Anchors - Bigger is Better ?

[Delfin]

Originally Posted by Cotemar

The problem with the convex anchor designs is that they have a “Problem Bend” which pulls a blade through the seabed cutting it into two and pushing it to the sides.

Just like this log splitter with the convex blade cutting through this log and pushing the separated pieces of log to the sides.

Gee, by putting the words "Problem Bend" in bold and providing colored pictures, it really makes a completely nonsensical concept seem rational.

For myself, I have always noticed the Catastrophic Defect inherent in all concave, hoop style anchors. This Catastrophic Defect causes soil to move towards the center of the fluke, then piling up in front of the hoop. This Catastrophic Defect explains why hoop style anchors, when they drag, do so because a ball of weeds or other non-compressible material pushes aft on the hoop, causing the tip to pitch up, resulting in a loss of holding. In addition, the Catastrophic Defect results in the hoop style, concave anchor not being able to dive to denser soil conditions below the surface.

This Catastrophic Defect is overlooked by anchor manufacturers because while it is a Catastrophic Defect, it does make the anchor cheaper to build.

[Delfin]

Originally Posted by motion30

What my question is. What effect scope has on each anchor? My other point is none of the anchors in the test were "Holding" ,all three were dragging . If all one can hope for is for an anchor to slow ones progress and not stop it, you are in trouble Do you disagree?

I think we're conflating a couple of testing parameters here. Using a load cell, you can measure the peak holding capacity of an anchor. I have no clue what that would be for the Excel vs. Manson+Rocna test because it isn't tested, other than to say whatever it is, the Excel's exceeds the combination of the other two in those conditions. So the video just shows the relative efficiency of the designs.

I guess whether dragging puts you in trouble depends on how much drag over how great a distance. And whether you drag is a function of the 'Ultimate Holding Capacity" Knox describes. Higher UHC would seem to be preferable, all things considered, but then you have to factor in cost, how well the hook fits your boat, etc.

I think in the real world, infinite scope is usually what you're dealing with when the anchor is setting. I know that's not true when people back down vigorously on their hooks after dropping them, but I've never really been convinced that is the best way to set a hook. Be that as it may, IMO, what matters in an anchor test is that each anchor be subjected to identical conditions, whatever they are. Deep water tests can't provide that, and while I wouldn't presume that AR's tidal tests are definitive of performance under any conditions other than those presented, they do provide identical conditions to anchors tested, you can see what is going on and so are a guide to the efficiency of different designs.

[motion30]

Originally Posted by Delfin

I think we're conflating a couple of testing parameters here. Using a load cell, you can measure the peak holding capacity of an anchor. I have no clue what that would be for the Excel vs. Manson+Rocna test because it isn't tested, other than to say whatever it is, the Excel's exceeds the combination of the other two in those conditions. So the video just shows the relative efficiency of the designs.

I guess whether dragging puts you in trouble depends on how much drag over how great a distance. And whether you drag is a function of the 'Ultimate Holding Capacity" Knox describes. Higher UHC would seem to be preferable, all things considered, but then you have to factor in cost, how well the hook fits your boat, etc.

I think in the real world, infinite scope is usually what you're dealing with when the anchor is setting. I know that's not true when people back down vigorously on their hooks after dropping them, but I've never really been onvinced that is the best way to set a hook. Be that as it may, IMO, what matters in an anchor test is that each anchor be subjected to identical conditions, whatever they are. Deep water tests can't provide that, and while I wouldn't presume that AR's tidal tests are definitive of performance under any conditions other than those presented, they do provide identical conditions to anchors tested, you can see what is going on and so are a guide to the efficiency of different designs.

.
My contention is this particular test shows the anchors efficiency in a situation that simply not a real world circumstance. This is not the enviorment in which an anchor needs to work. I am not saying this is not the best anchor in the world. What I am saying is that this video does little to convince me. That's all

[Delfin]

Originally Posted by motion30

.
My contention is this particular test shows the anchors efficiency in a situation that simply not a real world circumstance. This is not the enviorment in which an anchor needs to work. I am not saying this is not the best anchor in the world. What I am saying is that this video does little to convince me. That's all

Fair enough. But hopefully you would agree that however we characterize the relevance to real world anchoring these tests are, on a comparable basis the AR product is superior to the anchors shown, in these conditions.

[Shas Cho]

Rex wrote:
...give Anchor Right A break and get back to anchors

Anchors is what I want to talk about.
I'm talking about anchors
and you keep talking about Rex and his persecutors.
Stop taking things personally.
Stop making unfounded claims
and boasting about certification.
Just tell us about your anchors
and when there's nothing to say,
you are allowed to say nothing.

Act like a professional, Rex.
Demanding personal respect is a dead-end street.
That's not how you sell anchors.
If your anchors are selling like hotcakes, as you say,
then your job is done.
You don't need to promote any more.
You don't see Bill Gates on the forums
making claims and slinging sarcasm at his challengers.

So, back to anchors-
The videos appear to show
that your anchor and the Rocna
set with equal rapidity
and resist breaking out with equal tenacity.
The Super Sarca shows greater resistance
to dragging more than a couple of yards.
Would you agree that that is a realistic appraisal?
Care to comment?

