Chesapeake Anchor Holding Power Test

Carl,
Some people think surface area is everything. Not so. A big anchor near the surface could be pulled out whereas a smaller anchor buried deep w tons of seabed on top of it may not pull out w the same force.

Refer to what happened in the Fortress test. How can it be otherwise explained? A car applies power to the drive wheels on ice .. nothing happens. But on dry pavement ... Bad analogy? You can fly through the air easily but through the water you need more force. And in a seabed even much more. Perhaps the huge difference in the volume of seabed pressing down on the anchor is not anywhere linear giving a big advantage to the deeply set anchor.

But probably this big difference applies at wildly different levels in different bottoms. So Carl I think your "big is better" and "surface area is everything" philosophy probably applies more often. Quite likely most of the time.

But I can see where at times a smaller anchor may have greater holding potential.

Delfin said:

By the way, does this mean you are finally willing to admit you are not a Zulu warrior???

Click to expand...

:lol:

Delfin said:

This is the fundamental reason I go on about the only limitation I see in hoop style anchors - if they don't dive, their maximum hold is static so what you get setting it in 20 knots is pretty much what you'll get in 80 unless it drags and hits something solid.

Click to expand...

Delfin, with respect, this is just not right.

Here is the Mantus setting deeper in response to stronger wind.

First is the initial set with the engine which is equivalent on my boat to about 25-30 knots of wind:




Next an actual wind force of 25-30 knots of wind. The anchor is very similar, but has set just a fraction deeper:




Next 45-50 knots and much deeper again:



Naturally the holding power increases as the anchor dives deeper.

Note: this is true of any of the rollbar anchors. The Mantus is just an example. I have seen the Rocna and others do exactly the same thing. In softer substrates they will be buried deeper again, but the same principal holds true. The anchor will dive deeper. This suggestion that rollbar anchors do not dive, bears no resemblance to what is observed in practice. In soft substrates the rollbar will disappear completely in strong wind.

Sorry no photos of 80 knots

Noelex

Nice beach, now for those organic mud, gravel, rock and boulder piles I seem to find on the bottom more often than not. One anchor for all bottoms is my mantra and that is where the Chesapeake test and it's clones fall short.

Strong and heavy anchors, like a rugby or American football players have stood the test of time. Nothing magic that way but it doesn't lead to 37 pages and counting which is the whole advertising purpose.

sunchaser said:

Noelex

Nice beach, now for those organic mud, gravel, rock and boulder piles I seem to find on the bottom more often than not. One anchor for all bottoms is my mantra and that is where the Chesapeake test and it's clones fall short.

Strong and heavy anchors, like a rugby or American football players have stood the test of time. Nothing magic that way but it doesn't lead to 37 pages and counting which is the whole advertising purpose.

Click to expand...

Bingo.

manyboats said:

Carl,
Some people think surface area is everything. Not so. A big anchor near the surface could be pulled out whereas a smaller anchor buried deep w tons of seabed on top of it may not pull out w the same force.

Refer to what happened in the Fortress test. How can it be otherwise explained? A car applies power to the drive wheels on ice .. nothing happens. But on dry pavement ... Bad analogy? You can fly through the air easily but through the water you need more force. And in a seabed even much more. Perhaps the huge difference in the volume of seabed pressing down on the anchor is not anywhere linear giving a big advantage to the deeply set anchor.

But probably this big difference applies at wildly different levels in different bottoms. So Carl I think your "big is better" and "surface area is everything" philosophy probably applies more often. Quite likely most of the time.

But I can see where at times a smaller anchor may have greater holding potential.

Click to expand...

I don't think we are disagreeing on anything, are we? Two identical anchors, one made of depleted uranium and the other aluminum. The heavier anchor will dive deeper and hold better than the aluminum anchor will. That's just physics. And, as anchors scale up and the weight per square inch of surface area also goes up the heavier anchor will simply be more efficient in digging deeper than the lighter anchor will. Maybe there is one, but I can't think of a situation where that would not be true.

