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8 minutes ago, estarzinger said:

... but it would be fun and probably enlightening to see steve try to determine if you have 2 anchors, or 4 anchors on board and a storm is forecast, what the best way to deploy them in a storm would be.

Some challenges are:

  • Dragging 2-3 well-set anchors takes scary force. I explored rigging using smaller anchors for this reason.
  • Every storm has a different wind direction change progression. Do you plan for the progression, or build a 360 degree rig?
  • The types of failure depend on the bottom type. In very soft mud you can expect even well set anchors to move some, so you plan on some stable dragging. On a rocky or very firm bottom failures will be sudden.
  • If you have a spread of anchors and some one drags down on you, you will get tangled and anchors will pull.

More than one answer, I'm sure. I tested some of my ideas by anchoring a 34' cat in 25 knots or so with 2-pound anchors, to watch them strain under a realistic motion. I also did both static and veering pulls. It was fun and I learned some stuff that worked reliably, and some stuff that never worked.

 

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When I started the anchor videos, it was just the underwater stuff and on-screen text.  Right away the accusations started flying that I was working for a particular anchor manufacturer.  Understandab

Winch testing commences.

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6 minutes ago, thinwater said:

Somewhere you mentioned switching mostly to toggled soft shackles. Have you tried those with snubbers or no? 

Why a klemheist instead of a Prusik or girth hitch? Even a simple girth hitch won't slip on chain.

Yea, I'm mostly using toggles these days and they are stronger, and work just fine . . . . but they don't seem very popular, . . . . which I get as all textile is elegant and normally way strong enough.

The Klemheist seems the easiest to get off after it has been loaded heavily - but i've never systematically tested that, just sort of my impression.

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3 hours ago, estarzinger said:

Yea, I'm mostly using toggles these days and they are stronger, and work just fine . . . . but they don't seem very popular, . . . . which I get as all textile is elegant and normally way strong enough.

The Klemheist seems the easiest to get off after it has been loaded heavily - but i've never systematically tested that, just sort of my impression.

Yup, makes sense, both parts.

I'll have to try the klemheist for that. Probably faster too. Lately I'm using rope rode, and a Prusik to connect the bridle. Might try the klemheist there too, since the Prusik can get tight.

 

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I want to set a snubber and ignore it. If it is not windy I don't want a hook to fall off because it's not stretched out, If it's been blowing all night and the snubber is long and then it calms down at 2 am and it then droops to the bottom.

We changed the soft shackle about every year with typically about year on the hook. 8mm chain. Showed a bit of wear but I'm sure some was just pushing it through the rough chain link not from real chafe from movement.

I think each leg of my 10mm climbing rope bridle was about 25'. When drawn to scale on a 40' cat it looks like this:

image.png.c9fdf7c98f2a1b6e418e622132d08599.png

 

(Lacking a windlass on my current sailing co-op boats I always anchor in about 30' at most 40' of water.)

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16 minutes ago, Zonker said:

I want to set a snubber and ignore it. If it is not windy I don't want a hook to fall off because it's not stretched out, If it's been blowing all night and the snubber is long and then it calms down at 2 am and it then droops to the bottom.

We changed the soft shackle about every year with typically about year on the hook. 8mm chain. Showed a bit of wear but I'm sure some was just pushing it through the rough chain link not from real chafe from movement.

I think each leg of my 10mm climbing rope bridle was about 25'. When drawn to scale on a 40' cat it looks like this:

image.png.c9fdf7c98f2a1b6e418e622132d08599.png

 

(Lacking a windlass on my current sailing co-op boats I always anchor in about 30' at most 40' of water.)

We don't have Zonkers precision for the foretriangle of our bridle, in light winds the size of the foretriangle does not matter, nor does the amount of bridle deployed cause concern.  But once winds develop beyond 35 knots than we would deploy more total bridle, because now the priority is the elasticity, and if the winds are getting to 45 knots (which would be exceptional (as anchoring exposed to 45 knots would be an error in choosing the anchorage) we would prioritise elasticity for the possible developing chop or swell as well as the impact of gusts and wind shear, not the dimensions of the foretriangle.

Its not only how long is your snubber but what is the diameter and then how do the two dimensions, length and diameter, relate to the yacht.  We started off in our quest for the perfect bridle using 12/13mm used climbing rope and once we were comfortable with what we were doing we invested in new rope 12/13mm x 30m on each arm (usually only using the 10m down the deck + 6m approx to the chain hook).  We found we were not now getting the stretch (different age of rope?) and downsized to new 30m x 10mm.  6t cat.  We carry the 12/13mm we retired as a storm bridle and the original used rope is used as mooring lines (they were about 15m long, each).  We would apply a back up, or storm, bridle if normal bridle looks as if it is going to be stretched beyond 10%.  But combined we would want the 2 bridles to both be kept within about a 10% stretch limit.  Our bridle is 2 separate ropes and not difficult to rig.

It would be unusual for us to anchor in really shallow water.  In shallow water exposed to the sea or ocean the waves build up when its shallow and becomes uncomfortable.  Typically we would anchor in 15' or more (we draw 3' 3" and the bow roller is about 4'6" from the water).

We often deploy a second anchor, on a mixed rode, but this is to control veering caused by shear or for tight anchorages with bullets aka wiliwaws.  If a storm is forecast - we go and find somewhere with 'real' shelter (and are not embarrassed to tie to tree and rocks - for which we carry shore lines and some spare lengths of chain (to go round the rocks).  If the forecast is for the wind to veer its simple to just deploy more rode to better balance the tension on each rode.

 

We don't carry 'spare' anchors all our anchors are large enough to be primaries, except for our FX 37 which is. chosen for thin soupy mud and is a bit oversize for us for sand.

 

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1 hour ago, Zonker said:

I think each leg of my 10mm climbing rope bridle was about 25'. When drawn to scale on a 40' cat it looks like this:

image.png.c9fdf7c98f2a1b6e418e622132d08599.png

So the legs of your bridle are about 1.5 X beam from bow to chain? 

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3 hours ago, thinwater said:

.........I'll have to try the klemheist for that. Probably faster too. Lately I'm using rope rode, and a Prusik to connect the bridle. Might try the klemheist there too, since the Prusik can get tight.

 

I use a hitch that the German's call a KreuzKlemmKnot often called a Heddon Hitch. Its simpler than the Klemheist and comes undone easily.