- Shas

[motion30]

Originally Posted by motion30

.
My contention is this particular test shows the anchors efficiency in a situation that simply not a real world circumstance. This is not the enviorment in which an anchor needs to work. I am not saying this is not the best anchor in the world. What I am saying is that this video does little to convince me. That's all

Yes I agree in that test it seems.to provide more drag pressure . I also believe the new style anchors are a big improvement over older designs and ..
Bigger is better

[Delfin]

Originally Posted by motion30

Yes I agree in that test it seems.to provide more drag pressure . I also believe the new style anchors are a big improvement over older designs and ..
Bigger is better

Agreed. Now I won't worry about you if I see you anchoring upwind from me during a gale....

[Dockhead]

Originally Posted by noelex 77

There is a lot incentive for manufacturers to recommend small anchors, especially when selling anchors to production boat builders.
Get a contract to fit all new Beneteau's with your anchor and that is a large number of units sold.
The smaller the anchor recommended the cheaper it is to supply it and there are big savings in anchor winch sizes and bow roller construction.
If the consumer complains Beaneteau will deflect the criticism by stating that they have fitted the manufacturers recommended size. (Not picking on Beaneteau all the manufactures do this sort of thing. They just sell a lot of boats so are a good example).

As well the average consumer believes it must be better if the manufacturer is recommending a smaller model. In fact there seems to be an inverse relationship. The better anchor designs recommend larger anchors (as an overall trend rather than a specific rule)

The above may be cynical view, but I believe this is partially why we get such small anchors recommended. (Together with the fact that very few boats actually anchor overnight or in any wind)

Companies like Mantus, and Rocna are to be applauded for their honesty.

Also, the boat will sail much better without all the mass in the bow, which will really kill the sailing performance of a light boat like a Bene.

But I think all the manufacturers are guilty of this. My boat was delivered new with a 25kg Delta and 40 meters of 12mm chain, which hardly covered the floor of the standing-room chain locker. Bringing that up to 45kg of anchor and 100 meters of chain added a couple hundred kilos right in the nose - ouch.

It's even worse for cats.

[Dockhead]

Originally Posted by Delfin

The Wasi doesn't appear to be made anymore. The dimensions of the Ultra swivel are about identical to the Wasi, and is tested in the 1/2" size I have to double the breaking strength (38,000 lbs) of my G4 chain, whatever the angle of pull. Fragile?

If it has been tested in a straight side pull to double the breaking strength of the chain, then I take my words back. But how can it be? With that lever arm, it would have to made of kryptonite.

[Shas Cho]

Originally Posted by Delfin

...what matters in an anchor test is that each anchor be subjected to identical conditions, whatever they are. Deep water tests can't provide that, and while I wouldn't presume that AR's tidal tests are definitive of performance under any conditions other than those presented, they do provide identical conditions to anchors tested, you can see what is going on and so are a guide to the efficiency of different designs.

Deep water tests are more difficult, certainly,
and maybe we won't have those in our lifetime.
But that's the info we need for real-world application.
It's not impossible, just difficult.
Divers on the bottom with cameras,
or a remotely operated submersible,
maybe use a structure such as an oil drilling rig to pull from?

The balance bar testing is ideal
for demonstrating the difference between two anchors
at any given point.
And in these videos the bar remains balanced
until well after the dragging has commenced.
So if the goal is to set and to *not* drag,
it would appear that these anchors are more or less identical.

One thing seems odd to me-
I've read and heard anchor function and development
discussed by sailors from Ulysses to Hiscock,
Pardy to Alain, Peter, and Rex.
But where are the physicists?
Where are the engineers?
Where, dare I say it, are the *certificated* people?
Why is anchor function and development
being studied by people without the education and facilities
to apply modern knowledge and mathematics to the question?

It seems to me that that is where the money needs to be spent.
Hire people with education and training and experience
in geology, friction, compression, hydrodynamics and so on.
Then we would see real progress,
both in design and testing and the analysis of the data.
to approach the topic in a scientific manner?

[Shas Cho]

Originally Posted by Delfin

You're observing a comparison of UHC in Anchor Right's beam testing method.

Thanks for the link, Delfin.
I'm learning a lot here.

Actually, what we are observing
as the anchors plow (or "plough" for the British traditionals)
through the bottom
is DHF, the Dynamic Holding Force.
Point 1 in the linked article.
UHF is measured with the anchor stationary-
"THE PLATEAU VALUE OF THE SHF IS THE UHC OF THE ANCHOR"
(not my caps).
Point 4.

when I look at those videos...
I see the convex Excel and thin hoop SS also dig in but dive deeper and demonstrate higher ultimate holding force.

As above, we are seeing the DHF, not the UHF.
Certainly they dive deeper
and yes, they demonstrate higher DHF.
No doubt about it (in these conditions).
But this difference in DHF appears
only after dragging for a couple of meters.
So far as the video shows us,
their setting speed and SHF are nearly identical.
And that's what I want my anchor to do-
set immediately and stay put.
Right?

