Strike!

When I was a kid, my two older brothers were standing in the front door watching a massive electrical storm through the screen door. I was afraid to get too close to the doors or windows because of what sounded to me like earschplittenloudenboomers. Each bolt of lightning shook the house and rocked the neighborhood. They were both leaning against the door jam with their hands resting on the aluminum weather stripping when suddenly, a bolt of lightning struck the power line in the alley behind our house. Both brothers howled like wolves and nearly jumped out of their fur. The energy of the lightning strike enveloped the house and they got a good shock. As far as we know, it wasn't severe enough to cause any damage, but they were always a bit goofy so it's hard to tell.

Can that happen if you're standing on a metal catwalk and lightning strikes the building?

That was the question on the mind of a reader, "a sound technician with over 35 years of experience, but with limited electrical engineering knowledge," who wrote: "I have a contract to provide theatrical sound, stage-lighting and video services at a university.  Recently, the university allowed multiple cell phone companies to install equipment on the roof of the theatre.  The cell phone tower equipment installed by one company includes a conduit from the roof to the stage area catwalks on the inside of the building.  The conduit is bonded via a decent gauge wire to the exposed steel of the building.  (The cell phone company) also installed a heavy wire from inside the same conduit to the exposed steel of the building.  My concern is, what happens in the event of a lightning strike or other electrical issue from their equipment?  The building's steel is exposed throughout the catwalk area above the stage and the steel most likely is also connected to our double-purchase rigging system steel. Are we at risk for a shock in this situation?  Does it matter if the heavy wire is for lightning suppression versus just a heavy ground wire for their installation?" (to continue reading click here)

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