The pull is inline with the loop so you wrap your sling around the chain or rope towards you and only two wraps, very simple to teach to newbie crew.  Works well on chain, enough friction to keep it in place and much easier to undo than a Prusik knot.

hedden_hitch.jpg

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I hear you about exposed anchorages. But sometimes where we cruised we were somewhat exposed. Coral atolls don't provide much wind protection but do keep the ocean swells at  bay. 

image.png.a576cb2878ea0cd16c3d5a83fae13969.png

The 10mm bridles held in sustained (>1 hour) 50 knot winds. A few seconds after this picture the bows of our boat disappeared in rain in a major squall.

I got them pre-used from a local climbing gym that would retire them after some time (I'm not sure if it was on the basis of time or hard falls). So they probably were not as strong as brand new. They stretched lots and did feel like they were the right size.

Our boat simply didn't shear compared to monohulls which would veer all over the place. I think this is pretty common to most cats.

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2 hours ago, MikeJohns said:

I use a hitch that the German's call a KreuzKlemmKnot often called a Heddon Hitch. Its simpler than the Klemheist and comes undone easily.

The pull is inline with the loop so you wrap your sling around the chain or rope towards you and only two wraps, very simple to teach to newbie crew.  Works well on chain, enough friction to keep it in place and much easier to undo than a Prusik knot.

hedden_hitch.jpg

Thanks. I'll try that too. Looks fast.

The problem with klemheist, autoblock, bachmann, and perhaps the hedden (have not used) is that they are somewhat more sensitive to rope size and stiffness, and they can slide if they get too loose. I won't use them climbing because of bad experiences. I will use either a prusic, mechnical ascender, or Camp Goblin (fall arrest). But anchoring is different.

 

 

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3 hours ago, Zonker said:

.................They stretched lots and did feel like they were the right size.......

The safe continual Working Load Limit is around 10% stretch for Nylon while breaking is around 40% stretch. The energy absorbed is proportional to the extension squared but only directly related to the k value of the spring. So you want more stretch in thinner rope rather than less stretch in thicker rope.

For best shock absorbing in the situation, it should stretch close to the working limit. Usually snubbers are way over size for their length for optimal use.

It's best to leave the 10% extension limit as the slack in the chain and then watch the bight to see how much it straightens.  For the best result for any particular scenario, the chain slack should be just taken up.

It's interesting to find some k values for the rope being used, then estimate the max surge velocity, then equate the potential energy with the final spring energy at 10% stretch, and derive an optimal diameter to a fixed length :-)

 

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26 minutes ago, MikeJohns said:

The safe continual Working Load Limit is around 10% stretch for Nylon while breaking is around 40% stretch. The energy absorbed is proportional to the extension squared but only directly related to the k value of the spring. So you want more stretch in thinner rope rather than less stretch in thicker rope.

For best shock absorbing in the situation, it should stretch close to the working limit. Usually snubbers are way over size for their length for optimal use.

It's best to leave the 10% extension limit as the slack in the chain and then watch the bight to see how much it straightens.  For the best result for any particular scenario, the chain slack should be just taken up.

It's interesting to find some k values for the rope being used, then estimate the max surge velocity, then equate the potential energy with the final spring energy at 10% stretch, and derive an optimal diameter to a fixed length :-)

 

Or wing it with whatever is handy, for many of us. Once we have our 100' of chain out, we're on nylon. 

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2 hours ago, MikeJohns said:

The safe continual Working Load Limit is around 10% stretch for Nylon while breaking is around 40% stretch. The energy absorbed is proportional to the extension squared but only directly related to the k value of the spring. So you want more stretch in thinner rope rather than less stretch in thicker rope.

For best shock absorbing in the situation, it should stretch close to the working limit. Usually snubbers are way over size for their length for optimal use.

It's best to leave the 10% extension limit as the slack in the chain and then watch the bight to see how much it straightens.  For the best result for any particular scenario, the chain slack should be just taken up.

It's interesting to find some k values for the rope being used, then estimate the max surge velocity, then equate the potential energy with the final spring energy at 10% stretch, and derive an optimal diameter to a fixed length :-)

 

 

We'ed agree with the 10%.  But when you reach that 10% you need to have a fall back to ensure you don't exceed the 10% or not by much.  Because we control the length of our snubbers (which can be 100') using sheet winches  at the cockpit we can winch our snubber,  to 'close' to the bow roller, add a second bridle with its own hook, and then release.  It takes a bit of care to release such that the  extra snubber takes the snatches but does not allow the original bridle to exceed that magic 10%.  When we winch in the original snubber it is still about 60' long - so we still have plenty of snubbing - more than most have (ever).

Most cat bridles are not really snubbers, too short too beefy. 

 

Mike.Johns - look at SCRAMP - its am app that uses the accelerometer in an iPad, or phone - its designed for marine application (but not anchoring).  Its free.  It will provide surge velocity.  I've loaded it for months now - but have not had the weather to use it (blame Covid).

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9 hours ago, thinwater said:

I will use either a prusic, mechnical ascender, or Camp Goblin (fall arrest). But anchoring is different.

yea,  agree with this.

For mast climbing I use Prusik, ascender and gri-gri.

I did some max grip strength testing on all these gripper options, but I never did any sort of cyclic grip reliability testing - my anecdotal experience is consistent with yours and logically you would expect grip reliability to be inversely related to ease with which they are to undo. 

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Wondering what the loading difference is on each end of all chain rode.  All the snubber attachment discussion had me thinking about the other end.  We have all chain with a pretty big Vulcan anchor.  I use a two bow shackle attachment to the hook.  A 7/16 Crosby shackle is the biggest we can use in the chain end, have always considered it the weak link.  I'm guessing it will never see the same loading profile as a snubber attachment point on the other end, but would be curious if Steve or anyone has ever done a load cell comparison.

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19 hours ago, estarzinger said:

Can't say I have vast experience, and happy not to.  I just muddle along.

Sure, but you’ve been muddling about for like 20 years and two boats and a circumnavigation and high latitudes...  I’m all ears :-)
 

19 hours ago, estarzinger said:

for the triple snubber set-up - super simple idea, never did any 'math' on any of this - 3 independent snubbers, rigged so most elastic one took load first, 2nd most elastic and 2nd strongest took some load when the first stretched a way, and then strongest one (least elastic) took some load when the 2nd one stretched a bit.  In actual practice mostly just to provide backup in case one chafed thru.  I only very rarely used all three, not too infrequently used two and sometimes those two were the 2nd and 3rd ones just skipping the first.

 

Thanks for this!  (Presumably  this means you used different materials and diameters for the various snubbers?  I can see how, for high latitudes work, you’d really want to have this dialled in...)

 

19 hours ago, estarzinger said:

The more contentious storm issue is how best to deploy multiple anchors.  I know what I do, but I really don't know if it is in anyway theoretically best (or might be worst).  It would be complicated (like most anchoring things) but it would be fun and probably enlightening to see steve try to determine if you have 2 anchors, or 4 anchors on board and a storm is forecast, what the best way to deploy them in a storm would be.

