[Towertalk] Windload "partway up"

[K7LXC@aol.com]

In a message dated 5/23/02 7:54:49 AM Pacific Daylight Time, swca@swbell.net 
writes:

> > If I place 4 square feet at the mid point of the tower do I need to change
>  > what the top of the tower could hold?
>  
>  I have been dying to ask Steve this same question, since I think he said in
>  Dayton that "you just add it all up."  My basic understanding makes me 
think
>  that 10 square feet halfway up a 100' tower is not the same as the same 
load
>  at the top of the tower.

    Jeez - you're asking a non-engineer?!? As I understand it, a typical 
tower spec is for the WHOLE tower so you can parcel it out anyway you want 
but it's also typically the headload on top that we normally deal with - it's 
also the 'worst case' loading. And, yes, things change when you move things 
around.

    Aside from the bending moment and other reactions, don't forget that the 
limiting tower spec is leg strength so it doesn't matter where the load is 
since it all turns into leg compression at some point. 

Cheers,
Steve     K7LXC
TOWER TECH