Lots of it, but this is misleading since government regulation of underground construction is mostly about proving that you won’t accidentally dig through pipes or other utilities, or cause nearby buildings to collapse. The need to do that manifests as a regulatory expense because governments are responsible for keeping the records about these things, but in a differently-arranged society that cost would still exist somewhere else. In 1863, they had it easy since there wasn’t nearly so much pre-existing construction to worry about.
(In the modern world, this could be solved by founding new cities with better planning up front.)
Also, China can dig tunnels for vastly lower prices than the US.
And China still doesn’t have lengths of tunnel within an order of magnitude (or 4?) of its roadways, because tunnels are just that expensive no matter where you are or under how corrupt or laissez-faire a government you’re digging under.
What is the cost of moving dirt in an open-air mine? This would give some figures on the automated cost of moving dirt apart from non-automated labor, regulatory barriers, cost of avoiding existing pipes, etc.
A quick google led me to this page, which tells me that the cost of moving dirt is a very complicated topic with its own jargon, and that the cost depends somewhat on the geology of the dirt to be moved, the slope of the ground in question, and, very importantly, the cost of the fuel required to run the earthmoving equipment.
However, one estimate on the page (dated 2007, so using 2007 diesel prices and driver wages) was $2100 for a 3000-yard ditch (assuming I understand the jargon correctly, that would be an eight-foot ditch (I don’t know if that’s width or depth, the word used is ‘cut’)).
A ditch, or an open-air mine, is also a lot easier than a tunnel because you don’t have to worry about the roof falling in on you (I understand properly shoring up a tunnel roof is another very complicated topic, which most certainly reduces the speed at which you can dig, which in turn means you’d need to keep paying your workers for longer to cover the same distance, thus adding a multiplier to the earth-moving cost)
There’s also ventilation, and pumping if you’re going to be digging below the water table. These are ongoing costs: you need to keep incurring them for as long as you want your tunnel system to remain viable, not just during the initial digging phase.
This page suggests that avoiding water during the mining process is yet another complicated and surprisingly expensive topic, and one that often requires exploratory digging before one commits to a major tunnel. I don’t know if transit systems handle it in the same way, but it’s worth noting that people tend to build cities at low elevations and near major bodies of water.
$21,000 per 3000 yards of tunnel is an eminently practical price for a city. $210,000 is $2100 per 30-yard-wide house. Dig big trench, lay down premanufactured tunnel pipe sections, close up trench. We’re not talking subways here.
$210,000 would strike me as cheap for a permanent above-ground structure of that size, never mind an underground one. Looked at another way, $2100 sounds about right for thirty yards of concrete storm sewer pipe but orders of magnitude off for transit—prefabricated tunnel sections big enough to drive cars through and strong enough to carry however many tons of earth or rubble would not be cheap to make or to move into place, especially if there isn’t an above-ground transport grid to carry them on.
(In the modern world, this could be solved by founding new cities with better planning up front.)
The local geology is another major issue, so presumably that would be a major factor in the decision of where to build your world city. Various modern cities are built on hard volcanic stone, so digging beneath them is fairly pointless.
Lots of it, but this is misleading since government regulation of underground construction is mostly about proving that you won’t accidentally dig through pipes or other utilities, or cause nearby buildings to collapse. The need to do that manifests as a regulatory expense because governments are responsible for keeping the records about these things, but in a differently-arranged society that cost would still exist somewhere else. In 1863, they had it easy since there wasn’t nearly so much pre-existing construction to worry about.
(In the modern world, this could be solved by founding new cities with better planning up front.)
If you were building a city from scratch and routing pipes through the same tunnel, that would not be an issue.
Also, China can dig tunnels for vastly lower prices than the US.
Also, not much force has been put into automating the digging process.
And China still doesn’t have lengths of tunnel within an order of magnitude (or 4?) of its roadways, because tunnels are just that expensive no matter where you are or under how corrupt or laissez-faire a government you’re digging under.
What is the cost of moving dirt in an open-air mine? This would give some figures on the automated cost of moving dirt apart from non-automated labor, regulatory barriers, cost of avoiding existing pipes, etc.
A quick google led me to this page, which tells me that the cost of moving dirt is a very complicated topic with its own jargon, and that the cost depends somewhat on the geology of the dirt to be moved, the slope of the ground in question, and, very importantly, the cost of the fuel required to run the earthmoving equipment.
However, one estimate on the page (dated 2007, so using 2007 diesel prices and driver wages) was $2100 for a 3000-yard ditch (assuming I understand the jargon correctly, that would be an eight-foot ditch (I don’t know if that’s width or depth, the word used is ‘cut’)).
A ditch, or an open-air mine, is also a lot easier than a tunnel because you don’t have to worry about the roof falling in on you (I understand properly shoring up a tunnel roof is another very complicated topic, which most certainly reduces the speed at which you can dig, which in turn means you’d need to keep paying your workers for longer to cover the same distance, thus adding a multiplier to the earth-moving cost)
There’s also ventilation, and pumping if you’re going to be digging below the water table. These are ongoing costs: you need to keep incurring them for as long as you want your tunnel system to remain viable, not just during the initial digging phase.
This page suggests that avoiding water during the mining process is yet another complicated and surprisingly expensive topic, and one that often requires exploratory digging before one commits to a major tunnel. I don’t know if transit systems handle it in the same way, but it’s worth noting that people tend to build cities at low elevations and near major bodies of water.
$21,000 per 3000 yards of tunnel is an eminently practical price for a city. $210,000 is $2100 per 30-yard-wide house. Dig big trench, lay down premanufactured tunnel pipe sections, close up trench. We’re not talking subways here.
$210,000 would strike me as cheap for a permanent above-ground structure of that size, never mind an underground one. Looked at another way, $2100 sounds about right for thirty yards of concrete storm sewer pipe but orders of magnitude off for transit—prefabricated tunnel sections big enough to drive cars through and strong enough to carry however many tons of earth or rubble would not be cheap to make or to move into place, especially if there isn’t an above-ground transport grid to carry them on.
What is the cost of building a ship compared to a submarine?
http://en.wikipedia.org/wiki/Tunnel_boring_machine
I dint know what you are expecting. The technology started in 1825.
The local geology is another major issue, so presumably that would be a major factor in the decision of where to build your world city. Various modern cities are built on hard volcanic stone, so digging beneath them is fairly pointless.