Iron deposits mined from under the city
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I would like to have a city sitting on top of a large iron deposit that will be mined by the inhabitants of the city. Is that feasible for them? Won't the city collapse under the mines? Are there some other issues I should be aware of?
mines city
asked 7 hours ago
gruszczygruszczy
1384
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add a comment |
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I would like to have a city sitting on top of a large iron deposit that will be mined by the inhabitants of the city. Is that feasible for them? Won't the city collapse under the mines? Are there some other issues I should be aware of?
mines city
asked 7 hours ago
gruszczygruszczy
1384
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gruszczy is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
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6
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Why on Earth would anybody do this? Iron ore deposits are not particularly rare, and iron ore is not particularly expensive; which is to say, it's dirt cheap and has always been dirt cheap. (Current price for excellent iron ore is about 90 USD per metric ton; that's 2 grams of gold for 1 ton of iron ore.) Moreover, economically viable iron ore deposits are extensive; the inhabitants would normally be extracting the ore from the mountains around the city, not from beneath the city itself. Even the question speaks about a "large" deposit of iron ore; why then go underneath the city?
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– AlexP
7 hours ago
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Good points, thanks! The territories outside of the cities are generally unsafe, so people limit the exposure to minimum (mostly for growing food).
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– gruszczy
6 hours ago
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presumably the danger is on the surface, is there anything to stop them tunnelling out from within the safe area? depending on what the threat is from, short-term surface expeditions or breaches to create (and then partially fill in, depending on drilling technology or etc) ventilation.
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– Giu Piete
5 hours ago
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That's a cool idea - but the danger is actually both above and below. It's the iron itself that makes the city safe.
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– gruszczy
5 hours ago
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You ask about issues but not opportunities, so I'll just leave this as a comment: if it's particularly dangerous outside the city, the spaces excavated by the mines could be converted into living space to expand the city. Sure, it would take something structurally solid to do this, but I hear you have a lot of iron handy... it would probably take a lot less iron to reinforce the new living spaces than one pulled from those spaces, since living spaces are mostly empty air.
$endgroup$
– Ed Grimm
59 mins ago
add a comment |
$begingroup$
I would like to have a city sitting on top of a large iron deposit that will be mined by the inhabitants of the city. Is that feasible for them? Won't the city collapse under the mines? Are there some other issues I should be aware of?
mines city
asked 7 hours ago
gruszczygruszczy
1384
New contributor
gruszczy is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
I would like to have a city sitting on top of a large iron deposit that will be mined by the inhabitants of the city. Is that feasible for them? Won't the city collapse under the mines? Are there some other issues I should be aware of?
mines city
mines city
asked 7 hours ago
gruszczygruszczy
1384
New contributor
gruszczy is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 7 hours ago
gruszczygruszczy
1384
New contributor
gruszczy is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked 7 hours ago
gruszczygruszczy
1384
New contributor
gruszczy is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
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asked 7 hours ago
gruszczygruszczy
1384
asked 7 hours ago
gruszczygruszczy
1384
1384
New contributor
gruszczy is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
gruszczy is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
gruszczy is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
6
$begingroup$
Why on Earth would anybody do this? Iron ore deposits are not particularly rare, and iron ore is not particularly expensive; which is to say, it's dirt cheap and has always been dirt cheap. (Current price for excellent iron ore is about 90 USD per metric ton; that's 2 grams of gold for 1 ton of iron ore.) Moreover, economically viable iron ore deposits are extensive; the inhabitants would normally be extracting the ore from the mountains around the city, not from beneath the city itself. Even the question speaks about a "large" deposit of iron ore; why then go underneath the city?
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– AlexP
7 hours ago
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Good points, thanks! The territories outside of the cities are generally unsafe, so people limit the exposure to minimum (mostly for growing food).
$endgroup$
– gruszczy
6 hours ago
$begingroup$
presumably the danger is on the surface, is there anything to stop them tunnelling out from within the safe area? depending on what the threat is from, short-term surface expeditions or breaches to create (and then partially fill in, depending on drilling technology or etc) ventilation.
$endgroup$
– Giu Piete
5 hours ago
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That's a cool idea - but the danger is actually both above and below. It's the iron itself that makes the city safe.
$endgroup$
– gruszczy
5 hours ago
$begingroup$
You ask about issues but not opportunities, so I'll just leave this as a comment: if it's particularly dangerous outside the city, the spaces excavated by the mines could be converted into living space to expand the city. Sure, it would take something structurally solid to do this, but I hear you have a lot of iron handy... it would probably take a lot less iron to reinforce the new living spaces than one pulled from those spaces, since living spaces are mostly empty air.
$endgroup$
– Ed Grimm
59 mins ago
add a comment |
6
$begingroup$
Why on Earth would anybody do this? Iron ore deposits are not particularly rare, and iron ore is not particularly expensive; which is to say, it's dirt cheap and has always been dirt cheap. (Current price for excellent iron ore is about 90 USD per metric ton; that's 2 grams of gold for 1 ton of iron ore.) Moreover, economically viable iron ore deposits are extensive; the inhabitants would normally be extracting the ore from the mountains around the city, not from beneath the city itself. Even the question speaks about a "large" deposit of iron ore; why then go underneath the city?
