Demonstration footage of boat anchors
 

http://video.google.com/videoplay?do...61924924082592

" Demonstration and comparison testing footage of plow and claw type
boat anchors vs a Rocna. Includes interview footage ... all »"

8 Minutes 20 sec ,

Mic 67

Demonstration footage of boat anchors
 

A few observations:

First I noticed a number of other patterns on the beach including a Spade
but no test results for them.
Second, beach sand reacts very different from ocean bottom. And most
important, the test were done with effectively infinite scope. Zero angle
between the rode and the beach. This works against fixed shank patterns
like the claw and the plow because it holds the shank down keeping it from
righting. Setting on a normal 4 or 5 to 1 scope the rode is angled upward
which lifts the shank and helps right the anchor. When set on a 4:1 scope
the claw type will set easier than almost any other pattern which accounts
for its popularity. It just doesn't have the holding power.

The Rocna does have good holding power and is relatively inexpensive but the
big hoop just compensates for poor balance.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"Mic" wrote in message
...
http://video.google.com/videoplay?do...61924924082592

" Demonstration and comparison testing footage of plow and claw type
boat anchors vs a Rocna. Includes interview footage ... all »"

8 Minutes 20 sec ,

Mic 67

Demonstration footage of boat anchors
 

On Thu, 25 May 2006 11:00:39 -0400, "Glenn Ashmore"
wrote:

A few observations:

First I noticed a number of other patterns on the beach including a Spade
but no test results for them.
Second, beach sand reacts very different from ocean bottom. And most
important, the test were done with effectively infinite scope. Zero angle
between the rode and the beach. This works against fixed shank patterns
like the claw and the plow because it holds the shank down keeping it from
righting.

Humm...but wouldnt that apply to the Rocna too?
It would seem to and was one of my first thoughts of this test.
that is probably why an anchor with a mini float attached to it tend
or seems to be effect in keeping it in a good or better setting
position.

Setting on a normal 4 or 5 to 1 scope the rode is angled upward
which lifts the shank and helps right the anchor. When set on a 4:1 scope
the claw type will set easier than almost any other pattern which accounts
for its popularity. It just doesn't have the holding power.

Heres another link, go to the paragraph that starts "So we bought a
15# alloy SPADE which so far has done OK. ..."
"We recently learned that we were improperly setting the anchor, i.e.
we should be setting out only 3:1 scope then leave the anchor to work
down with surge. After it has been deployed for a time we can then
back down on it and/or let out more scope. "
http://goose--bumps.com/goosebumps-main.htm


The Rocna does have good holding power and is relatively inexpensive but the
big hoop just compensates for poor balance.

This seems to be addressed at
http://www.bluemoment.com/newanchors.html
"Some commentators incorrectly assume that a high tip weight is
required to push the tip into the seabed, quoting specifications such
as percentage-weight-on-tip (i.e. what percentage of the total weight
of the anchor rests on the tip when in a setting attitude)."

"However, the reality is that forces in the form of torque applied by
the rode as your boat pulls on it are far more important than the
relatively small amount of weight force present."

" “The SPADE was the best performer for a given weight. It was
roll-stable and held extremely well. It was also the most deeply
buried anchor. The Delta… and Bruce… gave about 60% of the SPADE's
hold.” This was before the Rocna was developed, and the Bügel was not
tested."


http://www.practical-sailor.com/boat.../01anchor.html
"Anchor Reset Tests
When direction is reversed 140°, a third of the anchors never broke
out, another third reset at some length, and two never reset."

"the Bulwagga anchor that challenges the Spade in every category. The
Bulwagga’s only shortcoming: It’s clumsy to handle and difficult to
stow."

I would think that the Bulwagga would be righted on the bottom every
time given it design.
http://www.noteco.com/bulwagga/multi...pdf_Jan_01.pdf

I am not advocating any particular anchor, I thought the footage of
this test maybe of interest.

I do believe that any anchors performance can be enhanced with the use
of a kellet or Anchor Catenary.

Mic67

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

Demonstration footage of boat anchors
 

I am not advocating any particular anchor, I thought the footage of
this test maybe of interest.

I do believe that any anchors performance can be enhanced with the use
of a kellet or Anchor Catenary.

Mic, please tell us something about you recent anchoring experiences,
e.g., type of boat you own, type of anchor/rode, bottom conditions,
weather, etc.

Demonstration footage of boat anchors
 

Demonstration footage of boat anchors
 

Knowledge is not made more true or false based upon the experience of
the person who holds it.

I respectfully disagree. Knowledge without experience is untested as
witnessed by the statement regarding kellets. Kellets can be useful
for reducing swing radius in a crowded anchorage under moderate
conditions, but do very little to enhance ultimate holding power of an
anchor, any anchor. The reason, as an experienced person would know,
is that the anchor rode, rope or chain, with or without kellet, will be
pulled nearly taut under heavy load.

Demonstration footage of boat anchors
 

On Sat, 27 May 2006 21:05:46 -0700, Stephen Trapani
wrote:

wrote:

I am not advocating any particular anchor, I thought the footage of
this test maybe of interest.