Also dictated by physics is the fact that a hoop anchor will be inhibited in digging as deeply as a well designed anchor without the hoop. Whatever Noelex thinks his pictures reveal about the product he promotes, the above photos show me a hoop anchor that predictably never buries itself - even in sand. I have no idea whether that is simply the resistance created by the hoop, or that combined with the rotational force on the hoop causing it to tip the flukes more level than they would be otherwise. Does anyone think that a Rocna wouldn't disappear under the sea bed if you could remove the hoop after it had done its job to get the set started? If Noelex's photos were of an equal weight Sarca Excel, Spade or Ultra, the picture would be of a beach because the anchor would be gone.

Carl
And buried 1" below the surface in sand is not what I'd call buried by diving.

And a short scope will keep an anchor from burying too.

Noelex,

I notice you have studiously, and in my mind dangerously, ignored the issues raised by Morgan's Cloud that roll bar anchors when filled with mud and subsequently forced to somersault can simply drag due to clogging.

Your vast experience of 7 years at anchor is better than the combined experience of the people who contribute to Morgan's Cloud (and others who have said the same thing) and you say anchors do not somersault but shuffle round. I note that this comment of yours has been contradicted by actual evidence. Possibly now you can concede you are wrong and the 75 pages of images and your comments lack credibility.

I also notice that in not one of your images of your set Rocna, which you suggest is well set, do we ever, not once, see a fully dived anchor - one that has disappeared completely. Yet other anchors disappear, my anchors completely disappear. The evidence is that you do not know how to set an anchor - or more likely your anchor is simply far too big (and simply cannot be set properly). Hold is dependent on depth, not weight of anchor, and your recommendation that your ridiculously large anchor is 'right' looks very suspect.

You have never once, to my knowledge, acknowledged the testing conducted by Fortress that show roll bar anchors in a poor light.

Frankly I think you are misleading the public by providing a rather glamorous dialogue omitting minor detail like, a clogged roll bar anchor might not reset, a ridiculously large anchor might be difficult to set deeply, like the shank of the Mantus has never been tested and shown to be adequate, like the roll bar on the Mantus can bend out of shape. Moreover you are quick to damn anchor for piling sand, yet you show images of Rocnas piling sand - but this is accepted.

You show anchors in the same anchorage and compare them - and are well aware that seabeds vary metre by metre - but this does not worry you, why spoil a good story with reality. Of course you only show convex anchors in a bad light and some of them you condemn (and look no better or worse than your favourites).

I can cherry pick and paste your images, as I guess you do, but why waste my time. If you want to compare anchors do it properly and stop appearing like a snake oil salesman. There are an increasing number of people who think you are a sham - which is a pity - you could have used those very excellent images for the good of Forum not for the good of a select and chosen few.

I am confidently expecting you t ignore this post - its too difficult for you to counter, and as in the past you will studiously ignore the dangers you are ignoring.

The issues that need discussion are:

Integrity of the engineering of the Mantus
Roll bar anchors clogging
The appalling performance of roll bar anchors in the Fortress tests
Your bias, without clarification, against convex anchors
Your ability to compare 2 anchors of different size, set different ways in different seabeds.

Your posts and your commentators on the thread look to have a focus, bias, that is unhealthy.

Jonathan

In all fairness...what makes Morgan's Cloud...whomever that might be any more of an expert on anchors and their good/bad features than anyone else? You keep making that referral but one example (reporting source) doesn't make it a fact.

Sure...great rep, lot's of miles, friends all around...but seriously...I've been around the block and never heard of them...but then I tend to follow commercial maritime work more than recreational.

Do you have dozens or more testimonials of roll bar anchors clogging to their detriment? If so please post.

Scott'

You must have forgotten:

http://www.trawlerforum.com/forums/s42/rocna-anchors-15571-2.html

Read all the posts to the bottom, including that long and detailed post, #32. You will note that you contributed to the thread. Its close to home, its from TF. Its full of detail, warts and all.

