A Uber ground was developed for dry areas during WW2. In damp areas, the concrete can do just what happened in the concrete pole test.
Per Wikipedia article: "A disadvantage of Ufer grounds is that the moisture in the concrete can flash into steam during a lightning strike or similar high energy fault condition. This can crack the surrounding concrete and damage the building foundation.” We have plenty of damp soil in northwest 7 land. Best, Rick > On Apr 17, 2017, at 9:57 PM, David Gilbert <xda...@cis-broadband.com> wrote: > > > That isn't even close to being the same condition and only serves to help > perpetuate a stupid myth that refuses to die among the ill informed. Anyone > that doesn't understand that a Ufer ground is essentially multiple ground > rods encased in concrete is indeed ill informed. And anyone who doesn't > understand the mechanisms and considerations behind a Ufer ground shouldn't > be making contributions to threads like this. > > Sorry for the ire displayed by me here, but this stupid topic keeps surfacing > year after year in ham radio circles ... and specifically this forum ... > without the least bit of thoughtful consideration behind it. I'm tired of > our hobby, supposedly a technically based one, being subject to definitively > stated exhortations that are so demonstrably wrong. > > Dave AB7E > > > > On 4/17/2017 9:09 PM, Rick Dettinger wrote: >> I don’t think its a myth. In the early 1970’s, the power company I worked >> for was testing out some hollow reinforced concrete poles. There was >> considerable concern by the line workers that the poles might be more >> dangerous to work on than wooden poles, in the event of an accident. To >> check this, we installed one of the poles in a sub station, and wrapped a >> 26KV 1200 amp feeder conductor around the pole. When the station breaker >> was closed, the pole exploded dramatically, with a large fireball. The >> results might have something to do with moisture content in the concrete. >> The results convinced us to only use the poles on transmission lines that >> wouldn’t be worked hot, like we did with distribution lines. Of course, the >> power levels are much higher in lightening strikes. The conduction paths >> should similar from encapsulated ground rods in a tower base to Earth. >> >> 73, >> Rick K7MW >> >> >> >>> On Apr 17, 2017, at 8:32 PM, Doug Renwick <ve...@sasktel.net> wrote: >>> >>> That myth refuses to die. I have 5 concrete tower bases with ground rods >>> partially encased and never a worry about an exploding base. >>> >>> Doug >>> >>> >>> -----Original Message----- >>> >>> -NEVER- encase a ground rod in concrete ... especially a tower base. >>> >>> As a retired 2-way radio tech, I'm aware of two towers that had to be >>> re-installed because of lightening strikes exploding their concrete bases. >>> >>> 73! >>> >>> Ken - K0PP >>> >>> >>> >>> --- >>> This email has been checked for viruses by Avast antivirus software. >>> https://www.avast.com/antivirus >>> >>> ______________________________________________________________ >>> Elecraft mailing list >>> Home: http://mailman.qth.net/mailman/listinfo/elecraft >>> Help: http://mailman.qth.net/mmfaq.htm >>> Post: mailto:Elecraft@mailman.qth.net >>> >>> This list hosted by: http://www.qsl.net >>> Please help support this email list: http://www.qsl.net/donate.html >>> Message delivered to k7m...@gmail.com >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:Elecraft@mailman.qth.net >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> Message delivered to xda...@cis-broadband.com > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to k7m...@gmail.com ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
