> If the guys and tower were made of the same material, the
>cooeficient of expansion of course would be the same. The guys are
>longer and would contract more but don't forget the tower will get
>shorter with temperature drop.
Except that the guys are not in the same plane as the tower, hence the
spec based on 45 degree angle. To understand this take the worst case
example where the tower is vertical (naturally) and the guys are horizontal.
The tower may shrink in the vertical but that doesn't help the guys in
the horizontal with any similarity in temp coeffficient. The guy will
increase in tension as the temp is lower (with an almost negligible
INCREASE in tension as the tower gets very slightly further away from
both vertical shrinkage as well as horizontal shrinkage) almost as if the
two end supports had no temperature coefficient effect.
If the guys are vertical (not very effective as a guy wire) and the guys and
tower have the same coefficient then they change the same and there
is no differential. So a typical guyfalls somewhere in between the
two scenarios. Hence the spec at 45 degrees.
73 John W0UN
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