Lightning 1, Data Link 0 in Omsk, Russia

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Bert Hickman
Stoneridge Engineering
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Bert Hickman
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On a sunny day (Mon, 13 Aug 2012 10:56:31 -0500) it happened Bert Hickman wrote in :

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Wow hope he did not have his earpiece in listening to mp3 at that end:-)

Reply to
Jan Panteltje

wouldn't want to be any where near anything connected to that wire :)

-Lasse

Reply to
langwadt

Examining that photo. The building lights streak, maybe the ionization off the horizontal rie, too. The strike is absolutely fixed. Perhaps it was 'strobed' into place.

Which leads me to, "Is this a valid photo, or was it a compilation?"

Reply to
Robert Macy

an

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Kirchhoff's law seems be hold

The left segment had less current than the right,

but yeah, the question still there... was it real or what?

Reply to
ccon67

I have no doubt that the photo is real. The photo is consistent with the video clip, but was taken from the opposite side of the pair of buildings and from a closer vantage point. Perhaps the shock from the closer blast jostled the camera a bit, AFTER the flash(es) occurred.

The video clip shows multiple strikes, so this was definitely a negative Cloud-to-Ground (CG) event. Positive CG lightning consists of a single, massive, discharge. The shower of sparks looks like burning steel droplets. The cable span was at least 400 feet (based upon estimated building height) so it's likely that a steel support cable was used to support the actual data link, and was (hopefully) connected to the buildings' lightning ground conductors. A small percentage of negative CG lightning strokes can exceed 200 kA on the first return stroke, and

100 kA on subsequent strokes. The extreme di/dt (10^10 - 10^11 A/s) of the return stroke, combined with skin effect and joule heating, may have caused the outermost layer (and any protective covering) to explosively ablate off the cable! A back of the envelope calculation indicates that the shorter cable segment would see over 3X the energy density as the longer span - consistent with the observed results. Some very interesting "natural" pulsed power effects appear to be at work here...

Bert

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Bert Hickman
Stoneridge Engineering
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Reply to
Bert Hickman

Welcome to "why I migrated my inter-building network to all-dielectric fiber optics in pvc conduit in the ground" - it's still not immune to a direct strike, but there's no particular reason for it to be struck, lacking any conductors. Random backhoe events are still an issue, of course...but the idiots (ours) that are likely to strike it wouldn't use a locator if I ran a trace wire, so I didn't. If we get more sophisticated idiots (or non-idiots) it's easy enough to run one before they dig.

If you have to go overhead, all-dielectric self-supporting is the way to go if there's any way you possibly can.

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Reply to
Ecnerwal

On a sunny day (Mon, 13 Aug 2012 11:28:35 -0700 (PDT)) it happened Robert Macy wrote in :

I was thinking it was a frame from the video (hitting this accidently is difficult). There are interpolated frames, clearly the camera was moving to the left. Motion vectors and stuff comes into play.

Reply to
Jan Panteltje

On a sunny day (Mon, 13 Aug 2012 16:27:23 -0400) it happened Ecnerwal wrote in :

I remember in the late seventies we did a microwave link with a gun diode. I designed the demodulaor, some other guy the Gun diode and horn. We used a reflector from an electric space heater as dish is testing.

This project after lightning killed the previous link...

That distance in the picture is close enough for some WiFi.

Reply to
Jan Panteltje

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