[BC] Bad tower design

[RichardBJohnson at comcast.net]

Don't laugh! Early Rohn towers had rivets holding cross-braces. Once 
wind pressure gets above a certain amount, these rivets (which 
operate in shear) break and the whole tower comes unglued with the 
"sprong" of a broken clock-spring!

During the '60s rebirth of AM radio, many local 1 kW stations were 
built with these aluminum hazards. You couldn't climb them unless you 
weighed less than 150 lbs, and the angle of the cross-braces would 
pinch anyone's feet who tried. I climbed several to change light 
bulbs, ignoring the cross-braces that would break off in my hands. I 
was very bold in my younger days.

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

----- Original Message -----
From: "R.V.Zeigler" <rzeigler at krvn.com>
[Snipped...]

...the rebar cross braces on the top section. Also had washers shimming the
flanges to make it straight as I remember.