How to Test Anchors?

[zeehag]

Originally Posted by boatman61

Throw em in the water... if they sink they're okay....

if they float, yer on acid.......

i never heard of anyone testing their anchor before i read this thread--is smost entertaining. does it make y eanchor better?? does this testing remove operator error???

i cant see what testing in a non seafloor environ is ging to do for those of us who
a)dont have that option, and
b) use our anchors routinely and therefore actually know what they will do under conditions found in anchorages that have no tbeen dredged.
\dredging anchorages kinda screws them up a lot-- removes the goo the anchors sit and set in.
seems this testing scheme is an overthought engineering boredom reliever that is an instead of sailing discussion. i have found the charts to be fairly accurate in the description of the bottom-- much more accurate than NOAA's attempts to render weather info. when the chart says silt over shale--DO NOT ANCHOR THERE.. nothing will hold.nothing. btdt. LOL..was saved by a church..LOL
when charts say MUD-- lol-is that...and holds well. just be aware of grasses on bottom-- mud grows grasses and weeds. duh.
i go with boatman on this one----practicality rules. pretense is just that.
practicing on a playing field is not anchoring-- dont forget the distance from deck to water is counted as part of the length needed for the anchor to hold in the mud. many folks forget to count those 4-10 ft as real length..is humorous to watch,
one can be entertainment or one can truly anchor--is your choice--i love watching entertainment. i donot like dodging it.

[GMac]

Why test anchors at all? Wouldn't the feedback via the interweb show what's good or not? There are literally many millions of real life anchor tests done each day around the world. If one was a shocker it would show up pretty quick. That has happened once or twice in the last few years.

Sure test for specific points of a anchor like setting characteristics, orientation, veering and what mess it makes of the seabed but in reality 99% of boats will never approach max holding power more than they will many other aspects of a anchor.

And if you test anchors surely you have to include rodes also.

An example. A few years back a new anchor arrived on the scene (that didn't start with a R) with well presented set of recommended rodes to use. Not long after we had punters coming in saying 'the anchor is crap and just doesn't work'. We said 'It's fine did you used the recommended rode behind it?. Try doing this then let us know how it goes'. We had a lot of calls saying 'It's working great and the anchor is brilliant'. The anchor comes out of Aussie where they anchor a lot in shallow sheltered waters, here we anchor in deeper waters on the edge of the Sth and/or Pacific Ocean. The rode recommendations were written for Aussie type anchoring. All we said to do was increase the chain length by an amount, often as short a length as 4mts. It made the difference between them not working and them working damn well.

So why test just anchors at all? In doing so are you really getting a true very usable result? I'd suggest often you aren't and at the same time you could be putting someone on a very bum track. We see that a lot where people search the web and see lots said about a specific anchor, they then get one only to find they are still dragging and having problems. We tune the rode and suddenly it all goes away. But in with that is we often have to tune the user a bit also as many do believe the somewhat outrageous claims some manufacturers do make.

Testing just the anchor to see it's max holding load could be just the same as Ford testing a motor to find it's max horsepower, which exceptionally very few drivers will ever get close to using, and then just dropping it into a car that has very dodgy brakes..... did I hear someone say Toymotor?

A anchor is only one part in a multi part system that must all work in harmony to get the best performance. So with that fact in mind is testing and often relying on just that one part really that sensible?

Yes we test anchors a fair bit but usually just to look at a specific aspect of them.... or to see just how outrageous the manufacturers claims actually are.

Play with the rodes used and you can make a 10kg lump of concrete out hold a 10kg new gen and somewhat contentious anchor. It can be done quite easily, we did it a month or so ago

[Kettlewell]

one can be entertainment or one can truly anchor--is your choice

Words to live by! Anchored in very crowded Newport, RI, and one morning I heard a voice very close by say, "What is it dear?" The answering voice said, "I think it's the end of a bowsprit." A nearby gaff rigged ketch had dragged anchor and was poking its bowsprit in through another boat's port.

[Kettlewell]

A anchor is only one part in a multi part system that must all work in harmony to get the best performance. So with that fact in mind is testing and often relying on just that one part really that sensible?

