More utility poles are metal these days.

[hurk27]

Anybody know if they ever run under ground power over mountains and hills or are they always overhead utility lines?

You don't see MV to HV 69kv to 345kv run underground very much as the cost of the conductors is very cost prohibited, but I would expect in mountainous areas the amount of rock encountered would be very hard to deal with for running underground, most runs I have seen were over head.

 

[Eddy Current]

You don't see MV to HV 69kv to 345kv run underground very much as the cost of the conductors is very cost prohibited, but I would expect in mountainous areas the amount of rock encountered would be very hard to deal with for running underground, most runs I have seen were over head.

Yeah, I didn't think about the rock, I was thinking about how hard it would be to pull conductors over a mountain, ha.

 

[JoeTroubleShoot]

Our POCO is moving a 138k line requiring a several mile run right next to city streets. They are using HUGE wooden poles. I would have to say they are 90 - 100 feet or better.

I wonder how long it took nature to grow those trees. With material technology as advance as it is, I think cutting down all those magnificent trees was terribly irresponsible.

I think the tallest wood poles are 90'. They swing around like crazy when you're at the top and there are no guys on it yet. Pretty wild.. feels like the top is swinging back and forth teen feet in each direction. I've never worked on anything taller as far as wood goes. I can't remember if anything larger wasn't available at the time or just not produced by anyone. I'm sure there are rules about the conservation of large trees although your probably right, there is likely someone hacking down big trees somewhere. Most poles come from fast growing wood. They're not ancient redwoods.

I would imagine it's not even worth it to go with wood for transmission. The price for poles over 50' goes up exponentially with every ten feet. I would imagine a 90' pole is close to 4k and you need two or three of them each structure. When you factor everything together over the life of a structure, it may even be more expensive for wood.

 

[J.P.]

They built some transmission lines in my area. Huge metal poles with a large concrete base. They had their steel reinforcements laying beside the holes for a while. You could have driven a pick up through them.

One day we saw a helicopters show up with lines hanging from them. They were putting the wire up on the poles with the helicopters I guess. I didn't see that part.

Later I met one of the lunatics that hangs under the chopper and works on the lines. It very windy here all of the time. I can't imagine how good the pilots have to be not to kill everybody.

I don't know what it cost to build those transmission lines, but it ain't cheap.....

 

[FionaZuppa]

anything wood keeps you utility/electrician folks working...... over time they will need maintenance or replacing.