$endgroup$
– AlexP
7 hours ago
$begingroup$
Good points, thanks! The territories outside of the cities are generally unsafe, so people limit the exposure to minimum (mostly for growing food).
$endgroup$
– gruszczy
6 hours ago
$begingroup$
presumably the danger is on the surface, is there anything to stop them tunnelling out from within the safe area? depending on what the threat is from, short-term surface expeditions or breaches to create (and then partially fill in, depending on drilling technology or etc) ventilation.
$endgroup$
– Giu Piete
5 hours ago
$begingroup$
That's a cool idea - but the danger is actually both above and below. It's the iron itself that makes the city safe.
$endgroup$
– gruszczy
5 hours ago
$begingroup$
You ask about issues but not opportunities, so I'll just leave this as a comment: if it's particularly dangerous outside the city, the spaces excavated by the mines could be converted into living space to expand the city. Sure, it would take something structurally solid to do this, but I hear you have a lot of iron handy... it would probably take a lot less iron to reinforce the new living spaces than one pulled from those spaces, since living spaces are mostly empty air.
$endgroup$
– Ed Grimm
59 mins ago
6
6
$begingroup$
Why on Earth would anybody do this? Iron ore deposits are not particularly rare, and iron ore is not particularly expensive; which is to say, it's dirt cheap and has always been dirt cheap. (Current price for excellent iron ore is about 90 USD per metric ton; that's 2 grams of gold for 1 ton of iron ore.) Moreover, economically viable iron ore deposits are extensive; the inhabitants would normally be extracting the ore from the mountains around the city, not from beneath the city itself. Even the question speaks about a "large" deposit of iron ore; why then go underneath the city?
$endgroup$
– AlexP
7 hours ago
$begingroup$
Why on Earth would anybody do this? Iron ore deposits are not particularly rare, and iron ore is not particularly expensive; which is to say, it's dirt cheap and has always been dirt cheap. (Current price for excellent iron ore is about 90 USD per metric ton; that's 2 grams of gold for 1 ton of iron ore.) Moreover, economically viable iron ore deposits are extensive; the inhabitants would normally be extracting the ore from the mountains around the city, not from beneath the city itself. Even the question speaks about a "large" deposit of iron ore; why then go underneath the city?
$endgroup$
– AlexP
7 hours ago
$begingroup$
Good points, thanks! The territories outside of the cities are generally unsafe, so people limit the exposure to minimum (mostly for growing food).
$endgroup$
– gruszczy
6 hours ago
$begingroup$
Good points, thanks! The territories outside of the cities are generally unsafe, so people limit the exposure to minimum (mostly for growing food).
$endgroup$
– gruszczy
6 hours ago
$begingroup$
presumably the danger is on the surface, is there anything to stop them tunnelling out from within the safe area? depending on what the threat is from, short-term surface expeditions or breaches to create (and then partially fill in, depending on drilling technology or etc) ventilation.
$endgroup$
– Giu Piete
5 hours ago
$begingroup$
presumably the danger is on the surface, is there anything to stop them tunnelling out from within the safe area? depending on what the threat is from, short-term surface expeditions or breaches to create (and then partially fill in, depending on drilling technology or etc) ventilation.
$endgroup$
– Giu Piete
5 hours ago
$begingroup$
That's a cool idea - but the danger is actually both above and below. It's the iron itself that makes the city safe.
$endgroup$
– gruszczy
5 hours ago
$begingroup$
That's a cool idea - but the danger is actually both above and below. It's the iron itself that makes the city safe.
$endgroup$
– gruszczy
5 hours ago
$begingroup$
You ask about issues but not opportunities, so I'll just leave this as a comment: if it's particularly dangerous outside the city, the spaces excavated by the mines could be converted into living space to expand the city. Sure, it would take something structurally solid to do this, but I hear you have a lot of iron handy... it would probably take a lot less iron to reinforce the new living spaces than one pulled from those spaces, since living spaces are mostly empty air.
$endgroup$
– Ed Grimm
59 mins ago
$begingroup$
You ask about issues but not opportunities, so I'll just leave this as a comment: if it's particularly dangerous outside the city, the spaces excavated by the mines could be converted into living space to expand the city. Sure, it would take something structurally solid to do this, but I hear you have a lot of iron handy... it would probably take a lot less iron to reinforce the new living spaces than one pulled from those spaces, since living spaces are mostly empty air.
$endgroup$
– Ed Grimm
59 mins ago
add a comment |
3 Answers
3
active
oldest
votes
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There are cities with extensive mining operations below them. The most famous is probably Paris.
https://www.nationalgeographic.com/magazine/2011/02/paris-catacombs/
Under Paris there are spaces of all kinds: canals and reservoirs,
crypts and bank vaults, wine cellars transformed into nightclubs and
galleries. Most surprising of all are the carrières—the old limestone
quarries that fan out in a deep and intricate web under many
neighborhoods, mostly in the southern part of the metropolis... Into
the 19th century those caverns and tunnels were mined for building
stone.