I agree 100%, but facts are useful when setting up a system. For example, when I put my rode together it is useful to know the breaking strains of the various components and their suggested working loads, but we have no idea what the actual forces needed to be overcome are. Same with the anchors. We set up the whole system to meet certain loading criteria, but then the item that attaches the whole system to the bottom is taken on faith, and the good words of many Internet commentators--always known to be highly reliable! I've anchored enough to know what works for me, and I have no real need to switch anchors or rodes or anything at the moment, but if I were to go out to purchase a new anchor at some future date I would like to be able to compare things like holding power vs. weight vs. price vs. setting ability, etc. Is it too much to ask that we can put some numbers on these things?

[Nicholson58]

Rock Solid Test Results » Rocna Anchors

Here is a straight up test of several anchors. The set up is that all anchors were tested in the same conditions. They were pulled in line with a measuring instrument under the same loading conditons. The videos are quite interesting. All testing was done on a wet beach where observations could be made.



The West Advisor: anchor testing

This is a link to the West Marine anchor test. Also done in a controled way with a load cell.

[Kettlewell]

I understand there have been a lot of anchor tests, but many (if not most) of them have had serious flaws in methodology. Dragging anchors on a beach has some relevance, but I think does not necessarily represent a real-world test. I understand there is quite a science to understanding bottom composition and saturated soils. The West Marine test raises interesting issues, but it is fatally flawed due to the inability of the two most popular cruising anchors at the time to even set properly--the CQR and the Bruce. Something was either very strange about that bottom or their technique as literally thousands of boaters all over the world were using those very same anchors successfully, including several famous and experienced cruising circumnavigators like the Hiscocks, the Roths, and the Pardeys, not to mention our own Evans.

[zeehag]

i willbe testing my 60 pound bruce and my new chain and my new to me windlass in ensenada mud thu, fri, sat..LOL....i will let ye know how they do....my shiplet is 28000 pounds displacement. wind is up and surge is straight in from sea--willbe a good test...

oh yes--mustnt forget the loose nut behind th wheel....

[ImaginaryNumber]

Originally Posted by Kettlewell

I understand there have been a lot of anchor tests, but many (if not most) of them have had serious flaws in methodology. Dragging anchors on a beach has some relevance, but I think does not necessarily represent a real-world test. I understand there is quite a science to understanding bottom composition and saturated soils. ....

One difference between a beach test and an underwater test is that underwater an anchor is partially buoyed by the water, which results in an underwater anchor "weighing" only about 7/8 of what an above water anchor "weighs". Likewise, fully saturated sand will weigh less, and perhaps be less compact, than moist but drained sand.

[GMac]

Originally Posted by Kettlewell

I agree 100%, but facts are useful when setting up a system. For example, when I put my rode together it is useful to know the breaking strains of the various components and their suggested working loads, but we have no idea what the actual forces needed to be overcome are. Same with the anchors. We set up the whole system to meet certain loading criteria, but then the item that attaches the whole system to the bottom is taken on faith, and the good words of many Internet commentators--always known to be highly reliable! I've anchored enough to know what works for me, and I have no real need to switch anchors or rodes or anything at the moment, but if I were to go out to purchase a new anchor at some future date I would like to be able to compare things like holding power vs. weight vs. price vs. setting ability, etc. Is it too much to ask that we can put some numbers on these things?

Good points there K. It just seems to me that way to many get so wrapped up in just the anchor they often end up paying more then they need to, mismatch their system and other not so good stuff.

There seems to be a search for the 'best' anchor when there just isn't one that can hold that title and there is unlikely to be one in the foreseeable future.

Besides the numbers many get to see aren't a true reflection of a anchor. In a recentish test programme a XXX anchor held close to 8 tonnes and that number gets pushed as 'look how good it is' BUT that was only one pull of many and in a seabed very very holding power friendly. That very same anchor in the same test programme didn't get above 4t odd at any other time, in one it just managed to top 1t. Those results are a true reflection of what actually happens in real life where we all get wildly differing numbers based on a range of variables.

So to get any real true holding numbers you do have to do a lot of pulls on a lot of varying seabeds, which does doesn't happen in 99% of tests.

We test anchors a lot but have found the best information as to what works and what doesn't is asking the punters who use them. As we deal with many each day and are nosey I'd have to say the 'best' anchor will have 3 specific boxes that must be ticked, those being -

- Will it hold enough for the boater who uses it where they do.
- Does it generally set well
- Of all the anchors (and there is a quite a few) that tick those boxes, which is cheapest.

