[TenTec] ufer ground?

[Tony Lelieveld]

Hi all,

Here is an article that I published in our club news letter in 2003.  You 
may find it interesting as it explains the origin of the "Ufer" ground 
system.

73, Tony VE3DWI.
*********************
An Ufer what???

Have you ever heard the expression “Ufer ground system”?  I have on 
occasion, and wondered what it meant too.  Finally curiosity got a hold of 
me and I had to know.  After some research on the internet I came upon some 
articles and thought to share the information I had garnished.  What follows 
is an excerpt of an internet article by Chris Scott & associates about this 
subject.

During World War II, a retired Vice President of Underwriters Laboratories, 
Herbert G. Ufer, developed it (the Ufer ground system) for the U.S. Army. 
Igloo shaped bomb storage vaults were being built, and possible static and 
lightning induced detonation problems were of concern.  Ground conductivity 
was poor, and to be effective enough, ground rods would have to be driven 
several hundred feet.  After much research and testing Mr. Ufer advised the 
Army to make connection to the steel bar that would internally reinforce the 
concrete foundation.  He had determined that concrete was more conductive 
than all but the best soil, and that this improved semi-conducting 
characteristic would enhance surface area contact with the surrounding soil.

The wire ties normally used would be extra secure, and attention would be 
given to bonding or welding the lattice-type network together.  The Army 
adopted the idea, and built the vaults as specified.  After construction 
ground resistance tests were made.  No measurement exceeded five Ohms.  This 
value was considered extremely low for the local soil conductivity.  Later 
tests confirmed stability.  Mr. Ufer went on to develop the concept of 
concrete encased grounding electrodes.  Many of his findings are detailed in 
IEEE Transaction paper #63-1505.  His system has since been used by the 
military, utility companies, Lake Tahoe lifts, and industry throughout the 
country.

Tony VE3DWI.
******************************
----- Original Message ----- 
From: "denton sprague" <denton at oregontrail.net>
To: "Discussion of Ten-Tec Equipment" <tentec at contesting.com>
Sent: Monday, August 12, 2013 9:20 AM
Subject: [TenTec] ufer ground?


I know this is kinda beating a dead horse to death, but ran across this 
today….
http://www.comm-omni.com/polyweb/ufertower.htm

first time I have ever heard of a ufer ground….a recent post by KI6CFW on 
eham also says this…

A ufer is a length of rebar (minimum of 20-25' or so long) embedded in the 
building's concrete footer.  One end of the rebar is bent up and extends out 
from the concrete (usually near the electric service panel).  The ground 
from the electric service panel is attached to the piece of rebar.


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