PCBs were used because they are really good thermal conductors, which is the same property desired of cooking oil for frying. In recent years, thieves in Kenya (which has yet to replace PCBs with something less toxic) have been vandalizing  transformers and selling the oil to street vendors, which has the twin effects of destroying the fragile electrical infrastructure and poisoning the neighborhood.
This company wasn’t just irresponsible, it was malicious. At one point, a contractor it hired to dispose of the oil was caught spraying it along rural roadsides.
Related story – “How the Benzene Tree Polluted the World“:
It reminds me of the Vice News story about the illegal oil refineries which are present in the Niger River delta and the environmental and humanitarian destruction they are causing.
Additionally when authorities find illegally refined oil they simply dump it on site, contaminating the villages and markets where it is stored.
He really enjoyed the street food. But, as he told me, you had to be careful. How did a vendor have fresh fare without power nor evident means of fresh supply and cooling?
Well, per him, some vendors kept supplies submerged in formaldehyde.
I've never looked up independent confirmation of this, and I haven't been there and so had to worry about it. But he was, in my experience, a straight shooter and not one inclined towards tall tales.
Seriously, PCB/dioxin contaminated oil sold for frying? That is insane. But then, people sometimes adulterate sugar with lead acetate :(
Everything from copper to make pickles green, to molten lead to clarify wine.
Indeed it is. This is a widespread practice:
What comes to my mind is the Chinese milk & baby formula "sweetener" (melamine) incident from 2008 with 300,000 victims. 54,000 babies hospitalized! https://en.wikipedia.org/wiki/2008_Chinese_milk_scandal
Related: it was also in pet foods. 1 dog and 9 cats died during "taste test trials" and Petco pulled chinese-sourced products due to 1000 pet deaths. https://www.fda.gov/AnimalVeterinary/SafetyHealth/RecallsWit...
it was also implicated in farm animal feed and fish food.
yet almost ten years later, Petco once again pulled pet treat due to contamination!
And if they aren't adding poison, the wikipedia article links to a prior incident where 12 babies died from malnutrition, due to watered-down baby formula.
Such callous disregard for life (human and animal) is beyond comprehension.
And melamine. It wasn't added as a sweetener. It was added to boost apparent protein content, because it was less expensive than actual protein. As I understand it, the simple test for food protein content reported melamine as protein.
I mean, demand for PCB-tainted oil for dust suppression did decrease dramatically after PCB content and toxicity were widely known. And demand for melamine-supplemented baby food also decreased dramatically after people discovered the issue.
The problem was that more-or-less irreversible damage had already been done. Damages could be recovered through litigation, perhaps. But that doesn't fix poisoned ecosystems and children.
So we need regulation to punish market manipulation through dishonesty.
That's not the only source of problem. Another is managing the game theory of externalities. For example, if every transformer manufacturer is dumping its PCBs into rivers, no one manufacturer can afford to make "clean" transformers that dispose of PCB byproducts in a more ecological way as transformer buyers will presumably buy the cheapest one that meets the necessary performance characteristics. Regulation can add management of the ecological externality as a mandatory performance characteristic, disadvantaging no manufacturer relative to all others.
I see no confirmation on this. Sounds like an urban legend. All reports come from the one source which also talks about the legitimate reason of scrap stealing.
The doctors quote should be the biggest tip off.
If it makes people sick(Off what seems like a once off) why would street vendors use it? This is just nonsense.
Why do we demonize people from the underdeveloped world. Whats the point of cheap oil if your customers never come back. It lacks basic commercial sense. How can this become widespread.
Nonsensical urban legends on the other hand I'd guess they catch like us.
Another Urban Legend - transformers contain P2P, which tweakers drain them for. It's interesting lore at least, they are a big part of the community.
I feel like this should be easier to solve than it is. (:
Probably other browsers have something similar, either built-in or supplied as a plugin.
Crown Castle  owns a fair amount of cell towers across the US. If it's a freestanding tower, they often also own the land where it is situated on.