I do believe that any anchors performance can be enhanced with the use
of a kellet or Anchor Catenary.
A kellet serves more than one purpose:
#
Increase anchoring security and reduce the risk of the anchor dragging
by changing the angle of pull on the anchor to help it dig in
#
Reduce boat swing by up to 50%
They almost double the holding power of the anchor and reduce the
working load of the anchor by up to 50%.
"Having a lot of sag in the rode reduces shock loads and helps keep
the anchor dug in by reducing the angle between the rode and anchor.
The best you can do is an angle of "zero", which exists when the
anchor rode is flat on the bottom, and all the pulling forces are
horizontal. As tension increases, it reaches a point where the weight
of the rode is overcome, and the angle becomes positive. Positive
angles make the anchor work harder at keeping set, since the rode is
now pulling up on the anchor. If the tension continues to increase,
the catenary reduces to a straight line, and eventually the anchor
pulls out."

It is clear that some people respond to these informational posts from
links that havent read the material much less understood it.



Mic, please tell us something about you recent anchoring experiences,
e.g., type of boat you own, type of anchor/rode, bottom conditions,
weather, etc.

Knowledge is not made more true or false based upon the experience of
the person who holds it. For one thing, the person could have gotten the
knowledge from a very experienced person (as much of the links Mic posts
clearly are), for another, experience doesn't prevent anyone from being
wrong about anything, for another, theories should be judged upon their
adherence to the canons of rationality, not upon who they come from.

Well said and understood.

Heres and interesting thought.

2 lawyers in a civil matter both have the same number of years
experience, no agreement on the statue can be made. What percentage
does each lawyer have of being correct as decided by the court? 50-50
right? Or less than 50% chance of being right but still the same %
chance of being right accorded to each lawyer? If you have any
experience then you should have the answer;

I would say that for the most part I would concur with that which is
in many of the sailing informational links. Or provide the links as
something new or different, as it appears that these interests are in
common with others, with an exception it seems. Thats OK.



--
Stephen

-------

For any proposition there is always some sufficiently narrow
interpretation of its terms, such that it turns out true, and
some sufficiently wide interpretation such that it turns out
false...concept stretching will refute *any* statement, and will
leave no true statement whatsoever.
-- Imre Lakatos

Demonstration footage of boat anchors
 

Interesting footage, I noted that the Rochna test seemed to be wetter sand.
The CQR type plow was identical to my experience, 50% failed launchings.
This was cured by my changing to a Delta, a non jointed plow. My CQR
knockoff, now resides in the garden.
Lee Haefele
Nauticat 33 Alesto
"Mic" wrote in message
...
http://video.google.com/videoplay?do...61924924082592

" Demonstration and comparison testing footage of plow and claw type
boat anchors vs a Rocna. Includes interview footage ... all »"

8 Minutes 20 sec ,

Mic 67

Demonstration footage of boat anchors
 

Demonstration footage of boat anchors
 

So if I believe this, don't I have the knowledge of an experienced
person about it?

Yes you have the knowledge but without experience to evaluate it, that
is the issue that I have with inexperienced people passing along second
hand "knowledge" as "fact".

I have the experience to know that a kellet will not increase ultimate
holding power of an anchor, nor will it significantly decrease shock
loads under the conditions where it is important. I know from
experience that even a 3/8 chain rode will be pulled bar taut with
approximately 1200 lbs of pull on it. Once the rode is bar taut, a
kellet is worthless. A kellet is useful for reducing swing radius in
light to moderate conditions. Period.

Demonstration footage of boat anchors
 

Demonstration footage of boat anchors
 

Stephen, the type of anchor has no impact on the effectiveness of a
fully loaded rode with a kellet. Why? Think about how a kellet works.
A kellet artificially increases the catenary of a partially loaded
rode. That can be useful to decrease swing radius in light to moderate
conditions. It may also assist with setting an anchor on scope too
short for conditions.
All well and good until the wind starts to blow, the rode loads up and
pulls taut, and now the low angle achieved by the initial use of the
kellet returns to the higher angle associated with short scope. At
exactly the time you need maximum effectiveness from your anchor, the
rode is puled bar taut, returning your swing radius to its normal
dimension, and decreasing the effective holding power of your anchor.
A kellet can be useful in certain specific circumstances but to claim
universal effectiveness is foolhardy. When the wind starts to blow I
like to know that my anchor was properly set on the correct scope for
conditions, not set in a way that partially compensates for short
scope. Here's the proof: Have you ever heard of a large commercial
ship or a naval ship relying on a kellet to anchor? Of course not.
How would you like to be in front of a board of inquiry or Court
Martial proceeding explaining why you entrusted your ship to short
scope because you used a kellet on Mic's recommendation.

Demonstration footage of boat anchors
 

Glenn Ashmore wrote:
A few observations:

First I noticed a number of other patterns on the beach including a Spade
but no test results for them.
Second, beach sand reacts very different from ocean bottom. And most
important, the test were done with effectively infinite scope. Zero angle
between the rode and the beach. This works against fixed shank patterns
like the claw and the plow because it holds the shank down keeping it from
righting. Setting on a normal 4 or 5 to 1 scope the rode is angled upward
which lifts the shank and helps right the anchor. When set on a 4:1 scope
the claw type will set easier than almost any other pattern which accounts
for its popularity. It just doesn't have the holding power.

The Rocna does have good holding power and is relatively inexpensive but the
big hoop just compensates for poor balance.

Mic 67

Glenn, we did not include in our video the Spade, nor the Delta, SARCA,
Buegel, and a few others, mostly for reasons of time. That video is already
nearly 10 mins long, and we wanted to keep our message simple: old types bad,
new types good. The most popular types are plows and claws so that is what we
target.

