How about a bus? The fiber to a datacenter i used to work at kept going out at almost consistent intervals during almost normal business hours. Turns out the conduit wasn't deep enough and the city built a bus stop on top of it and it would sag just enough to go out but only when a bus was at the stop.

[–] pwshguy@programming.dev 6 points 1 year ago

That's pretty similar with what happened with me and the train. Kept getting random drops from a plant. I went out to investigate and everything tested perfect and the network was staying up. That was until a freight train rolled by. Turns out AT&T had run the line by shoving a piece of PVC through the gravel between two cross-ties, then running the cable through it.