The price is a very big determining factor of most anchor purchases, a lot more than most would realise or admit to themselves

Only a minuscule number of punters/Builders/designers ask us 'what is the best anchor?'. A lot ask 'what is the best anchor for me?'. A lot ask 'what would you recommend?'. Everyone asks 'What's it cost?'.

[markpierce]

In my mud-bottomed waters, the tidal current reverses several times a day. So ready-resetting in that environment is of high importance. It would be best if the anchor rotated rather coming loose and having to bury itself again. What anchors would be best in that environment? A Bruce-type first comes to mind. Self-resetting should be a factor in testing/rating anchors.

[Adelie]

Originally Posted by GMac

There seems to be a search for the 'best' anchor when there just isn't one that can hold that title and there is unlikely to be one in the foreseeable future.

I disagree, I think that with a good testing program you could determine which anchors are 'best' under specific conditions of seabed & loading. And, while it would be somewhat subjective, you could determine which anchor or which several anchors are best in most conditions and highlight the conditions where an alternative would be better. Also I think that close observation of the physics of anchors could lead to tweaks that would somewhat improve the designs that already exist.

Originally Posted by GMac

Besides the numbers many get to see aren't a true reflection of a anchor. In a recentish test programme a XXX anchor held close to 8 tonnes and that number gets pushed as 'look how good it is' BUT that was only one pull of many and in a seabed very very holding power friendly. That very same anchor in the same test programme didn't get above 4t odd at any other time, in one it just managed to top 1t.

Basic consumer rule number #1, if the seller is telling you something is really great, look for an indifferent independant party to confirm and/or give you the whole story.

Originally Posted by GMac

So to get any real true holding numbers you do have to do a lot of pulls on a lot of varying seabeds, which does doesn't happen in 99% of tests.

Exactly, to get any kind of valid results for statistical comparison you need to have 30-50 tests of each anchor in each kind of seabed under each loading scenario.

Originally Posted by GMac

We test anchors a lot but have found the best information as to what works and what doesn't is asking the punters who use them.

Best info doesn't mean it's particularly good info, only that it is better than the very limited physical testing that has been done or no info at all.

I'm not trying to knock people's opinions but anecdotal evidence is pretty subject to a number of errors. Key among them being people's tendancy to feel more positively about whatever item among several considered once they've made a choice they've bought it (general observation) and the limited number of anchors most boaters have experience with, thus limiting their ability to make comparisons.

Anecdotal evidence can be wrong even among very savvy observers. In the late 80's 'observational' studies tauted high dose chemotherapy with bone marrow transplants as an effective way to 'dramatically' shrink tumor size in women with breast cancer. Several 10's of thousands of women underwent the procedure before well designed studies showed the procedure increase mortality over conventional treatments.

I'm not saying we should ignore people's observations since at this point all we have is anecdotal reports and poorly designed tests, I'm lamenting the fact that we are unlikely to get much better until somebody ponies up a bunch of dough for better.

[GMac]

Originally Posted by Adelie

I disagree, I think that with a good testing program you could determine which anchors are 'best' under specific conditions of seabed & loading. And, while it would be somewhat subjective, you could determine which anchor or which several anchors are best in most conditions and highlight the conditions where an alternative would be better. Also I think that close observation of the physics of anchors could lead to tweaks that would somewhat improve the designs that already exist.

So by disagreeing you are actually agreeing there is 'a best for a given set of circumstances' but there is 'no one best all over' anchor. That's what I've been saying for years.

Basic consumer rule number #1, if the seller is telling you something is really great, look for an indifferent independant party to confirm and/or give you the whole story.

Totally agree especially if the seller is also the manufacturer or brand marketer. But the big question now is just who do you ask? There definitely are anchor camps where one group will argue very strongly a XXX is better because. Just as you'll find groups who say a YYY is better because. 99% of those haven't actually tried many anchors. At the moment those groups are seemingly stronger than ever especially in one or 2 camps. Both camps will argue they have the best one when 9 out of 10 haven't even tried the other option so they are talking from a uninformed stand point. If you watch those groups close you will notice many will argue a point or more you know they haven't actually experienced themselves, they will and do argue points they have read about, often on the net.

Suss the interweb? Again very hard to do due to it being flooded with often misleading and with a good sized splash of marketing bollocks at it's finest, information out of one camp. That has moved into the physical domain also which is leading many to get bum information. The people who have fallen for that are usualy very easy to spot.

