Anchors - Bigger is Better ?

[Shas Cho]

Originally Posted by Delfin

The drag observed is induced by exceeding the UHF

Not exactly.
I don't mean to be pedantic,
and I'm not sure that some of these distinctions are of value
to anyone but academics,
but according to Knox, the drag begins
when the Static Holding Force is exceeded.
UHF is measured (and this seems a bit silly to me)
by dragging a bit,
then stopping the winch, holding the strain,
and measuring the pull after it declines as much as it will.
Sort of a "post-drag holding force".
I'm not clear on the value of that measurement.
"My anchor holds better after dragging than yours does!"
Not exactly a real-world application.

I view "Efficiency" similarly.
I'm interested in Static Holding Force.
What do I care about the weight-to-SHF ratio
as used by most testers,
or Knox's weight-to-UHF?
Surely the Danforth-type sheet metal models
will always rank very high in efficiency,
won't they, even with quite low SHFs or UHFs?
Just tell me which anchor will hold my boat in a blow.

The AR video shows that in the conditions shown, his product appears to be the best.

You and I have exchanged views on this a couple of times, Delfin.
I'm thinking we are failing to communicate.
Speaking only of the Super Sarca vs Rocna video
what I see is this-
nearly identical (and impressively quick) setting
followed by a straight, balanced, perpendicular boom
as the UHFs are exceeded and the anchors begin to drag simultaneously.
The boom remains even and balanced
until both anchors have dragged perhaps two metres,
at which point the Super Sarca begins to lag behind the Rocna.
So the anchors are equal in performance
until the Rocna evinces a decreasing DHF over a long distance.
No?
Yes?

If I'm mistaken
or if you are focussing on a different part of the video
could you please explain that to me?
I'd like to be comparing apples to apples with you.

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.

Ah.
Thanks for the positive assumption

asking hard questions of manufacturers of critical safety equipment seems like a good practice, although not everyone agrees.

Absolutely.
The path to Truth is paved with Reason and Evidence.
Our entire modern science is based upon the proposition
that *every* assertion *must* be questioned.
Without that we have only religion.
And good anchors were not developed during the Dark Ages.

- Shas

[JonJo]

Originally Posted by Shas Cho

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?

Oddly, lurking in the background, there are engineers involved in the development of anchors.

Mantus employs them and I believe Peter Smith, Rocna, is an engineer.

But if we had people who knew anything we would have no anchor threads

Jonathan

[JonJo]

So getting back to anchors.

And getting back to anchors now that many have read John Knox articles.

Most anchor tests subject anchors to holding capacities well in excess of the loads those same anchors are ever likely to encounter. I am speaking from memory but the WM/Sail tests back in 2006 produced holding capacities of around 2t for 15kg anchors. The Voile et Voileur tests produced similar sorts of holding capacity levels. Both tests, VetV and WM were conducted by a tub boat under water in depths likely to be used by an anchoring yacht. The tests of WM and VetV are in different parts of the world, so different seabeds. There ar eman y other tests with similar results.

A 15kg anchor might suit a 35'/40' yacht (assuming we are not going BIB).

Given these anchors will hold 2t (as I say my memory might be wrong) why 'Bigger is Better'. Why this desire to have say an ultimate holding capacity of 3t when the yacht is very unlikely to enjoy 1t (and 1t is pretty excessive for a 35'/40' yacht).

My interpretation is that a Bigger anchor will set less deeply than a smaller anchor (and this will be accentuated in a very hard seabed), and a less well set anchor does not seem desirable.

Jonathan

[Shas Cho]

Rex, old buddy,
you requested that I ask you something
that would allow you to increase your credibility.
How would this do?

Is there a video of the Super Sarca "trip release" function in action?
I see a cartoon in which is works a treat,
but I'm curious about the real-world application.
It seems to me that even if the skipper
could know the precise orientation of the anchor
and could back the boat precisely in line with the shank,
a slightly taut rode would allow the shackle to slide to the rear
only if the rear of the shank were higher than the front;
a rather rare orientation, given the boat's position above the anchor.
Normally a slack rode would allow the shackle to slide to the rear
but the shackle would immediately slide to the front again
the moment any tension is applied to the rode.

