[TowerTalk] scariest repairs

[jim Jarvis]

The N7NV analysis is impressive.

Tower deflection is attributed largely to guy stretch.

I've been on top of 80' sailboat masts, which are intended to be  
flexible at their
top... which don't flex more than 1-2" under peak loads.   (yes, I've  
been up there
to free a fouled haliard, under load, pitching and rolling.)

I'm wondering if guy stretch is permitting 45g to move by almost a  
face width @ 100',
if perhaps we aren't tensioning the guys adequately.    To be sure,  
we tension the
bejeezus out of boat shrouds and stays.   You don't want the mast to  
pump and
dissipate energy, you want the energy peaks to translate to boat motion.

In the case of tower flex, that will tend to load-shed, making the  
structure less
susceptible to peak load damage.   So it's not a bad thing.

I'm still feeling dissonance between my intuition and the analysis I  
just looked at.

n2ea