As a kid there was a big exciting (to me through my parents' eyes) movement to put our neighborhood power lines underground, but they fk'ed it up somehow and power started going out so often we got a generator.
I want to say it was some issue with the water table? Poorly protected? Too low? Whenever a big rain would come they'd flood and cut off? I might be making that part up, kid memories.
I'm sure that has a lot to do with the incopetents that managed it and little to fo with underground cables in general.
Ask New York City. It's expensive af every time a change needs to be made underground because you have to dig everything up, and once you're down there, it's just a nest of wires in conduit so knowing which one you're supposed to work on can be a challenge.
Underground wires have to be insulated to prevent short circuits to ground. The longer a wire needs to go, and the more power it needs to carry, the thicker it needs to be. Since insulation goes around the outside, this increases exponentially and the cable quickly becomes mostly insulation in many cases, which is expensive and inefficient.
Also, there's only so much ground you can dig up before you hit bedrock. So, in some cases, power infrastructure expansion is limited because there's nowhere to bury the wires.
In many places it's easier to let the damage happen and repair it cheaply.
Yet in London, power lines are buried, alongside gas and water supplies and most of the telephony network.
Its a choice about what cost is acxeptable for the long term benefits of protection from the elements and safety generally. It costs more upfront, but extends the lifespan of cables as theyre protected from temperatures, UV, fainfall, and falling tree branches.
When they do need repair / replacement it requires digging but theyre generally subsurface, and many utilities are under pavements or to one side of the road, allowing roads to be kept partially open. But they generally require repair less frequently than exposed cabling.
Why do they have to be dug back up? Would it not be possible to make an extra level for all cables when you dig for sewers or subways?
This also solves the grounding problem.
If you only want to do the minimum for every change then yeah, just put it above ground, but that’s how business works, governments are suppose to plan long term.
Yeah i was in high school in perth in the 90s so i remember poles disappearing.
Perth has expanded massively in the last 10-15 years, i'm not surprised initial estimates were way off. Or even less surprised than normal since i believe every single infrastructure project in history has been late and overbudget.
Where I live, ground settling causes problems with utilities. Gas company had to come last week to redo line to my house because it had dropped a foot.
In addition to cost (as everyone else said), work and worker qualifications. Working on underground lines requires special confined spaces training and certification, because it is more dangerous, could deal with not just electricity, but potentially hight temperatures, water, sewage, toxic gas, lack of oxygen, etc. There are even fewer people willing to do that compared to riding a bucket to the overhead lines.
Some unprepared countries tried this, in an effort to modernize. Without interdeparrment communication, good documentation, coordination, signage and, well, maps that included depth data that are maintained and updated in real time, yould have frequent outages each time one works department or private contractor did some digging in an inocuous patch.
It's shitty to maintain underground wiring and it's shitty to trench it in the first place, so while you are saving money in the long run, you're paying upfront to run it and your routine maintenance costs are higher in short bursts instead of lower cost per issue, but a lot more issues. This makes people angry the money line didn't go up enough that month and now you're fired... even though you saved them money in the long run.
You can't run it very far underground. I won't get into the physics, but suffice it to say, running power underground tends to be "leaky", and it will bleed away very quickly over relatively short distances.
Sunk Costs. Tech for trenching and boring has gotten a lot better, it costs less to do than it did 100 years ago, but moving the lines now and tearing down the old ones would cost money upfront and no one wants to pay for that.
I’ve lived in areas where they aren’t underground BECAUSE of potential severe weather. The powerlines run through miles of wilderness and are serviced by helicopter. Which doesn’t come out when the weather’s bad. But if they were buried (which would be massively more expensive) they’d tear up lots of wilderness and flood/break regularly due to soil movement and tree growth.
Plus, running conduit through rock is a lot harder than drilling a few holes to mount a pole.
Where I am now? It’s all in conduit under the street beside the storm drains, except where there hasn’t been new development to pay for it. Seems like they have to service the conduits a lot more than the poles though, and fixing a pole line stays out of the way of traffic and takes a couple of minutes, where fixing underground shorts involves blocking off a lane, snaking the cables, and bringing in specialists — takes up to 3 hours for a similar repair.
We used to insulate cables with basically waxy paper, not exactly the most waterproof of materials, and if you want to bury lines long term you need to enclose the sections in some kind of corrosion resistant waterproof pipe so you don't have to dig them up completely every time you need to do maintenance
So this really wasn't a practical option until petrochemicals came onto the scene, but also the improvements to metallurgy and grid technology were probably necessary to really make this feasible
Imagine trying to track down shorts underground constantly...
