[TowerTalk] ground rod depth problem due to rocky soil -- solutions?

[David Gilbert]

Think of the earth as a large lossy conductor.  You can get pretty much 
the same effect by contacting it with a few low resistance "probes" in a 
localized area or a lot of higher resistance "probes" spread over a 
larger area.  The former often benefits from the typically higher 
moisture content the deeper you go, but if everything on your site is 
rock that probably doesn't hold anyway.

In my opinion, if the "soil" in your area is not high conductivity in 
the first place (i.e., it's rock), you're probably better off with the 
larger area approach even if you were able to drive the rods in deeper.

73,
Dave   AB7E




On 11/12/2012 2:30 PM, Mat Eshpeter wrote:
> I am finally getting around to putting up my 60' AN Wireless tower on top of a rocky ridge in WV. I rented a Hilti demo hammer and got about 1/3 of my rods in to the ground at least 4' -- but the majority are only 2 or 3 feet deep because of the rocks/ledges. I don't think I have much of a choice other than to cut the rods off and drive the remnants into the ground field and exothermically weld my 20 gauge copper strap to all of these shallow rods.
> Other than paying big money for a well drilling rig to drill some deep 6" holes and filling them with bentonite (which may not be possible given the slope of the land and the fact that I now have 8 trenches running 75' out from the tower pad) do I have any other practical alternatives?
> tnx,Matkk1c