I do know that the traditional ones are triangle shaped such that they each form the intersection of a hexagon tessellation (hence the cell in cellphone) such that you have three towers pointed into every hexagonal cell.
They can be built into decorative lighting poles such that you would really have to pay attention to notice them.
To elaborate on a few of the statements from the post
Poles in my neighborhood tend to have consecutive numbers. I don't think this was carefully planned.
There are three because that is one way to change the three-phase power to single-phase, something I wish I understood better. Truly, we live in an age of marvels.
I have tried to imagine what the number-burning device looks like, but I'm not at all sure. Is it like a heated printing press, or perhaps a sort of configurable branding iron?
Without the Internet I would just have to wonder what these were and what OSMOSE meant.
My father was the volunteer emergency service coordinator (and power station operator) in the tiny town where we grew up. his use of road names + power poles ids + direction & distance was frequently complimented by the accident investigators when they came to look at shit (and later the court cases for some)
Remote areas with 10s of KMs of power line and 0 other features :|
I could talk about this subject for hours so let me know if you have any other questions.
You can read a bit more about the calculations here
Edit: noted that 200kVA is the maximum rating, not default rating.
There is a science and an art to sizing residential xfmrs. Generally is depends on the square footage, number of bedrooms and type of fuel used to condition the house.
Probably where GP is running into problem(like most electrical utilities) is that the use of electricity per square foot keeps going up.(caused by the increase of electrical devices in the home) So while the xfmr might have been sized correctly when installed 20-40 years ago, it is no longer sufficient. This causes problems.
Source: I was a distribution engineer for 7 years.
But I never thought about pole xformer sizing until this house. Our 35kVA (summer) faceplate xformer services nine homes. Even though it browns, it keeps on working. They've got a lot of margin, it seems
No, that's not correct.
Three transformers is for changing 3 phase medium power, to 3 phase regular voltage (for commercial customers).
For single phase home customers, you run a single one of those phases along a street and attach center tapped transformers to it.
The center tap means from the top to the center is 120v, and from the center to the bottom is another 120v. This gives something called "split phase", and is how homes in the US are wired.
This allows you to get 240v in the house if you need it by attaching to the top and bottom of the transformer.
The center tap of the transformer is also attached to the ground, and to the neutral power line (back to the generator). This gives what is called "zero voltage" (voltage is always relative, there is no such thing as absolute zero voltage - so you just have to pick something, and call it zero).
True but there are a few variations. And you also have to remember that each of those single-phase lines runs back (at some point to a three phase transformer. One very important facet of creating the single-phase spurs is to make sure the load is reasonably balanced.
Three phase 240 VAC is also cheaply converted to 120 VAC single phase in the same transformer by putting a center-tap into one side of the transformer's delta-connected coils. You will get 120 VAC from that center tap to either of the adjacent hot connections but you'd better not connect anything between the center-tap and the opposite hot connection!
Of course if you coil up that conductor and pass a magnet by it you're going to get shocked ;)
But he told me an interesting story - the utility had about 50,000 power poles in their network. But due to various historical reasons and how their assets were digitized over the years he reckoned there were probably about 1000 of them that were on their maps, but that didn't actually exist anymore. And interestingly, he thought the inverse was also true; that there were perhaps 1000 poles out there that weren't on any of their maps. Big ten meter tall poles, some probably carrying live cables - didn't know they were there.
I can totally see how this would happen. When I bought my house, the power/utility lines were hanging about four feet off the ground in my backyard. Apparently the previous owner didn't care.
I called the utility company to complain, and they sent someone out with a new full size pole, who basically just shoved it in the ground in the corner of my property to prop up the lines.
As far as I can tell, there are no identifying marks anywhere on the pole. No label, no inspection, no nothing. Except a sign that says "Danger, do not put ladder on this cable", which is on the fiber optic cable that runs along the pole.
Another problem that must be considered is that utility workers, while highly competent at their profession, are not always great with working on computers. They generally write everything down on paper and then have one of the younger linemen input the changes into the electronic records system.