That’s not exactly true. The first undersea transatlantic cable was laid in 1854, well before petrochemical coatings. Admittedly, it didn’t last long. But the third cable in 1866 did last quite a while.
That's interesting, but also a special case. Those were specifically underwater cables, they needed to be kept wet
And even after we created rubber, we definitely did not coat normal cables in rubber, ever since the properties of latex were discovered we've basically never had enough to fully meet the demand. Rubber is really useful for all sorts of things, and latex trees take a decade to start producing and only produce for another couple decades. Discovering alternatives using petrochemicals was a really big deal because of that
My point stands... The wires we used for early electricity and telephone transmission had minimal insulation, if any at all. Definitely nothing suitable to use underground until much later. Here's a breakdown of the time frames for insulation (and note that cost was a significant part of the decision, even today we don't use weather proof insulation unless the situation calls for it)
In the 1880’s the first insulated cables were insulated with gutta percha, a natural latex material produced from the sap of trees of the same name. This insulation needed to be kept constantly wet or it would dry out and fail to insulate the conductors. This material was largely replaced by rubber and vulcanised bitumen.
By the 1890’s mass impregnated paper insulation was being used on cables and voltages as high as 10kV.
In 1906 armoured cables were introduced which had flexible sheathing and two cloth covered, rubber insulated conductors.
In the 1930’s the first trials with PVC insulations were being made in Germany and by the end of the second world war there were significant varieties of synthetic rubbers and polyethylene.
By the 1950’s PVC was commercially viable and replaced rubber cables in many areas particularly in domestic wiring, aluminium was also starting to be used widely as an alternative conductor
The 1970’s heralded XLPE insulations replacing paper insulated cables in medium voltage applications.
In the 1980’s optical fibres were being introduced in overhead lines for data transmission and condition monitoring, and further use of XLPE in high voltage transmission lines between 66 and 240kV. Also high temperature super conductivity materials were discovered. PVC alternatives (LSZH cables) which were safer in fires were being developed in response to a number of tragic public fires which demonstrated the dangers of smoke and toxic gases from various materials including PVC’s.
By the 1990’s polymers were being extended to use in EHV, extra high voltage, applications and the use of optical fibres in overhead lines was becoming widespread.
Where I am from, they've been doing that for a few decades now. We get snow and windy autumns, so trees fall on the lines, snapping them, leaving tens of thousands without electricity. Also the snow packs on the branches of the trees, making them either snap or just sort of lean on the power lines, snapping them, leaving tens of thousands without electricity in -25C degree weather.
Which would have saved a bunch of money from upkeep and accidents?
That's highly debatable. Putting something in the ground instead of the air just adds a different set of factors eating away at the cables. Accidents happen underground as well as above. Excavators or farming equipment regularly cut cables buried in fields or at construction sites. The deeper you bury cables to avoid that the higher the cost gets. Also maintaining a network of buried cables has its own problems: Want to know where an overland power line was cut? Just look where the cable dropped. Want to know where a buried line broke? Start digging up the whole strand between the two transfer points.
Overall: Overland lines are cheaper and easier to maintain.
There are probably lots of different reasons. But they will all boil down to whether it really made financial sense in the long run.
In my area there’s a lot of rock. So burying lines can have a much higher expense even in the long run.
And I’ve also lived in some areas with a lot of hills/mountains. Burying lines in areas like that means you need a lot more line than if you just stretched it between poles or towers over the valleys.
Where I am, way cheaper for upkeep to have on poles. Some jackass is trying to force my entire neighborhood to underground our power lines for no reason other than aesthetics and they say it'll cost the average homeowner here $50k each. If it goes through I'm thinking of Molotov cocktailing the fucker's house.
Both in New Zealand and the UK (the places I've lived), many copper POTS lines were underground, same as fibre. Out of the urban area it actualy makes more sense to go over head for cost and repair.
For HV power lines I believe that heat retention is a major factor in underground, and there are plenty of 'last mile' that is underground - but that is not HV and a lot less load
Some one with better answers will come along and explain it better I'm sure
Cause it’s always tempting doing the short sighted solution since the cost seems very low given how quickly you get the benefit.
But once you get the benefit, the cost can keep growing even though you’ve already experienced the political high from bringing new infrastructure.
It’s like the sunken cost fallacy, once you accepted the short sighted solution was a good deal, you kind of set yourself up to keep thinking it’s still worth it even though the formula gets worse as time goes on.
