[TowerTalk] Grounding Rod Lenght

[Jim Lux]

----- Original Message -----
From: "Alan C. Zack" <k7acz at cox.net>
To: "Jim Lux" <jimlux at earthlink.net>
Cc: "James" <jameswarren at swbell.net>; <towertalk at contesting.com>
Sent: Monday, February 16, 2004 7:53 PM
Subject: Re: [TowerTalk] Grounding Rod Lenght


> Jim,
> Good info here.  Question please.  If a city Building Department is
> requiring your antenna tower project to be to code, can you request to
> study the code from one of their books?

I would think so.... They don't have to help you find stuff, but they should
certainly have a copy of the code available for inspection (and probably for
copying to take away at a "nominal" cost (close to actual cost of making the
copies)).

The local public library also usually has all the local codes.


> Reason I ask is I'm in the process of getting a building permit for a
> small tower.  U.S. Towers provided me with drawings and wind calcs for
> 70 MPH.  Not good enough.  The US Towers drawings are to USB-97 specs,
> they want IBC-2000 specs.  The wind specs are to 70 MPH, they want 90
> MPH.  Sales at U.S. Towers has refereed it to their outside contracted
> PE.  They don't have an in-house PE.  They farm stuff like this out to
> a contracted PE then charges the customer for the info.  Still better
> than trying to find someone from scratch to do it for you.  Any
> possible suggestions?  (I am an EE and IE but not a PE)
> Thanks.......

With a few hours of work, you should be able to determine which sections of
the code are controlling in your situation, and then you should be able to
do some analysis and calculations, which might be sufficient to make the guy
or gal at the counter happy.  On the other hand, if they're looking for a
wet stamp and signature, nothing you do will help.  However, your knowing
what's going on, and doing a lot of the "grunt work" might make getting that
stamp and signature easier/less expensive.

Don't expect getting it done for $50, though, unless you've got a close
friend who's a P.E., or there's some other sort of "deal" to be worked.  You
can call ARRL, who has lists of P.E.s who are "ham friendly", which might
save you something on the initial consultation, at least.



Be aware that "the code" won't tell you how to do the calculations. It will
just give you the requirements: that is, something along the lines of
"structures shall be designed to withstand a XYZ mi/hr wind without failure,
and ABC mi/hr without permanent deformation" and "material property factor
of safety of 2.0 shall be used for all strength calculations" and stuff like
that.

>