Also utilities often have several record systems in place, some being GIS based, and some being mobile computer based with check in with a central database. These systems are almost never developed and worked on by the same people, so inconsistencies abound. It's normal for the inventories to diverge, and for updates to take weeks to propagate from one system to another.
You're absolutely correct on this point. When I was working as a transmission system operator the older guys (all in the 50s and 60s) would complain all day and night about the new "computer apps" that were introduced in our day to day workflow. They all preferred the old "pen and paper" way of doing things...Like you said, I'd be the who would end up putting the written switching procedures into the application we used since the older guys basically refused to learn it...
They would much rather use pen and paper to report what they did or didn’t do, with little appreciation for the reporting that could be done with a bit of input on the computer.
We make significant revenue based on accurate maps and good data as well. Just fixing our attachment rental inventory and keeping it accurate pays for all of the GIS system and upkeep with money to spare.
Some examples: http://archive.seattleweekly.com/news/960949-129/whats-up-wi...
Could you expand on that? My elementary school had a playground structure made of old utility poles. Other than getting pitch on our clothes, they didn't seem particularly hazardous.
Some of the older ones near me have already been vandalized by woodpeckers
(edit -- add commercially available lumber clarification)
The electrical outlets in your home have two power-carrying prongs. The third prong is just for safety (it connects to the ground), and should never carry power unless something is going horribly wrong. In that case, the power should hopefully prefer to reach the ground through that third wire than through your human body.
Anyhow, the voltage in those two power-carrying wires is constantly switching directions. At one moment, the left wire will be +170 volts relative to the right wire, and then they will slowly switch places over the next 1/120 of a second so the right wire is at +170 volts. They continue trading places, completing a cycle every 1/60 of a second.
At some point in this cycle, the voltage difference between the two wires will be zero, which means that no power will be flowing at that moment (power = voltage * current). On the average, the wires will deliver the same amount of power as-if they had a constant 120 volts between them, which is why people say that electricity in the USA runs at 120VAC. The peak-to-peak voltage is 170V, but the "RMS" average voltage is 1/√2 of that, or 120V.
Anyhow, those brief moments of time where no power is flowing are a problem for a power company, who would like to deliver energy in a continuous stream. So, they build their power system with three wires. Each wire reaches its maximum voltage 1/180 of a second after the previous wire. Since the voltages on each wire are sine waves, when one wire is at 0, the other wires are at +√3/2 and -√3/2 of their maximum voltages. Therefore, there is no point where the power stops. In fact, due to a mathematical quirk, the power delivery is actually constant, even though the voltages on the three wires are constantly changing.
Turing three-phase voltage into two phase voltage is pretty easy. Just pick any two of the three wires and hook them into the home. The difference of any two sine waves is just another sine wave at the same frequency, so you automatically have single-phase power. In practice, the power company will try to balance the load between the three pairs of wires by sending different pairs into different houses or even neighborhoods.
Edit: As several people have pointed out, this isn't quite how it works in real life. See the comments below for details about the hot vs. neutral wire and how both 240V and 120V are available in the home at the same time.
Only one of the prongs carries power. The other is attached to the earth, and is always at zero volts.
> and then they will slowly switch places over the next 1/120 of a second so the right wire is at +170 volt
No. The power prong (the smaller one) will switch from -170 to +170. The other one (the neutral) is always at zero (measured relative to you).
> Turing three-phase voltage into two phase voltage is pretty easy. Just pick any two of the three wires and hook them into the home.
This is not what they do. If they did they would not be able to have a neutral, and you would also not have an option of 240v. Homes don't have two phases, they have split phase.
Instead they take a single phase, and attach it to a center tapped transformer, which I described here: https://news.ycombinator.com/item?id=16380133
> Just pick any two of the three wires and hook them into the home.
In actuality the phases have 240 volts between them, not 120. And from any phase to neutral is 208 volts (which some devices make use of). (Those are voltages to customers. Internally they use other voltages - in particular when they use a single phase, power a street with it - they care about the voltage to neutral, not the voltage relative to another phase.)