You can tour the Paris catacombs full of bones, but the tunnels were there before they put the bones there. And there are apparently many more tunnels than are occupied by bones. Kansas City also has extensive limestone quarries beneath it, although of course more recent (and less chaotic) than the ones in Paris.
I found reference to the Kiruna Mine which is a mine underneath a city of 24,000. Wikipedia states that subsidence related to the mine has affected some parts of the city.
answered 5 hours ago
WillkWillk
111k26207464
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Pretty sure one of the oldest salt mines has a city on top of it. Somewhere in Hungary or Poland.
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– user2259716
5 hours ago
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Wieliczka, should have thought about it! Thanks.
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– gruszczy
5 hours ago
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@gruszczy It does raise the question of why not just live in the mine?
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– user2259716
5 hours ago
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Good point - I think it makes sense for people to do live there! They would need to be aware though that iron is keeping them safe though.
$endgroup$
– gruszczy
5 hours ago
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Underground quarries sound very cool too, will be useful!
$endgroup$
– gruszczy
5 hours ago
add a comment |
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If iron is that valuable, sure.
Detroit, Michigan is built on top of some pretty extensive salt mines.
The first image shows the vertical extent of the salt mines:
The second picture shows the horizontal extent of the mines:
All that you really need for a city to live on top of the mine is to have the mine deep enough and/or have enough structure left around the mine so it doesn't collapse (you want that anyway).
answered 5 hours ago
ShadoCatShadoCat
15.1k2051
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Sweet! Thanks a lot for a great example!
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– gruszczy
5 hours ago
2
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And have it not be a coal mine that catches fire...
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– Jon Custer
4 hours ago
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Your first pic is heavily stylized and not in any way indicative of the actual extent. The real mine is over a thousand feet underground. en.wikipedia.org/wiki/Detroit_salt_mine
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– ceejayoz
16 mins ago
add a comment |
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It's possible, but you almost certainly need steam engines (or some kind of magical steam engine analog). A good real life analog would be Butte, Montana. Butte had a number of mines, primarily owned and operated by the Anaconda mining company. Wikipedia tells me that from 1880 to 2015, 15 million metric tons of ore were extracted from underneath the town. Most of the mines were producing copper ore. It is said of Butte that it's "A mile high and a mile deep" -- the city sits a mile above sea level, and the deepest mines reach a mile down. At its peak, the town had a population of about 40,000. There was quite a bit of labor unrest; Butte was
the site of the longest strike in US history, the worst hard rock mining disaster, and was the birthplace of one of the most active and radical labor unions, the Western Federation of Miners.
Something to consider is that large-scale mining is very resource intensive, and requires trade with outside regions. The energy to run the mines and the food to feed the miners probably needs to be imported, and then once the ore is produced, it needs to be shipped off to somewhere that wants ore in the quantities that its being produced in.
The mines will probably be pretty deep if the mining is not going to totally destroy the integrity of the surface. This means hard rock mining, probably for something with an industrial value like copper. Hard rock mining is really slow. Before dynamite, a couple of guys would pound an iron rod into the rock face until a bit cracked off. Progress could be as slow as 0.2 inches a day. Blasting speeds things up immensely, but is dangerous. Pneumatic drills come later, and also speed things up quite a bit.
The deeper the mine goes, the harder and more costly it becomes to keep them running. Once a mine shaft crosses below the water table, it becomes necessary to run pumps around the clock the prevent the mines from filling up with water. Furthermore, fans must be run to circulate fresh, breathable air from the surface down into the shafts where the miners are working. Elevators must be run to move miners down into the mines and to move ore back out. All of this gets harder and harder the further down you go. The costs are fixed costs, so the mines will run 24/7.
Keeping the mines running requires a lot of resources. You need to power the fans, the pumps, and the elevators, and you need to power them all of the time. And you need wood to build supports for the mine -- a lot of wood. In the case of Butte, the need for wood was so great that they were importing mahogany from South America for the supports. Even just producing enough energy requires steam power or its magical equivalent, and either way the fuel must be imported.
All of the ore produced must then be processed and shipped out. In the case of Butte, the Anaconda Company built an entire other city nearby to smelt the ore. This too is a big operation, requiring lots of fuel and water, and it absolutely wrecks the environment. Transporting the ore out then requires still more energy. Industrial mining is only possible because locomotives make it cheap to move tons and tons of materials around -- if the mines are producing thousands or tens of tons of ore a day, they need a way to transport that over long distances to whatever market needs all this ore.
answered 10 mins ago
svangordonsvangordon
1011
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3 Answers
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3 Answers
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$begingroup$
There are cities with extensive mining operations below them. The most famous is probably Paris.
https://www.nationalgeographic.com/magazine/2011/02/paris-catacombs/
Under Paris there are spaces of all kinds: canals and reservoirs,
crypts and bank vaults, wine cellars transformed into nightclubs and
galleries. Most surprising of all are the carrières—the old limestone
quarries that fan out in a deep and intricate web under many
neighborhoods, mostly in the southern part of the metropolis... Into
the 19th century those caverns and tunnels were mined for building
stone.