If the anchor were caught under a coral head
or stuck beneath a mass of interwoven weed roots
or a mooring cable, electrical line, etc,
the initial attempts to raise it
would likely leave the for'd end of the shank
pointing more or less toward the surface.
The shackle might be persuaded to slide aft,
but again would return to the for'd end
as soon as tension is applied.

Secondly,
if the slot really *is* effective
in moving the point of lift to the anchor's stern,
how often will this happen unintentionally
when the wind or tide reverses the tension on the anchor?

And finally,
I don't know the precise dimensions
of the Super Sarca shank and its shackle slot,
but the primitive and approximate method
of simply laying my engineer's rule on the computer image
indicates that the slot removes as much as 30 percent
of the depth of the shank at the for'd end.
That's a lot of material being removed.
I'm sure the manufacturer has tested the shank
both with and without this full-length slot-
by how much does it reduce the shank's
resistance to lateral bending?

Thanks.

- Shas

[conachair]

Originally Posted by JonJo

Given these anchors will hold 2t (as I say my memory might be wrong) why 'Bigger is Better'. Why this desire to have say an ultimate holding capacity of 3t when the yacht is very unlikely to enjoy 1t (and 1t is pretty excessive for a 35'/40' yacht).

From a cruising perspective a size or so up might well be a help. You might end up using less scope than is ideal, anchor on questionable seabed, weather severe storms, develop a strong urge to go to the high latitudes....
Or all those at the same time.

Most of the sizing guides seem to echo this.

All for a little more weight up front and some beer tokens.

Local weekends or lunch stops then indeed, why bother.

[Shas Cho]

Originally Posted by JonJo

Peter Smith, Rocna, is an engineer.

That makes sense.
I had the impression that mostly it's sailors working on intuition
(or attempting to satisfy certification requirements).

Given these anchors will hold 2t...

As a comparison
(and ammo for your position, BTW)
it is common in our part of the world
to use a 2-ton concrete block as a year-round mooring.
Concrete in salt water loses 50% of it's weight,
so most moorings are effectively one ton.
Of course, we do hear stories
of yachts arriving at the beach
with their concrete block in tow...

Why this desire to have say an ultimate holding capacity of 3t when the yacht is very unlikely to enjoy 1t (and 1t is pretty excessive for a 35'/40' yacht).

Why do most Americans want a car engine
with 60% more horsepower than they are ever likely to use?
No, that's a poor analogy.
Here's a better one-
I don't want a door lock that stops the *average* burglar-
I want to stop anything short of King Kong!

The reason *I* want more holding power than I am likely to need
is that I *might* need it!
Joshua Slocum sure wished he had had a larger anchor
in the Straits of Magellan
A storm, an unanticipated wind shift,
being obliged to anchor in sub-optimal holding ground,
even having another boat drag or drift down on me some night.
IMO, it's impossible to have too much holding power.
The only reason I don't have a 400-pound anchor
is that my boat and I can't handle it!

My interpretation is that a Bigger anchor will set less deeply than a smaller anchor (and this will be accentuated in a very hard seabed), and a less well set anchor does not seem desirable.

I hear that regularly, Jonathan,
but I haven't seen any actual experimental data to support it.
Do larger anchors really set poorly?
If so, can you explain why that is?
I understand that a boat may be unable
to back down forcefully enough
to set a large anchor properly,
but it seems to me that if the force of the wind or current on the boat
is strong enough to create a need for a large anchor,
that force itself will set the anchor.
Am I missing something?

- Shas

[congo]

Shas Wrote:

Rex, old buddy,
you requested that I ask you something
that would allow you to increase your credibility.
How would this do?


Rex Wrote:


Shas old buddy, you are like a bucket full of holes, plug one and ten open up, you have many questions of which I really do not believe you don’t understand, no I am not going to continue to humour you, our certifications answers all of your theory, that’s good enough for me, good enough for your country men as we are selling anchors to them, our reputation and anchor performance obviously good enough for customers worldwide.

Our credibility of certification is good enough for Water Police, Coast Guard, AMSA, 400 TON COMMERCIAL VESSELS that’s all we have to please.


