Jesus's middle name is Hume! Caution: Some NSFW images within!

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Rubycon

Rubycon

Madame President
Aug 10, 2005
17,768
485
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Gibsons said:
I wonder if Rubycon would like to explain this one to us.
Click to expand...

It's mostly in Russia, but apparently it's a "big thing" to fault transmission lines.

It's extremely dangerous and if caught the perp could be facing charges of domestic terrorism against a wide area power distribution system.

Typically what they do is hurl an object over one of the lines. It's heavy enough to make the trip yet light enough to be launched easily. A 175# crossbow with eyed bolt would probably work. Attached to this projectile is monofilament line that has a test (strength before breakage) high enough to withstand open pull but not so thick to impede flight of the carrying projectile. Additionally, this material needs to be dry and the humidity low or the perp will get the new look! :biggrin:

Once a line is "tagged" successfully, the carrier line gets attached to a conductive wire on the ground. Some perps may even connect this to an explosive charge such as a bullet hit squib, 150g cracker, blasting cap, etc.

Usually they will use several hundred meters of monofilament. They'll hook it to an ATV, etc. and slowly pull away lifting the conducting wire closer and closer to a single phase of the transmission line. When it gets close enough, there is an arc that looks similar to lightning with a deafening clap with a fundamental of the carrying voltage. (50Hz in USSR) If further effects were connected on the ground those will detonate as well. The effect is quite spectacular and apparently it gets done fairly often over in Russia.

http://www.youtube.com/watch?v=mqRT7J86rco


In that animated GIF it appears the overcurrent protection at the nearest substation failed to swing into action in a timely manner and allowed a phase to phase fault to play along the wires quite similar to a Jacob's ladder following the wind. Transmission phase to phase faults are quite destructive if not quenched rapidly.
 
shortylickens

shortylickens

No Lifer
Jul 15, 2003
80,287
17,082
136
cDH5VsQ.jpg
 
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