You can tour the Paris catacombs full of bones, but the tunnels were there before they put the bones there. And there are apparently many more tunnels than are occupied by bones. Kansas City also has extensive limestone quarries beneath it, although of course more recent (and less chaotic) than the ones in Paris.
I found reference to the Kiruna Mine which is a mine underneath a city of 24,000. Wikipedia states that subsidence related to the mine has affected some parts of the city.
answered 5 hours ago
WillkWillk
111k26207464
$endgroup$
$begingroup$
Pretty sure one of the oldest salt mines has a city on top of it. Somewhere in Hungary or Poland.
$endgroup$
– user2259716
5 hours ago
$begingroup$
Wieliczka, should have thought about it! Thanks.
$endgroup$
– gruszczy
5 hours ago
$begingroup$
@gruszczy It does raise the question of why not just live in the mine?
$endgroup$
– user2259716
5 hours ago
$begingroup$
Good point - I think it makes sense for people to do live there! They would need to be aware though that iron is keeping them safe though.
$endgroup$
– gruszczy
5 hours ago
$begingroup$
Underground quarries sound very cool too, will be useful!
$endgroup$
– gruszczy
5 hours ago
add a comment |
$begingroup$
There are cities with extensive mining operations below them. The most famous is probably Paris.
https://www.nationalgeographic.com/magazine/2011/02/paris-catacombs/
Under Paris there are spaces of all kinds: canals and reservoirs,
crypts and bank vaults, wine cellars transformed into nightclubs and
galleries. Most surprising of all are the carrières—the old limestone
quarries that fan out in a deep and intricate web under many
neighborhoods, mostly in the southern part of the metropolis... Into
the 19th century those caverns and tunnels were mined for building
stone.
You can tour the Paris catacombs full of bones, but the tunnels were there before they put the bones there. And there are apparently many more tunnels than are occupied by bones. Kansas City also has extensive limestone quarries beneath it, although of course more recent (and less chaotic) than the ones in Paris.
I found reference to the Kiruna Mine which is a mine underneath a city of 24,000. Wikipedia states that subsidence related to the mine has affected some parts of the city.
answered 5 hours ago
WillkWillk
111k26207464
$endgroup$
$begingroup$
Pretty sure one of the oldest salt mines has a city on top of it. Somewhere in Hungary or Poland.
$endgroup$
– user2259716
5 hours ago
$begingroup$
Wieliczka, should have thought about it! Thanks.
$endgroup$
– gruszczy
5 hours ago
$begingroup$
@gruszczy It does raise the question of why not just live in the mine?
$endgroup$
– user2259716
5 hours ago
$begingroup$
Good point - I think it makes sense for people to do live there! They would need to be aware though that iron is keeping them safe though.
$endgroup$
– gruszczy
5 hours ago
$begingroup$
Underground quarries sound very cool too, will be useful!
$endgroup$
– gruszczy
5 hours ago
add a comment |
$begingroup$
There are cities with extensive mining operations below them. The most famous is probably Paris.
https://www.nationalgeographic.com/magazine/2011/02/paris-catacombs/
Under Paris there are spaces of all kinds: canals and reservoirs,
crypts and bank vaults, wine cellars transformed into nightclubs and
galleries. Most surprising of all are the carrières—the old limestone
quarries that fan out in a deep and intricate web under many
neighborhoods, mostly in the southern part of the metropolis... Into
the 19th century those caverns and tunnels were mined for building
stone.
You can tour the Paris catacombs full of bones, but the tunnels were there before they put the bones there. And there are apparently many more tunnels than are occupied by bones. Kansas City also has extensive limestone quarries beneath it, although of course more recent (and less chaotic) than the ones in Paris.
I found reference to the Kiruna Mine which is a mine underneath a city of 24,000. Wikipedia states that subsidence related to the mine has affected some parts of the city.
answered 5 hours ago
WillkWillk
111k26207464
$endgroup$
There are cities with extensive mining operations below them. The most famous is probably Paris.
https://www.nationalgeographic.com/magazine/2011/02/paris-catacombs/
Under Paris there are spaces of all kinds: canals and reservoirs,
crypts and bank vaults, wine cellars transformed into nightclubs and
galleries. Most surprising of all are the carrières—the old limestone
quarries that fan out in a deep and intricate web under many
neighborhoods, mostly in the southern part of the metropolis... Into
the 19th century those caverns and tunnels were mined for building
stone.
You can tour the Paris catacombs full of bones, but the tunnels were there before they put the bones there. And there are apparently many more tunnels than are occupied by bones. Kansas City also has extensive limestone quarries beneath it, although of course more recent (and less chaotic) than the ones in Paris.
I found reference to the Kiruna Mine which is a mine underneath a city of 24,000. Wikipedia states that subsidence related to the mine has affected some parts of the city.
answered 5 hours ago
WillkWillk
111k26207464
answered 5 hours ago
WillkWillk
111k26207464
answered 5 hours ago
WillkWillk
111k26207464
answered 5 hours ago
WillkWillk
111k26207464
111k26207464
$begingroup$
Pretty sure one of the oldest salt mines has a city on top of it. Somewhere in Hungary or Poland.
$endgroup$
– user2259716
5 hours ago
$begingroup$
Wieliczka, should have thought about it! Thanks.
