[TowerTalk] wind loading

[Al Williams]

I have received a number of responses to my question wanting a simple
conversion of tower square footage ratings for windspeed of 80mph rather
than 70mph.  Almost all responders were of the theme that many factors have
to be taken into consideration and that I did not supply enough information.

While I can understand this to be true for a definitive answer to a given
installation i.e. terrain, antenna
& related equipment locations etc., it seems to me that  none of these
change just because the wind speed increases from 70 to 80mph.  Whatever
conditions the tower manufacturer assumed for his 70 mph specification are
to be assumed to remain, all that changes is the wind speed.

Are the professional tower engineers telling us that the manufacturers tower
wind load specifications are useless (like antenna beam gains) unless all of
the factors clearly stated--terrain, buildings, trees, guy wires (if any),
rotor and antenna lead-ins placement?

There must be thousands of ham towers, many that have say a 8 sq ft beam at
70' and a 5 sq ft beam at 40'.  Must each of these installations have
individual wind loading calculations performed? Some at 70mph, others at
80mph, still others at 90mph etc?

k7puc


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