By the way, the next time there is a Mantus thread, we should get you to ask some questions.

I'm not sure how to take that

- Shas

[Delfin]

Originally Posted by Dockhead

If it has been tested in a straight side pull to double the breaking strength of the chain, then I take my words back. But how can it be? With that lever arm, it would have to made of kryptonite.

It only bends 30 degrees, but like you I questioned the manufacturer on the testing certificate they got and the answer I got was that it was tested in all directions to get their yield strength. Is Kryptonite hard?

I can tell you that the attachment pin to the anchor itself is huge (3/4" on my 1/2"), and is not dependent on threads to hold it in place.

[Delfin]

Originally Posted by Shas Cho

Thanks for the link, Delfin.
I'm learning a lot here.

Actually, what we are observing
as the anchors plow (or "plough" for the British traditionals)
through the bottom
is DHF, the Dynamic Holding Force.
Point 1 in the linked article.
UHF is measured with the anchor stationary-
"THE PLATEAU VALUE OF THE SHF IS THE UHC OF THE ANCHOR"
(not my caps).
Point 4.



As above, we are seeing the DHF, not the UHF.
Certainly they dive deeper
and yes, they demonstrate higher DHF.
No doubt about it (in these conditions).
But this difference in DHF appears
only after dragging for a couple of meters.
So far as the video shows us,
their setting speed and SHF are nearly identical.
And that's what I want my anchor to do-
set immediately and stay put.
Right?

You may be right about the UHF and DHF distinction, but I'm not sure....

Yes, you want your anchor to set as quickly as possible (all 3rd generation anchors do), and stay put. The staying put part is where it gets tricky, since it is affected by bottom type, but all things being equal, the UHF of a diving anchor will always be greater than an anchor that dives less deeply since the density of the sea bed is usually going to go up with depth. IMO, hoop anchors hold great, but they won't hold as great as an anchor that can bury itself, and the hoop has to inhibit burying since it presents itself perpendicular to the sea bed. I think this is why the Spade, Ultra, Excel and Kobra test as well as they do.

The drag observed is induced by exceeding the UHF, which I think has to be greater for the anchor with higher DHF, or so it seems, so we may be talking about a distinction without a difference. In Knox's case, he argues for what he calls 'Efficiency', which is the UHF divided by the weight. I guess, but like you, I just want my anchor to set quickly and within the limits of physics, resist dragging as much as possible. The AR video shows that in the conditions shown, his product appears to be the best.

Originally Posted by Shas Cho

I'm not sure how to take that

- Shas

If you had followed the conversation on prior threads about a manufacturer who must only be referred to in positive terms, you'd get it. Just being snarky, as they say, but asking hard questions of manufacturers of critical safety equipment seems like a good practice, although not everyone agrees.

[Dockhead]

Originally Posted by noelex 77

Unfortunately I get to see a lot of boats drag. My estimation is about 50% have used incorrect technique (low scope for example) and 50% their anchor has just let them down.

It is rare to see an anchor that is below the recommended size so my conclusion is that the anchor sizing charts are not correct, especially when I see boats drag in only 30 knots wind.

I have some sympathy for the anchor manufacturers. Consumers assume, incorrectly, that better anchors would specify a smaller size. Therefore there is considerable pressure on them to promote smaller anchors.

Most cases I see are simply the result of the crew's not setting the anchor. Throw it overboard, and go below to make cocktails.

[Shas Cho]

Rex Wrote:
Its plough, not (plow)
big difference

Rex, Rex, Rex.
You complain about people
discussing your statements rather than anchors,
then you come up with something like this?
That's just childish.
The difference between 'plow' and plough'
is merely American English versus British English.
I was raised on an American farm
and we used plows.
Now can we please discuss anchors?

Rex Wrote:
didn’t you see the adjustable wheel on the front of the plough, this is called the depth wheel, no horse or tractor will pull a plough when you lift [the depth wheel] up as the plough sheer will continue to bury...

There is more than one way to control the depth on a plow.
Before the depth wheel was invented
depth of penetration was controlled
by the farmer raising or lowering the lever handle
at the rear of the implement.
On a plough anchor, of course,
the lever is on the front of the tool.
Raise it up, the plow tip heads for the surface.
Lower it, the tip heads for the centre of the earth.

The problem facing sailors and anchor makers
is that the boat is nearly always *above* the anchor,
attempting to steer the point to the surface.
Hence the need for infinite scope.

And yes, agricultural ploughs *are* specifically designed
to slice through the soil with a minimum of resistance
while turning soil to the side.
That is the intent, the goal of the designer.
Nearly the opposite of the anchor designer's goal.

Rex Wrote:
I really like this filtering

This seems to be one of your favourite comments
and it is evidently intended to wound.
It hasn't hurt my feelings at all yet, though,
because I have no idea what you are talking about.
I assume "filtering" to be a forum-related term,
but not being a forum junky I am unfamiliar with it.
Please explain so that I can be properly offended.
Or better yet, let's just talk about anchors.

- Shas