Detroit's salt mine: City beneath the city
detroitnews.com
detroitnews.com
But you had to be sixteen to enter the mine so my Dad said I'd have to wait. I was so interested that when I turned fifteen I told him that I wanted to go down in the mine on my sixteenth birthday and he agreed.
However that year there was a big collapse in a mine in Louisiana that was under a lake. An oil company got mixed up and drilled down into the mine. The water entered through the hole draining the lake. Though the workers miraculously survived the payouts by the insurance companies were huge.
https://en.wikipedia.org/wiki/Lake_Peigneur#Drilling_disaste...
So then the insurance companies, stunned by the large payouts, banned anyone who wasn't an employee from the mines. Seeing those pictures just brings back all the disappointment.
GIS link: https://tinyurl.com/yx5amaux
(My mother was born there.)
The drill had penetrated one of the lower levels that protruded further underneath the lake, not the top of the mine as one might assume. This gave workers on the upper levels more time to evacuate. The fact that it happened very early in the morning might also have helped.
> Days after the disaster, once the water pressure equalized, nine of the eleven sunken barges popped out of the whirlpool and refloated on the lake's surface.
https://eu.detroitnews.com/EU-learn-more/ has more info. Apparently, they claim/think they can’t show you a direct URL without setting a cookie.
Well, it _is_ progress relative to “can’t let you in”, but where do these kind of policies come from?
[1]: https://webapps.stackexchange.com/questions/135222/why-does-...
https://www.gannett-cdn.com/presto/2020/01/20/PDTN/dd7f14d1-...
The elevator car was very small, and we were packed in, nose-to-buttcheek, since I was quite small myself at the time. Oy. It was only closed at the bottom -- it was shaped like a hot air balloon basket, with the upper sides open. We kids were strictly admonished to not even try to touch the sides of the shaft as they went by, though I don't think I could reach that far up anyway.
Our ears popped several times on the way down. The ride to the bottom took over a minute, which seemed very long for an elevator not stopping at any other floors!
The ride down was dark, which gave our eyes time to adapt. Once we reached the bottom, the mine seemed bright, although the light level was probably quite low in absolute terms. I remember the light fixtures being attached to the ceiling, drilled straight into the salty rock.
There were vehicles down there! This blew my mind, and even at the young age, I recognized them as older style vehicles, Jeeps and such which had been down there for years. I have no idea how they were kept from rusting immediately. The air tasted of salt. Everything was covered in salt dust.
We were given a ride on a vehicle of some sort, I don't remember if we were in the back of a Jeep or on a trailer hayride-style, but we covered quite some distance into the mine. The room-and-pillar system was pointed out, and we got to see the conveyor bringing salt from the active face being mined at the moment, though we didn't get close to the active room itself.
They let us grab some lumps of salt to bring them home. Whatever you could fit in a backpack to ride the elevator back up, is what I was told. Some of those samples made it into my rock collection, some are still in my memory-box. I don't know what became of the others, but I was using one as a paperweight in elementary school.
I don't know why they closed the mine to tours, but it's a great loss to education. Obviously experiences like that are transformative to a young kid!
In the years since, I've oft wondered if the exceptional stability of that geological formation might make it good for other sorts of uses. Archive storage, or perhaps it's the "secret undisclosed location" where important people scuttle off to when bad things happen.
The size of the mine, several miles and with extents under four cities, is remarkable. It's surely expanded further since this map was made:
http://www-personal.umich.edu/~copyrght/image/solstice/sum99...
Rust isn't a huge problem because the environment is very dry. Salt doesn't cause rust, it just makes it worse.
Also I've never been in a mine since then.
Salt has a sweet-spot where it works. Too warm and you don’t need it. Too cold and salty water freezes anyway.
The rust belt is just right for using salt.
The drawback with sand is that it doesn't dissolve in water, so silts everything up.
And throwing sand down really doesn't do much.
Across the lake in Wisconsin we reuse the leftover brine from the cheese industry. Its more effective and more effective per unit used than straight salt.
Takes the freezing point down to 0°F or lower. Combine that with how dry it gets here in the winter and you get a powerful combination of melting and sublimation.
https://www.mlive.com/business/west-michigan/2016/02/why_hol...
Make America Detroit Again?
It was run since 13th century till 1996
Also another salt mine that was also used across many centuries lies just around the cordner: Bochnia Salt Mine (https://en.wikipedia.org/wiki/Bochnia_Salt_Mine).
> Welcome to The Detroit News’s EUROPEAN UNION EXPERIENCE
Anyone got a link working outside the US?
This process doesn't always make sense economically, so it's understandable that Detroit uses their own salt for deicing and imports food-grade salt from places where it's cheaper to make. Or maybe in the past they just didn't care about a bit of contamination.
I'm not sure how well that would work alongside the existing salt mining operations, though.
I think people who design and implement these sleazy dialogs should be ashamed of themselves.
Maybe all of those old test chambers were vitrified in salt instead of just concrete, come to think of it...
At it's peak the system used ~3MW power plant to run the system.
[1] or at least were; the project was shutdown in 2004 and while the paths of the antenna lines still seem to be visible on satellite photos[2] it looks like the lines themselves may have been removed.
[2] The transmission station itself is at https://goo.gl/maps/q5BwduBqbBpAaf1L9 with the 28 mile antenna segment running roughly north south just to the west, one 14 mile segment running east-west a little to the north of the facility and the second to the south.