[TowerTalk] Wind Loading Question.

[Michael Keane K1MK]

Hi Ted,

At 02:40 PM 2/12/07, k2qmf at juno.com wrote:
>Hello All,
>
>I have a question regarding wind loading.
>
>When tower or antenna manufactures rate
>their products in MPH wind loading do they mean constant wind
>or wind gusts??

When a manufacturer spec's according to a standard such as EIA-222, 
it's an 'average' wind speed. Survival loads are then computed by 
applying, among other things, a 'gust factor' on top of the pressure 
due to the average wind speed in order to account for gusts above the average.

Now in detail, the different version of EIA-222 have employed 
different averaging schemes over the years, so one has to pay close 
attention to exactly how an antenna or tower is spec'd.

It's good to be sure you know precisely what a manufacturer says in 
their specs.

>For instance what would a tower rated at 20 Sq Ft. in 60 MPH winds
>really mean??  Is it safe in 60 MPH winds with some gusts to 70 MPH ???

Yes, usually. As always, YMMV.

73,
Mike K1MK

Michael Keane K1MK
k1mk at alum.mit.edu