100%.

Maybe sounds silly, but are there books on this sort of thing?  I actually don’t even recall seeing any such thing (only Earl Hinz’s old but comprehensive book on mooring and anchoring.) The Pardeys, of course, did the storm sailing tactics book, and lots has been written on the huge topic of seamanship, but I wonder if someone has tried to synthesize some info somewhere (without claiming it to be the authority on it).  About as much as I grasp about storm anchoring is that “big anchor + extra scope + chafe protection” (and maybe even motoring ahead to keep strain off the rode in some cases) = good.  More than that, well...not at all!

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I don't think anyone wants to claim to be an authority on anchoring, since it varies so much between areas, bottoms, and boats! There are only people who have cruised a lot, people who have done some testing, and people who are just sure.

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While reading this I though of something we did on the 378 I was stationed on in the USCG.  The docking lines where 3" in diameter and over 300 feet long.  At the end that went to the pier we spliced in a light line that was 20% longer then the distance between the splices.  When that loop when tight you needed to ease the line.  We also used the same thing on tow lines.  In that case the light line was tied with clove hitches.  
It seems like the same thing could be used to confirm the loads where where you wanted them on the stubber. I remember we used 20% where people here talk about 10%.  Just need to change the distances. 

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1 hour ago, seaker said:

While reading this I though of something we did on the 378 I was stationed on in the USCG.  The docking lines where 3" in diameter and over 300 feet long.  At the end that went to the pier we spliced in a light line that was 20% longer then the distance between the splices.  When that loop when tight you needed to ease the line.  We also used the same thing on tow lines.  In that case the light line was tied with clove hitches.  
It seems like the same thing could be used to confirm the loads where where you wanted them on the stubber. I remember we used 20% where people here talk about 10%.  Just need to change the distances. 

Stretch is material and weave dependent.  The 10-12% BS WLL is fairly normal for nylon, but the elongation to break can range from 35-85%, with lower numbers for DB and higher numbers for climbing ropes. Additionally, stretch and permanent elongation change with age and use history. For example, a rope that has been used hard may be stretched nearly 10% with no load (Did you measure the rope when it was new? Did you measure it the same way?). Add that to your figuring.

This is only a science when you have all of the information... which most often you don't.

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3 hours ago, SASSAFRASS said:

Wondering what the loading difference is on each end of all chain rode.  

If the chain is being lifted off the bottom (so there is a more than zero angle at the shank) then you can do math, and the difference is relatively small - just as an example (45kts 175' of 3/8" chain in 20' of water for Hawk): 1082lbs at bow vs 1056lbs at anchor shank.  (btw, there is a decent little iphone app called anchor chain calculator which makes the math easy).

If the chain is not being lifted off the bottom, it would depend on bottom friction on the chain, which would vary greatly depending on the location.  If you dive your anchor Im sure you have seen instances where the load on the shank is likely near zero even with some significant wind loading on the boat.

 

 

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24 minutes ago, estarzinger said:

I might well be a vampire or a zombie.

That's a frightening concept. So now you're spreading unsafe anchoring practices to take others over to the dark side of the undead?

That is a new spin on some of your advice.

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On a light note, I thought I'd share a pic from our recent vacation.   There were not a lot of options for tying off our stern line but thanks to our Fortress stern anchor, we found a solution (obviously NFG if nasty weather is expected)

Apologies for the rotated pic. I could not get it to rotate

Fortress in "Bush mode" :D

20210903_115315.thumb.jpg.a978bf2e4ef86675f59ed690dbafa453.jpg

Edited by py26129
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40 minutes ago, py26129 said:

On a light note, I thought I'd share a pic from our recent vacation.   There were not a lot of options for tying off our stern line but thanks to our Fortress stern anchor, we found a solution (obviously NFG if nasty weather is expected)

Apologies for the rotated pic. I could not get it to rotate

Fortress in "Bush mode" :D

20210903_115315.thumb.jpg.a978bf2e4ef86675f59ed690dbafa453.jpg

Speaking of bushes, Then there was the time my boat anchored itself in a bush one fine December winter storm :-). (And seeing how she had nine lives, like a cat —the boat’s name was Calico, after all— she sensibly came to rest with her rubber gunwhale “bumper” strip, and not her fragile fibreglass hull, precisely where the rocky bit sticks out of the cliff at the head of the bay :-) :-) )

05ACB6E4-A215-45DB-AD04-644337CDE90F.jpeg

1ADBE95E-E6B7-4839-A1AB-71A607327D40.jpeg

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On 9/7/2021 at 5:08 PM, Saw Q said:

 

..............look at SCRAMP - its an app that uses the accelerometer in an iPad, or phone - its designed for marine application (but not anchoring).  Its free.  It will provide surge velocity.  I've loaded it for months now - but have not had the weather to use it (blame Covid).

I use Android based phones and I've been using the sensors for a while for data logging, validated/adjusted against some large expensive calibrated instruments we used to clamp on. 

I've been using logging apps such as the "Physics toolbox suite".  These modern phones/computers  are very capable data loggers once you work out their limitations.

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3 hours ago, TwoLegged said:

Lewmar produces a lot of good quality gear.  Maybe not the best, but usually pretty good.

So it's weird that they sell such a poor anchor

Developing an anchor that will be successful in the market place AND in the use requires a wide range of skills not the least of which is a good bit of "art".  It is easy to imagine a large(ish) corporation lacking in that department, especially if a "committee" is involved.  

Apple had Steve Jobs.  

Who does Lewmar have? 

Is he/she a world class anchor fanatic?

Steve

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11 minutes ago, Panope said:

Developing an anchor that will be successful in the market place AND in the use requires a wide range of skills not the least of which is a good bit of "art".  It is easy to imagine a large(ish) corporation lacking in that department, especially if a "committee" is involved.  

Apple had Steve Jobs.  

Who does Lewmar have? 

Is he/she a world class anchor fanatic?

Steve

They can make an anchor correctly, while the Delta is not at the top of its class for holding, it's well made. That they choose not to with the Claw indicates that it is marketed to people who largely don't give a shit.

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7 hours ago, Ishmael said:

They can make an anchor correctly, while the Delta is not at the top of its class for holding, it's well made. That they choose not to with the Claw indicates that it is marketed to people who largely don't give a shit.

I beg to differ. In my experience marketing people do give a shit, just they don't know shit.

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29 minutes ago, European Bloke said:
7 hours ago, Ishmael said:

They can make an anchor correctly, while the Delta is not at the top of its class for holding, it's well made. That they choose not to with the Claw indicates that it is marketed to people who largely don't give a shit.