Your comments about scope are just plain wrong. This is important. No anchor
is designed to work with a particular scope; on the contrary, all anchors
work better the more scope you have. The ideal is horizontal, hence the use
of chain or kellets to attain an angle lower than that of a straight line
between the anchor and the boat. We therefore use a horizontal angle in any
testing to provide a level playing field; otherwise those boaters more
experienced would object to a particular scope being used, as it may favor
(or hurt) a particular anchor.

The shank, articulated or not, has nothing to do with scope affecting how the
anchor sets. The Delta, Spade, and Rocna, all depend on what's called three-
point geometry for their setting; i.e. they lie on their sides initially then
screw into the substrate.

The "big hoop" does not compensate for "poor balance"; rather the roll-bar
ensures the anchor rights itself, without relying on a dedicated weight in
the tip, an inefficiency common amongst other designs.

Demonstration footage of boat anchors
 

Mic wrote:
A few observations:

Humm...but wouldnt that apply to the Rocna too?
It would seem to and was one of my first thoughts of this test.
that is probably why an anchor with a mini float attached to it tend
or seems to be effect in keeping it in a good or better setting
position.

Mini floats have the drawback of detracting from the anchor's overall weight
underwater, and also are difficult to construct with any decent amount of
durability.

I would think that the Bulwagga would be righted on the bottom every
time given it design.

The Bulwagga has three flukes mounted in an equilateral arrangement. This
means there is no right way up :)

The drawback is that only 2 of its 3 flukes are ever in use. Furthermore its
design is difficult to make strong enough (flukes are just flat plate - catch
one in rock or coral and see what happens). It is however an excellent,
superior alternative to Danforth-type anchors.


I do believe that any anchors performance can be enhanced with the use
of a kellet or Anchor Catenary.


waynebatrecdotboats is largely correct is his assertations that kellets are
of little ultimate use. They suffer from a catch-22 whereby they work well in
light conditions, but by the time conditions are bad enough that you care,
the rode will have been pulled nearly tight, and the kellet will make next to
no difference - and of course it is at this point that you would probably
like it to.

Do not rely on catenary from either chain or kellet to absorb shock. Use a
nylon snubber to do this.

Kellets are good at reducing your swing radius, and their functionality
really ends there. Put the weight of the kellet into the anchor instead, so
you have a larger anchor, and you will see a much better return on ultimate
holding power.

A good angle of pull on the anchor should be attained by the use of adequate
scope.

Those interested in the theory can study the math he
http://alain.fraysse.free.fr/sail/ro...ces/forces.htm
That site considers most factors involved and arrives at a sensible
conclusion with regard to "the best rode" that we can support on the basis of
experience.

Demonstration footage of boat anchors
 

Lee Haefele wrote:
Interesting footage, I noted that the Rochna test seemed to be wetter sand.
The CQR type plow was identical to my experience, 50% failed launchings.
This was cured by my changing to a Delta, a non jointed plow. My CQR
knockoff, now resides in the garden.
Lee Haefele
Nauticat 33 Alesto
http://video.google.com/videoplay?do...61924924082592

[quoted text clipped - 4 lines]

Mic 67

The Rocna wasn't tested in wetter sand, although this is a problem with our
video, in that it looks like it. The problem is the plow and claw are shot
from the same point as the Rocna (the camera doesn't move). Furthermore both
the claw and plow drag up the beach fairly quickly, and at this point yes the
sand is dryer :) - but not where they started.

I know that sounds like excuses but what can you do. See this pic that shows
the beach waterline and the location of the Rocna tests against those of the
others: http://www.rocna.com/images/remote/t..._waterline.jpg

For those that are interested the proper video is on our website (
www.rocna.com and select "watch the video"). All versions are higher quality
than the Google one, and there is a double-resolution one also if you have a
broadband connection.

Demonstration footage of boat anchors
 

Do not rely on catenary from either chain or kellet to absorb shock. Use a
nylon snubber to do this.

Kellets are good at reducing your swing radius, and their functionality
really ends there. Put the weight of the kellet into the anchor instead, so
you have a larger anchor, and you will see a much better return on ultimate
holding power.

A good angle of pull on the anchor should be attained by the use of adequate
scope.

Well said, and as I pointed out, there's nothing like experience.

Demonstration footage of boat anchors
 

On Mon, 29 May 2006 12:19:23 GMT, "craigsmith" u22396@uwe wrote:

Mic wrote:
A few observations:

Humm...but wouldnt that apply to the Rocna too?
It would seem to and was one of my first thoughts of this test.
that is probably why an anchor with a mini float attached to it tend
or seems to be effect in keeping it in a good or better setting
position.

Mini floats have the drawback of detracting from the anchor's overall weight
underwater, and also are difficult to construct with any decent amount of
durability.

Yep, but the design of the mini float has a purpose which appears, and
as I recall, in keeping it in a good or better setting position.
Which from the Rocna test seemed to show as being a factor in the
setting of an anchor and thus my observations of the design of the
Bulwagga.

I would think that the Bulwagga would be righted on the bottom every
time given it design.

The Bulwagga has three flukes mounted in an equilateral arrangement. This
means there is no right way up :)

Which would mean that is a good thing?

The drawback is that only 2 of its 3 flukes are ever in use. Furthermore its
design is difficult to make strong enough (flukes are just flat plate - catch
one in rock or coral and see what happens). It is however an excellent,
superior alternative to Danforth-type anchors.

This would tend to support the statement that there is no one anchor
for all conditions. Nor is there any controlled anchor test that
could be considered "ultimate", only relative, that I know of as most
every anchoring situation is a unique combination of variables,
granted there are similarities. Now if for example the Rocna tests
proved that another anchor was better would Rocna make those results
know? The good thing about the Rocna tests is that they made the
effort and those that see it can decide for themselves.



