[TowerTalk] Re: K8DX Tower Collapse--Conv. wisdom ain't so!

[T A RUSSELL]

>Contrary to what George K3GP wrote:
>
>>The position of the failed tower structure and the antennas on the 
>>ground are consistent with the conventional wisdom that a failing 
>>guyed tower will fall within 50% or less of it's height.
>
>It didn't happen this way at my qth.  The 90 feet of Rohn 25 with 
>205BA/155BA/4 el 10m/G7 was layed out straight for the full length of 
>the tower.  Two-thirds of the 90 feet in my yard, and the other third 
>with all destroyed antennas in the neighbors yard.  Not a pretty 
>picture.  Don't believe the 50% conventional wisdom.
>
>73 de Rick, N6CR in HOTlanta, GA.
>.....................................................................

WARNING:  Don't delude yourself into believing ALL towers will
fall within some smaller radius than their height.  Note that this
scenario usually occurs with VERY  TALL towers which have
MULTIPLE  guy points in each direction.  

SHORTER  (AMATEUR)  TOWERS with a SINGLE anchor for
each direction OFTEN fall straight out to their FULL height when
there is an anchor failure.  I have personally  seen three such 
instances.  TWO, where the guys pulled through the cable clamps
at the anchor, one (picture) where an equilizer plate main bolt failed
(cheap counterfeit bolt), and one where the anchor bolt pulled through
a telephone pole elevated support that was located too close to a 
garage roof and the pole had rotted out.   EVERY  ONE of those towers
fell straight out to it's full height.

de  Tom  N4KG


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