[TowerTalk] Windload at 90 mph (Was: Plumbing a tower)

[Clay Curtiss]

> One could look at the off-vertical situation by considering that
> installing it non vertical puts a static side load on the whole thing.
> The load would be sin(theta)*weight.  Say the whole thing weighs 1000
> pounds (I don't know if this is plausible.. it's just easy to calculate)
> and you're 2 degrees off vertical (about 3.5 feet in 100).  The side
> load is about 35 pounds (distributed along the whole thing).  That's
> pretty small compared to the wind load (90 mi/hr = about 20 lb/sq ft,
> and you know the tower has a lot more than 10 square feet of cross
> sectional area)
>

Is 20 lb/sq ft correct for 90 mi/hr winds?  I've run several of the 
published formulas in the past and seen other references that would 
indicated that 36 lb/sq ft is a good number to use at 90 mph.  I realize 
that it is dependent on height above ground and other factors.  Have I 
miscalculated or am I in the right ballpark?

73,
Clay  W7CE