But I agree - Morgan's Cloud are not well known outside their 'sphere' so the above posts bring it closer to home for you.

I'm not going to ask how many you want for statistical significance, as it should not be necessary - but I'll try to provide more later.

Jonathan

Djbangi said:

Noelex,

I notice you have studiously, and in my mind dangerously, ignored the issues raised by Morgan's Cloud that roll bar anchors when filled with mud and subsequently forced to somersault can simply drag due to clogging.

Your vast experience of 7 years at anchor is better than the combined experience of the people who contribute to Morgan's Cloud (and others who have said the same thing) and you say anchors do not somersault but shuffle round. I note that this comment of yours has been contradicted by actual evidence. Possibly now you can concede you are wrong and the 75 pages of images and your comments lack credibility.

I also notice that in not one of your images of your set Rocna, which you suggest is well set, do we ever, not once, see a fully dived anchor - one that has disappeared completely. Yet other anchors disappear, my anchors completely disappear. The evidence is that you do not know how to set an anchor - or more likely your anchor is simply far too big (and simply cannot be set properly). Hold is dependent on depth, not weight of anchor, and your recommendation that your ridiculously large anchor is 'right' looks very suspect.

You have never once, to my knowledge, acknowledged the testing conducted by Fortress that show roll bar anchors in a poor light.

Frankly I think you are misleading the public by providing a rather glamorous dialogue omitting minor detail like, a clogged roll bar anchor might not reset, a ridiculously large anchor might be difficult to set deeply, like the shank of the Mantus has never been tested and shown to be adequate, like the roll bar on the Mantus can bend out of shape. Moreover you are quick to damn anchor for piling sand, yet you show images of Rocnas piling sand - but this is accepted.

You show anchors in the same anchorage and compare them - and are well aware that seabeds vary metre by metre - but this does not worry you, why spoil a good story with reality. Of course you only show convex anchors in a bad light and some of them you condemn (and look no better or worse than your favourites).

I can cherry pick and paste your images, as I guess you do, but why waste my time. If you want to compare anchors do it properly and stop appearing like a snake oil salesman. There are an increasing number of people who think you are a sham - which is a pity - you could have used those very excellent images for the good of Forum not for the good of a select and chosen few.

I am confidently expecting you t ignore this post - its too difficult for you to counter, and as in the past you will studiously ignore the dangers you are ignoring.

The issues that need discussion are:

Integrity of the engineering of the Mantus
Roll bar anchors clogging
The appalling performance of roll bar anchors in the Fortress tests
Your bias, without clarification, against convex anchors
Your ability to compare 2 anchors of different size, set different ways in different seabeds.

Your posts and your commentators on the thread look to have a focus, bias, that is unhealthy.

Jonathan

Click to expand...

Sadly, I think one of the reasons anchor threads become passionate is because a significant manufacturer - Rocna - was caught intentionally deceiving the public in a way that was disgraceful. As a result, whenever someone relentlessly posts, a la Craig Smith, information that to someone with a bit of technical background or simple real world experience is clearly fallacious, hackles get raised and tempers along with them. For whatever reason, for every Fortress or Anchor Right doing testing to determine how to improve their product, or demonstrate its effectiveness, there is a manufacturer who enlists surrogates to fill the Internet with transparent b.s. that many, but clearly not all find disgraceful. I suppose all this means is caveat emptor. The world is full of charlatans promoting hot air and all buying decisions - especially those relating to anchors - should be undertaken with a skeptical mind.

I appreciate the input of folks like Jon Neeves, a.k.a. the Zulu warrior, who undertakes objective tests without affiliation to a manufacturer for providing information that can be helpful in making an appropriate choice. But as far as I am concerned, any manufacturer who engages in the kind of deceptive trade practices that Rocna has engaged in or that I suspect Mantus is engaged in should be shunned. Just my opinion.

FWIW we had a conversation today with the folks who have the 40' sloop that recently moved next to us on our finger dock. They have a Rocna 20 as we do, and they just completed a cruise to the Desolation Sound area, so I asked them how their anchor did.