$endgroup$
– gruszczy
5 hours ago
$begingroup$
@gruszczy It does raise the question of why not just live in the mine?
$endgroup$
– user2259716
5 hours ago
$begingroup$
Good point - I think it makes sense for people to do live there! They would need to be aware though that iron is keeping them safe though.
$endgroup$
– gruszczy
5 hours ago
$begingroup$
Underground quarries sound very cool too, will be useful!
$endgroup$
– gruszczy
5 hours ago
add a comment |
$begingroup$
Pretty sure one of the oldest salt mines has a city on top of it. Somewhere in Hungary or Poland.
$endgroup$
– user2259716
5 hours ago
$begingroup$
Wieliczka, should have thought about it! Thanks.
$endgroup$
– gruszczy
5 hours ago
$begingroup$
@gruszczy It does raise the question of why not just live in the mine?
$endgroup$
– user2259716
5 hours ago
$begingroup$
Good point - I think it makes sense for people to do live there! They would need to be aware though that iron is keeping them safe though.
$endgroup$
– gruszczy
5 hours ago
$begingroup$
Underground quarries sound very cool too, will be useful!
$endgroup$
– gruszczy
5 hours ago
$begingroup$
Pretty sure one of the oldest salt mines has a city on top of it. Somewhere in Hungary or Poland.
$endgroup$
– user2259716
5 hours ago
$begingroup$
Pretty sure one of the oldest salt mines has a city on top of it. Somewhere in Hungary or Poland.
$endgroup$
– user2259716
5 hours ago
$begingroup$
Wieliczka, should have thought about it! Thanks.
$endgroup$
– gruszczy
5 hours ago
$begingroup$
Wieliczka, should have thought about it! Thanks.
$endgroup$
– gruszczy
5 hours ago
$begingroup$
@gruszczy It does raise the question of why not just live in the mine?
$endgroup$
– user2259716
5 hours ago
$begingroup$
@gruszczy It does raise the question of why not just live in the mine?
$endgroup$
– user2259716
5 hours ago
$begingroup$
Good point - I think it makes sense for people to do live there! They would need to be aware though that iron is keeping them safe though.
$endgroup$
– gruszczy
5 hours ago
$begingroup$
Good point - I think it makes sense for people to do live there! They would need to be aware though that iron is keeping them safe though.
$endgroup$
– gruszczy
5 hours ago
$begingroup$
Underground quarries sound very cool too, will be useful!
$endgroup$
– gruszczy
5 hours ago
$begingroup$
Underground quarries sound very cool too, will be useful!
$endgroup$
– gruszczy
5 hours ago
add a comment |
$begingroup$
If iron is that valuable, sure.
Detroit, Michigan is built on top of some pretty extensive salt mines.
The first image shows the vertical extent of the salt mines:
The second picture shows the horizontal extent of the mines:
All that you really need for a city to live on top of the mine is to have the mine deep enough and/or have enough structure left around the mine so it doesn't collapse (you want that anyway).
answered 5 hours ago
ShadoCatShadoCat
15.1k2051
$endgroup$
$begingroup$
Sweet! Thanks a lot for a great example!
$endgroup$
– gruszczy
5 hours ago
2
$begingroup$
And have it not be a coal mine that catches fire...
$endgroup$
– Jon Custer
4 hours ago
$begingroup$
Your first pic is heavily stylized and not in any way indicative of the actual extent. The real mine is over a thousand feet underground. en.wikipedia.org/wiki/Detroit_salt_mine
$endgroup$
– ceejayoz
16 mins ago
add a comment |
$begingroup$
If iron is that valuable, sure.
Detroit, Michigan is built on top of some pretty extensive salt mines.
The first image shows the vertical extent of the salt mines:
The second picture shows the horizontal extent of the mines:
All that you really need for a city to live on top of the mine is to have the mine deep enough and/or have enough structure left around the mine so it doesn't collapse (you want that anyway).
answered 5 hours ago
ShadoCatShadoCat
15.1k2051
$endgroup$
$begingroup$
Sweet! Thanks a lot for a great example!
$endgroup$
– gruszczy
5 hours ago
2
$begingroup$
And have it not be a coal mine that catches fire...
$endgroup$
– Jon Custer
4 hours ago
$begingroup$
Your first pic is heavily stylized and not in any way indicative of the actual extent. The real mine is over a thousand feet underground. en.wikipedia.org/wiki/Detroit_salt_mine
$endgroup$
– ceejayoz
16 mins ago
add a comment |
$begingroup$
If iron is that valuable, sure.
Detroit, Michigan is built on top of some pretty extensive salt mines.
The first image shows the vertical extent of the salt mines:
The second picture shows the horizontal extent of the mines:
All that you really need for a city to live on top of the mine is to have the mine deep enough and/or have enough structure left around the mine so it doesn't collapse (you want that anyway).
answered 5 hours ago
ShadoCatShadoCat
15.1k2051
$endgroup$
If iron is that valuable, sure.
Detroit, Michigan is built on top of some pretty extensive salt mines.
