[Ham-Mac] Re: Ground for new shack

[Michael A. Miller]

All

Brian Short wrote in part:

> but discharging lightning through the cement can
> (as I understand it) cause it to explode through nearly instantaneous
> expansion of moisture.

A dramatic example of why you don't want large current flows through  
concrete is here:

http://www.osha.gov/SLTC/etools/construction/electrical_incidents/ 
cranefire.html

A crane touched a 46Kv power line, which shorted through the boom to  
ground, heating the rebar in the roadway, which exploded.

-=- Mike Miller, KC0NXN
-
mike_miller@acm.org (Mike Miller)
http://homepage.mac.com/mike_miller/