Turns out they bought the anchor in 2010 when they and the boat lived in the SFO Bay area. It replaced a CQR. They subsequently did a lot of sailing in Mexico and then across to French Polynesia before bringing the boat to the PNW. They said their experience with the Rocna has been outstanding. They said it has never failed to set, and compared to the CQR, they said it sets almost immediately as opposed to the CQR which always had to be dragged around a little bit before it would finally dig in and set.

They have used the Rocna in sand, mud, rock, and coral. In French Polynesia they rode out a storm in an exposed anchorage with sustained winds of 45 mph for several hours. There was a reef a few boat lengths behind them (they said it had not been the smartest place to anchor).

They said all the other other boats in the anchorage drug their anchors "all over the place" and had to use their engines to get themselves out of trouble, sometimes several times if their reset didn't hold. But they said they didn't budge at all during all this.

They've been sailing for many years in a whole lot of places along the West Coast, Mexico, and in the Pacific, and in their opinions (with no prompting from me ) the Rocna is the best anchor they've ever used.

Granted, this is just one data point. But as with so many of the similar user testimonials I've been reading over the years, the anchor's performance in real-life situations continues to defy all the theoretical drawbacks it's supposed to have as outlined in discussions like this one.

Marin,

I'm with you on most of this.

I think the Rocna works well. All the reports I hear of the Rocna in sand, particularly by people who have changed from a CQR, are glowing, really glowing. But it does not mean its 'the best' it just means its better than the CQR. I'm prejudiced as I know the background and I try, maybe unsuccessfully, to be fair Its not about the 95% of success stories. Its about the failures and the ability to admit that their might be 'weaknesses' and that these weaknesses might be overcome by having a different design (as well) ready and available.

There are enough stories to suggest that if the fluke clogs and if the wind changes then the anchor might not re-set. There is the Fortress evidence to suggest the anchor might not set in thin mud. We can all go into denial or we can consider that these stories might have some substance. If we accept they might have some substance then there are very simple measures to reduce the risks, use a Fortress in thin mud (not exactly onerous) and use 'another style' in clogging seabeds, Ultra, Spade, Excel etc - again, not exactly onerous.

But if we decide that the 'stories' of thin mud and clogging seabeds are a fairy tale we are in danger of misleading people less knowledgeable than us - and they might meet thin mud or clogging seabeds - and I do not think we can completely ignore the risks. My view is they are very real risks - I hope you can take a wait and see, be cautious, maybe make mention that it might be a risk, and not ignore it out of hand I know you are not selling anchors (unless Boeing are diversifying) so you have nothing to lose. Someone selling anchors might prefer not to see any mention of negativity - but this is real life, with healthy dissent and we independents have no financial interest - all we want to ensure is that people are not misled, people are aware there 'might' be risks - they should check and then make their own judgement. But I cannot agree that we sweep these problems under the carpet.

Jonathan

edit I do agree with Delfin, we are very sensitive to deceit in 'anchors' there is an underlying fear (actually its not a fear it has actually happened) that maybe some (in the industry) have not learnt and are still treating us like suckers.

Don't see much difference between the old and new.

I will never trust an anchor Manufacturer again, I had to take my rocna of and replace it with an Excel.

Regards Rex.

Djbangi said:

Marin, I'm with you on most of this.

I think the Rocna works well. All the reports I hear of the Rocna in sand, particularly by people who have changed from a CQR, are glowing, really glowing. But it does not mean its 'the best' it just means its better than the CQR……...There are enough stories to suggest that if the fluke clogs and if the wind changes then the anchor might not re-set.

But I cannot agree that we sweep these problems under the carpet.

Jonathan

Click to expand...

Jonathan, small but important point of order here, but all the reports of hoops and/or flukes clogging would, I strongly suspect, be of those on anchors with concave flukes. As far as I know, my Super Sarca is the only hooped anchor with a convex fluke. Thus far, and in bottoms with what I call 'weapons grade' sticky mud, my roll bar has never clogged.

