Absolute Best Ankr?

zoidberg

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Our good friend John Harries, of 'Attainable Adventure Cruising' has just published this most controversial article, with a pair of official-looking tables he's copied from 'SV Panope's site.


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He does go on to qualify his choices, and then apologises for them, then changes them around ( as you do! )


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The article he published has attracted more than a decent share of 'informed comment' - much as it might do here. :ROFLMAO: Given he has just sold his heavy 'ruffy-tuffy' expedition boat, and may not have to face the web-storm of protest that it will likely generate, I thought to expose it here ( but 'redacted' a bit in line with his requests ).

He'd rather you subscribed to his channel/site/publication, unless you've discovered how to bypass that small inconvenience. :ROFLMAO:
 

zoidberg

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John H. DOES mention the Sainted Rocna - but elsewhere in his published article. And he explains what he considers a failure sufficient to put it out of the runners for his 'Top 10 Table'.

One would need to access his very helpful - and sometimes controversial - publication to follow the several arguments. I found it well worth the subscription.... for multiple reasons.
 

Gary Fox

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I subbed them for a year, yes lots of interesting pieces. There is almost too much info out there in a way, and you can spend too much time knawing the end of your pencil, agonising over this or that choice of anchor etc...
 

zoidberg

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Yes.

Perfect is the enemy of good, or more literally the best is the enemy of the good, is an aphorism which is commonly attributed to Voltaire.

Aristotle, Confucius, and other classical philosophers propounded the principle of the golden mean

Perhaps the best way forward is simply to go use what you have, and enjoy being on the water again.

;)
 

Neeves

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John Harries conducted a 'survey' which as far as I know was never published as such and found that Rocna (and by association) Supreme could trip and when clogged with the seabed in which the anchor had been set would allow the yacht to be driven ashore. He based his assessment on actual yachts on beaches.

Subsequent to Harries comments he received a lot of criticism from Rocna owners, some of which he implied was not very pleasant.

I did some work

Anchor Resetting Tests | Practical Sailor

and can confirm Haries comments - if the fluke is clogged the anchor will not re-set until it self cleans as the yacht is dragging the anchor across the seabed.

Steve Godwin aka Panope has now done some more recent work in which he yaws or reverses tension on anchors and has found the same performance 'issues'

This is all well known but there has been no rash of Rocna for sale on eBay and no-one has admitted to dumping their Rocna/Supreme pronto and buying a Spade (Harries recommendation followed by the Excel).

In good clean sand, if you anchor in such, does not illustrate this issue and it only become a problem if your yawing is sufficiently severe or you suffer a complete tension reversal, change of tide or wind, and you are anchored in a cloying seabed. You will know how cloying your seabeds are by the time it takes you to wash your fluke clean when you retrieve your anchor.

Obviously if the issue actually occurs to you it could be a surprise and a pretty massive financial cost.

My crude estimation is that Rocna is possibly the most popular anchor currently (no need to argue about it - it IS just a guess) and most people factor this negativity of performance into their thinkings - saying it will not happen to me (and given the lack of evidence that it happens often) their decision has some weight behind it. Interestingly since Haries with drew their recommendation for Rocna, I did my work - there has been only one reported case of a Rocna anchor dragging and a yacht being wrecked (and it may have had nothing to do with clogging).

My view is that if you are buying a new anchor, now, there are plenty of anchors with the same holding characteristics that do not exhibit this clogging issue - so why buy one? I cannot comment on all of them but we have Excel, Mantus, Viking, Vulcan, Ultra, Knox, Kobra, Fortress, LFX and Epsilon. Haries damns Rocna (and Supreme by association) for failure in one seabed (though there are number of seabeds with the offending characteristics, mud, clay and weed etc etc). The Panope vids cover only specific seabeds, local to him. My testing was in a seabed which I knew would be a problem and allowed me to actually watch the anchors washing themselves clean. As Panope uses the same seabeds he is not covering the gamut of seabeds in which we all anchor - his ideas are also seabed specific (and I criticise his absence of holding capacity).

But there is no perfect anchor, they are all a compromise.

Harries does not do himself too many favours in his assessment as he ignores or minimises the galvanising issues with Spade, the fact its hollow shank might corrode from the inside, the fact the ballast chamber can hold seawater and the steel corrode and the exposure of lead alongside steel in the ballast chamber is a recipe for corrosion. - He puts Spade at the top of the list. He also rightly mentions that when you buy an anchor price should not be a critical issue as if you keep the anchor for a few years its cost is .......peanuts.

Concluding on his minimising the issues with Spade, which to me seems as likely to occur as a Rocna allowing a yacht to finish up on a beach - I have to question what else he recommends using the same analytic procedures. His procedure seem to be: we have had no issues, my correspondents have had no issues - so mention of Spade corroding is a non event. I beg to differ.