The first image shows the vertical extent of the salt mines:
The second picture shows the horizontal extent of the mines:
All that you really need for a city to live on top of the mine is to have the mine deep enough and/or have enough structure left around the mine so it doesn't collapse (you want that anyway).
answered 5 hours ago
ShadoCatShadoCat
15.1k2051
answered 5 hours ago
ShadoCatShadoCat
15.1k2051
answered 5 hours ago
ShadoCatShadoCat
15.1k2051
answered 5 hours ago
ShadoCatShadoCat
15.1k2051
15.1k2051
$begingroup$
Sweet! Thanks a lot for a great example!
$endgroup$
– gruszczy
5 hours ago
2
$begingroup$
And have it not be a coal mine that catches fire...
$endgroup$
– Jon Custer
4 hours ago
$begingroup$
Your first pic is heavily stylized and not in any way indicative of the actual extent. The real mine is over a thousand feet underground. en.wikipedia.org/wiki/Detroit_salt_mine
$endgroup$
– ceejayoz
16 mins ago
add a comment |
$begingroup$
Sweet! Thanks a lot for a great example!
$endgroup$
– gruszczy
5 hours ago
2
$begingroup$
And have it not be a coal mine that catches fire...
$endgroup$
– Jon Custer
4 hours ago
$begingroup$
Your first pic is heavily stylized and not in any way indicative of the actual extent. The real mine is over a thousand feet underground. en.wikipedia.org/wiki/Detroit_salt_mine
$endgroup$
– ceejayoz
16 mins ago
$begingroup$
Sweet! Thanks a lot for a great example!
$endgroup$
– gruszczy
5 hours ago
$begingroup$
Sweet! Thanks a lot for a great example!
$endgroup$
– gruszczy
5 hours ago
2
2
$begingroup$
And have it not be a coal mine that catches fire...
$endgroup$
– Jon Custer
4 hours ago
$begingroup$
And have it not be a coal mine that catches fire...
$endgroup$
– Jon Custer
4 hours ago
$begingroup$
Your first pic is heavily stylized and not in any way indicative of the actual extent. The real mine is over a thousand feet underground. en.wikipedia.org/wiki/Detroit_salt_mine
$endgroup$
– ceejayoz
16 mins ago
$begingroup$
Your first pic is heavily stylized and not in any way indicative of the actual extent. The real mine is over a thousand feet underground. en.wikipedia.org/wiki/Detroit_salt_mine
$endgroup$
– ceejayoz
16 mins ago
add a comment |
$begingroup$
It's possible, but you almost certainly need steam engines (or some kind of magical steam engine analog). A good real life analog would be Butte, Montana. Butte had a number of mines, primarily owned and operated by the Anaconda mining company. Wikipedia tells me that from 1880 to 2015, 15 million metric tons of ore were extracted from underneath the town. Most of the mines were producing copper ore. It is said of Butte that it's "A mile high and a mile deep" -- the city sits a mile above sea level, and the deepest mines reach a mile down. At its peak, the town had a population of about 40,000. There was quite a bit of labor unrest; Butte was
the site of the longest strike in US history, the worst hard rock mining disaster, and was the birthplace of one of the most active and radical labor unions, the Western Federation of Miners.
Something to consider is that large-scale mining is very resource intensive, and requires trade with outside regions. The energy to run the mines and the food to feed the miners probably needs to be imported, and then once the ore is produced, it needs to be shipped off to somewhere that wants ore in the quantities that its being produced in.
The mines will probably be pretty deep if the mining is not going to totally destroy the integrity of the surface. This means hard rock mining, probably for something with an industrial value like copper. Hard rock mining is really slow. Before dynamite, a couple of guys would pound an iron rod into the rock face until a bit cracked off. Progress could be as slow as 0.2 inches a day. Blasting speeds things up immensely, but is dangerous. Pneumatic drills come later, and also speed things up quite a bit.
The deeper the mine goes, the harder and more costly it becomes to keep them running. Once a mine shaft crosses below the water table, it becomes necessary to run pumps around the clock the prevent the mines from filling up with water. Furthermore, fans must be run to circulate fresh, breathable air from the surface down into the shafts where the miners are working. Elevators must be run to move miners down into the mines and to move ore back out. All of this gets harder and harder the further down you go. The costs are fixed costs, so the mines will run 24/7.
Keeping the mines running requires a lot of resources. You need to power the fans, the pumps, and the elevators, and you need to power them all of the time. And you need wood to build supports for the mine -- a lot of wood. In the case of Butte, the need for wood was so great that they were importing mahogany from South America for the supports. Even just producing enough energy requires steam power or its magical equivalent, and either way the fuel must be imported.