They don't have your questionnaires as they know the goods of our product.

In respect to your questions it’s just another forum asking the same questions and after I thrash it out six months will pass, another Shas or Noelex will start all over again, really cannot be bothered, all of the arguments you put forward and others our answers obviously suffice as we are twenty years young and growing.


Not very professional you say, Shas I was born unprofessional, difference being I am honest.
You and others continue with the visual of the boom test, if I was to pull those anchors with the 4x4 it would stop and wheel spin, the visual was to show the difference in behaviour between concave and convex, we have a seven ton winch pulling those small anchors, do you really think those anchors would lock up under those circumstances.


What you should all understand is it is not to show anchors just dragging but depth concentration, concept, and regardless for the boat size those anchors were designed for you would pull the front of the boat before you had the desired effect of those demos.

As far as the slot goes have a go at Manson, they have copied our concept, surely this must add some credibility to our concept, ask them your questions.


Having a go at Mantus some one said, hang on wasn't it Greg that said he was going to show our anchors were made from cornflakes-cardboard, fair suck of the Sav.


I suppose the rest of you had better get in early on more questioning as Shas will now have the highway blocked for another long 3 or 4 consecutive posts.


Regards Rex.

[Delfin]

Originally Posted by Shas Cho

Not exactly.
I don't mean to be pedantic,
and I'm not sure that some of these distinctions are of value
to anyone but academics,
but according to Knox, the drag begins
when the Static Holding Force is exceeded.
UHF is measured (and this seems a bit silly to me)
by dragging a bit,
then stopping the winch, holding the strain,
and measuring the pull after it declines as much as it will.
Sort of a "post-drag holding force".
I'm not clear on the value of that measurement.
"My anchor holds better after dragging than yours does!"
Not exactly a real-world application.

I view "Efficiency" similarly.
I'm interested in Static Holding Force.
What do I care about the weight-to-SHF ratio
as used by most testers,
or Knox's weight-to-UHF?
Surely the Danforth-type sheet metal models
will always rank very high in efficiency,
won't they, even with quite low SHFs or UHFs?
Just tell me which anchor will hold my boat in a blow.



You and I have exchanged views on this a couple of times, Delfin.
I'm thinking we are failing to communicate.
Speaking only of the Super Sarca vs Rocna video
what I see is this-
nearly identical (and impressively quick) setting
followed by a straight, balanced, perpendicular boom
as the UHFs are exceeded and the anchors begin to drag simultaneously.
The boom remains even and balanced
until both anchors have dragged perhaps two metres,
at which point the Super Sarca begins to lag behind the Rocna.
So the anchors are equal in performance
until the Rocna evinces a decreasing DHF over a long distance.
No?
Yes?

If I'm mistaken
or if you are focussing on a different part of the video
could you please explain that to me?
I'd like to be comparing apples to apples with you.



Ah.
Thanks for the positive assumption



Absolutely.
The path to Truth is paved with Reason and Evidence.
Our entire modern science is based upon the proposition
that *every* assertion *must* be questioned.
Without that we have only religion.
And good anchors were not developed during the Dark Ages.

- Shas

Ok, I re-read and actually paid attention to what Dr. Knox wrote, and I largely agree with your interpretation of the meaning of UHF, SHF, and DHF. But, what I see in the balance beam test of the Super Sarca vs. Rocna test is normal drag prior to setting, then superior DHF for the Sarca. If you stopped, you'd measure the SHF, which once the balance beam tips towards the Sarca would be higher for the Sarca than the Rocna. If you continued to drag the anchors, then the SHF would remain in favor of the Sarca because it is burying itself more cleanly, and eventually the UHF as measured by the maximum SHF would favor the Sarca. If we can agree on that, we can agree that in these conditions, the Sarca is superior. If we can agree on that, then we can take a big bong toke, fill our lungs with THC, then go to a Chinese restaurant for some MSG.