>> The electrical outlets in your home have two power-carrying prongs.
>Only one of the prongs carries power. The other is attached to the earth, and is always at zero volts.
Voltages are about potential differentials, so "zero volts" is relatively meaningless without context.
The neutral line is required by the electric code to be connected to earth at the electric panel, but even if it were not, any ungrounded appliances would work correctly.
Both prongs absolutely carry power. Slap an ammeter on the neutral line; it should be identical to that on the hot line. Don't actually do this, but if you were to cut the neutral line with a live circuit, you would see sparks. This is particularly important when working on circuits with a shared neutral (two hot lines on alternate halves of the split phase with a single neutral line); despite the breaker being off for your hot line, you can get shocked when working on junction boxes for the neutral line. Yes this is up-to-code in all states (though a few places either recommend or require ganging the circuit breaker when doing so).
>> and then they will slowly switch places over the next 1/120 of a second so the right wire is at +170 volt
> No. The power prong (the smaller one) will switch from -170 to +170. The other one (the neutral) is always at zero (measured relative to you).
Here you use voltages as a relative measure, which is correct. As a nitpick you do assume that the person is grounded. Walking on carpet in the winter, I can be at a potential of thousands of volts away from that though.
[everything from here after in ars's comment is correct and I have no more nitpicks]
Both carry current. But not power. Power is volts * amps, and the neutral is defined as zero volts (if you ignore the voltage drop).
> you can get shocked when working on junction boxes for the neutral line
Only from the voltage drop on that wire. It's not the full 120v. (Unless it's cut of course, but that's a whole different story.)
> Here you use voltages as a relative measure, which is correct.
First you introduce the concept, then later, explain other less important details. And that's how I wrote it.
> Walking on carpet in the winter, I can be at a potential of thousands of volts away from that though.
It's a good nitpick :)
Obviously voltage is relative. So I'm measuring with respect to me. With respect to me the hot has power, and the neutral doesn't.
i.e. If I attach a light bulb between me and either of the two electrical wires, will it light?
But you're right "carrying power" is a poorly defined term. The problem is that it's hard to use a term that is both clear, and strictly correct.
What he has already pointed out is that voltage is a relative unit. Zero volts by itself is meaningless. It would be just as correct to say that the hot wire is at zero volts and the neutral wire and the rest of the planet are at 120VAC. Also earlier you mentioned that from phase to phase inside a house was 240v but phase to ground was 208v. This isn't correct and it's simple trigonometry to prove why. You can visualize voltage potential in any polyphase AC system as the distance between points on a circle. Ground is the center of the circle and the individual phase is a point on the circle offset by the phase angle. For a split phase system there is 180 degrees between the two phases and cos(0) - cos(180) gives you the fairly obvious distance of 2x the radius. This means for 120v from phase to ground you get 240v phase to phase. In a three phase system there's 120 degrees between phases so if you have 120v from phase to ground you have (cos(0)-cos(120))*120v=208v. For what you're saying to be possible you would need 98.85 degrees between phases which is obviously not a nice integer division of 360 degrees.
"Electric power in watts produced by an electric current I consisting of a charge of Q coulombs every t seconds passing through an electric potential (voltage) difference of V is
P = work done per unit time = VQ/t = VI
Note that V is the "electric potential difference" and it take two conductors to supply power.
Only if something were actually drawing moderate current to cause the arc. But yes, one side of that cut is likely to end up "hot" and could give you a decent shock.
(How many levels deep can we nitpick here...)
I'm not buying this (in the USA). I've been in my breaker box. For a typical 110 volt outlet, the black (hot) wire is connected to the breaker, which is connected to one of the wires coming into the house from the street. The white (neutral) wire is connected to the same ground bracket that the bare (ground) wire is connected to.
240 volt connections (like my dryer and range) are taking a hot line from one of the lines coming into the house and another hot line from the other line coming into the house. You can see it on the bus bars in the breaker box. That's why dual breakers are used. Adjacent breakers pull for different bus bars.
