[BC] The Worst I've Ever Seen!

[RichardBJohnson at comcast.net]

This looks as though it was built from spare parts scoffed-up by a power-line worker. Aside from the obvious, there is a much more egregious problem that shows no engineering was done whatsoever. The tower is free to move in the vertical direction. This means that there is some combination of winds which will cause a resonant condition to exist, where the guy lines will oscillate up and down, exciting the tower to jump up and down. When you constrain something in a saddle, supported only by its weight, there needs to be something that damps the resonances. In this instance, I see nothing.

The tower will bounce up-and-down. If the primary frequency of the bounce excites any secondary resonances in the guy lines, a resonance is established which stores energy. The amount of stored energy will increase until something breaks, releasing the stored energy.

As I see it, there is some wind condition, perhaps even a small breeze, which if sustained, will take this contraption down. All you need is the right intercept angle between some guy lines and the prevailing wind to store the needed energy.

To understand how this works, go to your favorite radio station and stand at a guy anchor. Hit a guy-line sharply with a 2x4 or something that won't nick the guy-line and watch the "standing wave" travel up the guy to the tower, then back down to the anchor. In the olden days, riggers used to time this round-trip to gustimate the tension of the guys. The idea was to have them all be the same. This is the resonant frequency of that guy line. Imagine now the response if the tower could bounce at the same frequency or some sub-multiple thereof!

Cheers,
Richard B. Johnson
Book: http://www.AbominableFirebug.com/

----- Original Message -----
From: "Tom Spencer" <Radiofreetom at gmail.com>

OH

MY

.....

Well, as a DIY project, it's a fair - to - middlin' antenna, I guess..

I agree that no rigger in his right mind would want to try climbing 
it... which may explain why it's not lit any more...

Barry Mishkind wrote:
> Here is a tower that ...
>
> ... well, you'll just have to see it to believe it.
>
> http://www.thebdr.net/articles/warstories/worst/Worst-tower.pdf

-- 
Tom Spencer
PG-18-25453 (nee' P1-18-48841)
http://radioxtz.com/