[bfloyd4445]

Originally Posted by JonJo

I tried to raise the question:' is a bigger anchor better' on the terminated SARCA Excel thread. Its not about a specific design but about whether 'bigger is better'

A thesis was proposed that a bigger anchor was better than 2 anchors with part of the argument based on the anchor in question being a new generation anchor. I am sure 'new generation' was not universally defined but for the sake of this thread I'm thinking of (in no particular order), Fortress, Spade, Super SARCA, Rocna, Supreme, Excel, Boss and Mantus (if someone want to add something I've missed, be my guest).

The argument, or thesis, was described here:

One Big Anchor Better Than Multiple Anchors In Almost All Situations

The thesis has had supporters on CF, witting or unwitting.

Simplistically the debate is:

In high latitudes conditions will be more taxing but carrying one anchor larger than normally recommended should be sufficient (those who enjoy lower latitudes suffering from cyclones, typhoons and hurricanes might care to bristle). The anchor carried should be one size larger, but the authors carry an anchor 2 sizes larger - which, in my biased opinion, seems to indicate some of their thinking. I repeat the thesis is predicated by the idea we are referring to modern anchors.

I care to differ:

I have tested a whole range of modern anchors with a winch from a beach, all anchors in the water. Testing anchors of 10-15kgs we stop the testing when the loads reach 2t as the anchors have dived so deep it takes so long to dig them out. An anchor maker, not Australian, has tested a 15kg anchor with a 90t tugboat (they had to upgrade the chain etc) to 5t. A common comment of anchors actually used under arduous conditions (quoted have been cyclones and hurricanes) suggest retrieval of 'normal' sized anchors after a big blow can be time consuming (they have dived so deep) and in the extreme have been abandoned. Classification Societies allow a 30% reduction in anchor weight for SHHP anchors, over the USL codes - so why go 2 sizes up?

So holding capacity is not an issue - even a 15kg anchor will produce a 'holding capacity' well in excess of the load needed to hold a yacht for which the USL recommends that size.

An argument is - how about poor holding seabeds, excellent point - but what sort of poor holding seabeds, ones with weed that might clog a concave anchor? rock in which only a fishermans/Luke might hold, thin mud - so if we are going to oversize - which design do we put our eggs into?

Interestingly the advocates of big is better - seem to use only one type of anchor - coincidence?

If your yacht would normally use a 33kg model of one specific brand then 2 sizes bigger is their 55kg model. Good for the anchor maker's income and probably good for windlass sales - but is it necessary?

Of most interest would be respondents who have used the recommended sized (new gen) anchor, found it wanting, and bought the same design only bigger - and found it satisfactory.

I haven't read this thread but I have done a bit of anchoring and bigger does not always work. #1 is a Danforth anchor with a bit of chain and lots of rode. This setup has never let me down. #2 is a delta quickset with lots and lots of rode with a but of chain. The Danforth holds better with lots less rode but the delta looks much nicer on the bow

[congo]

noelex 77 Wrote:

Witnessing a test that anchor manufacturer is conducting does not sound independent to me.

Obviously the anchor manufacturer has control over at least some of the parameters. The size of tug, speed of pull etc.

If the manufactures have control of these parameters why would they not select these test protocols to for their advantage?.

It seems a tad naive to think they would do otherwise, this of course applies to all manufacturers and diminishes the already low regard I have for the relevance of the current certification process (for our sized anchors).

At the end of day they still have to meet the (low) requirement for holding power, but it sounds like they are given considerable leeway.
I hope they are not permitted some choice with parameters such as to where the test takes place, and therefore can pick an appropriate substate where their anchor tests well.

Perhaps Rex would like to elaborate on how the testing locations are chosen?


Rex Wrote:

Well noelex 77 my friend there are not to many places where one can test any more here in Vitoria, no less than 3 permits have to be issued, the bay that we tested in is not large but has a wide variety of bottom types, sand ,mud clay weed excetra, for the sand and shell test we had to locate to another bay, and yes long waits for the beurocrats to again issue permits.

T.A.T.S. STANDS FOR TIDAL ANCHOR TEST SKID, it operates on an incoming tide and follows out the outgoing tide, location is selected at low water, soil types are recorded and can change through the distance between high and low water, after soil testing is complete each area is marked of with stakes and tape to identify pervious soils types recorded, try doing this with a tug.