I do believe that any anchors performance can be enhanced with the use
of a kellet or Anchor Catenary.


waynebatrecdotboats is largely correct is his assertations that kellets are
of little ultimate use. They suffer from a catch-22 whereby they work well in
light conditions, but by the time conditions are bad enough that you care,
the rode will have been pulled nearly tight, and the kellet will make next to
no difference - and of course it is at this point that you would probably
like it to.

If the conditions cause the anchor chain to become taut there is no
cantenary effect from a kellet or chain. So it is not of "ultimate"
use under those conditions. But who said it was?
Wayne was just trolling. The fact that by using a kellet in heavy
weather anchoring is that a chain is less likely to become taut than
without one except in extreme conditons and circumstances. In other
words a chain will go taut latter (if at all depending on the
conditons) with the use of a kellet or more chain than sooner without
based on experience and knowledge. At which point the concern would
not just be that of ultimate holding power but chafe, deck hardware
strenght, integrity of snubbers, etc.

A kellet ought not be a substitute for scope but under certain
conditions and reasons an anchors performance can be enhanced.

Gord May who you are aware of and is probably one of the most helpful
and respected persons in the internet sailing community:
http://www.cruisersforum.com/forums/...read.php?t=276
"In heavy weather, I always deploy 15 Lb "Sentinal" (Kedge) weights,
suspended a few feet above bottom."
Gord May
GordATBoatpro.zznDOTcom ~ (Requires Decription)

Although he does not give his reasons why, and I am sure that he
doesnt believe that it will have an effect on a taut chain. But it is
likely that he believes that the use of a kellet in those conditions
is an aid to anchoring and to delay or totally avoid a taut chain that
would/might occur without it use.

http://www.anchorbuddy.co.nz/
"They...
Increase anchoring security and reduce the risk of the anchor
dragging by changing the angle of pull on the anchor to help it dig in
*
Reduce boat swing by up to 50%
*
Make life at anchor much more comfortable
Anchor weights, (also known as chums, kellets, sentinels, anchor
angels) have been used for generations to anchor boats more securely.
They almost double the holding power of the anchor and reduce the
working load of the anchor by up to 50%. They are an advanced
technique in safe, secure anchoring."

Do not rely on catenary from either chain or kellet to absorb shock. Use a
nylon snubber to do this.

Kellets are good at reducing your swing radius, and their functionality
really ends there. Put the weight of the kellet into the anchor instead, so
you have a larger anchor, and you will see a much better return on ultimate
holding power.

So the claim that Anchor Buddy makes "They almost double the holding
power of the anchor and reduce the working load of the anchor by up to
50%." is false? Ultimate holding power has to do as much with bottom
conditions, boat windage, anchor design, sea conditions and resetting
ability than just weight alone.

http://www.anchorbuddy.co.nz/faq.html
This faq reasonably addresses the issue of using a larger anchor and
the practical aspects of a kellet. Thats not to say that a bigger
anchor is not better, and how big is big enough isnt always a
consenus. And I have read time and again that its not the weight of
the anchor but its geometric design, but this too is often
contradicted.

And certainly there is no consenus on what the best anchor is,
probably because there is no one best anchor for all conditions. So
for the ultimate holding power the anchor has to match the bottom
conditions.

A good angle of pull on the anchor should be attained by the use of adequate
scope.


Sailing since '67 Mic.

Demonstration footage of boat anchors
 

"craigsmith" u22396@uwe wrote

Your comments about scope are just plain wrong. This is important. No
anchor
is designed to work with a particular scope; on the contrary, all anchors
work better the more scope you have. The ideal is horizontal, hence the
use
of chain or kellets to attain an angle lower than that of a straight line
between the anchor and the boat. We therefore use a horizontal angle in
any
testing to provide a level playing field; otherwise those boaters more
experienced would object to a particular scope being used, as it may favor
(or hurt) a particular anchor.

I stand by my statement about the rode. I spent 3 days doing in the water
tests in the BVI/USVI last year with several Bruce and plow patterns to see
how they stacked up with the Spade. Tests were conducted in the coral sand
bottom at Deadman's Bay, Peter Island, eel grass over sand at Setting Point,
Anegada, heavy marl in Coral Bay, St. John and soupy mud in Great Cruz Bay.
Rode was 3/8 HT. Using weighted pool noodles to mark the drop and set
points and steel tapes we recorded the setting distance among other things
at various scopes. As the scope was increased past about 4:1 the setting
distance increased significantly on almost every pattern. Most would not
begin to set until the shank was lifted off the bottom. On the other hand,
once set, holding power increased with increasing scope leveling out just
past 7:1 in all bottoms on most patterns with slightly more rode required in
the soupy mud.

I have plenty of stills of the results but no movies.

Going down again Wednesday with my camcorder but not hauling 3 anchors like
last time. We have 2 boats with 3 different patterns and I may try to bum a
couple more from the charter company.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

Demonstration footage of boat anchors
 

Mic stated:
So it is not of "ultimate"
use under those conditions. But who said it was?
Wayne was just trolling. The fact that by using a kellet in heavy
weather anchoring is that a chain is less likely to become taut than
without one except in extreme conditons and circumstances. In other
words a chain will go taut latter (if at all depending on the
conditons) with the use of a kellet or more chain than sooner without
based on experience and knowledge. At which point the concern would
not just be that of ultimate holding power but chafe, deck hardware
strenght, integrity of snubbers, etc.

