Singing Cold Power Lines
Name: Diane R.
Date: May 2004
What makes power lines "sing" when it gets cold?
I regret that I have no answer for this. I am not familiar with the
"singing" phenomenon. High voltage power lines often make a crackling
sound, and the answer why can be found by doing an Internet web search.
Though I am not an expert on this phenomena, I can express a few opinions.
Power lines "sing" when they vibrate. I believe this has nothing to do with
the current they are carrying.
I would expect the singing to become more noticeable during cold weather as
the wires then contract and the tension increases, raising the frequencies
at which they tend to vibrate; the higher frequencies would probably be much
more noticeable. It is also true that during winter (when temperatures tend
to be colder), there are more frequently high winds which would excite the
vibrations of the wires.
Best, Dick Plano, Professor of Physics emeritus, Rutgers University
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