[TowerTalk] Self-supportig tower base size

[Alan AB2OS]

I certainly haven't studied in detail the base specs. for every 
manufacturer's towers, but I must say that to me the AN Wireless specs. 
seem very comprehensive: five different sizes of base, each in two 
different designs, the size to be used depending not only on the height 
of the tower but whether it is the Light Duty or Heavy Duty model and 
the maximum expected wind speed.

E.g., the 60' Light Duty tower I plan to erect in an 80mph wind-speed 
zone requires a base 7' square x 5' deep = approx. 9 cu. yds. of 
concrete. This is supposed to be good for an antenna or antennas with an 
effective surface area of 15.6 sq. ft.

The 60' Heavy Duty version requires a base 8' square x 5' deep and is 
supposed to be good for an antenna or antennas with an effective surface 
area of 69.3 sq. ft. in an 80mph zone.

Note: all the AN Wireless towers are self supporting.

Alan AB2OS


On 07/23/04 02:12 pm Red put fingers to keyboard and launched the 
following message into cyberspace:

> Be cautious about applying one manufacturer's recommendations to another 
> manufacturer's tower in deciding on dimensions for the base of a self 
> supporting tower.
> 
> Total weight of base, tower, and everything on the tower is one 
> variable.  Minimum radius of the bottom of the base from its center is 
> another.  The sum of the wind induced moments is a third major 
> variable.  Soil characteristics are a fourth variable.

<snip>