On 4/1/99 10:41 AM, Gary McDuffie, Sr. at mcduffie@scottsbluff.net wrote:
>THIS IS NOT SOMETHING I'VE SEEN RECOMMENDED BY A TOWER MANUFACTURER, ITS
>JUST AN IDEA THAT CAME TO MIND WHEN READING THE QUESTION.
>
> \ / X = Tower
> \ / : = Equalizer or splitter
> \ / -- = Short guy to Equalizer
> X--:
> / \
> / \
> / \
>
>Again, angle on the right pair of guys wouldn't be critical, as long as
>they were equal and not too shallow (the ascii diagram looks too shallow
>to me).
>
>Take aim guys. Fire away. Is this doable?
I'm no mechanical engineer, and I don't pretend to understand the
subtleties of materials and such. But it occurs to me that in order to
get sufficient tension on the odd guys (ie 10% of breaking strength), the
short guy is going to have even more tension (eg do the vector math).
This makes the short guy a potential weak link, unless he's made of a
stronger (most likely larger) material than the other guys.
Assuming this is the case, the other question is how loads are
distributed amoung the guys. For a wind load from the right-hand side of
the (er,...) page, tension along the short guy is going to be distriuted
in some fashion between the split guys. If this arrangement results in
some sort of mechanical lever action, you could have a problem (or
compensate with stronger materials).
That said, one of the most amazing things about towers is that they have
design rules of 2 or 3 in most cases. That means a PROPERLY DESIGNED,
INSTALLED and LOADED tower has 2 to 3 times the necessary strength to
meet all the design loads. This design rule permits some allowance for
improper installation, improper maintainence, material degradation and
still have a safe tower. That's why we have all these goofy stories about
people doing all sorts of nasty things with towers and antennas and
getting away with it. (most of the time)
So, it might work. Only a PE could tell you for sure.
Bill Coleman, AA4LR, PP-ASEL Mail: aa4lr@radio.org
Quote: "Not within a thousand years will man ever fly!"
-- Wilbur Wright, 1901
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