An attempt to correct misinformation and ill considered advice is not a
troll, it is normal newsgroup give and take. If you can't take the
heat stay out of the kitchen.

As I stated earlier, 3/8 chain will go taut at about 1200 lbs. That is
not an extreme condition at all, if fact it is only about 20% of the
safe working load of 3/8 HT chain. If you don't believe me, show up
with your strain guages and I will provide the test boat. I routinely
set my anchor with approximately that load and have suffered no loss of
deck hardware or anything else. It is also about the force generated
by my boat in about 30 to 35 knots of wind, windy but certainly not
extreme. I have sized my ground tackle to withstand 50 to 60 knot
conditions, approximately the force of a full blown thunder squall. So
far, so good. A kellet would serve no purpose whatsoever except
clutter.

Demonstration footage of boat anchors
 

Glenn said:

I stand by my statement about the rode. I spent 3 days doing in the
water
tests in the BVI/USVI last year with several Bruce and plow patterns to
see
how they stacked up with the Spade. Tests were conducted in the coral
sand
bottom at Deadman's Bay, Peter Island, eel grass over sand at Setting
Point,
Anegada, heavy marl in Coral Bay, St. John and soupy mud in Great Cruz
Bay.
Rode was 3/8 HT. Using weighted pool noodles to mark the drop and set
points and steel tapes we recorded the setting distance among other
things
at various scopes. As the scope was increased past about 4:1 the
setting
distance increased significantly on almost every pattern. Most would
not
begin to set until the shank was lifted off the bottom. On the other
hand,
once set, holding power increased with increasing scope leveling out
just
past 7:1 in all bottoms on most patterns with slightly more rode
required in
the soupy mud.


That's why my anchoring modus is to lower the anchor in a controlled
fashion to the bottom, let out a little scope to let it drag to proper
position, and then let out 3-1 (faster than the boat moves, but not to
pile the chain on top of the anchor) and stop. Nearly all the time,
the boat will drift back, and, the anchor set. If not, nearly always
(otherwise), it will shortly set, as seen by the chain going taut. I
just tripped on that by doing it, not by reading the reports; it seems
to work...

Then I let out my anticipated scope, usually 5 to 7:1, in a bunch
(faster than the boat moves). That causes the boat to veer off and
blow down. As the chain starts to tigthen, it pulls the bow back
around, and, again, I look for the jerk (not the one standing over the
windlass button).

If it comes up short and hard, I assume it's reasonably set, back down
to be sure, and then attach the snubber and let out the required extra
to allow the chain to hang straight down...

YMMV as to your method, but it's pretty painless and doesn't involve
backing down until it's reasonably sure to be set.

L8R

Skip

Morgan 461 #2
SV Flying Pig KI4MPC
http://tinyurl.com/p7rb4 - NOTE:new URL! The vessel as Tehamana, as we
bought her

"And then again, when you sit at the helm of your little ship on a
clear
night, and gaze at the countless stars overhead, and realize that you
are
quite alone on a great, wide sea, it is apt to occur to you that in the
general scheme of things you are merely an insignificant speck on the
surface of the ocean; and are not nearly so important or as
self-sufficient
as you thought you were. Which is an exceedingly wholesome thought,
and one
that may effect a permanent change in your deportment that will be
greatly
appreciated by your friends."- James S. Pitkin

Demonstration footage of boat anchors
 

Mic wrote:
The Bulwagga has three flukes mounted in an equilateral arrangement. This
means there is no right way up :)

Which would mean that is a good thing?

Yes, of course.

This would tend to support the statement that there is no one anchor
for all conditions.

Well, how many anchors do you want to carry onboard. Our ideal is a general
purpose anchor that addresses the failings of the old traditional plows and
claws, provides excellent performance in everything from very soft mud to
very hard sand (all extremes), cuts through weed and grass, is strong enough
to deal with being fouled or used with rock or coral, and so on.

The argument of carrying a claw, plow, Danforth, and fisherman's, each to
address the problems of the others, is nonsense nowadays, because it is
possible to consolidate the weight into perhaps two anchors that will more
reliably and safely meet all requirements. More may be carried as required,
but are not needed to compensate for the poor aspects of the others.

We know from experience that a Rocna will be happy in ALL conditions (except
rock, for which this is no ideal anchor - use a grapnel and be prepared to
lose it). But we are biased and you may choose not to believe us :)

A kellet ought not be a substitute for scope but under certain
conditions and reasons an anchors performance can be enhanced.

So what? Of course it can, no-one is debating the fact that weight can
provide a bit of shock-absorption and also decrease the rode angle - but not
by enough to make it worthwhile.
http://alain.fraysse.free.fr/sail/rode/dynam/dynam.htm and study the whole
page, particularly sections 2 and 6.

Gord May who you are aware of and is probably one of the most helpful
and respected persons in the internet sailing community:
http://www.cruisersforum.com/forums/...read.php?t=276
"In heavy weather, I always deploy 15 Lb "Sentinal" (Kedge) weights,
suspended a few feet above bottom."
Gord May
GordATBoatpro.zznDOTcom ~ (Requires Decription)

I have read much of Gord May's ideas about anchoring, and much of it is very
misleading and some of it just plain wrong. He is absolutely not an authority
on this topic.

http://www.anchorbuddy.co.nz/
"They...
So the claim that Anchor Buddy makes "They almost double the holding
power of the anchor and reduce the working load of the anchor by up to
50%." is false?