This is just a guess, but I think it might be because not everyone needed or had a phone at first.
They only connected a few important buildings at first, and then started tying in more. If they had started underground, they'd have to dig up the streets every time someone bought their first telephone.
That's exactly what's happening where I am. Wildfire danger is so high they have to shut down city power every time there's serious wind, as there aren't enough fire services to cover all the potential fires from downed lines. Now a good chunk of tax dollars are going to moving lines underground, though arguably it'll take some time.
Under ground cabling has a shorter lifespan than above ground and are harder to access due to limited access points for maintenance. They are also prone to things like flooding and tree roots. Still look a heck of a lot better than above ground, though.
Thats not true - underground cabling has a longer lifespan as they're protected from rainfall, surface temperatures and UV. Tree roots and flooding is a factor of maintenance and location. E.g. an inner city location is unlikely to experience flooding and roots can be guided away from cables as they follow path of least resistance.
In much of Europe, buried cables is the norm, and they co-locate with buried gas and water supplies. Telephone cables were the one exception but with fibre optic cables even that is largely underground now especially in dense urban areas.
Old copper telephone lines werent buried for convenience as they were easy to install out to new properties as and when needed. Every house needed water and electricity but telephone connections varied, and some buildings needed multiple. But this was just from pole to home. The poles connected to cabinets on a street and the rest of the network of trunks were buried, at least in much of Europe.
It does cost more initially but with the benefit of lower cost in maintenance long term.
In Japan cables are often above ground, but presumably because of Earthquake risk. In the US I dont know why buried cables is less common. Possibly because many utilities were private and so went for short term cheaper costs? Most European utilities were public owned - and even if now privatised, the expectation remains burying.
I was always taught maintenance wise that the insulation around underground cabling (which is necessary since earth is a great conductor) degrades and leads to a shorter maintanable life for the cables than above ground ones. I could be wrong, though.
In addition to being higher cost, buried lines aren’t great for long distance, high power transmission. That’s part of the reason off-shore wind uses high voltage DC rather than AC power
53 replies
Telephone... lines? They're wireless, duh. /s
As a kid there was a big exciting (to me through my parents' eyes) movement to put our neighborhood power lines underground, but they fk'ed it up somehow and power started going out so often we got a generator.
I want to say it was some issue with the water table? Poorly protected? Too low? Whenever a big rain would come they'd flood and cut off? I might be making that part up, kid memories.
I'm sure that has a lot to do with the incopetents that managed it and little to fo with underground cables in general.
Here they are for residential supply. It's been this way for almost 50 years.
For high voltage AC, underground calling is actually a nightmare from a maintenance perspective.
More expensive to build. That doesn't get offset by accidents and whatever. Also harder to repair in case something really is broken with it.
Ask New York City. It's expensive af every time a change needs to be made underground because you have to dig everything up, and once you're down there, it's just a nest of wires in conduit so knowing which one you're supposed to work on can be a challenge.
Underground wires have to be insulated to prevent short circuits to ground. The longer a wire needs to go, and the more power it needs to carry, the thicker it needs to be. Since insulation goes around the outside, this increases exponentially and the cable quickly becomes mostly insulation in many cases, which is expensive and inefficient.
Also, there's only so much ground you can dig up before you hit bedrock. So, in some cases, power infrastructure expansion is limited because there's nowhere to bury the wires.
In many places it's easier to let the damage happen and repair it cheaply.
Yet in London, power lines are buried, alongside gas and water supplies and most of the telephony network.
Its a choice about what cost is acxeptable for the long term benefits of protection from the elements and safety generally. It costs more upfront, but extends the lifespan of cables as theyre protected from temperatures, UV, fainfall, and falling tree branches.
When they do need repair / replacement it requires digging but theyre generally subsurface, and many utilities are under pavements or to one side of the road, allowing roads to be kept partially open. But they generally require repair less frequently than exposed cabling.
Why do they have to be dug back up? Would it not be possible to make an extra level for all cables when you dig for sewers or subways?
This also solves the grounding problem.
If you only want to do the minimum for every change then yeah, just put it above ground, but that’s how business works, governments are suppose to plan long term.
fiber optics solve most of this for comms. clearly doesn't help for electricity.
Because then all the phone calls would have sounded muffled.
Couldn't you just yell a little louder into the phone to make up for it?
You’re thinking of “too quite” which can be solved with louder speech. Muffled remains unclear regardless of volume.
Incorrect. "Too quite" can only be cancelled out by some "not very".
