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

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

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

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.

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.


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.


--
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

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.

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

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

wrote:
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.

Can't an inexperienced person get knowledge from experienced people?

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.

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



--
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

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.