Thanks for that correction Peter, just like Eric said, I cannot eat my cereal with an upside down spoon.

Regards Rex.

sunchaser said:

Noelex

Nice beach, now for those organic mud, gravel, rock and boulder piles I seem to find on the bottom more often than not. One anchor for all bottoms is my mantra and that is where the Chesapeake test and it's clones fall short.

Strong and heavy anchors, like a rugby or American football players have stood the test of time. Nothing magic that way but it doesn't lead to 37 pages and counting -----


------which is the whole advertising purpose.

Click to expand...

+1

If your suggestions were to be found to be correct:

Are not advertisers meant to declare their financial interest? What are the moral or ethical implications to Moderators advertising, at all, and then same question but specifically on behalf of organisation that advertise on that Forum.

I'm simply a Veteran Member, which I think means I'm very old - we need a Guru to possibly answer the conundrum.


The Fortress Chesapeake tests made no claim to be anything but a one seabed test. They make no mention, that I have seen, that the results are in any way applicable to any other seabed. The make no claim to excellence, or not, of a Fortress in any other seabed. They published all the results (warts and all), they had independent observers on board.

It would be nice if they did the same in other seabeds - but I think they might have spent enough money already, maybe another anchor maker will step up.

Jonathan

Rex said:

Thanks for that correction Peter, just like Eric said, I cannot eat my cereal with an upside down spoon.

Regards Rex.

Click to expand...

Yeah…hard to clog or overload an upside down spoon, Rex.

Ah…if that last post was meant to be a quote someone else made, but the ID of the OP was lost in the translation, I could go back in and add it for you if desired, as you won't be able to edit it yourself now.

Peter B said:

Jonathan, small but important point of order here, but all the reports of hoops and/or flukes clogging would, I strongly suspect, be of those on anchors with concave flukes. As far as I know, my Super Sarca is the only hooped anchor with a convex fluke. Thus far, and in bottoms with what I call 'weapons grade' sticky mud, my roll bar has never clogged.

Click to expand...

Peter, I stand rebuked.

I am guilty as charged.

You are correct, I have never seen (or heard) any report of a convex, roll barred anchor that has clogged in sticky mud and specifically (as I think it one of a kind) a SARCA nor the more recent Super SARCA. But I have also never heard of a Knox clogging (but I suspect there are not many out there, maybe give them time) nor a Bugel (or its copies) of which there large numbers. And whilst on the subject, no mention of clogging of a Spade nor Ultra. The Ultra seems to come up super clean, the Spade can sometimes have a little compacted mud (nothing to comment on) but whether this is due to the Ultra being stainless or some design feature - do not know.

The reason for mentioning the Spade and Ultra (more the Spade) is that the upper surface of the fluke of Spade is very similar, strikingly so, to the upper surface of the Rocna. The angles are the same (the Spade is rounded a bit more, the fluke 'plan' the same - so the mechanism seems to be the roll bar. Edit, unless the weighted toe is also advantageous at 'stopping' clogging. close edit

But to be fair many owners of the Rocna and Manson suggest that the 'clogged' fluke is indicative that the anchor is working and setting up compression. So it is a well recognised phenomena.

Jonathan

another edit

and talking of eating cereal with an upturned spoon:


When the Delta was introduced (and the Bruce had been around for a few years by then and I suspect making inroads) Simpson Lawrence used to give lectures on their new Delta. This must have been in the early 90s. The party trick was take a tennis ball and a Bruce and ask someone in the audience to catch the tennis ball in the fluke of the Bruce (they breed them tough and strong in Glasgow). Apparently with great success. They then asked anyone in the audience to catch a tennis ball with the Delta.

The argument is as old as the hills (and Scottish hills are pretty old).