In australia buried lines are fairly common. It's more expense and harder to do maintainence, but it's also way better and safer.
Perth started burying their lines in the 90s. It was supposed to take 30 years. Last I heard, they're about half done.
Yeah i was in high school in perth in the 90s so i remember poles disappearing.
Perth has expanded massively in the last 10-15 years, i'm not surprised initial estimates were way off. Or even less surprised than normal since i believe every single infrastructure project in history has been late and overbudget.
There were supposed to be five pyramids at Giza. Cutbacks...
j/k
Bet the power stays on more during storms and shit as well.
Poles get knocked over, struck by lightning, trees, blah blah.
Where I live, ground settling causes problems with utilities. Gas company had to come last week to redo line to my house because it had dropped a foot.
Very very expensive. For fiber, though, it’s starting to make sense economically.
In addition to cost (as everyone else said), work and worker qualifications. Working on underground lines requires special confined spaces training and certification, because it is more dangerous, could deal with not just electricity, but potentially hight temperatures, water, sewage, toxic gas, lack of oxygen, etc. There are even fewer people willing to do that compared to riding a bucket to the overhead lines.
Source: Worked for electrical utility
High population of native predators:
Don't know why they don't this in your place. Here, power, phone, fiber, everything is underground for years now.
Some unprepared countries tried this, in an effort to modernize. Without interdeparrment communication, good documentation, coordination, signage and, well, maps that included depth data that are maintained and updated in real time, yould have frequent outages each time one works department or private contractor did some digging in an inocuous patch.
Source: am malaysian.
They are in lots of places. Most British villages/towns/cities all utilities are now underground. Its quite rare to see low voltage powerless now
$$$
There's 3 answers.
Except high voltage lines outside the city everything is mostly underground here in Germany.
In the city i live in (Victoria, BC) the wealthiest part of town has buried lines. Everywhere else, they're on poles.
In areas prone to severe weather they tend to get buried.
Especially after multiple event trash pole mounted ones.
I use to live in Huntsville Alabama. Between the tornadoes and ice storms Huntsville utilities just gave up and started burying them.
I’ve lived in areas where they aren’t underground BECAUSE of potential severe weather. The powerlines run through miles of wilderness and are serviced by helicopter. Which doesn’t come out when the weather’s bad. But if they were buried (which would be massively more expensive) they’d tear up lots of wilderness and flood/break regularly due to soil movement and tree growth.
Plus, running conduit through rock is a lot harder than drilling a few holes to mount a pole.
Where I am now? It’s all in conduit under the street beside the storm drains, except where there hasn’t been new development to pay for it. Seems like they have to service the conduits a lot more than the poles though, and fixing a pole line stays out of the way of traffic and takes a couple of minutes, where fixing underground shorts involves blocking off a lane, snaking the cables, and bringing in specialists — takes up to 3 hours for a similar repair.
I guess Dickle has no time for proofreading because need to post 10 times a day
The poors get overhead lines, the wealthy get underground
We used to insulate cables with basically waxy paper, not exactly the most waterproof of materials, and if you want to bury lines long term you need to enclose the sections in some kind of corrosion resistant waterproof pipe so you don't have to dig them up completely every time you need to do maintenance
So this really wasn't a practical option until petrochemicals came onto the scene, but also the improvements to metallurgy and grid technology were probably necessary to really make this feasible
Imagine trying to track down shorts underground constantly...
That’s not exactly true. The first undersea transatlantic cable was laid in 1854, well before petrochemical coatings. Admittedly, it didn’t last long. But the third cable in 1866 did last quite a while.
The cables were coated in gutta-percha.
This is undersea cabling, not underground, but saying we used to coat them in waxy paper is what I would disagree with.
That's interesting, but also a special case. Those were specifically underwater cables, they needed to be kept wet
And even after we created rubber, we definitely did not coat normal cables in rubber, ever since the properties of latex were discovered we've basically never had enough to fully meet the demand. Rubber is really useful for all sorts of things, and latex trees take a decade to start producing and only produce for another couple decades. Discovering alternatives using petrochemicals was a really big deal because of that
My point stands... The wires we used for early electricity and telephone transmission had minimal insulation, if any at all. Definitely nothing suitable to use underground until much later. Here's a breakdown of the time frames for insulation (and note that cost was a significant part of the decision, even today we don't use weather proof insulation unless the situation calls for it)
Where I am from, they've been doing that for a few decades now. We get snow and windy autumns, so trees fall on the lines, snapping them, leaving tens of thousands without electricity. Also the snow packs on the branches of the trees, making them either snap or just sort of lean on the power lines, snapping them, leaving tens of thousands without electricity in -25C degree weather.