The recommendation of Spade seems very much based on loyalty and emotion - if I believed in recommendations based here, on loyalty and emotion, I suspect I'd be buying a Rocna :(

To me - Spades do corrode, Rocnas can clog - live with it, most who own these anchors are happy (as they still use them). But if you are buying an anchor maybe consider whether the weaknesses of the other anchors are less critical (than clogging or corrosion). Most anchors are rubbish in thin soupy mud, except Fortress, most anchors do not react well in cobblestones (though our use in one stony seabed has been successful with Excel), most anchors will not cope with heavy weed - all anchors work well in sand. Knox can have something caught in that split toe - we have closed it with a low profile bolt arrangement, sex bolt, (works well and the anchor suffers no issues)

Declaring any possible bias, we use Excel, Spade and Fortress and would be happy with a Kobra, Viking or Knox (though we cannot store a roll bar anchor on our bow roller). We would not touch a Mantus. We cannot justify an Ultra, despite what Haries might say and reserve judgement on Vulcan, LFX and Epsilon. None of these anchors are perfect - but we could live with those faults. We also prioritise lightweight anchors, which limits our choice to aluminium Excel, Spade and Fortress and the weight saving Viking. We would not buy a Rocna nor Supreme, because of the clogging issues (and their weight) - and there are alternatives which do not clog, have an equal hold and are light.

Jonathan
 
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Neeves

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I think the best anchor is the one with a shedload of chain attached to it!

Its an anchor thread so I disagree.

But I assume you were being flippant

Any anchor worth carrying should perform with a short length of chain and a decent length of nylon rode. In fact a decent anchor should work with a nylon rode (though abrasion might be an issue (but that's another matter).

If an anchor needs a 'shed load of chain' there is something wrong with the anchor. I'd go a bit further - a shed load of chain will not make a poor anchor reliable. The chain is simply needed to join anchor to yacht (and abrasion resistance). Modern anchors, Rocna or Spade etc, will set with the rode at 30 degrees to the horizontal, maybe higher, perfect for a decent length of nylon.

Sorry

Jonathan
 

Sandy

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I subbed them for a year, yes lots of interesting pieces. There is almost too much info out there in a way, and you can spend too much time knawing the end of your pencil, agonising over this or that choice of anchor etc...
Same here. I know a few of the occasional contributors, but found John a little unmoving in his thinking, i.e. it works for them so it must be right, and an prefer sites like that to have an open mind.
 
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The main premise at Attainable Adventure Cruising (AAC) is recommendations and analysis based on real world experience for (remote) adventure cruising and not tests. Rocna used to be supported by AAC because of its ground breaking improvement in anchor technology. In keeping with their premise, real world experience has demonstrated that Rocna is not the most suitable anchor for the type. The whole article is worth a read to understand how the spade came out on top.

There is no doubt that any of the anchors listed are good enough for the majority of sailors by a country mile, as is a CQR and Bruce etc.
 

Neeves

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Good luck with that.

How do you know - you have never tried it.

Instead of guessing - try it. Take a Rocna or Excel deploy rode to give you a 30 degree angle - and try it, you will be surprised - in a decent sand or mud seabed. I'd not suggest it will work so well in a very hard and scoured sand. Now take a longer length of nylon and try that as well. You will need to be gentle as you tension the rode - but as soon as the toe engages - increase the tension.

I know because I've tried it.

I'm also not suggesting it be common practice - just that it works and you don't need chain.

And it will not work with a Delta, CQR nor Bruce (or it might, I've not tried it). Let me know :)

Jonathan
 

jimi

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How do you know - you have never tried it.

Instead of guessing - try it. Take a Rocna or Excel deploy rode to give you a 30 degree angle - and try it, you will be surprised - in a decent sand or mud seabed. I'd not suggest it will work so well in a very hard and scoured sand. Now take a longer length of nylon and try that as well. You will need to be gentle as you tension the rode - but as soon as the toe engages - increase the tension.

I know because I've tried it.

I'm also not suggesting it be common practice - just that it works and you don't need chain.

And it will not work with a Delta, CQR nor Bruce (or it might, I've not tried it). Let me know :)

Jonathan
why on earth should i do that! I've got a perfectly good cqr with a swivel and chain. Works every time for me. I've also got 100 m of octoplait after my 50m of chain which I can deploy in extreme conditions or depth. I don't see the point in setting an anchor in a way that requires a diver with an underwater walkie talkie to set it right! I just want something that works first time, everytime just by chucking it over the side paying out 5 times the depth and engaging a bit of reverse to dig it in.
 

Neeves

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There is an archaic belief that the tension angle imposed on your anchor is determined by the amount of chain you deploy and the depth of water + height of bow roller above the seabed. This belief goes along with the idea of catenary. But lets not get into catenary here.

Angle of tension.

When your modern anchor sets the toe of the anchor and the shank end engage together and as the toe (and fluke behind the toe) buries the shackle end of the shank also buries. As the shank buries it drags down chain and the chain is also buried. However the chain has surface area and resists penetration and develops a reverse catenary. The reverse catenary lifts the shackle from the angle dictated by the rode. So the tension angle is the angle of the shackle - not the scope. In the extreme the shackle can be at 60 degrees to the horizontal in a deeply set anchor. How do I know - I've measured it.

If you want to maximise the performance of your anchor - reduce the chain size, reduce the shackle size and throw away the swivel. There are some constraints - you need to have a chain and shackle of the correct strength - hence the use of high tensile chain.

If you don't believe any of this go and look at the Vryhof or Bruce website and in every drawing of a buried anchor - they have a rode with a reverse catenary. Vryhof have a programme that allows them to calculate shackle angle based on seabed shear strength and depth of burial of anchor. Sadly we have to dig the anchors out to get an idea. Bruce actually ell devices, called boosters (check their website) that reduces or eliminates the reverse catenary (and they work, as I know someone who has used them).

Jonathan
 
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