Why do I get concerned about it? Simply because Rocna are continually using this forum to push their own commercial interests and supporting their arguements with twaddle.
Twister_Ken
Well-known member
Which is a shame, coz I suspect it's actually a damn fine hook. But I keep looking for reasons not to buy one and choose a competitor instead.
Scotty_Tradewind
Well-known member
well I think you will find that you are swapping for an anchor that 'works' within a few feet almost every time and that because it's more likely to stay in that position you are likely to have less requirement for all that chain.
www.sailingscotty.com
Conachair
Guest
RichardS
N/A
It's no surprise that Craig should favour Rocna - it would be madness if he didn't - but I find it refreshing that someone from a major manufacturer is prepared to join in a public forum at all - most will not!
Richard
Poignard
Well-known member
well I think you will find that you are swapping for an anchor that 'works' within a few feet almost every time and that because it's more likely to stay in that position you are likely to have less requirement for all that chain.
www.sailingscotty.com
It does 'work' every time - if it didn't I would have got rid of it. And I don't use 'all that chain' unless I need to. In settled conditions I use four times the depth at HW, or 3 times if somewhere very sheltered and confined.
You, and your anchor manufacturer, are offering me a solution to a problem I don't have!
Rigger Mortice
N/A
Hardly a major manufacturer. It's Father, son and maybe one or two others.
But they still talk twaddle. Utter twaddle. Most other manufacturers who come on here speak some sense.
I must admit that I also find the way they berate their competitors completely out of order.
But they still talk twaddle. Utter twaddle. Most other manufacturers who come on here speak some sense.
I must admit that I also find the way they berate their competitors completely out of order.
Rigger Mortice
N/A
You're more charitable than I am. I suspect that it is an OK anchor but there is no way I would buy one. I don't like the way they do business.
In any event my Danforth is fine. It has never let me down
AndrewB
Well-known member
Err, well, despite the total lack of interest, I thought you might be curious.
We held fine - wind now down to 25kts. Anchoring in 10m (at high tide) on gravel, the chain was split into two 50m lengths set approx 30deg apart, one with a 45lb CQR on the end and the other a sort of vaguely 60lb CQR lookalike.
A yacht nearby dragged - I didn't ask if they had a Rocna.
Rigger Mortice
N/A
Pure luck of course. And all that heavy metalwork hanging of your bow.
If you had a 10lb Rocna and 3 metres of chain you would have been just as well off. They'll shortly be back with the figures to prove it.
What were the gusts reaching?