In a breaker box, one wire (white) gets tied to ground, and the other wire (black or red) goes between +170 (relative to ground) and -170 (relative to ground). The black and red wires are 180 degrees out of phase, so when the black wire is at +170, the red wire is at -170. This gives a 340V peak difference between the black and red wires, which averages to 240V. You get your normal 120V outlet power between the hot legs and ground/neutral, and you get your 240V dryer & water heater power between the two hot legs themselves.
So, in a normal outlet, we can safely say that one wire is "more positive" than another, and that this flip-flops through time. When we look at voltages relative to ground, though, one wire stays put at 0V while the other goes between +170 and -170. It's just a question of where you put your reference frame.
In Europe, you have three phases (R,S,T) and neutral. Here the diff between any phase and neutral is 250V, and the diff between any two phases is 380V.
Is that everywhere, to every building?
In the USA, of necessity, power generation is three phase, large scale power distribution is three phase. What's confusing is that the previous discussion didn't differentiate between residential and commercial.
In USA residential areas nobody gets all three phases to their house or apartment. As discussed in previous comments, a house gets two hot wires and a neutral. In fact, to save money, sometimes entire neighborhoods only get one or two phases: "spur lines" branching off the main line to provide power to side streets often carry only one or two phase wires, plus the neutral
In commercial and industrial settings it's common and necessary to deliver all three phases to the building. E.g. large electric motors require all three phases.
It is true that the voltage between live and neutral changes sign, so neutral is sometimes 170V above live. But neutral is almost always at ground, and live goes to -170V relative to ground.
That last paragraph though seems wrong, so OP may have been confused himself when writing.
Grounding to earth itself mainly serves to hold the potential of your house near that of the pole.
The best explanation of why three I was ever given hinged on "it's the number-of-phases argmin for the needed volume of wiring".
 two phases in quadrature, which is very different from split phase, which is not two phase at all.
I tried to word my explanation as accurately as I could, but I had to leave out a lot of tricky details for people who aren't electrical engineers. You have to be careful not to mix up regular averages, RMS averages, and instantaneous values when you deal with AC. If you get them wrong, you come to incorrect conclusions, such as the idea that single-phase electricity has zero power. The average voltage is indeed zero, but you can't use regular averages when you calculate power delivery, only instantaneous voltage differences and currents. You get RMS averages when you integrate those instantaneous values over time, and that brings in the the cos(phi) issues you mention.
In some places though, (I know it's common in New York, and also in a lot of datacenters), they do something like you describe, and hook 2 phases of a 3 phase system together. Since these are only 120 deg out of phase from each other instead of 180 in the split-phase system, you get less voltage, specifically 208V.
Under normal circumstances, the "hot" and "neutral" forms a continuous loop. But the pump that moves the water is connected to the "hot" hose. It alternates between pushing water out and sucking it back in. The "neutral" hose comes back from whatever is using the water and empties out into the tank that the pump uses as its water supply.
As long as the loop stays intact, anything the pump pushes out to hot will come back around in the neutral and get dumped back into the tank. Anything the pump sucks out of the hot will come back around from the neutral and get sucked out of the tank.
If you cut the neutral hose, the hot hose can still work, but only if you have a water reservoir at the other end big enough to accommodate a complete cycle of pushing and pulling. The pump operator doesn't like this too much, because it makes them reliant on customers to keep their water tanks in good condition, and if one gets damaged out there, the pump can't work as efficiently, and it could get damaged too. It's just safer for them to provide a second hose back to their own water tank.
But if you cut the hot hose, breaking the loop, neutral's got nothing. The water in it just sits there. This is where the ground hose comes in. It is also shoved into the water tank at one end, same as neutral. It's sole purpose is to complete a loop back to the water tank in case the regular loop fails, so that water doesn't spray too far or let air get into the pump. Ground is the emergency backup return path.
Connecting electrical wires to a ground rod pounded deep into the earth is like sticking the loose ends of your hoses in the ocean. You can pull as much water out of it as you need, and dump as much into it as you need. Sea level stays the same.
