I’ve seen this phenomenon many times over the years, while walking the dog out behind our house. The cables wiggle between these two particular power poles, but NOT between the adjacent poles (or any others, along this pole line). There is no wind, no earthquakes, no herds of animals or large vehicles/machinery anywhere nearby when this is happening. I honestly have no idea why this happens sometimes. Thoughts? I mean, sure, it’s probably ghosts, right? But any other explanation would be appreciated…
Did you measure the distance between the poles? I suspect it’s different from all the other spans, so this one happens to have a resonant frequency that exactly matches whatever vibration source is already there (could be the tension too). As for sources of vibration, wind is probably it, even if it’s not strong. If it just happens to create the right frequency, the cable will vibrate just like a violin string.
No, I’ve never tried to quantify the variables in that way. Just out walking the dog, and notice this strange behavior from time to time. I always assumed the poles were placed a specific distance apart, but honestly, I’m not sure. I suppose if I ever have the urge to pace it out to get a good estimate, I will…
I work with telecom cables. This happens when the cable isn’t rotated when hung. If it’s hung without any rotations the wind catches it and it’ll dance like this
I guess my only question is, why is this happening when there is literally no wind blowing?
Look up the following: “aeolian vibration“.
This is most likely due to a differing tension between that span and the spans on either side of it. It has more “sag” (even if only fractionally different) therefore it is more susceptible to what I referenced above.
I assume that line is communication, and the tension on them is enormous. Did you happen to get a closer look at the spiralling on it? I can’t tell by this video if it’s armouring or a grip.
Perhaps that section is exactly centered between two different sources of vibration, so the vibrations meet and amplify at that point?
This is indeed very interesting. I can reccomend asking the telecom company that owns the line with a quick email as to whats going on here, they usually like to answer such questions. Maybe post in a sub thats more familiar with mechanics/electronics or even general asklemmy?
i love that this is a mystery that the internet cannot easily solve, thank you for sharing :)
You’re sure there’s no squirrel hiding there taunting you and your dog?