I beg to differ. In my experience marketing people do give a shit, just they don't know shit.

EB, Ish was talking about the buyers, not the marketers.  The claw sells to people who think that it looks like a Bruce, so it must work like a Bruce ... and don't know that subtle differences degrade its capabilities so severely that it doesn't work like a Bruce.

Lewmar's marketers are cynically exploiting the ignorance of buyers.  There is interesting potential here for a lawsuit, because there is a good case to be made that the Lewmar Claw is not fit for the purpose for which it is sold.

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6 hours ago, TwoLegged said:

Lewmar's marketers are cynically exploiting the ignorance of buyers.  There is interesting potential here for a lawsuit, because there is a good case to be made that the Lewmar Claw is not fit for the purpose for which it is sold.

I'm not buying the whole Irish thing with you, Leggs. I'm pretty sure you're actually that ambulance-chasing lawyer on the billboards inside the Reno, Nevada airport.

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42 minutes ago, IStream said:

I'm not buying the whole Irish thing with you, Leggs. I'm pretty sure you're actually that ambulance-chasing lawyer on the billboards inside the Reno, Nevada airport.

I hoped that my secret would be safe :(

Anyway, now that it's out: dial 1-800-TWO-LEGS to get our team of legal eagles working for YOU!  No win, no fee!

And if you too have been shipwrecked by a useless Claw Anchor, call direct to our team of marine specialists: 1-800-W-ANCHOR

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It seems like there are a lot of lame anchors out there. Maybe we should sue the navy for the navy anchor first. I've got a pretty high regard for Lewmar, but I never bought a Claw from them.

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Props to you Panope for this thread.  I finally had my first anchor-pull when the Delta that came with our boat dragged under a 180-degree shift and increase to maybe 35-40 knots in what had started as a very sheltered bay with soft mud bottom.  After recovering and resetting the Delta I threw out a second 7.5kg original Bruce, but the line-squall had passed anyway. 

I hope you do find a 10kg original Bruce to test, because Bruces are still out there, and it would be interesting to see how they stack up in your comparison - especially versus the Lewmar Claw: is it the basic design, or those little details you were pointing out.  Good work.

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7 hours ago, bacq2bacq said:

I hope you do find a 10kg original Bruce to test, because Bruces are still out there, and it would be interesting to see how they stack up in your comparison - especially versus the Lewmar Claw: is it the basic design, or those little details you were pointing out.  Good work.

WTF? 

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If an individual is concerned over their anchor they will have knowledge, directly or indirectly.  of Steve's work.   Based on that work - if they have issues they will already be using one of the anchors at the top of the list, say the top five.  Either people are happy - or they will have changed.

If a Lewmar Claw, Delta, CQR etc - is that bad the owners will already have changed.  If they are happy - it will be difficult to influence their choice as they maybe don't anchor much (or in trying conditions), or are lucky and know something that allows them to anchor safely.

Influencing the many is easier than influencing the last few.

The market also has considerable inertia - Rocna, despite, or because of, bendy shanks is one of the best known brands, it has been damned for retaining mud and then dragging - have many taken notice?  How many here have dumped their Rocna......Mantus has never been tested for ultimate hold (does anyone care?), its shank bent (did anyone care?), its toe bent, (did anyone care ?).  there are other factors influencing usage....

Anchor design has reached a plateau - new anchors are much of a muchness - a tweak here, a tweak there. 

Spade was the last big step (though never really recognised, part of the problem), what is the next big step?

 

 

 

 

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The German Yacht.de report I linked to here before also tested an imitation 10kg bruce. Didn’t say if it was lewmar or someone else. 

They likewise awarded it a very low score. 

My translation:

Soft mud: The anchor dragged around 9 meters through the mud before it held

Slimy mud with grass: The anchor did not find any holding in the thick grass

Hard sand: On the hard substrate it dragged around 9 meters before it held

Very soft sand near shore: Dug itself in quickly from one side and then righted itself; went in deep

Holding test on mud with some grass: The anchor held to around 500 kg before it started to drag

Summary: This Bruce copy failed extensively in the tests. Only in soft sand did it show some of its qualities, but did not have good holding power. 

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19 hours ago, bacq2bacq said:

I hope you do find a 10kg original Bruce to test, because Bruces are still out there, and it would be interesting to see how they stack up in your comparison - especially versus the Lewmar Claw: is it the basic design, or those little details you were pointing out.  Good work.

You could actually make that come true by donating a Bruce to Steve and Paypal him $500 or so. 

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2 hours ago, Blue Crab said:

You could actually make that come true by donating a Bruce to Steve and Paypal him $500 or so. 

Have him send me the $500, and I will just tell you what the result would be :)

10kg bruce holding power sucks compared to other 10kg designs in almost all bottoms.  10kg bruce will beat 10kg claw but generally not by a huge amount.  If you want a decent bruce copy - we found the Manson Ray to be quite reliable (at least in the large sizes we used).

Back when Bruce's were more available and popular the general wisdom was that they did not scale down well and you did not want to use anything less than 20kgs (and still like one size bigger than you would use in another design). I think that is generally good advice still; I always found this 'scaling' answer a bit suspect (there was a time when anchor shapes did generally get cruder in the really huge sizes, that is still generally true for ships today, but less true today for stationary platforms), but there is no question that a bigger anchor will cover up design sins.

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43 minutes ago, estarzinger said:

Back when Bruce's were more available and popular the general wisdom was that they did not scale down well and you did not want to use anything less than 20kgs

That general wisdom did not accord with my experience.

The 5kg Bruce which we used when cruising a J/24 was a wee wonder.  Only about 6' of chain on it, and it never dragged, whatever the conditions.

We had bought a 7.5kg Bruce in response to the doom-mongers, but soon decided that we didn't need it, so we used the 7.5kg as a static mooring.  The only flaw in that plan was that it held so well that by the end of the season it took a huge effort to lift it.

Yes, I know that modern anchors are better.  But those days, every one else was using CQR or Danforth, and compared to them the wee Bruce was a piece of magic.

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19 hours ago, TwoLegged said:

That general wisdom did not accord with my experience.

Even when 'general wisdom' is 'generally correct (which is certainly not always)  there are (almost) always exceptions.  Here I guess the leprechauns probably sprinkled some ferry dust on your wee bruce :) 

 

Out of curiosity - this was doing coastal cruising in ireland?  My memory is generally quite thick mud bottoms?

I would have guessed a danforth would do better than the tiny bruce. Are there alot of weeds in the mud?  Our huge Bruce's just chomp right past weeds with mass so I dont generally notice them unless extremely thick.

There are frequent wind changes, perhaps that causes the danfoths to trip out regularly?

