On Sat, 18 Sep 2004 22:04:06 -0400, "NOYB" wrote:


"Short Wave Sportfishing" wrote in message
.. .

On Sat, 18 Sep 2004 19:46:04 -0400, Gene Kearns

And your "simplified look" does not apply.... an anchor rode does not
employ both ends at the same "Y" value.... therefore assumptions of
Y=Y'=0 do not obtain and is, therefore, the root cause of your lack
of understanding in this area. There isn't *anything* *attached* to
the middle.

Thanks for the link Gene, by the way, I missed that the first time
around.

But wouldn't the strain be equal at the arthimetical center and can be
equated to weight? It's really just another to figure energy
transfer, right?

I'm not totaly familiar with this so if I mess this up, it's an
electronic engineer with a math degree playing at mechanics, but
catenary defined means the shape of the line (or in this case rode) as
a curve. A funciton of strain would be weights at either end. Strain
can be defined as stored energy which is, I would think, distributed
evenly along the line to the end points. One way to define how much
strain is being applied would be to add weight to the middle and
measure the deflection.

At that point, it becomes a trig function - yes/no?

Yes, assuming the line itself has negligible mass compared to the weight
pulling on it...which is not a practical assumption when comparing it to an
anchor line and chain rode. I don't know why jackassby even used this
example. Jackassby's example describes a straight line...not a catenary.
It is not even close to replicating what is happening to an anchor line and
chain rode. The only time that Jax's example *may* similate an anchor line
is when the force of the wind is so great that the line and chain is
perfectly straight...which *never* happens in a real world situation anyhow.
If the wind pulled so hard that the line was perfectly straight, it wouldn't
be a catenary any longer...it would be a straight line. And if it were a
straight line, the vertical component of force exerted by the boat on the
anchor would be so high that the anchor would pull loose. Go look at the
website Gene posted:
http://alain.fraysse.free.fr/sail/ro...ic/sta_hom.htm

It explains it all.

Well, yes, but the static load page is "under construction" and that's
what I was looking for, but hey - at least I have a better picture of
what's what.

Interesting about that kellet thing - that makes a lot of sense. I
knew the term, but I didn't know the term, know what I mean?

Thanks.

Later,

Tom