The generator at the power company has 3 stators that are on equal distance between each other on a circle.
As the rotor rotates, it induces AC voltage at each of them.
Because the rotor rotates at a stable speed, the AC voltage follows a sine function.
Because the stators are placed 2/3pi apart, their sine waves have a phase difference of 2/3pi.
Because 2/3pi+2/3pi+2/3pi=2pi, if you add them all together then you get 0 (sin[2pi]=0) and this is your neutral wire.
Quite honestly I learned that very late in the university which is a pity.
Once you see how the real world translates to math, many things (like euler's formula which is of utmost importance for engineers) fall in place.
Incidentally, the closely spaced multiple wires within each conductor of an electrical transmission line, typically held apart by spacers, act to reduce the inductance of the transmission line, which reduces losses. The little "dumbbells" which are on each side of each tower, are vibration dampers to reduce metal fatigue.
The one-way plug ensures that the "hot" voltage stays in the wall when the device isn't on, so if you shove your wand into a toaster that's off you won't get electrocuted. Devices are always connected to neutral, and the switch connects them to hot.
Your standard 120V appliance outlets are only using a single phase and neutral. IIRC the smaller prong is hot and the larger prong is neutral.
Of course that's an ungrounded plug so they're in trouble either way, but you get the idea.
Another option (which I've never seen in the US) is plugs where the first chunk of the line/neutral prongs are insulated:
Someone put a lot of thought into the design. Ground at top to prevent accidents like you show. Ground pin is longer. Insulation covers enough of the pins that live and neutral disconnect before conductor is exposed from socket. Both will be fully disconnected before earth disconnects.
If you actually look at a NEMA 5 outlet with the ground pin compared to old ungrounded polarized NEMA 1 outlets the NEMA 5 outlet is rotated 180 degrees. The larger neutral slot is on the right on old outlets and with the ground pin down on a NEMA 5 outlet the neutral is on the left.
It's not just for people dropping coins or paper clips on it though. Some outlet covers are metal and if the screw is loose or damaged that's basically guaranteed to short out if something is plugged in with the ground pin on the bottom. Another common thing is people using a tape measure along a wall, it's so thin that if there's a small gap it could shock someone using it or if you're lucky just short against the neutral.
hot has black insulation, neutral white
hot wire insulation will be smooth, neutral ribbed
hot terminal screws will be brass, neutral silver (chrome)
The neutral side is connected to the ground. (Literally - they stick a metal pole in the ground.)
The 3rd wire, is also attached to the ground, and in the electrical box the two wires are attached together.
Anyway, that's why it's neutral - because it's attached to the ground, so it's at the same potential as you.
“Isn’t quite how it works” is a gross understatement. I apologize, but while there’s some correct facts, the entire narrative you spun clearly shows you don’t have the first clue what you are talking about. I really want to be as polite as possible, but what did you expect to accomplish by posting this?
And there's a revised 2014 edition in print: http://industrial-landscape.com/#/buy
The second part of the system, is that, normally, no one customer will use more than one of the three load lines. That is why most houses only have one transformer on the pole out side their house. The power company makes sure they balance connections evenly within a given area. If they do this properly, the common 4th wire has no load on it.
Some buildings do use all three phases, but they would be running large industrial machines that benefit from having that type of power.
I tried to find the Wikipedia article that covered all this, but can't seem to locate it specifically.
I've never seen 4 lines on a power line in New Zealand unless they're also carrying telephone lines.
I've always remembered it being 3 pin around where I grew up.
Oh, sweet naive summer child.
Interesting, thanks for pointing out how it's called and what's the purpose of it. I saw it around, but had no idea what it's for :)
I noticed though, that for example Optimum fiber network is using it, while Verizon one does not.
We had some issues with corrosive dog wee. Tar treatment sometimes works. Also steel collars to keep possums off the top structure.
In Europe there are other platforms above the transform and wire complex for bird nests. Storks, cranes all above the risky bit.