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15 minutes ago, estarzinger said:

Even when 'general wisdom' is 'generally correct (which is certainly not always)  there are (almost) always exceptions.  Here I guess the leprechauns probably sprinkled some ferry dust on your wee bruce :) 

Haha!  There was definitely some magic involved.  I tend to attribute it to my substantial stash of homebrewed alcohol under the cockpit, but it would be safer to give more credit to the little people.

17 minutes ago, estarzinger said:

Out of curiosity - this was doing coastal cruising in ireland?  My memory is generally quite thick mud bottoms?

Yes, it was coastal cruising in Ireland.  mostly south and south-west coasts.  Bottoms mostly thick mud, but some sand.  I esp remember a wild night in Derrynane harbour, a glorious natural harbour with little shelter and a sandy bottom.  it can get very squally in a blow, and there were lots of other boats dragging, but our magic wee 5kg Bruce held firm.

In hindsight, we had one other key advantage: lack of windage.  No coachroof, no coamings, no dodgers, no COTB, minimal deck gear, no furled genoa, no sails on deck overnight (mainsail and headsails were bagged and stowed).  Another bonus from going small and simple.

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On 9/18/2021 at 1:00 PM, Panope said:

 

Good observations. So, are you going to sharpen one of the Claws to see if that makes a profound difference? Yes, that would obviously increase corrosion.  But I have a 2-pound Claw I would like to use as a dinghy anchor, and that might make the difference; unlike the Mantus Dinghy Anchor, a 2-pound Claw is not enough for an inflatable. Corrosion is not really that big a deal in this application. I also use the 2-pound claw as a kayak fishing anchor, but in that case it is already enough.

There is something to be said for not TOO sharp. For the first year, until it got some wear on it, the Mantus Dinghy Anchor could easily puncture a tube.

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22 hours ago, estarzinger said:

... Back when Bruce's were more available and popular the general wisdom was that they did not scale down well and you did not want to use anything less than 20kgs (and still like one size bigger than you would use in another design). I think that is generally good advice still; I always found this 'scaling' answer a bit suspect (there was a time when anchor shapes did generally get cruder in the really huge sizes, that is still generally true for ships today, but less true today for stationary platforms), but there is no question that a bigger anchor will cover up design sins.

I have (and others) done scaling tests on consistent bottoms (not rock, weed, trash) and found the numbers consistent over an astoundingly wide range. But that consistent bottom caveat is very important. Also, I personally have not studied the Bruce/Claw design in this way.

I wonder if the blunt curves of the Bruce change the way is cuts into the bottom and scalability. Certainly, it does not like to roll over into setting position if there are weeds or trash... unless it is heavy enough to mash through them. Which could explain the difference in behavior with larger sizes.

It is so unique in shape and function, it is likely the rules are different. Interesting that Bruce has moved away from that design for platform anchors. Of course, these anchors do not have to self-right or rotate.

Bruce Anchor

 

 

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27 minutes ago, thinwater said:

Good observations. So, are you going to sharpen one of the Claws to see if that makes a profound difference? ..............

It's tempting, but once I modify an anchor, it sorta "kills it" for future tests. 

I learned a ton as a result of my MANSON SUPREME modifications, but I have since added (and will continue to ad) numerous numerous protocols that that the Manson 'misses out on'.

If I find another CLAW at a giveaway price, I will do it.

Steve

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........Speaking of 'give away' anchors......

Yesterday, after viewing my CLAW video, a gentleman offered to donate a GENUINE Bruce 10kg.  He lives several hours away and has offered to deliver it this weekend.

 

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1 hour ago, Panope said:

Yesterday, after viewing my CLAW video, a gentleman offered to donate a GENUINE Bruce 10kg.  He lives several hours away and has offered to deliver it this weekend.

Now that's a real gentleman.   A mensch.

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5 hours ago, Panope said:

It's tempting, but once I modify an anchor, it sorta "kills it" for future tests. 

I learned a ton as a result of my MANSON SUPREME modifications, but I have since added (and will continue to ad) numerous numerous protocols that that the Manson 'misses out on'.

If I find another CLAW at a giveaway price, I will do it.

Steve

Yup, I've modified a few anchors for testing. I understand. I'll probably have a go at one of my Claws (I have two, 2-pound Claws).

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I know, I', a killjoy.

 

Why this fascination with the historic and the also rans - why not more attention at differentiating those at the top of the pile.

 

In the past superficial attention was focussed at the top of the heap, for example - Rocna - it was flavour of the month, for years - and then Morgan's Cloud found a bucket of iced water.  No-one is going to buy a Bruce, but they may buy a M1, M2. Vulcan, Viking, Epsilon, Knox - where is the Achilies heel of today's 'anchor's fantastics'.

If you have a Bruce, Claw, Ray (or no name) and are happy - little that future tests might offer will change you mind.  

I wonder how many jumped on the bandwagon and bought .........? and wish more tests had been conducted

I know I'm a killjoy, on delete, burn the books - let's play to the gallery.

 

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41 minutes ago, Saw Q said:

I know, I', a killjoy.

 

Why this fascination with the historic and the also rans - why not more attention at differentiating those at the top of the pile.

 

In the past superficial attention was focussed at the top of the heap, for example - Rocna - it was flavour of the month, for years - and then Morgan's Cloud found a bucket of iced water.  No-one is going to buy a Bruce, but they may buy a M1, M2. Vulcan, Viking, Epsilon, Knox - where is the Achilies heel of today's 'anchor's fantastics'.

If you have a Bruce, Claw, Ray (or no name) and are happy - little that future tests might offer will change you mind.  

I wonder how many jumped on the bandwagon and bought .........? and wish more tests had been conducted

I know I'm a killjoy, on delete, burn the books - let's play to the gallery.

 

It's quite interesting to know how different a modern anchor really is to what many of us might currently use.

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29 minutes ago, European Bloke said:

It's quite interesting to know how different a modern anchor really is to what many of us might currently use.

West Marine, Voile et Voileurs, the Classification Socities and a host of others have done that since 2006.  It is well acknowledged that the current anchors have, roughly, 2 times the hold of the previous batch (which is why Rocna, Excel, Spade, Ultra are SHHP anchors and CQR, Bruce, Delta are HHP anchors).  We know the anchors pre, say, Spade have been superseded, we know the new ones all work somewhere - what we don't know are their weaknesses.  Rocna was the best thing since sliced bread - and many rushed off to buy one.  People still think Rocna are the best thing since sliced bread and many think the M1 is sliced bread, toasted with jam and cream on it......totally ignoring the cholesterol and sugar.......in fact they don't want to know - so better to burn the books, put on ignore - common attititude (look at the flak Morgan's Cloud received)

 

Currently M1, M2, Knox, Viking, Rocna, Supreme etc etc are all better than previous generations  - what we don't know are their weaknesses (as underlined by Morgan's Cloud removal of recommendation of Rocna).  What other anchor that are now 'top of the heap' are going to be shown to have fundamental weaknesses  tomorrow - or do we wait for 5 years time when yachts end up on beaches (which is what happened with Rocna).