Delfin said:

Good post. If I understand you correctly, I would take issue with this last, in that I can't see how a large anchor is ever less efficient than a lighter one. If you look at the ratio of weight to surface area of the Ultra as an example you can see what I mean. A 46# anchor has a "holding surface" of 50 cm2 per pound. My 176# anchor has a holding surface of 32 cm2 per pound. Which is more likely to dive the deepest - the one that has less weight per square cm it needs to bury or the one with more weight per square cm? Clearly the later. If this reasoning is correct, and I can't see how it is not, then the heavier the anchor the deeper it will bury. Your point about requiring more force to get the anchor to bury is of course correct. I think what that means is that as the force on the vessel increases, the more holding power a diving anchor will develop with the heavier developing the most holding. This is the fundamental reason I go on about the only limitation I see in hoop style anchors - if they don't dive, their maximum hold is static so what you get setting it in 20 knots is pretty much what you'll get in 80 unless it drags and hits something solid.

I've always assumed this is why the big Claw I had worked so well, 100% of the time. It was heavy enough relative to its surface area that it always dug in deep, while a lighter Claw would not have done so.

By the way, does this mean you are finally willing to admit you are not a Zulu warrior???

Click to expand...

In answer to your question on bigger is better. A bigger anchor can develop a higher hold than a smaller one. No doubt.

However whether the large anchor can realise that potential will depend on the load.

To be extreme, a 30' vessel simply does not have the windage to set deeply a 200lb anchor. That same vessel can fully set and bury a smaller, say 5lb,anchor. If the anchor was 'too' small that anchor will dive (its a modern anchor) and reach its maximum holding power potential and swim through the seabed (until it meets a bit of weed or shell - upon which it will surface and drag). Somewhere between that tiny swimming anchor and the monster that cannot be set deeply is the ideal - one that under no normal condition can reach that swim depth (and its maximum holding potential) but can get close to that full potential. Anything bigger than that ideal is simply ballast and a hole in your wallet. (and extra money for the anchor maker)

Anchor size charts have been developed over decades and have initially been based on pretty inefficient anchors. Modern anchors are now twice (I do not want to get picky) as good yet the weights are the same for the new, twice as good anchors, as the old anchors - and those old anchors were found to be 'about right'. We consequently seem to have doubled the safety margin (which is no bad thing). But we also, in general, are a bit more adventurous (and go further) so maybe that doubling of the safety margin might have been whittled somewhat. We also can carry more anchors which might return that safer margin.

But basically if a 100lb CQR/Bruce was good enough then a 100lb Rocna/Spade/Excel ought be equally good enough, if not twice as good.

Some say that a Bruce works better in bigger sizes, I have a friend who says they are superb beyond 70kg. I simply do not know - but this may be dependent on seabed.


I make it look black and white (which it definitely is not) - but hopefully you get the idea.

We went the other way and use an anchor slightly smaller than might be recommended (because the recommendation is based on worst case scenario) and our anchor is very, very good. When we get to, looking like, worst case scenario we deploy a second anchor (different style but same capacity), in a 'V'. Its a personal choice works for us, has done for years - not too many agree, they prefer bigger is better and in the extreme 'ridiculous is better'. There is nothing wrong with RIB - its just extra ballast and that hole in your wallet. (and I think of seaworthiness in big breaking seas when you are on passage). Now whether we need the extra anchor, in our V, I do not know - we are cautious and prefer to stay where we are and have never had the courage to test it.

The reality is that we never hear of modern anchors dragging in most seabeds as a result of them being too small (though many when they upgrade also upsize). So we hear of dragging, in weed where the anchor cannot penetrate - but not because the anchor was small (unless its mud). Consequently the evidence seems to suggest that BIB might allow you to sleep better, but might be unnecessary - and RIB is well R.

So if you know of anyone with any modern anchor that experienced dragging as a result of it being too small it would provide some background.

I'd welcome comment


Sorry no Zulus, just thick skinned Celts.

Peter B said:

Chris, would it be possible for you to beaf up the pulpit either side of the central manufacturers slot…(thinking stout timber lengths, screwed and epoxied in underneath), then mount an auxiliary free-standing roller to one side - maybe both sides - then you could have two other options open to you. I guess it would depend on the overall width of the pulpit platform at the outer end. If you added a sort of bridle loop over the top of each roller, that would prevent the anchor skipping off the roller. Just a thought.