It's an exaggeration.

The ultimate holding power of the anchor cannot be increased by the use of a
kellet, UNLESS it is really big enough in relation to the rest of the system.
You have to understand you are talking about absolutes; i.e. fixed weights
and scale.

For example a 10Kg Rocna, well set, may hold up to a tonne of force. This is
realistic. Assume you have appropriate rode. The anchor will cope with this,
assuming the pull angle is reasonably low. Now the appropriate Anchor Buddy
would be their 8Kg model. Do you honestly think that 8Kg is going to make the
slightest bit of difference to said pull angle, when there is a 1000Kg strain
on the rode?

As you say it will make a bit of difference when the storm has passed, and
there's only 100Kg strain on the rode. So what, you're not worried about
dragging anymore. Hence, a kellet makes next to no difference to ultimate
holding power.

Now consider how much extra holding power an 18Kg anchor would provide,
compared to the 10Kg. Or, if you have the area, add 8Kg more chain to the
system, so increasing the scope.

This faq reasonably addresses the issue of using a larger anchor and
the practical aspects of a kellet. Thats not to say that a bigger
anchor is not better, and how big is big enough isnt always a
consenus. And I have read time and again that its not the weight of
the anchor but its geometric design, but this too is often
contradicted.

It's both, and the focus depends on the anchor. Really weight is, or should
be, less of an issue, hence why the newer designs such as ours put more
emphasis on fluke area and dynamic performance. Consider how 10Kg weight-
force (a little less underwater anyway) compares with 1000Kg rode-force, as
in my example above, and you will see what I mean.

And certainly there is no consenus on what the best anchor is,
probably because there is no one best anchor for all conditions. So
for the ultimate holding power the anchor has to match the bottom
conditions.

Consensus should not be the basis for any kind of scientific decision,
especially not in a field where there are so many misconceptions and almost
dogmatic beliefs. Get to the bottom of the theory, do your own research, get
some experience, and make your own decisions.

--
Craig Smith
Rocna Anchors
www.rocna.com

Message posted via BoatKB.com
http://www.boatkb.com/Uwe/Forums.aspx/cruising/200605/1

Demonstration footage of boat anchors
 

On Tue, 30 May 2006 03:52:55 GMT, "craigsmith via BoatKB.com"
u22396@uwe wrote:

Mic wrote:
The Bulwagga has three flukes mounted in an equilateral arrangement. This
means there is no right way up :)

Which would mean that is a good thing?

Yes, of course.

This would tend to support the statement that there is no one anchor
for all conditions.

Well, how many anchors do you want to carry onboard. Our ideal is a general
purpose anchor that addresses the failings of the old traditional plows and
claws, provides excellent performance in everything from very soft mud to
very hard sand (all extremes), cuts through weed and grass, is strong enough
to deal with being fouled or used with rock or coral, and so on.

The argument of carrying a claw, plow, Danforth, and fisherman's, each to
address the problems of the others, is nonsense nowadays, because it is
possible to consolidate the weight into perhaps two anchors that will more
reliably and safely meet all requirements. More may be carried as required,
but are not needed to compensate for the poor aspects of the others.

We know from experience that a Rocna will be happy in ALL conditions (except
rock, for which this is no ideal anchor - use a grapnel and be prepared to
lose it). But we are biased and you may choose not to believe us :)

A kellet ought not be a substitute for scope but under certain
conditions and reasons an anchors performance can be enhanced.

So what? Of course it can, no-one is debating the fact that weight can
provide a bit of shock-absorption and also decrease the rode angle - but not
by enough to make it worthwhile.
http://alain.fraysse.free.fr/sail/rode/dynam/dynam.htm and study the whole
page, particularly sections 2 and 6.

Gord May who you are aware of and is probably one of the most helpful
and respected persons in the internet sailing community:
http://www.cruisersforum.com/forums/...read.php?t=276
"In heavy weather, I always deploy 15 Lb "Sentinal" (Kedge) weights,
suspended a few feet above bottom."
Gord May
GordATBoatpro.zznDOTcom ~ (Requires Decription)

I have read much of Gord May's ideas about anchoring, and much of it is very
misleading and some of it just plain wrong. He is absolutely not an authority
on this topic.

http://www.anchorbuddy.co.nz/
"They...
So the claim that Anchor Buddy makes "They almost double the holding
power of the anchor and reduce the working load of the anchor by up to
50%." is false?

It's an exaggeration.

The ultimate holding power of the anchor cannot be increased by the use of a
kellet, UNLESS it is really big enough in relation to the rest of the system.
You have to understand you are talking about absolutes; i.e. fixed weights
and scale.

For example a 10Kg Rocna, well set, may hold up to a tonne of force. This is
realistic. Assume you have appropriate rode. The anchor will cope with this,
assuming the pull angle is reasonably low. Now the appropriate Anchor Buddy
would be their 8Kg model. Do you honestly think that 8Kg is going to make the
slightest bit of difference to said pull angle, when there is a 1000Kg strain
on the rode?

As you say it will make a bit of difference when the storm has passed, and
there's only 100Kg strain on the rode. So what, you're not worried about
dragging anymore. Hence, a kellet makes next to no difference to ultimate
holding power.

Now consider how much extra holding power an 18Kg anchor would provide,
compared to the 10Kg. Or, if you have the area, add 8Kg more chain to the
system, so increasing the scope.