That's highly debatable. Putting something in the ground instead of the air just adds a different set of factors eating away at the cables. Accidents happen underground as well as above. Excavators or farming equipment regularly cut cables buried in fields or at construction sites. The deeper you bury cables to avoid that the higher the cost gets. Also maintaining a network of buried cables has its own problems: Want to know where an overland power line was cut? Just look where the cable dropped. Want to know where a buried line broke? Start digging up the whole strand between the two transfer points.
Overall: Overland lines are cheaper and easier to maintain.
There are devices that will measure how far away a break in a cable is.
There are probably lots of different reasons. But they will all boil down to whether it really made financial sense in the long run.
In my area there’s a lot of rock. So burying lines can have a much higher expense even in the long run.
And I’ve also lived in some areas with a lot of hills/mountains. Burying lines in areas like that means you need a lot more line than if you just stretched it between poles or towers over the valleys.
My street is the only one in my area that has buried lines. I suspect because a politician lives on it as well
Where I am, way cheaper for upkeep to have on poles. Some jackass is trying to force my entire neighborhood to underground our power lines for no reason other than aesthetics and they say it'll cost the average homeowner here $50k each. If it goes through I'm thinking of Molotov cocktailing the fucker's house.
do it anyway just to send the message.
Before hydraulics digging was hard AF. And it's still cheaper to put them on poles.
Both in New Zealand and the UK (the places I've lived), many copper POTS lines were underground, same as fibre. Out of the urban area it actualy makes more sense to go over head for cost and repair.
For HV power lines I believe that heat retention is a major factor in underground, and there are plenty of 'last mile' that is underground - but that is not HV and a lot less load
Some one with better answers will come along and explain it better I'm sure
Australia also has most of its telecommunications cabling underground
Cause it’s always tempting doing the short sighted solution since the cost seems very low given how quickly you get the benefit.
But once you get the benefit, the cost can keep growing even though you’ve already experienced the political high from bringing new infrastructure.
It’s like the sunken cost fallacy, once you accepted the short sighted solution was a good deal, you kind of set yourself up to keep thinking it’s still worth it even though the formula gets worse as time goes on.
In Australia our power lines are mostly aerial, but telephone/broadband lines are mostly underground.
This is just a guess, but I think it might be because not everyone needed or had a phone at first.
They only connected a few important buildings at first, and then started tying in more. If they had started underground, they'd have to dig up the streets every time someone bought their first telephone.
That's exactly what's happening where I am. Wildfire danger is so high they have to shut down city power every time there's serious wind, as there aren't enough fire services to cover all the potential fires from downed lines. Now a good chunk of tax dollars are going to moving lines underground, though arguably it'll take some time.
It is expensive as hell to bury anf maintain.
OP I get you, i lived in a placed that buried them and it was great. We never had outages and it looked great. I wish everywhere did it.
Under ground cabling has a shorter lifespan than above ground and are harder to access due to limited access points for maintenance. They are also prone to things like flooding and tree roots. Still look a heck of a lot better than above ground, though.
Thats not true - underground cabling has a longer lifespan as they're protected from rainfall, surface temperatures and UV. Tree roots and flooding is a factor of maintenance and location. E.g. an inner city location is unlikely to experience flooding and roots can be guided away from cables as they follow path of least resistance.
In much of Europe, buried cables is the norm, and they co-locate with buried gas and water supplies. Telephone cables were the one exception but with fibre optic cables even that is largely underground now especially in dense urban areas.
Old copper telephone lines werent buried for convenience as they were easy to install out to new properties as and when needed. Every house needed water and electricity but telephone connections varied, and some buildings needed multiple. But this was just from pole to home. The poles connected to cabinets on a street and the rest of the network of trunks were buried, at least in much of Europe.
It does cost more initially but with the benefit of lower cost in maintenance long term.
In Japan cables are often above ground, but presumably because of Earthquake risk. In the US I dont know why buried cables is less common. Possibly because many utilities were private and so went for short term cheaper costs? Most European utilities were public owned - and even if now privatised, the expectation remains burying.
I was always taught maintenance wise that the insulation around underground cabling (which is necessary since earth is a great conductor) degrades and leads to a shorter maintanable life for the cables than above ground ones. I could be wrong, though.
In addition to being higher cost, buried lines aren’t great for long distance, high power transmission. That’s part of the reason off-shore wind uses high voltage DC rather than AC power