[TowerTalk] Rohn 25;Tower flex

[Pat Barthelow]

Bear in mind also that moving isn't breaking.  A tower can potentially flex
>a pretty substantial (and scary, if you're up on top) distance without
>failing (and, in fact, that flexing is essential to avoid stress
>concentrations).

I can attest to the  'scary' sensation of ANY movement of a pole, or tower, 
to those on top.  While strapped off, on top of a very sturdy 65 ft wooden 
power pole, with a pulley/halyard tensioned dipole  at the top,  a  ground 
crew assistant was told to pull her up, tight, which he did... 
WHOAAAAA...the 50 pounds or so of pull bent the pole what seemed to me at 
the time, like 8 feet..real scary..  When I did the same thing on the 
ground, watching the top of the pole, what felt like 8 ft swinig, was really 
about 4 inches...Then there is the true story about the guy changing the 
lamps at Candlestick park when the 1989 earthquqke happened. Free standing 
lighting poles probably 150' tall,  He was interviewed shortly after the 
quake, and he was clearly shook up at his experience, hanging on through the 
earthquake...cant imangine what that woulld have been like...
73, de Pat AA6EG   aae6g at hotmail.com