According to Sloco we test anchors by having tugboats pull on them.
That's because wind, current, swells and other factors really don't
matter. Forces at sea are completely linear, just like the pull of a
tugboat.
I'd sure like to see a copy of that article Sloco has so much
confidence in. He bought it so much that he's carrying a puny Fortress
anchor to protect his dated dinosaur with the head in the v berth!



RB
35s5
NY

"Capt. Rob" wrote in message
oups.com...
According to Sloco we test anchors by having tugboats pull on them.
That's because wind, current, swells and other factors really don't
matter. Forces at sea are completely linear, just like the pull of a
tugboat.
I'd sure like to see a copy of that article Sloco has so much
confidence in. He bought it so much that he's carrying a puny Fortress
anchor to protect his dated dinosaur with the head in the v berth!



RB
35s5
NY

If you give it enough rode the pull is linear. That's why.

Amen!

If you give it enough rode the pull is linear. That's why.


You'd need a LOT of rode and it still would never be truly linear, Bob.
Even then it would never cover the shock loading due to long swells
combined with high wind. Did the tugboat back off then charge forward?
The test with a tugboat defines the anchor's abilities to some extent
but does not in anyway equal real world tests in various conditions.
The fact that Jeff found the anchor deficient in real world use means a
lot more than Teddy the Tugboat pulling on a 50-1 rode.

RB
35s5
NY


RB
35s5
NY

"Capt. Rob" wrote in message
ps.com...
If you give it enough rode the pull is linear. That's why.


You'd need a LOT of rode and it still would never be truly linear, Bob.
Even then it would never cover the shock loading due to long swells
combined with high wind. Did the tugboat back off then charge forward?
The test with a tugboat defines the anchor's abilities to some extent
but does not in anyway equal real world tests in various conditions.
The fact that Jeff found the anchor deficient in real world use means a
lot more than Teddy the Tugboat pulling on a 50-1 rode.

RB
35s5
NY


RB
35s5
NY


50:1 rode, if the rope was straight gives an angle of arcsin .02 = 1.15
degrees. Since the rope is catenary/hyperbolic the angle is less, the shank
lays on the bottom. Rope stretch is usually 10% under full load. 20 feet
water depth, 1,000 foot road, 100 foot stretch.

The tugboat test is a good one for testing relative holding power. Testing
with a tugboat under various conditions is good real world testing. The
conditions must be the same for different anchors tested otherwise the tests
could mean very little.

Don't forget the sea bottom plays a role too.

Mushroom anchors work very well with 1:1 rode in mud.

The tugboat test is a good one for testing relative holding power.


Relative holding power using a tugboat in conditions on the day of the
test. Anchors build reputations based on years of service on a variety
of boats and conditions. The tugboat test is interesting, but
ultimatley laughable as a primary reason to buy an anchor.
And the sea bottom could allow one anchor to get a better set and so
on. The tugboat test is loaded with problems.


RB
35s5
NY

Seems like a reasonable test to me. It would cover all conditions and all
possible scenarios, but it would be enough to make a reasonable comparison.

--
"j" ganz @@
www.sailnow.com

"Bob Crantz" wrote in message
. ..

"Capt. Rob" wrote in message
ps.com...
If you give it enough rode the pull is linear. That's why.


You'd need a LOT of rode and it still would never be truly linear, Bob.
Even then it would never cover the shock loading due to long swells
combined with high wind. Did the tugboat back off then charge forward?
The test with a tugboat defines the anchor's abilities to some extent
but does not in anyway equal real world tests in various conditions.
The fact that Jeff found the anchor deficient in real world use means a
lot more than Teddy the Tugboat pulling on a 50-1 rode.

RB
35s5
NY


RB
35s5
NY


50:1 rode, if the rope was straight gives an angle of arcsin .02 = 1.15
degrees. Since the rope is catenary/hyperbolic the angle is less, the
shank lays on the bottom. Rope stretch is usually 10% under full load. 20
feet water depth, 1,000 foot road, 100 foot stretch.

The tugboat test is a good one for testing relative holding power. Testing
with a tugboat under various conditions is good real world testing. The
conditions must be the same for different anchors tested otherwise the
tests could mean very little.

Don't forget the sea bottom plays a role too.

Mushroom anchors work very well with 1:1 rode in mud.

http://www.ussailing.org/safety/Stud...nchortest1.htm

http://www.ussailing.org/safety/Stud...nchor_test.htm

http://www.noteco.com/bulwagga/press.htm

These tests seem quite reasonable.

Seems like a reasonable test to me. It would cover all conditions and
all
possible scenarios, but it would be enough to make a reasonable
comparison.


I don't think you understand, Jon. The test was already done with one
tugboat in one set of conditions in one area. If you think this is even
remotely enough to guage anchor performance then perhaps you can
explain why so many people, including Jeff, don't count on the Fortress
in real world conditions....and yet it did oh so well in the tugboat
test.


RB
35s5
NY

I meant to say wouldn't cover all conditions, but....

--
"j" ganz @@
www.sailnow.com

"Capt. JG" wrote in message
...
Seems like a reasonable test to me. It would cover all conditions and all
possible scenarios, but it would be enough to make a reasonable
comparison.

--
"j" ganz @@
www.sailnow.com

"Bob Crantz" wrote in message
. ..

"Capt. Rob" wrote in message
ps.com...
If you give it enough rode the pull is linear. That's why.


You'd need a LOT of rode and it still would never be truly linear, Bob.
Even then it would never cover the shock loading due to long swells
combined with high wind. Did the tugboat back off then charge forward?
The test with a tugboat defines the anchor's abilities to some extent
but does not in anyway equal real world tests in various conditions.
The fact that Jeff found the anchor deficient in real world use means a
lot more than Teddy the Tugboat pulling on a 50-1 rode.

RB
35s5
NY


RB
35s5
NY


50:1 rode, if the rope was straight gives an angle of arcsin .02 = 1.15
degrees. Since the rope is catenary/hyperbolic the angle is less, the
shank lays on the bottom. Rope stretch is usually 10% under full load. 20
feet water depth, 1,000 foot road, 100 foot stretch.

The tugboat test is a good one for testing relative holding power.
Testing with a tugboat under various conditions is good real world
testing. The conditions must be the same for different anchors tested
otherwise the tests could mean very little.

Don't forget the sea bottom plays a role too.

Mushroom anchors work very well with 1:1 rode in mud.