Cheers,

Click to expand...

Thanks. Maybe. I continue to mull. I forgot to mention the centerline spotlight complication (improving the pulpit sides may help with that), but in any case my hesitance is also taking into account the part about how to make it all look acceptable (or at least not goofy), too

-Chris

Djbangi said:

So if you know of anyone with any modern anchor that experienced dragging as a result of it being too small it would provide some background.

Click to expand...

I do see often boats drag around here... but can't say it's because of anchor size.

Aside from the occasional soft/soupy/slimy mud issue, though, it seems most often to be about technique. Or lack thereof: drop the anchor, open a beer, we don' need no steenkin' "setting."

-Chris

HFS -This thread has turned into the silliest mud slinging (bottom composition pun intended) and spit ball throwing mess I've seen since 2nd grade. Come on now - guys - we're all grown ups, yet too many of these posts are becoming so repetitive and nonsensically condescending regarding what anchor, or what portion/design of what anchor is better that the other... or no good at all for that matter... there is little sense any longer being made. Newbies to this site must be simply shaking their heads in total confusion from the silly "cat fights" occurring on this thread!

Get real!

There are a bunch of good anchor designs represented here. Each has its own high points and not-so high points. But, each has its place in the marine industry as well as its need or attraction to different boaters.

All in all: "Different Strokes for Different Folks!

Haven't you all just about worn out the repetitive innuendoes about how others' anchors are just no damn good?? Face It - They are all good in one way or another!

Djbangi said:

In answer to your question on bigger is better. A bigger anchor can develop a higher hold than a smaller one. No doubt.

However whether the large anchor can realise that potential will depend on the load.

To be extreme, a 30' vessel simply does not have the windage to set deeply a 200lb anchor.
I'd welcome comment.

Click to expand...

I'm not sure that makes sense Jonathan. Using your example, the reason the 30' vessel wouldn't 'set' the 200# anchor is because it wasn't able to drag it so that it could engage the sea bed. If it can't move it a few inches to start that process, doesn't that mean the boat is anchored securely? If it were tied off to a mooring buoy it wouldn't be able to drag that either, but that is kind of the point. You are correct that in the small boat/big anchor scenario the potential holding capacity of the anchor may not be reached, but who cares if the reality is that the boat cannot drag the big hook so as to explore that potential?

Again, I cannot see how an anchor that has more weight per unit of surface that engages with the sea bed, of whatever gross weight, is not superior to a smaller anchor of the same design that has a lower weight per unit of surface area. I think the argument not to carry an anchor that is too large is one of weight on the bow, so I've always thought the rational approach is to carry the biggest hook you can carry that you can afford and that your ground tackle can handle. Which isn't to say you can't get fantastic holding from a smaller hook that digs in, just that that holding will be less than if the anchor were weightier.

On the question of Bruce types working better at heavier sizes, that has been my experience. I can tell the Ultra I have now is set better than the same size Claw because I have to get right over the thing to break it free from the sea bed, but in terms of holding, the Claw never failed in up to 55 knots of wind, while I have experience with a 44# Bruce dragging a couple of times over 20 years.

I have taken the liberty of cleaning up the mess in the Anchor Aisle. You've had your say, now let's get back to anchoring, Pleeeeaaaaaaasssssse! Please be careful...our anchor shoppers are a sensitive lot.

Thank you!

Delfin

The little vessel with the monster anchor is 'well' anchored. The point I was trying make was that the monster anchor is unnecessary and thus a waste of money. You might need a bigger bow roller, windlass, which means more power, maybe new cables etc. Obviously if you have money in plenty and the vessel will handle the humongous anchor then why not - but its not working as it was intended, part of its hold is simply weight - because it has not been pulled below the surface by engine or wind. Most new anchors are designed to dive and when they do dive they develop increased hold (because the shear strength of a seabed increases with depth - the seabed is more compacted with depth).

