[TowerTalk] RE: One Man Tower

[Pete Smith]

At 09:10 AM 2/18/04 -0500, Dudley Chapman wrote:
>After seeing your message I found this.  What do people think about these
>towers?
>
>http://www.onemantowers.com/


I was perplexed by the windload numbers.  The site says:


The wind speed ratings given below are from the engineer's certification 
for the Mark 4 tower design. The report is for the 15-meter (49.7 ft) tower 
and is expressed in the Load Range Factor Design (LRFD) standards used in 
the U.S.A. The antenna is assumed to have a surface area of 19 square feet.


Ratings are given for the antenna in its operating position at the top of 
the tower and for the antenna in its lowest position.


Terrain Category 2 (TC2) refers to open, relatively treeless terrain.
Terrain Category 3 (TC3) refers to suburban and forested terrain.


Antenna Up
TC2: 103 mph (167kph)
TC3: 120 mph (194 kph)


Antenna Lowered
TC2: 125 mph (202 kph)
TC3: 148 mph (239 kph)

I've never heard of LRFD standards in the ham antenna context (or anywhere 
else), and wonder how successful you would be in persuading your local 
building permit office to accept these numbers in lieu of the EIA 
standard-derived figures for 70mph, 90 mph and so on.  Looks like you might 
be putting yourself in for some extra engineering costs.

No prices on the site either.  It would be interesting to see how they 
compare with conventional crank-ups.


73, Pete N4ZR
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