Ask in a shop? Nope that's usually a little pointless also as most shops sell one or 2 brands only so will tend to talk those up at the expense of the ones they don't sell. That's common with any product, not just anchors.

Good clean balanced knowledgeable information about all options available is very very hard to find, it's out there though. Most anchor makers know, it's their best interest to do so, but they won't be saying it in public as often it's not in their interest.

At the end of the day 90% of anchor users can use just about anything with a good safe result as they will never push their gear to a point it'll make a difference. This whole anchor war is more just a cruising yacht thing than across all sections of boating.

Exactly, to get any kind of valid results for statistical comparison you need to have 30-50 tests of each anchor in each kind of seabed under each loading scenario.

Never going to happen and even if someone did that it the results would still be only average. To get a true result you'd need to do the 30-50 pulls with a large range of boats using a large range of rodes all operated by a large range of different people......... just like it does in real life. So as I said, it's never going to happen.

A lot of our testing is done using the same boat with the same rode with the same operator. The only variable is the anchor. What does that tell us? not much more than speed of setting comparisons, short scope comparisons and if we target it the max holding in that spot at that time. So it more shows trends rather than specific definitive results. If we change the operator the results can and often have changed. Which shows how well a anchor will do is often up to how well it's used.

Best info doesn't mean it's particularly good info, only that it is better than the very limited physical testing that has been done or no info at all.

I'm not trying to knock people's opinions but anecdotal evidence is pretty subject to a number of errors. Key among them being people's tendancy to feel more positively about whatever item among several considered once they've made a choice they've bought it (general observation) and the limited number of anchors most boaters have experience with, thus limiting their ability to make comparisons.

Anecdotal evidence can be wrong even among very savvy observers. In the late 80's 'observational' studies tauted high dose chemotherapy with bone marrow transplants as an effective way to 'dramatically' shrink tumor size in women with breast cancer. Several 10's of thousands of women underwent the procedure before well designed studies showed the procedure increase mortality over conventional treatments.

I'm not saying we should ignore people's observations since at this point all we have is anecdotal reports and poorly designed tests, I'm lamenting the fact that we are unlikely to get much better until somebody ponies up a bunch of dough for better.

Sort of agree but if we agree most testing is flawed, and most deep in the anchor game know they are to varying degrees, what's left? The end users. Ask enough and you soon get very clear patterns as to which anchors people have which issues with. The observations we garner from the end users do tend to parallel what we see in our testing. Combine the lot and there is a reasonably clear picture as to what anchor/s are best in what conditions.

[lancelot9898]

Originally Posted by markpierce

In my mud-bottomed waters, the tidal current reverses several times a day. So ready-resetting in that environment is of high importance. It would be best if the anchor rotated rather coming loose and having to bury itself again. What anchors would be best in that environment? A Bruce-type first comes to mind. Self-resetting should be a factor in testing/rating anchors.

Point well taken. To me it seems like the hinge design of the time tested CQR allows for such performance. Even though I've replaced my 35 lb CQR with a 45 lb Manson Supreme about three years ago, that little CQR held my boat all by itself in a Cat 1 hurricane some 20 years prior. The CQR had difficulity in soft mud and a lot of anchorages here on the Cheaspeake have such conditions.

[Nicholson58]

As long as the testing techniques are identical, such as on the wet beach against a load cell, the data will reasonably rank the anchors relative to one another. This is at least a less subjective method. It would be nice to see the tests repeated on a gravel or rocky or grassy bottom - etc.

We carry a CQR 75 # primary that was on the boat when we bought it. (3 other anchors also on board). Rocna looks far superior (relatively) according to level tests against equally sized anchors. Here is the interesting data for us. For our boat Rocna recommends a 55 Kg anchor - abut 80 % heavier than the CQR. It has about the same girth and length as the CQR but is massive. I suspect that part of its improved capability is based on the ability to force its way into the bottom. Pulling tests show it has an uncanny way of righting itself and digging in in about its own length. I will keep my CQR but will probably make the Rocna my new primary.

[CruisingKitty]

The French (Voiles et Voiliers) conducted an anchor test in which they compared performance after veering 70 and 180 degrees in in the Med in 2009. The English version Yachting Monthly -Anchor Test Nov09.