An anchor that dives and pulls its shank down with it (obviously) looks a more secure bet than a larger anchor with its shank exposed or only in the loose upper layers. In a sideways load the shank will offer no or little restriction to movement if it has no seabed support. Equally the more chain you can bury the more chain you need to pull through the seabed - sideways - before the anchor is impacted.

If you take a chain and lay it in the seabed and pull it in a straight line its easy to pull (depends on how much chain and how strong you are). Take the same chain and now try to pull it sideways and what was possible in a straight line is now impossible (now think of the same chain buried).

Most new anchors now appear to be developed with hard seabeds in mind, which is why they have very sharp toes. Contrarily the Bruce appears to have been developed for a softer substrate, and maybe a specific regional softer substrate, as it has a very blunt and extensive toe and leading edge.

Manyboats has made the point that anchors, or his anchors in his seabeds, do not dive - my experience is the opposite. I see the chain disappearing into the sand - and no sign of the anchor at all. Sometimes I lose 10' of chain. I remind anyone we use small anchors. If I want to take a picture of my anchor underwater I need to take it when set at around half revs, if I use full revs I generally will not see the anchor. This obviously depends on seabed - and Eric might only anchor in hard seabeds. We do have hard seabeds, but they are murky and I cannot take pictures.

To reassure Art, I believe all anchors work in sand - its the peripheral areas that cause the issues (and many never experience soft mud, cloying clays and light weed with no bare sand patches). But the more we know of the limitations of various designs the more informed decisions that can be made - so thanks to Fortress we have a small piece of the rather large jigsaw in place.

Some anchors work better in these marginal areas and defining which anchors are better in these marginal areas seems a meritorious focus. In the meantime - anchors are a compromise.

But I'm still awaiting posts of people who have dragged because their anchor was too small. Most people I see use anchors of around the recommended size, some (a minority) go up a size (which is neither here nor there). But even the people who rely on the anchor recommendation charts, with modern anchors, are not prone to dragging (and some of these people go to pretty outlandish places). In fact the comment that is common (though I cannot quote them) 'we used to regularly drag our CQR/Delta/Bruce but now we have our Supreme/Excel/Spade we never drag and sleep at night uninterrupted' and these are people who have replaced weight for weight or maybe gone up one size.

Jonathan

Carl,
Can only guess what Draggo had in mind design wise but like everyone else he probably was trying to design a better anchor. He sorta thinks surface area is everything but the most interesting and important element of his design is the minimizing of weight and appendages that are not fluke. The shank has to be the smallest in the world and the "righting mast" is not large .. partly as it starts at the top of the shank. It's clearly smaller than a roll bar. So the percentage of the anchor that is not fluke is so small the fluke area is bigger than any anchor. No other anchor (in this respect) gets closer to the unattainable holy grail.
But yes the early XYZ was not pitch stable enough to set .. very often.
The only XYZ tested since then was the wide tipped mud version that has a tip that wants to ride up rather than down so it dosn't set either.
The XYZ I have works very well for me but I lay my rode down carefully and have not put it to extremes enough to say it would be a super anchor.
I have w my modified XYZ but that's not on the market and is a specialty anchor that probably won't work on rocky bottoms or perhaps others.
So I think the XYZ may be a very good anchor but have no grounds to say w any degree of certainty. I don't think I've recommended it to anybody.
I intend to modify the XYZ fluke tip yet again to make it a more general purpose anchor.
But re your comment Carl yes I think the original XYZ was a diver and perhaps the current narrow XYZ Extreme is too. Don't see any other anchor that has more potential.

Carl I don't see how you can say an anchor is a diver because it's out of sight. A diver (I would think) would "dive" down a foot or so ... not an inch or so.

Jonathan,
I use almost exclusively smaller anchors (under 20lbs for a 30' boat) and have never dragged.

To provide some balance to the assertions that convex anchors pile up sand and concave anchors do not here are some images that show the exact opposite:

Photos of Anchors Setting. - Page 71 - Cruisers & Sailing Forums

Jonathan