More utility poles are metal these days.

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Eddy Current

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I have never worked in the lineman field, but I've noticed that these days more and more poles that are being put up are metal. I was just wondering what the advantages of metal poles over wood are?
 
Eddy Current said:
I have never worked in the lineman field, but I've noticed that these days more and more poles that are being put up are metal. I was just wondering what the advantages of metal poles over wood are?
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Metal probably has a longer life than wood.
Metal is more uniform in strength.
Bucket trucks are being used for most line work. Metal poles were harder to climb in the era of linepersons using belts and climbing gaffs:)

Depending on the pole:

AL -- street lighting pole
....AL corrosion does not flake off, once the initial layer of corrosion occurs the process stops because the rest of the AL is protected from contact with oxygen by the layer of corrrosion

Galvanized Steel -- traffic light pole, "std" utility pole, HV Transmission lines
....Utility grade galvanizing protects for a very long time

CorTen Steel -- HV Transmission lines
....CorTen is a special steel that has rust that doesn't flake off, once the initial layer of rust occurs the process stops because the rest of the steel is protected from contact with oxygen by the layer of rust

Reinforced Concrete -- mostly non-US

If we had not had the chestnut blight we'd probably still be using chestnut poles that seem to last forever until a drunk driver takes them out.
 
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Mass / RI reporting in, no metal utility poles here all wood unless we are talking long distance transmission and even those are often wood.
 
iwire said:
Mass / RI reporting in, no metal utility poles here all wood unless we are talking long distance transmission and even those are often wood.
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The Northeast Reliability Interconnect is a brand new 345kV line going in up here, and the majority of those poles seem are huge H-frame glue-lams.

nri_project3.jpg
 
Around here they're still wood. Recently a local POCO started installing 65' wood poles to upgrade their grid. Local town people sued because they said that the poles were too tall and ugly. After a few months of bickering the State affirmed the POCO's right to install the poles.
 
Around here most new poles are wood until you get to the 138kv level, then most are metal. Have also seen some fiberglass ones on a 34.5kV line. Most of the run was with wood poles but they used fiberglass at a curve in the highway. Not sure why.
 
Here in south Florida prestressed concrete is most common for electrical distribution.
Traffic signals use either prestressed concrete or galvanized steel.
Aluminum is most common for highway lighting.

For hardened infrastructure there are some mega monster concrete poles. This includes distribution to essential facilities like hospitals, jails, EOC's, police & fire stations, etc.

Highways (traffic signals, signs) used to always be designed for 70 mph wind loads. After the storms of Charlie, Francis, Ivan, Jean, Rita, Katrina & Wilma that all changed. Even a single highway sign now has a pole that would hold a herd of elephants.

After those storms I remember one main bridge in particular coming into town had no lighting for about 5 years. Every year DOT would put the repairs out to bid but nobody ever bid it because everyone was so busy not only from the storms but it was concurrent with a building boom. As to replacing signs, that took years too. Today all the exit numbers are painted on the pavement for the benefit of mutual aid forces being able to know where they are on a map. Even when you work in a city, and work for the city, you think you know all the streets until one morning when there are no signs. Imagine being a mutual aid responder from halfway across the country and being told go here - do that. GPS is the savior today but still not everyone has them.

The point of all this rambling is that when it comes to what material is used for a given application, local perils trump capital & installation costs.
A cheap pole today could cost you a fortune tomorrow.
A better pole today means you still have a pole tomorrow.

As to transmission infrastructure immediately coming out of a power plant, I don't know of any built in the past 10 years. Existing is mostly iron. I don't know if there's any wood left around here or not.
 
mgookin said:
Here in south Florida prestressed concrete is most common for electrical distribution.
Traffic signals use either prestressed concrete or galvanized steel.
Aluminum is most common for highway lighting.

For hardened infrastructure there are some mega monster concrete poles. This includes distribution to essential facilities like hospitals, jails, EOC's, police & fire stations, etc.

Highways (traffic signals, signs) used to always be designed for 70 mph wind loads. After the storms of Charlie, Francis, Ivan, Jean, Rita, Katrina & Wilma that all changed. Even a single highway sign now has a pole that would hold a herd of elephants.

After those storms I remember one main bridge in particular coming into town had no lighting for about 5 years. Every year DOT would put the repairs out to bid but nobody ever bid it because everyone was so busy not only from the storms but it was concurrent with a building boom. As to replacing signs, that took years too. Today all the exit numbers are painted on the pavement for the benefit of mutual aid forces being able to know where they are on a map. Even when you work in a city, and work for the city, you think you know all the streets until one morning when there are no signs. Imagine being a mutual aid responder from halfway across the country and being told go here - do that. GPS is the savior today but still not everyone has them.

The point of all this rambling is that when it comes to what material is used for a given application, local perils trump capital & installation costs.
A cheap pole today could cost you a fortune tomorrow.
A better pole today means you still have a pole tomorrow.

As to transmission infrastructure immediately coming out of a power plant, I don't know of any built in the past 10 years. Existing is mostly iron. I don't know if there's any wood left around here or not.
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You forgot the granddaddy of them all, Hurricane Andrew. After that, some larger prestressed poles are often round instead of the traditional square to offer less wind loading. One that comes to mind is the transmission line from Homestead to the upper Keys was rebuilt with round concrete.
 
texie said:
You forgot the granddaddy of them all, Hurricane Andrew. After that, some larger prestressed poles are often round instead of the traditional square to offer less wind loading. One that comes to mind is the transmission line from Homestead to the upper Keys was rebuilt with round concrete.
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The original poles were square prestressed that ran down card sound road from turkey point, Andrew took them out as well as chopped off all the 200'+ Australian pines that were to the east of the road, it seems that in the two Hurricanes I have seen both Andrew and Katrina the pines in both storms all snapped off at the 30' level???
 
I've seen a few fiberglass ones over the years. Normally when we run pvc laterals to a pole we run up the first 8' of the pole and use 2 hole straps to secure to the wood, but on those fiberglass the poco (of course) specs we put stainless steel banding all the way around the pole to secure the riser conduit to the pole. NO SCREWS.
 
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.
 
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