This faq reasonably addresses the issue of using a larger anchor and
the practical aspects of a kellet. Thats not to say that a bigger
anchor is not better, and how big is big enough isnt always a
consenus. And I have read time and again that its not the weight of
the anchor but its geometric design, but this too is often
contradicted.

It's both, and the focus depends on the anchor. Really weight is, or should
be, less of an issue, hence why the newer designs such as ours put more
emphasis on fluke area and dynamic performance. Consider how 10Kg weight-
force (a little less underwater anyway) compares with 1000Kg rode-force, as
in my example above, and you will see what I mean.

And certainly there is no consenus on what the best anchor is,
probably because there is no one best anchor for all conditions. So
for the ultimate holding power the anchor has to match the bottom
conditions.

Consensus should not be the basis for any kind of scientific decision,
especially not in a field where there are so many misconceptions and almost
dogmatic beliefs. Get to the bottom of the theory, do your own research, get
some experience, and make your own decisions.

I appreciate the fact that you have participated in this discussion as
the representative of an anchor company. And I have read many of your
items in different forums. I think it was a good business decision to
give one of your anchors to Dashew for his new boat to keep (he was
using a Spade?) and thus evaluate. I expect his review will be
unbias.

Mic sailing since '67

--
Craig Smith
Rocna Anchors
www.rocna.com

Message posted via BoatKB.com
http://www.boatkb.com/Uwe/Forums.aspx/cruising/200605/1

Demonstration footage of boat anchors
 

I appreciate the fact that you have participated in this discussion as
the representative of an anchor company. And I have read many of your
items in different forums. I think it was a good business decision to
give one of your anchors to Dashew for his new boat to keep (he was
using a Spade?) and thus evaluate. I expect his review will be
unbias.

Thanks.

We didn't give Dashew a Rocna, he bought it. No for Wind Horse he originally
had a Bruce knock-off made by a local NZ company that produce copies of just
about anything, but we talked him into a Rocna.

So far so good although he hasn't yet published a full review. He originally
said he wanted a good amount of time and experience on different seabeds etc
before commenting. He has always been a big proponent of Bruces, so any
change in his position will be significant.

--
Craig Smith
Rocna Anchors
www.rocna.com

Message posted via http://www.boatkb.com

Demonstration footage of boat anchors
 

"craigsmith via BoatKB.com" u22396@uwe wrote

For example a 10Kg Rocna, well set, may hold up to a tonne of force. This
is
realistic. Assume you have appropriate rode. The anchor will cope with
this,
assuming the pull angle is reasonably low.

Just wondered what type of rode would handle this force? On your site, you
recommend the 10Kg anchor for cruising boats up to about 30'. What would
teh corresponding chain/rode dimensions be to match teh anchor strength?

The Rocna anchor looks quite interesting and seems to be a good idea, at
least for some anchoring conditions.

A few comments:

1. Testing by pulling with a truck with little or no scope angle does not
really prove anything ( but is easier to film!)

- Would it not be better to do a comparison of the anchors with a larger
scope angle and typical rode/chain combinations. This may take a lot of
testing using a boat, a diver, undewater cameras etc, but as you said "Get
to the bottom of the theory, do your own research, get some experience, and
make your own decisions". Seems to me that pulling an anchor along a beach
with a truck is not the best way to make a scientific conclusion.

- What happens if the bottom is soft mud or weed as we often see in the
Great Lakes - Will the roll bar still work, or will it just sink in and not
roll? I would like to have seen some comparisons of anchors setting in less
ideal conditions.

- The part showing the difficulty of getting the anchor unstuck is not too
encouraging for those of us with bad backs :)

2. The web site does not give the size of the attachment slot for the
shackle. Can you fit a shackle that will take a 1 tonne working load through
the slot?

In our area, most boats seem to have a Bruce or knockoff - But, more
recently we see Delta or knockoffs. Nothing really works well in weed and
soft mud but weight helps. The knockoff Bruces are a cheap way of getting
weight, so I suspect that might be the driving force. In fact, I have just
added a 15Kg Bruce type because my 10Kg Delta just does not work that well
(10M, 5T cruising sail).

GBM

Demonstration footage of boat anchors
 

The angle of attack of the pulling force aside:

Isn't it funny how the other anchors start out in hard sand? You can
see large parts falling off while the anchors are high speed dragged;
that sand looks hard enough to drive on.
The rocna starts out in a muddy pool of 'quicksand' that is so soft
that even the pieces of mud/sand that the rocna piles up melt back into
the surface immediately. Watch the left foot of the guy who tries to
work it free after the test sink in. And the rocna gets a nice slow
motion pull.

All that doesn't necessarily make it a bad anchor, but this video shows
a seriously bad test. The test proves two things we already knew: The
most important factor in anchoring is the substrate, and good marketing
requires artful lying. This was too blunt, mate, try again!

Demonstration footage of boat anchors
 

On Tue, 30 May 2006 09:16:42 -0400, "Lakesailor"
wrote:

For example a 10Kg Rocna, well set, may hold up to a tonne of force. This
is
realistic. Assume you have appropriate rode. The anchor will cope with
this,
assuming the pull angle is reasonably low.

Just wondered what type of rode would handle this force? On your site, you
recommend the 10Kg anchor for cruising boats up to about 30'. What would
teh corresponding chain/rode dimensions be to match teh anchor strength?

1/2 inch (12mm) 3 strand nylon has a breaking strength of about 7,000
lbs and a Safe Working Load approximately 1/3 of that. Typical anchor
rode for a 30 foot boat would be about 200 ft of 1/2 inch 3 strand,
shackled to 15 or 20 feet of either 1/4 or 5/16 inch chain. That is
enough rode to safely anchor in 30 ft of water.