Aussie poles are made from wood which is harder than nails. Unbelievably strong stuff which years of soaking in very nasty chemicals defends from termites which are ubiquitous.
"the prime of miss jean brodie" is set in pre-WWII scotland and an opening credit scene walks past two concrete lamp posts. My mother (who was an architectural historian) leaned over and said "anachronistic: that wasn't introduced until the 1950s" which goes to show fanaticism over street furniture and the poles is deep deep down...
I'd be interested to know how that project went, and if it was successful.
I think most references to fire risk with electricity distribution are actually arguing for underground wiring in the longer term.
I like honest authors.
I found some cost estimates: "The estimated cost for constructing underground transmission lines ranges from 4 to 14 times more expensive than overhead lines of the same voltage and same distance. A typical new 69 kV overhead single-circuit transmission line costs approximately $285,000 per mile as opposed to $1.5 million per mile for a new 69 kV underground line (without the terminals). A new 138 kV overhead line costs approximately $390,000 per mile as opposed to $2 million per mile for underground (without the terminals)." (2, page 17) Also, diagnosing and correcting faults is much easier above the ground than under, and you'd be surprised how often jackasses with backhoes take out underground infrastructure.
Source: Worked as a phone technician a while ago, climbed in these poles for a living. I hated climbing in "service poles" (individual poles not connected to the steel cable, used in cases where a house is far from the street), they'd wobble like crazy.
(Also, residential three phase power is fairly common except for the brits).
Wood rots and breaks. Burial has flood issues. The solution is to install better poles.
Most commonly, the poles are concrete with a square cross-section. Some are round concrete, spun while hardening to allow a hollow interior. Some are galvanized steel, with perhaps a decagonal cross section.
One near my house is about 2 feet thick, with a label that says 50,000 pounds.
These are not fragile. :-)
At the micro scale: Toronto Hydro had to start a campaign of replacing its handwells or spraying then with an insulating coating because children and pets were getting shocked.
At the macro scale:
Mmoke from vault fire: Nearby building closed for 6 months for decontamination
Over here (Austria) utility poles effectively don’t exist. Everything is below ground and all households get three phases.
We currently have a number of open positions: https://www.opusonesolutions.com/careers/#navigation-positio...
Pretty much... I did data entry for 10 weeks in 2006 putting scanned records of wayleaves into a GIS system for Central Networks (a UK based electricity infrastructure company). Basically they had a record of every single pole, pylon etc, and a record of the legal agreement to access the pole for maintenance (a huge number are on private land, like in a farmer's field or your back garden or an office parking lot). All these records had been input into a GIS system by taking the (very) rough map reference and the pole number, putting that into structured fields, andthen everything else was just scanned documents - my work was part of the upgrading of that (which had been done years before) to completely structured data and a very accurate placement on the map.
For legal reasons a lot of the original documents are still kept somewhere. Typically these documents outline both the placement, access arrangement and any payments (which may be ongoing) made to ensure access.
I think the oil's for cooling, actually.
In the Czech Republic (or at least in some parts) pole numbers and their positions are shared with emergency services. If you are disoriented, reading the number identifies your exact position. Works for railway crossings as well.
Truly amazing craftsmanship, right there. Infrastructure that's backwards -and forwards - compatible. Unhackable, able to run for decades or centuries at a time.
I yearn for the analog.
There is talk here to also build phone lines with poles in the future as it is cheaper, hope this never happens.
What is this? You're "interested in utility infrastructure" !?
7000 Volt lightning?
most household uses ... they want single-phase power!?
In 1910, maybe.
Huh? In the USA all residential is single-phase. Although there's a center tapped transformer involved, which is what gets you both 120 V and 240 V from one phase. This arrangement is called "split-phase": https://en.wikipedia.org/wiki/Split-phase_electric_power#Nor...
Name one "household use" in the USA (which is where the author lives) that doesn't use single-phase power? I'll give you a head start, I once lived in an apartment building that used 120V/208V for electric hot water heaters. But offhand I can't think of anything else.