Not as easy as you'd think for transmission lines. California has one and it cost something like $10mil to fix a fault. The whole thing has to be filled with pressurized mineral oil with no impurities and each conductor needs to be wrapped in tons of layers of paper. The fault was caused because ground shift tore some of the paper and shorted the phases.
They had to literally freeze the pipe with liquid nitrogen to form makeshift plugs out of frozen oil to work on it.
Compare that to overhead where you can just send a random guy out there to walk it and say "yup, looks good" and worst case you drop a dude on the line from a helicopter.
Edit: Looking at the video again, those are fucking distribution poles. They absolutely shouldn't be using this equipment by distribution lines, the span distance isn't long enough and the treeline clearance isn't far enough. One snag and they're killing power for the town.
wow I had no idea about the pressurized mineral oil. and yeah after I posted this I realized how hard it would be to trench over dozens of miles of rocky mountain areas. sinking poles is several orders of magnitude easier
Yep, another bonus of poles is rent. Power companies can charge rent to telecoms that want to attach to their poles. Can't charge rent on a hole (though there are some kinda trying by pulling extra conduit and selling it to ISPs)
now I've been reading about all the operational reasons for why the oil is there. very interesting, also apparently an environmental hazard after the line is decommissioned
Yeah, it's really not a good idea. They only put it in because of NIMBYs. Ironically they all now have a n environmental hazard waiting to happen in their back yards instead of a few high voltage pylons.
just bury the fucking power lines.
Not as easy as you'd think for transmission lines. California has one and it cost something like $10mil to fix a fault. The whole thing has to be filled with pressurized mineral oil with no impurities and each conductor needs to be wrapped in tons of layers of paper. The fault was caused because ground shift tore some of the paper and shorted the phases.
They had to literally freeze the pipe with liquid nitrogen to form makeshift plugs out of frozen oil to work on it.
Compare that to overhead where you can just send a random guy out there to walk it and say "yup, looks good" and worst case you drop a dude on the line from a helicopter.
Edit: Looking at the video again, those are fucking distribution poles. They absolutely shouldn't be using this equipment by distribution lines, the span distance isn't long enough and the treeline clearance isn't far enough. One snag and they're killing power for the town.
wow I had no idea about the pressurized mineral oil. and yeah after I posted this I realized how hard it would be to trench over dozens of miles of rocky mountain areas. sinking poles is several orders of magnitude easier
Yep, another bonus of poles is rent. Power companies can charge rent to telecoms that want to attach to their poles. Can't charge rent on a hole (though there are some kinda trying by pulling extra conduit and selling it to ISPs)
now I've been reading about all the operational reasons for why the oil is there. very interesting, also apparently an environmental hazard after the line is decommissioned
Yeah, it's really not a good idea. They only put it in because of NIMBYs. Ironically they all now have a n environmental hazard waiting to happen in their back yards instead of a few high voltage pylons.
Earthquakes.