Those that sponsor anchor testing surely want in depth testing - not a regurgitation of what has been published, many times.

 

The Devil's Advocate

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4 hours ago, Saw Q said:

I know, I', a killjoy.

 

Why this fascination with the historic and the also rans - why not more attention at differentiating those at the top of the pile.

 

In the past superficial attention was focussed at the top of the heap, for example - Rocna - it was flavour of the month, for years - and then Morgan's Cloud found a bucket of iced water.  No-one is going to buy a Bruce, but they may buy a M1, M2. Vulcan, Viking, Epsilon, Knox - where is the Achilies heel of today's 'anchor's fantastics'.

If you have a Bruce, Claw, Ray (or no name) and are happy - little that future tests might offer will change you mind.  

I wonder how many jumped on the bandwagon and bought .........? and wish more tests had been conducted

I know I'm a killjoy, on delete, burn the books - let's play to the gallery.

 

This is not a new POV, Cap. No joy was killed by this post.

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7 hours ago, European Bloke said:

It's quite interesting to know how different a modern anchor really is to what many of us might currently use.

And there's a practical side to this.  Comparing a more recent design to what I currently have informs deciding whether to upgrade.  When I got my boat, I didn't trust the floppy old danforth it came with, so I bought a claw.  That seemed the best available option at the time, but it did occasionally give me trouble.  When the original Rocna came along, I bought one.  It was a big improvement, and I've been very happy with it so far.

I can't say I'm surprised to find that the Rocna also has its weakness, but should I upgrade again?  Knowing what the weakness is, and how it compares to other anchors helps me to weigh up

  • how often I'll face the risk of it not setting in a wind shift
  • whether I can mitigate the risk (say, setting a bahamian moor or standing an anchor watch when a big wind shift is expected)
  • how big an improvement I can get (and at what cost) in a new anchor

If you're buying a new anchor you only have to compare among the top contenders (within your budget that is).  I sometimes think whether to upgrade is a harder question than simply what is the best because you're evaluating the incremental improvement over your existing anchor.

 

 

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10 minutes ago, Corryvreckan said:

I can't say I'm surprised to find that the Rocna also has its weakness, but should I upgrade again?  Knowing what the weakness is, and how it compares to other anchors helps me to weigh up

  • how often I'll face the risk of it not setting in a wind shift
  • whether I can mitigate the risk (say, setting a bahamian moor or standing an anchor watch when a big wind shift is expected)
  • how big an improvement I can get (and at what cost) in a new anchor

If you're buying a new anchor you only have to compare among the top contenders (within your budget that is).  I sometimes think whether to upgrade is a harder question than simply what is the best because you're evaluating the incremental improvement over your existing anchor.

If the difference was say a 10% or even 25% improvement in holding power, I'd shrug and postpone it to when Santa drops a sack of €500 notes down the chimney.

But it seems that the problem with the Rocna is an exceptionally high incidence of no-reset. That seems to me to be a major flaw rather than a marginal one.

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4 hours ago, TwoLegged said:

If the difference was say a 10% or even 25% improvement in holding power, I'd shrug and postpone it to when Santa drops a sack of €500 notes down the chimney.

But it seems that the problem with the Rocna is an exceptionally high incidence of no-reset. That seems to me to be a major flaw rather than a marginal one.

I'm not so sure about 'exceptionally high incidence'.  It is a real issue, there have been some spectacular failures - but if your are cognisant of the issue - maybe you can manage it.  The incidences actually seem rare - or less yachts would have Rocna on the bow roller.  Buying from new - you might avoid - there are other anchors without the same fault - if you have a Rocna, as mentioned, a more difficult choice.  

We know about the issue with Rocna, Supreme, see Practical Sailor or Morgan's Cloud - its well known amongst the geeks - what is not well known are the faults of Spade, Ultra, M1, M2, Epsilon etc (if any - maybe in there is the perfect anchor (or less imperfect).   In fact we know of the faults  - but they are either suppressed or not significant.   If they are all as good then - buy on price (except maybe the cheapest, Kobra, is not easily available in the US (our outside Europe).

 

Its easy to differentiate Bruce and Excel - Excel wins hands down - but what are its faults (or is it perfect?)

 

Steve has mentioned a number of times - the rode is a critical component to an anchor's performance - no-one has queried this - it seems a better avenue to explore than retesting a CQR (which is a design almost 100 years old) or Delta and Bruce (which are almost 50 years old).

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5 hours ago, TwoLegged said:

If the difference was say a 10% or even 25% improvement in holding power, I'd shrug and postpone it to when Santa drops a sack of €500 notes down the chimney.

But it seems that the problem with the Rocna is an exceptionally high incidence of no-reset. That seems to me to be a major flaw rather than a marginal one.

I know people who swear by their Rocna. I have a a Rocna, a Bruce, a CQR, and a Danforth, all in the right size range for my boat. They all have their place. The one that is always on my boat as a kedge is the Danforth. The others rotate through from the dock to the bow roller. That says something. Horses for courses I suppose.

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44 minutes ago, Jim in Halifax said:

I know people who swear by their Rocna. I have a a Rocna, a Bruce, a CQR, and a Danforth, all in the right size range for my boat. They all have their place. The one that is always on my boat as a kedge is the Danforth. The others rotate through from the dock to the bow roller. That says something. Horses for courses I suppose.

I am struggling to understand exactly what the "place" is for a CQR that is not better served by a Rocna when both are at hand.

 

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1 hour ago, Saw Q said:

We know about the issue with Rocna, Supreme, see Practical Sailor or Morgan's Cloud - its well known amongst the geeks - what is not well known are the faults of Spade, Ultra, M1, M2, Epsilon etc (if any - maybe in there is the perfect anchor (or less imperfect). 

I think it is worth considering that some of the anchors that do particularly well in Panope's tests have not been sold in large numbers and may have shortcomings that are poorly understood as a result, whether as a consequence of build quality or inherent design defects.

Most people who own anchors use them infrequently and in good conditions.  It takes a large population of anchors to smoke out problems that affect either the worst 1% of the anchors or most demanding 1% of the uses.

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4 minutes ago, 2airishuman said:

I am struggling to understand exactly what the "place" is for a CQR that is not better served by a Rocna when both are at hand.