All of the ore produced must then be processed and shipped out. In the case of Butte, the Anaconda Company built an entire other city nearby to smelt the ore. This too is a big operation, requiring lots of fuel and water, and it absolutely wrecks the environment. Transporting the ore out then requires still more energy. Industrial mining is only possible because locomotives make it cheap to move tons and tons of materials around -- if the mines are producing thousands or tens of tons of ore a day, they need a way to transport that over long distances to whatever market needs all this ore.
answered 10 mins ago
svangordonsvangordon
1011
New contributor
svangordon is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
add a comment |
$begingroup$
It's possible, but you almost certainly need steam engines (or some kind of magical steam engine analog). A good real life analog would be Butte, Montana. Butte had a number of mines, primarily owned and operated by the Anaconda mining company. Wikipedia tells me that from 1880 to 2015, 15 million metric tons of ore were extracted from underneath the town. Most of the mines were producing copper ore. It is said of Butte that it's "A mile high and a mile deep" -- the city sits a mile above sea level, and the deepest mines reach a mile down. At its peak, the town had a population of about 40,000. There was quite a bit of labor unrest; Butte was
the site of the longest strike in US history, the worst hard rock mining disaster, and was the birthplace of one of the most active and radical labor unions, the Western Federation of Miners.
Something to consider is that large-scale mining is very resource intensive, and requires trade with outside regions. The energy to run the mines and the food to feed the miners probably needs to be imported, and then once the ore is produced, it needs to be shipped off to somewhere that wants ore in the quantities that its being produced in.
The mines will probably be pretty deep if the mining is not going to totally destroy the integrity of the surface. This means hard rock mining, probably for something with an industrial value like copper. Hard rock mining is really slow. Before dynamite, a couple of guys would pound an iron rod into the rock face until a bit cracked off. Progress could be as slow as 0.2 inches a day. Blasting speeds things up immensely, but is dangerous. Pneumatic drills come later, and also speed things up quite a bit.
The deeper the mine goes, the harder and more costly it becomes to keep them running. Once a mine shaft crosses below the water table, it becomes necessary to run pumps around the clock the prevent the mines from filling up with water. Furthermore, fans must be run to circulate fresh, breathable air from the surface down into the shafts where the miners are working. Elevators must be run to move miners down into the mines and to move ore back out. All of this gets harder and harder the further down you go. The costs are fixed costs, so the mines will run 24/7.
Keeping the mines running requires a lot of resources. You need to power the fans, the pumps, and the elevators, and you need to power them all of the time. And you need wood to build supports for the mine -- a lot of wood. In the case of Butte, the need for wood was so great that they were importing mahogany from South America for the supports. Even just producing enough energy requires steam power or its magical equivalent, and either way the fuel must be imported.
All of the ore produced must then be processed and shipped out. In the case of Butte, the Anaconda Company built an entire other city nearby to smelt the ore. This too is a big operation, requiring lots of fuel and water, and it absolutely wrecks the environment. Transporting the ore out then requires still more energy. Industrial mining is only possible because locomotives make it cheap to move tons and tons of materials around -- if the mines are producing thousands or tens of tons of ore a day, they need a way to transport that over long distances to whatever market needs all this ore.
answered 10 mins ago
svangordonsvangordon
1011
New contributor
svangordon is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
add a comment |
$begingroup$
It's possible, but you almost certainly need steam engines (or some kind of magical steam engine analog). A good real life analog would be Butte, Montana. Butte had a number of mines, primarily owned and operated by the Anaconda mining company. Wikipedia tells me that from 1880 to 2015, 15 million metric tons of ore were extracted from underneath the town. Most of the mines were producing copper ore. It is said of Butte that it's "A mile high and a mile deep" -- the city sits a mile above sea level, and the deepest mines reach a mile down. At its peak, the town had a population of about 40,000. There was quite a bit of labor unrest; Butte was
the site of the longest strike in US history, the worst hard rock mining disaster, and was the birthplace of one of the most active and radical labor unions, the Western Federation of Miners.
Something to consider is that large-scale mining is very resource intensive, and requires trade with outside regions. The energy to run the mines and the food to feed the miners probably needs to be imported, and then once the ore is produced, it needs to be shipped off to somewhere that wants ore in the quantities that its being produced in.
The mines will probably be pretty deep if the mining is not going to totally destroy the integrity of the surface. This means hard rock mining, probably for something with an industrial value like copper. Hard rock mining is really slow. Before dynamite, a couple of guys would pound an iron rod into the rock face until a bit cracked off. Progress could be as slow as 0.2 inches a day. Blasting speeds things up immensely, but is dangerous. Pneumatic drills come later, and also speed things up quite a bit.
The deeper the mine goes, the harder and more costly it becomes to keep them running. Once a mine shaft crosses below the water table, it becomes necessary to run pumps around the clock the prevent the mines from filling up with water. Furthermore, fans must be run to circulate fresh, breathable air from the surface down into the shafts where the miners are working. Elevators must be run to move miners down into the mines and to move ore back out. All of this gets harder and harder the further down you go. The costs are fixed costs, so the mines will run 24/7.
Keeping the mines running requires a lot of resources. You need to power the fans, the pumps, and the elevators, and you need to power them all of the time. And you need wood to build supports for the mine -- a lot of wood. In the case of Butte, the need for wood was so great that they were importing mahogany from South America for the supports. Even just producing enough energy requires steam power or its magical equivalent, and either way the fuel must be imported.