When Robertson turns up it is easy for them to confirm what we have recorded, and then starts the process, as you could imagine this is all very hard work and expensive.

One other thing should be notice all testing is strickly supervised by a officer of Robertson, these officers are rotated, over the testing time, I think it was three months we had three different individuals supervising.

noelex 77 I don’t see why you are interested, certification you made clear doesn’t cut it with you, so who cares?

Any way it looks like you have competition of your own, you will be finding it tough to get your posts in?

Regards Rex.
__________________

[noelex 77]

Originally Posted by congo

noelex 77 I don’t see why you are interested, certification you made clear doesn’t cut it with you, so who cares?

I think I have made clear I don't think much of the SHHP classification.

You have a point. While the anchor is only tested to a low holding power and the proof load is in a vertical direction (and not a high figure) the details of how the test is conducted mean little.

My hope is one day we might have some meaningful criterion and then the test protocols assume much more importance. They both have to be right for the test to be valid. Since we, the consumers ultimately pay for these tests there is some incentive in improving them.

I took Johnathan's advice and have written to the AMSA, but I don't really hold out much hope of effecting change. Perhaps if consumers realise there is little value in the current certification manufacturers will stop paying for it and then we will get cheaper anchors, or will demand a more relevant standard and we will get a meaningful test that helps sort out good anchors from the rest.

I am still not sure from your answer if you are allowed to pick the test location.

I notice the certificate indicates that the holding test was conducted at Shallow Inlet. Was that your choice or was is chosen by the testing authorities?
I am not having a go at you, just trying to understand how the process works. If you had control of the testing location I am sure other manufacturers had the same freedom.

[congo]

noelex 77,

Why on earth didn't you go to AMSA before instead of beating the drum, would have been the smart way to go, AMSA are sometimes the only hope you have when lost at sea, I am sure they will come back, regardless of how many ways probes nooks and crannies you have sought through with me my answers clearly do not suffice, I will leave your last question up to AMSA.

Like I said before, you are hollow on this subject, I will just have to leave you hollow and allow rule makers to fill you in, by the way, it was the rules at the time of the N.M. S.C. AMSA have since taken most of their roll over.

At the end of the day any anchor testing that proves a product worthy of strength performance should be applauded.


Regards Rex.
.

[Shas Cho]

Originally Posted by congo

Shas old buddy, you are like a bucket full of holes, plug one and ten open up

Nearly every question I've asked
has been a specific response to some statement you've made, Rex,
or to a video you've made.
I thought you were talking and showing videos
in order to have a discussion about your anchors.
You've convinced me that it's just because you like to talk.
Now that I know that, I'm done.

It's too bad that you see every question as
"having a go" at you.

You've convinced me of one thing.
My next anchor will be either another Spade or a Rocna
because I can see that if I had a problem
or even a question with a Sarca
I wouldn't get a straight answer from you.

*sigh*

I'm off.

-Shas

[Shas Cho]

Originally Posted by Delfin

If we can agree on that, then we can take a big bong toke, fill our lungs with THC, then go to a Chinese restaurant for some MSG.

How about agreeing to let it slide, Delfin?
I'm done discussing Anchor Right products.
I do raise beautifully clean sativa in my hydroponic garden
and I like Chinese food-
come on down!

Actually, I have dreams of sailing to Port Townsend next fall
for the Wooden Boat Festival-
maybe we can meet up!

- Shas

[congo]

Shas Wrote:

I thought you were talking and showing videos
in order to have a discussion about your anchors.
You've convinced me that it's just because you like to talk.
Now that I know that, I'm done.

Rex Wrote:

Not true Shas, it wasn’t me putting up the videos.

Sorry to hear you are done, If I have offended,_disappointed you I sincerely apologize.
If you were to purchase one of our anchors and wasn’t happy you would enjoy a full refund, the chances of you purchasing one of our anchors is Christmas coming but twice a year, if you are going to purchase another anchor make sure it’s either Spade, Ultra or fortress.

You have made one point, the boom test, not in 7 years have I had the queries that you put forward, pleased to see Delfin summarised it perfectly, I will learn from this and change the commentary.
Further I will check my manners and see if I can improve.

Regards Rex.