Sometimes you just prefer the company of a loyal Scot to a Kiwi prick.

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16 minutes ago, 2airishuman said:

I think it is worth considering that some of the anchors that do particularly well in Panope's tests have not been sold in large numbers and may have shortcomings that are poorly understood as a result, whether as a consequence of build quality or inherent design defects.

Most people who own anchors use them infrequently and in good conditions.  It takes a large population of anchors to smoke out problems that affect either the worst 1% of the anchors or most demanding 1% of the uses.

This gets at something I've noticed.  Every few years, a better anchor comes out at the same time as people start to notice the weaknesses of the previous best.  There's probably something to the idea that we only notice the weaknesses of the anchors that see the most use. 

One big mental block about upgrading anchors is that I really don't want to shell out for another new anchor only to have to upgrade again in five years.  After all, it's not like the anchors I currently have have gotten any worse (and they've served me well for the sailing I do) - it's just that development has progressed. 

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59 minutes ago, 2airishuman said:

I am struggling to understand exactly what the "place" is for a CQR that is not better served by a Rocna when both are at hand.

 

About 1/2 mile South West of the Port Townsend Boat Haven is one such place.  Seabed consists of what I call "sandy mud".

In that location, a genuine CQR with a hinge that is not wornout, will outperform a Rollbar Rocna in terms of: Resetting, Veering, and Holding Power.

The only thing the Rocna does well in that location is the initial set (instantaneous).  I note that CQRs also set very rapidly in that seabed.

The above applies to anchors in the 20lb and 45lb ranges.  I have zero data for other sizes.

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28 minutes ago, 2airishuman said:

I am struggling to understand exactly what the "place" is for a CQR that is not better served by a Rocna when both are at hand.

 

In sand the Rocna is terrific and sets so easily after using CQR type plows, they take some effort setting at times.

But in some cohesive bottoms the Rocna can foul, doesn't dig in past the initial set, and under load shears out a large gob of the bottom and that remains wedged in the anchor preventing resetting.

It's happened to me twice with a Rocna, then the boat heads off downwind fast and the anchor does not reset.  Both times it was an exposed anchorage to wind, and gusting over 30 knots . Initial set was good, scope over 5:1 using chain.

The last time it happened we were just landing ashore there was a heavy gust and we noticed the boat drifting rapidly past , we chased it with the RIB  and in 200m of drag staying at the same depth along the coast the anchor never once even partially reset even when it went over a good sand patch. It came up full of sticky muddy clay that took some clearing out. 

The plows don't do that. If you cruise in areas with good sand or avoid strong gusty winds with cohesive bottoms then there will  never be a problem.

 

 

 

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5 hours ago, MikeJohns said:

In sand the Rocna is terrific and sets so easily after using CQR type plows, they take some effort setting at times.

But in some cohesive bottoms the Rocna can foul, doesn't dig in past the initial set, and under load shears out a large gob of the bottom and that remains wedged in the anchor preventing resetting.

It's happened to me twice with a Rocna, then the boat heads off downwind fast and the anchor does not reset.  Both times it was an exposed anchorage to wind, and gusting over 30 knots . Initial set was good, scope over 5:1 using chain.

The last time it happened we were just landing ashore there was a heavy gust and we noticed the boat drifting rapidly past , we chased it with the RIB  and in 200m of drag staying at the same depth along the coast the anchor never once even partially reset even when it went over a good sand patch. It came up full of sticky muddy clay that took some clearing out. 

The plows don't do that. If you cruise in areas with good sand or avoid strong gusty winds with cohesive bottoms then there will  never be a problem.

 

 

 

Mike

 

You reiterate in real life exactly the mechanism that Practical Sailor found

https://www.practical-sailor.com/sails-rigging-deckgear/anchor-resetting-tests

The PS testing was after the condemnation by Morgans Cloud - but spent more time looking at what happens when an anchor drags.

MC and PS were both working on feed back from the market place.  

One of the issues is that people are very reluctant to admit they might have been gullible, listened to the hype, and bought a lemon (and in their defense - people are still buying).  

People will defend an M1, M2, Vulcan - but they have no hold data - contradictions abound - but, please, shoot the messenger - we don't want to sully the reputation of our heroes - even if the product might actually be ........a lemon.

Shame really - some new anchors might be as dangerous as a Rocna, or CQR - but we don't want to know that.

 

 

You reap what you sew.

 

 

 

 

 

 

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28 minutes ago, Corryvreckan said:

Sow, dammit!  You reap what you sow.

... sorry, one of my pet peeves

carry on.

Mine as well,

 

I blame Mac's autocorrect and then not knowing how to correct once posted.

 

Apologies

 

 

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5 hours ago, Saw Q said:

 

People will defend an M1, M2, Vulcan - but they have no hold data - contradictions abound 

 

 

 

 

 

 

 

 

 

See Vulcan in there, wondering what negative feedback there is?  Can only comment on the one we have, it's pretry huge so I would not group with any other sizes and the performance.  Both our Vulcan and the smaller rocna we have show a weak point in that if the blade tip fouls, clay shells mud clump or anything like pants line garbage etc, they won't set at all.  The garbage is probably the same with almost any design but the sticky crap seems to be mostly these two.  Have only had issues on a initial set, having to haul and clean.  So far no issues with it resetting in a big wind or tidal shift.  Ironically I have never had luck with a cqr, which was our secondary on our last boat. It was a newer genuine model. 

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When anchors are over powered, they tend to fail either by hard-lockup followed by popping out, or by stable dragging. The Fortress is an example of the first. The Delta in soft mud is an example of the latter. Others fall in the middle; the Mantus M1 will drag, but an anchor with a steeper angle (Rocna, Manson, others) may hold more, but then pop-out and struggle to reset if the boat is dragging fast.

Which is better, and why. Yes, I know this is an open ended question with more than one answer. It's more fun that way.

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22 hours ago, thinwater said:

but an anchor with a steeper angle (Rocna, Manson, others) may hold more, but then pop-out

..when your anchor ‘pops out’, it’s time to engage motor and get the crystal off the table…

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Columbus Day (Show us your Tits) Regatta ... umpteen years running. There's no real holding at all near Elliot Key. 

0 dark 30. It rarely fails. And expensive things start bumping in the night.

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  • 2 weeks later...

Just spent a couple days sitting out a gale SE, and for once strongest times were during the day, as opposed to O dark 30, so with this thread in mind, had a chance to really examine what was happening.

Was in a reasonably protected spot, so no waves per se, but wind whistling through about 30kts or so.

As has been previously mentioned, forces were typically cyclical – gust comes in, surge on the line, ease. Repeat. So no strong steady state pull.

