[TowerTalk] Guying a self-supporting tower - Yes

[Tom Rauch]

> One element of this debate is whether or not you can
generally
> say that for any free standing tower structure there
exists a
> specific guy wire configuration that will result in an
increase in
> the overall  wind load capability of the tower structure.
My guess
> is that the answer is to that question is almost alway
"Yes".

I'd guess the same. Unless you do something really stupid
like use 1/2 inch EHS on a light self support and crank the
tension way up.

> I think a good starting point to answer this question
would be
> to compare the compressive force in the stressed tower leg
> (leeward side) of the self-supporting configuration at
maximum
> rated wind load with the compressive force induced by the
guy
> wires at no wind load. If the compressive force due to guy
> tension with no wind load was a significant portion (say >
5%)
> of the maximum compressive force in the leeward leg of the
> max wind loaded unguyed tower, then I would begin to worry
that
> I was sailing into dangerous waters where additional
structural
> analysis would be warranted to make sure that the
supplemental
> guys weren't degrading the mechanical integrity of the
> free-standing structure.

Certainly a safety guy at minimal tension wouldn't do
anything harmful. I can't imagine spreading the tension over
a wider footprint to a guy anchor and placing compression on
all legs instead of only one or two is a bad thing. The
force would go way down when the angle of the line being
tensioned increases.

I'd bet unless you really overdo things everything gets much
better. It'd be interesting to see some actual numbers.

73 Tom