All of the ore produced must then be processed and shipped out. In the case of Butte, the Anaconda Company built an entire other city nearby to smelt the ore. This too is a big operation, requiring lots of fuel and water, and it absolutely wrecks the environment. Transporting the ore out then requires still more energy. Industrial mining is only possible because locomotives make it cheap to move tons and tons of materials around -- if the mines are producing thousands or tens of tons of ore a day, they need a way to transport that over long distances to whatever market needs all this ore.
answered 10 mins ago
svangordonsvangordon
1011
New contributor
svangordon is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
$endgroup$
It's possible, but you almost certainly need steam engines (or some kind of magical steam engine analog). A good real life analog would be Butte, Montana. Butte had a number of mines, primarily owned and operated by the Anaconda mining company. Wikipedia tells me that from 1880 to 2015, 15 million metric tons of ore were extracted from underneath the town. Most of the mines were producing copper ore. It is said of Butte that it's "A mile high and a mile deep" -- the city sits a mile above sea level, and the deepest mines reach a mile down. At its peak, the town had a population of about 40,000. There was quite a bit of labor unrest; Butte was
the site of the longest strike in US history, the worst hard rock mining disaster, and was the birthplace of one of the most active and radical labor unions, the Western Federation of Miners.
Something to consider is that large-scale mining is very resource intensive, and requires trade with outside regions. The energy to run the mines and the food to feed the miners probably needs to be imported, and then once the ore is produced, it needs to be shipped off to somewhere that wants ore in the quantities that its being produced in.
The mines will probably be pretty deep if the mining is not going to totally destroy the integrity of the surface. This means hard rock mining, probably for something with an industrial value like copper. Hard rock mining is really slow. Before dynamite, a couple of guys would pound an iron rod into the rock face until a bit cracked off. Progress could be as slow as 0.2 inches a day. Blasting speeds things up immensely, but is dangerous. Pneumatic drills come later, and also speed things up quite a bit.
The deeper the mine goes, the harder and more costly it becomes to keep them running. Once a mine shaft crosses below the water table, it becomes necessary to run pumps around the clock the prevent the mines from filling up with water. Furthermore, fans must be run to circulate fresh, breathable air from the surface down into the shafts where the miners are working. Elevators must be run to move miners down into the mines and to move ore back out. All of this gets harder and harder the further down you go. The costs are fixed costs, so the mines will run 24/7.
Keeping the mines running requires a lot of resources. You need to power the fans, the pumps, and the elevators, and you need to power them all of the time. And you need wood to build supports for the mine -- a lot of wood. In the case of Butte, the need for wood was so great that they were importing mahogany from South America for the supports. Even just producing enough energy requires steam power or its magical equivalent, and either way the fuel must be imported.
All of the ore produced must then be processed and shipped out. In the case of Butte, the Anaconda Company built an entire other city nearby to smelt the ore. This too is a big operation, requiring lots of fuel and water, and it absolutely wrecks the environment. Transporting the ore out then requires still more energy. Industrial mining is only possible because locomotives make it cheap to move tons and tons of materials around -- if the mines are producing thousands or tens of tons of ore a day, they need a way to transport that over long distances to whatever market needs all this ore.
answered 10 mins ago
svangordonsvangordon
1011
New contributor
svangordon is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
answered 10 mins ago
svangordonsvangordon
1011
New contributor
svangordon is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
answered 10 mins ago
svangordonsvangordon
1011
answered 10 mins ago
svangordonsvangordon
1011
1011
New contributor
svangordon is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
svangordon is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
svangordon is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
add a comment |
gruszczy is a new contributor. Be nice, and check out our Code of Conduct.
gruszczy is a new contributor. Be nice, and check out our Code of Conduct.
gruszczy is a new contributor. Be nice, and check out our Code of Conduct.
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6
$begingroup$
Why on Earth would anybody do this? Iron ore deposits are not particularly rare, and iron ore is not particularly expensive; which is to say, it's dirt cheap and has always been dirt cheap. (Current price for excellent iron ore is about 90 USD per metric ton; that's 2 grams of gold for 1 ton of iron ore.) Moreover, economically viable iron ore deposits are extensive; the inhabitants would normally be extracting the ore from the mountains around the city, not from beneath the city itself. Even the question speaks about a "large" deposit of iron ore; why then go underneath the city?
$endgroup$
– AlexP
7 hours ago
$begingroup$
Good points, thanks! The territories outside of the cities are generally unsafe, so people limit the exposure to minimum (mostly for growing food).
$endgroup$
– gruszczy
6 hours ago
$begingroup$
presumably the danger is on the surface, is there anything to stop them tunnelling out from within the safe area? depending on what the threat is from, short-term surface expeditions or breaches to create (and then partially fill in, depending on drilling technology or etc) ventilation.
$endgroup$
– Giu Piete
5 hours ago
$begingroup$
That's a cool idea - but the danger is actually both above and below. It's the iron itself that makes the city safe.
$endgroup$
– gruszczy
5 hours ago
$begingroup$
You ask about issues but not opportunities, so I'll just leave this as a comment: if it's particularly dangerous outside the city, the spaces excavated by the mines could be converted into living space to expand the city. Sure, it would take something structurally solid to do this, but I hear you have a lot of iron handy... it would probably take a lot less iron to reinforce the new living spaces than one pulled from those spaces, since living spaces are mostly empty air.
$endgroup$
– Ed Grimm
59 mins ago