[TowerTalk] wind zone maps

[Clay Autery]

Thanks, I was hoping it was something like that...  :)

73,

______________________
Clay Autery, KY5G

On 6/12/2017 1:18 PM, JVarney wrote:
> When TIA-222-H comes out it will implement the ASCE standards.
> But the ultimate design forces between TIA-222-G and -H
> are roughly equivalent, so need to worry :-)
>
> Under -G, the 90 mph standard requires the use of a "load
> factor" (similar to a safety factor).  There are several load
> cases to be considered, but the one that most commonly controls
> is 60% SF on wind and 20% on weight. Adding these multipliers
> means that towers under -G have been designed to the ASCE
> numbers all along anyway.
>
> The -H standard has no safety factors applied to wind loads.
> Instead, the tower is designed to fail or barely survive the
> design speed, 105 mph in your case.  The -H wind speeds are
> the statistically expected "300 year" wind storms.
>
>
> 73 Jim K6OK