[TowerTalk] "Wind Load" "Wind Area"

[Jim Lux]

At 09:00 PM 12/9/2006, AD5VJ  Bob wrote:
>In searching around learning abt WINDLOAD, I have found two terms 
>that seem to be the same:
>
>"Wind Load" "Wind Area"
>
>Are these one and the same?



No..
Load is the actual force on the structure.. approximately equal to :

Force (in lbs) = V^2 * Area/391   (for V in mi/hr, Area in sq ft, 
sealevel pressure, 59F, etc.etc.etc)

Towers will come "rated" in area, but what they are really doing is 
taking the load rating and working backwards to an area, with an 
*assumed* wind speed (70 mi/hr or 100 mi/hr)...

Taking 70 mi/hr as an example

F= 70*70/391 * Area ->   12.5 lbs/ft^2

SO, if the tower designer thinks the tower can take a 100 pound load, 
at 70 mi/hr this would be a 8 sq ft area.