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Originally Posted by djh
Even though the construction costs are higher, I would wonder if it would be more long-term cost-effective to use metal support infrastructure in urban alleyways. Ultimately I think the power and cable lines would be better-off underground, but every time a neighbourhood wooden pole needs replacing, it might be smart to go with metal over wood.
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Actually they replace wooden poles with concrete ones in some places. The pole closest to my parents place out on the Island is concrete. But... it blocks wireless signals.
https://www.bchydro.com/news/conserv...placement.html
http://www.twu-stt.ca/en/immediate-d...concrete-poles
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Concrete poles have been found to experience damage to the bolts when a system fault occurs due to insulator failure or fallen tree/branch contacting both the conductor and the pole. The fault current may travel through the hardware (bolts) to the concrete pole reinforcing steel to ground. Because of the high impedance between the bolt and the reinforcing steel, the initial fault current might not be high enough to trip the protection. Arching between the bolt and the pole may cause damage to the bolt and cause hardware to fall from the pole.
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Also I believe that answers the question about why they don't use metal poles.
Quote:
Originally Posted by djh
After doing some initial googling, there are lots of companies that offer metal power poles as an alternative to wood, and state, just as I had surmised, that over the long term, metal poles end up cheaper than wooden ones. In fact, a US steel lobbying organisation (obvious biased noted) claimed close to one million steel poles have been installed since 1998, and are used in 600 of 3100 US electric utilities (an interesting set of links here: https://www.steel.org/The%20New%20St...y%20Poles.aspx) |
You have to factor in the environment. I'd suggest that Most of the US and Canada north of Nevada is unsuitable steel poles due to road salt. All the lamp stands out here are often rusted up to 2m up the pole, and they do occasionally fall over when winds hit 100km/h (basically 80% of hurricane-force winds.) Areas that get precipitation or no precipitation without road salt seasons have little opportunity to rust.
In BC, they might not be very suitable unless they were to be washed and painted every year. The concrete option is probably more cost-effective until concrete is too expensive.