And that got me wondering if maybe that is why some of the old classic anchors (i.e my trusty Bruce) which don’t do as well on stead pull anchor tests, but do seem to hold fine in the real world.

 

I’m guessing it might be hard to develop a safe test protocol (think cleat ripping out and decapitating poor old Steve). But now that you have several sizes of one type of anchor, might be possible with one of the smaller examples. Forces required to yank out, compared to the steady state. Captain Obvious seems to suggest it should be roughly the same, but that’ the beauty of what Steve is doing – real world test data to prove or disprove some of these long held assumptions.

 

Along that same lines, a couple other “mythbusters” type tests.

Big anchor/small chain, small anchor/big chain – most of us are pretty convinced big anchor wins, but would be interesting to get some actual proof.

 

Same with actual wind loading – once Panope is back in the water – a series of load cell readings to see if the main boat/wind/pressure chart everyone uses is actually ballpark correct. You did one in 20kts, but does it correlate with some other wind readings. This is the one I’m most personally curious about – in all my years of using exclusively a Bruce (with an admittedly oversized one), have never yet dragged – but is that simply because we are lucky, or actual forces in “normal” (<35kts) winds never approach max holding power, even in poor holding ground.

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4 hours ago, mayday12 said:

Just spent a couple days sitting out a gale SE, and for once strongest times were during the day, as opposed to O dark 30, so with this thread in mind, had a chance to really examine what was happening.

Was in a reasonably protected spot, so no waves per se, but wind whistling through about 30kts or so.

As has been previously mentioned, forces were typically cyclical – gust comes in, surge on the line, ease. Repeat. So no strong steady state pull.

And that got me wondering if maybe that is why some of the old classic anchors (i.e my trusty Bruce) which don’t do as well on stead pull anchor tests, but do seem to hold fine in the real world. Or are we are we just grasping, that there might be some different mechanism at work, because an oversized Bruce held in <35 knots? The Bruce held because that is not much wind and it was big enough. Yes, this could be tested, but there is no theory that suggests a pulsating pull changes the rank-order, and this HAS been tested for both soil and platform anchors. A pulsating pull does change holding capacity, but that is a complex subject (depends on the frequency and the setting history--this has been studied). A pulsing wind can either increase (deeper set) or decrease (yawing can destroy hold) the capacity of the anchor.

I’m guessing it might be hard to develop a safe test protocol (think cleat ripping out and decapitating poor old Steve). But now that you have several sizes of one type of anchor, might be possible with one of the smaller examples. Forces required to yank out, compared to the steady state. Captain Obvious seems to suggest it should be roughly the same, but that’ the beauty of what Steve is doing – real world test data to prove or disprove some of these long held assumptions. In fact, I have tested the behavior of smaller anchors in 20-30 knots with a real boat an a load cell. They were operating at their limit, similar to a storm from the anchor's perspective, because they were undersized. The results were as theory predicts for pulsing and oscillating loads. Yes, I'd love to see more of that sort of testing, but if you want to get direction changes in there too, it can take days per anchor (and you can't be sleeping). Not practical.

Along that same lines, a couple other “mythbusters” type tests.

Big anchor/small chain, small anchor/big chain – most of us are pretty convinced big anchor wins, but would be interesting to get some actual proof. This one is complicated, but I'm pretty sure most of the permutations have been tested. The one possible exception is at very short scope in shallow water... which is dumb. I've always thought a smarter approach was to size each for purpose, and not go to either extreme.

Same with actual wind loading – once Panope is back in the water – a series of load cell readings to see if the main boat/wind/pressure chart everyone uses is actually ballpark correct. You did one in 20kts, but does it correlate with some other wind readings. This is the one I’m most personally curious about – in all my years of using exclusively a Bruce (with an admittedly oversized one), have never yet dragged – but is that simply because we are lucky, or actual forces in “normal” (<35kts) winds never approach max holding power, even in poor holding ground. Honestly, I doubt you would learn much interesting below 45-60 knots, and it's not safe to test in those conditions. Also unlikely to gather enough comparable data to decode it.

Wind load is proportional to V squared to a very good level of agreement from 5-60 knots, and most likely well beyond. The action is turbulent, so it is all about energy.

Is there a "wind  pressure chart" that everyone uses? If we are talking about ABYC H-40 table 1, that is NOT a wind pressure chart. It is a working load specification chart. Not at all the same thing, and different from wind load by a considerable multiple (3-6x).

I=Please see above.

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4 hours ago, mayday12 said:

a series of load cell readings to see if the main boat/wind/pressure chart everyone uses is actually ballpark correct.

The ABYC one that people like West Marine publish was used to size deck gear (cleats/mooring bollards) and was never supposed to represent real loads. Real loads are about 1/3-1/4 of these values.

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I have absolutely no scientific evidence for this, but I've noticed that some of the peak loads seem to result from sailing around the anchor. Some boats sail around much worse than others. I think those boats may be much harder on anchors than their size and displacement suggest. That coupled with the fact that they pull the anchor from different directions can't help.

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4 hours ago, European Bloke said:

I have absolutely no scientific evidence for this, but I've noticed that some of the peak loads seem to result from sailing around the anchor. Some boats sail around much worse than others. I think those boats may be much harder on anchors than their size and displacement suggest. That coupled with the fact that they pull the anchor from different directions can't help.

Yup, I did a bunch of testing on this a few years ago. Most of this is boat, ground tackle, and situation dependent, but yawing can reduce the holding security (reduced holding capacity plus increased load) by more than 75%, depending on the severity. This makes arguing over 35-pounds vs 45 pounds (28%) almost secondary to steady anchoring.

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On 9/23/2021 at 9:48 AM, thinwater said:

When anchors are over powered, they tend to fail either by hard-lockup followed by popping out, or by stable dragging. The Fortress is an example of the first. The Delta in soft mud is an example of the latter. Others fall in the middle; the Mantus M1 will drag, but an anchor with a steeper angle (Rocna, Manson, others) may hold more, but then pop-out and struggle to reset if the boat is dragging fast.

Which is better, and why. Yes, I know this is an open ended question with more than one answer. It's more fun that way.

Had that happen in an unanticipated (thankfully short) squall in a mangrove "storm hole" in belize(unanticipated in direction, was supposed to be NW, was S, and I was sleeping on deck in case we did have one come in). just kept moving straight back to the mangroves behind us. Catamaran in there with us ended up in the trees. We were able to power into it till that squall passed, but a bit nerve racking. 

 

As to yaw'ing, we use a bridle on our boat, seems to work fine to keep us "sailing" in just the one direction, so steady pull on the anchor. I just tie it onto the main rode with a just a clove hitch. Thinking I'll use a dyneema webbing loop and a prusik next time. 

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