For a storm anchor I'd use 5/8 inch 3 strand nylon with 5/16 HT chain.

Shackles rated for 2,200 lbs are easy to find.

Demonstration footage of boat anchors
 

Lakesailor wrote:
Just wondered what type of rode would handle this force? On your site, you
recommend the 10Kg anchor for cruising boats up to about 30'. What would
teh corresponding chain/rode dimensions be to match teh anchor strength?

Up to 33', at light displacement. Our sizing is conservative; in practice,
even a boat of that size will need up around 70 knots of wind to generate
something like a tonne of force. Wave action etc adds to the equation but if
you restrict the model to considering only wind, you can see how we are
talking about "extremes"; most boats, especially of that size, are not set up
to handle those conditions. Accordingly you can't really expect the rode to
be strong enough - and what about whatever the rode's attached to? :)

Anyway, you would normally use 6mm chain with a Rocna 10, 8mm if you wanted.

G40:
6mm - SWL: 350Kg, break 1000Kg
8mm - SWL: 800Kg, break 3200Kg

so you would use the 8mm, or a high tensile grade of the 6mm, if you needed
the strength. Rope matched to chain is usually stronger, so that's not an
issue.

2. The web site does not give the size of the attachment slot for the
shackle. Can you fit a shackle that will take a 1 tonne working load through
the slot?

Shackles: use the largest size the pin of which will fit through the last
link of chain. So the chain dictates the size used, and the slot on the
Rocna's shank is ample. A quality tested 8mm shackle for 6mm chain or 9/10mm
for 8mm should not introduce a weak-point.

The Rocna anchor looks quite interesting and seems to be a good idea, at
least for some anchoring conditions.

For all anchoring conditions, that's the point :)

1. Testing by pulling with a truck with little or no scope angle does not
really prove anything ( but is easier to film!)

It levels the playing field as I said above. The guy going on about shanks
etc and scope affecting setting behavior is wrong and also missing the point.

If you set your anchor using the relatively weak power of a sailboat's engine
and prop, if you're using decent rode then the actual angle of pull you're
placing on the anchor during setting is not the same as the scope; i.e. if
you have out 5:1, the angle is not dictated by that trigonometry, but rather
the catenary of the chain, which will make the pull surprisingly flat - it
may even be horizontal, with part of the chain remaining on the bottom.

Does not apply to powerboats with 1,000 HP using two meters of chain and a
bit of string.

- Would it not be better to do a comparison of the anchors with a larger
scope angle and typical rode/chain combinations. This may take a lot of
testing using a boat, a diver, undewater cameras etc, but as you said "Get
to the bottom of the theory, do your own research, get some experience, and
make your own decisions". Seems to me that pulling an anchor along a beach
with a truck is not the best way to make a scientific conclusion.

Yes, it would be better, but our video is supposed to be a simple
demonstration of why the traditional plows and claws are bad, and simply why
we've bothered coming up with the Rocna.

A "proper" video would be an hour long and would still be hurt by the fact
that we are not independent, so the validity of such a production would
always be vunerable. So, we're not really the people to do it - although I
would like to at least re-do our existing one at some point, to address some
of its problems.

- What happens if the bottom is soft mud or weed as we often see in the
Great Lakes - Will the roll bar still work, or will it just sink in and not
roll? I would like to have seen some comparisons of anchors setting in less
ideal conditions.

No it works fine, the roll-bar's radius is quite large for exactly that
reason.

Weed and grass are difficult for any anchor. It's also pointless testing or
doing demonstrations, because every patch of weed is different to the next.
The cynical viewer could claim we just did the test over and over again
before it happened to work.

The important factors are a certain amount of tip-weight, a low profile fluke
with sharp edges, and dynamics that encourage force from the rode's pull to
be transfered to the anchor's tip, so it cuts in. So the Rocna meets this
requirement, and is a further improvement on the WASI or German Buegel, which
is very popular now in the Mediterranean (weed city).

- The part showing the difficulty of getting the anchor unstuck is not too
encouraging for those of us with bad backs :)

Well that was after over a tonne of force was applied to it - most of the
time you'll never get it that stuck, and if you do, you probably won't mind a
bad back as payment :)

Although, it's not really a problem. Reduce the scope to 1:1 and leave it for
a few mins, and wave action will work it out. Or if you're in a hurry power
it out backward.


In our area, most boats seem to have a Bruce or knockoff - But, more
recently we see Delta or knockoffs. Nothing really works well in weed and
soft mud but weight helps. The knockoff Bruces are a cheap way of getting
weight, so I suspect that might be the driving force. In fact, I have just
added a 15Kg Bruce type because my 10Kg Delta just does not work that well
(10M, 5T cruising sail).

GBM

Deltas are generally good, except in soft mud. They simply don't have the
fluke area. Peter used to have a 40Kg Delta on his boat, and incidents in
soft stuff were one of the main reasons for designing the Rocna - and he had
already eliminated other types over the course of his lifetime, selecting the
Delta as the then best option.

I am sure that a 15Kg Delta would have offered a similar if not better
upgrade in your case. Understand your point about cheap weight, but you get
what you pay for.

But the simple solution is try a newer type - you don't have to put up with
those problems any more. Bulwagga, WASI, Rocna.

--
Craig Smith
Rocna Anchors
www.rocna.com

Message posted via BoatKB.com
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