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JAXAshby
 
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whoring, for what it is worth, you couldn't tell the difference.


Date: 9/18/2004 9:18 AM Eastern Daylight Time
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On 18 Sep 2004 03:43:41 GMT, (JAXAshby) wrote:

whoring, you done be had. hope you enjoyed it, even if you do walk a little
for a few days.



From: JohnH
Date: 9/17/2004 1:06 PM Eastern Daylight Time
Message-id:

On Fri, 17 Sep 2004 09:49:10 -0400, "Gene Kearns"
wrote:

On 15 Sep 2004 12:26:41 GMT,
(JAXAshby) wrote:

2) It serves as a shock absorber, helping to absorb the boat's movement
due
to the wave action.

you obviously do not understand the mathematics of catenaries. NOBODY
chains a
boat to a dock, or a rock on shore.


Nobody needs the properties of a catenary at a dock, either. Nobody
makes a big deal about creating a catenary, when tying to a dock.
Nobody in their right mind would even mention such a stupid and
unrelated concept, if they were trying to make a logical argument.

It doesn't take much of a wind to pull chain tight enough to be

considered
zero
point zero zero zero zero zero three seven three of a shocker absorber.

Stoopid, stoopid, stoopid.

The intrinsic shape of a catenary is the shock absorber. Once the
shape of the catenary has been pulled tight enough for the resultant
to become a line, all holding power is pretty much lost, as the
vertical component on the anchor increases. At that point, by
definition, we aren't talking about catenaries, anyway.

So, which is easier to pull tight, a line catenary or a chain
catenary?

Here is a URL that will conclusively... and mathematically, prove that
Jax doesn't have a clue what he is talking about..... and, moreover,
that he is just plain wrong (again). This website includes a snappy
macro driven spread sheet that will work out nearly any what-if you
could ever imagine concerning line, chain, scope, tension, etc., etc.,
etc. It really *is* neat....

http://alain.fraysse.free.fr/sail/ro...ic/sta_hom.htm

Wow. Great site. Thanks.

John H

On the 'Poco Loco' out of Deale, MD,
on the beautiful Chesapeake Bay!


Jax, for what it's worth, I value your opinion about as much as that of
Krause.

John H

On the 'Poco Loco' out of Deale, MD,
on the beautiful Chesapeake Bay!








  #62   Report Post  
Harry Krause
 
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JAXAshby wrote:
whoring, for what it is worth, you couldn't tell the difference.



Oohhh...

John Whoring.

Great!


You don't mind if I borrow that one, eh?


--
Not dead, in jail, or a slave? Thank a liberal!
And don't forget to pay your taxes so the rich don't have to!
  #63   Report Post  
Harry Krause
 
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Gould 0738 wrote:
JAXAshby wrote:
whoring, for what it is worth, you couldn't tell the difference.



Oohhh...

John Whoring.

Great!


You don't mind if I borrow that one, eh?


The only thing worse than Jaxashby running out of meds and mounting his
keyboard for a day or two has to be Jaxashby runing out of meds, mounting his
keyboard, and you encouraging him, Harry.



Hey! Jax doesn't often come up with anything worthwhile...but that
"nick" for Herringbrain is a keeper.


--
Not dead, in jail, or a slave? Thank a liberal!
And don't forget to pay your taxes so the rich don't have to!
  #64   Report Post  
Calif Bill
 
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Chuck, Maybe we need more anchor chain to keep both bodies down.

"Gould 0738" wrote in message
...
JAXAshby wrote:
whoring, for what it is worth, you couldn't tell the difference.



Oohhh...

John Whoring.

Great!


You don't mind if I borrow that one, eh?


The only thing worse than Jaxashby running out of meds and mounting his
keyboard for a day or two has to be Jaxashby runing out of meds, mounting

his
keyboard, and you encouraging him, Harry.



  #67   Report Post  
JAXAshby
 
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genie, knock it off. you are a mechanic on twenty year aircraft engines of
seventy year old engine designs. what you know about catenaries wouldn't

fill
a plastic coffee stirrer spoon from Mickey D's.


I'm still appreciate you explaining the mathematics of catenaries.


here is a utterly simple book for you (it is $48). I was looking for one a
little more engineering oriented, but still quite simple and only goes in the
special case of oil rig anchors ($1,015, plus shipping and handling), but I
can't remember the exact title. (I don't have it in my personal library)


What happens during the interaction of forces on the rode would be
most fascinating.

Later,

Tom








  #68   Report Post  
JAXAshby
 
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What happens during the interaction of forces on the rode would be
most fascinating.


a way to simplified look at it is to consider the chain/rode/line to have zero
weight pulled between two points (say 100 feet apart), then hang a 1# weight in
the center point and check how much strain it put on the end points when the
weight hangs 20 feet, then 10 feet, then 5 feet, then 1 foot, then 1 inch, then
1/10th inch. Just use trig to figure the forces.

the forces get out of hand ********VERY******** quickly. Even worse, is that
the weight in the middle (or chain) has momentum as the boat rocks, so the
"natural" position of the weight overshoots and makes for seriously high
g-loads.


  #70   Report Post  
JAXAshby
 
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a way to simplified look at it is to consider the chain/rode/line to have
zero
weight pulled between two points (say 100 feet apart), then hang a 1# weight

in
the center point and check how much strain it put on the end points when the
weight hangs 20 feet, then 10 feet, then 5 feet, then 1 foot, then 1 inch,

then
1/10th inch. Just use trig to figure the forces.


So what would the forces be using your example?


I don't have a trig calc handy, but do this. divide 50 feet by 20 feet, then
10 feet, then 5 feet, then 1 foot, then 1 inch, then 1/10th inch. that will
give you the tangent of each angle.

look up each tangent, then divide each number into 1#. that will give you the
#'s force on the end points of the line.

a catenary is worse and much, much, much more difficult to calculate, but the
above will give you an idea of the HUGE forces involved once the chain starts
to pull tight

Later,

Tom








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