[TowerTalk] Ground Rods in rocky soil

[Joe - WDØM]

Hi Bill,

Had a major problem here in the Rockies with 
grounding.  We have bedrock 6 inches under the 
soil all over our 5 acre lot.  After talking to 
the locals, one in particular who installs 
microwave towers on rocky terrain on top of the 
mountains, he told me they use 50 foot lengths of 
copper ribbon/strap about 2 inches across as a 
ground.  They don't bury it, but run it away from 
the base of the tower and just let it sit on top 
of the rocks.  He said in all the years he's been 
doing this, he has yet to see any significant 
damage to the equipment, despite numerous direct hits to the towers.

My web page has a few details about it:

http://home.centurytel.net/WD0M/

Click on Ham Radio, then Lightning Protection.

Since I couldn't put my concrete base into the 
ground, I had to put the concrete on top - held 
in place with 25 lengths of re-bar which were 
cemented into the bedrock.  (Click on Tower 
Project for the details).  Quite a 
challenge.  It's worked well - I've had a direct 
hit, and all that got fried were two ICE 
protectors - and ICE repaired them for free - great company!

I've lived in KH6 for a few years (Oahu) , and 
never had any problems with 
lightning.  Nonetheless, in your location, I'd 
pursue something to help put my mind at ease.

Cheers,

Joe
WDØM






At 10:50 AM 1/18/2007, Cqtestk4xs at aol.com wrote:
>After being spoiled by Florida's sugar sand in which you could dig  a hole
>for a base for holes and anchors by hand and drive a ground rod down  by
>"jetting" it, I now live on one of the biggest rock piles in the world.
>
>Most of the Big Island of Hawaii has solid lava rock.   Fortunately, my area
>is a little bit better...a mix of clay, small rocks  and rocks up to a foot
>across, certainly not the kind of stuff easy to 
>get  into.  Sometimes the layer
>of pure clay is just a few inches thick, in  other places it can be ten feet
>deep.  Ground rods and copper are  pretty expensive out here and I don't want
>to experiment losing rods just a  couple of feet into the ground and getting
>stuck at that depth.
>
>I know I can use a backhoe to dig the holes and will have one on the
>property to dig the cesspool, but what is the 
>best way to go getting ground rods  in?
>  I asked the locals at one of the radio club meetings and they weren't  much
>help.  Responses were.....most guys just drive it in a foot or so and  use
>radials.  Since the station will sit on a hill, 
>I really don't feel too  secure
>putting the rod in only a foot, however I do plan on running the radials,
>since I know it will help.
>
>Any ideas?
>
>Bill K4XS/KH7XS
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