48
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
this post was submitted on 21 Dec 2023
48 points (96.2% liked)
Mildly Interesting
17270 readers
15 users here now
This is for strictly mildly interesting material. If it's too interesting, it doesn't belong. If it's not interesting, it doesn't belong.
This is obviously an objective criteria, so the mods are always right. Or maybe mildly right? Ahh.. what do we know?
Just post some stuff and don't spam.
founded 1 year ago
MODERATORS
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.
I immediately thought of the original Tacoma Narrows Bridge, which collapsed after wind caused a resonance to build up and literally shook itself apart: https://en.wikipedia.org/wiki/Tacoma_Narrows_Bridge_(1940)
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...