[TowerTalk] Push Up Mast Guying and loading

[Rob Atkinson]

Dave,

I think you say you can go out 10 feet.  I take that to mean you can
put your guy anchors out no farther than ten feet from the masts which
are 40 feet tall.  That's not far enough.  The guys will have a larger
force component pointing down than they will pointing out away from
the masts.  If you view each guy as a triangle hypotenuse and the mast
as the vertical side, there is a force diagram with two components,
one pointing down and the other pointing out  in the direction of the
guy, perpendicular to the mast.  That  component needs to be greater
than the one pointing down in order for the guy to do its job.   You
only achieve that if the guy anchor is out more than 1/2 the height of
the mast (and it should really be out at least 75% of height for the
top guy).  Less than 1/2 and the guys don't function.   I don't know
where you live but such an arrangement may work temporarily but the
first prolonged windstorm you have may bring the whole thing down.
I'm writing this from having learned these lessons the hard way.   You
could go up 20 feet and maybe be okay.  any higher and I'd consider
something free standing like a couple of small free standing towers
in concrete or telephone poles.

73

rob / k5uj