Hidden 150 feet below ground in the Kansas City area.....

[Miningman]

Semper Vaporo --- Thank you. Always and ever steam!

[aegrotatio]

Deggesty

As to caves, there  was, sixty years ago, a cave near Walhalla, S.C. It was the start of a railroad tunnel that was not completed. Clemson University was using it to cultivate mushrooms.

Bleu cheese!! Amazing!

https://www.roadsideamerica.com/tip/1178

 

[SALfan]

I've been to this facility or one like it, years and years ago.  My employer at the time was making and installing metal shelving and catwalk that mounted between lines of shelving, to a government agency which was fitting out their space for paper document storage.  In the room where the installer was working, the lights were on for about 100 yards from the wall we entered through, and I don't know how far it went beyond that.  The "room" was at least 200 feet wide, and all of this was full or would be full of row after row of metal shelving 20 or 30 feet high (can't remember if there was one or two levels of catwalk above the floor).  We were shipping them an 18-wheeler or two per week of shelving parts and catwalk panels, and the installers were keeping up with deliveries.  That is the most shelving I have ever seen in one place in my life.  It was very impressive.  

 

[tree68]

Deggesty

As to caves, there  was, sixty years ago, a cave near Walhalla, S.C. It was the start of a railroad tunnel that was not completed. Clemson University was using it to cultivate mushrooms. 

Sliding OT:  Some old coal mines in PA are used for that purpose.  We have a local farmer who ships hay there for the bedding for the mushrooms...

[Deggesty]

Thanks, aerogratio.

I was told, in 1960, that mushrooms were grown in it. I ventured into one day, but did not have a flashlight with me so I did not go very far.

Dynamite certainly was not used, for Alfred Nobel did not perfect it until 1867.

An aside--for a time, Amtrak, in its information about the route from New York to Florida, stated that Union officers used dynamite to dig the cave under Petersburg that became the "Crater." Amtrak's writer was not up on military procedure or the history of dynamite. That information was not in later editions of the information.

[Convicted One]

Miningman

Thank you. Always and ever steam!

 

Subtropolis might make an interesting use of a steam "tank" engine?  

[Vern Moore]

Last time I had to go into the caves a BNSF GP-38 was moving cars around on the tracks area being actively mined. Lots of gas and diesel vehicles in there; tractor-trailers like mine, employee vehicles, smaller delivery vehicles and a lot of vehicles being stored for the winter, like RVs, boats and race cars.

[Convicted One]

According to another source, Subtropolis has a total square footage of 55 million sq ft, of which only 14 million  sq ft are being marketed as business space available for lease.

Of that 14 million, 6 million sq ft  are presently occupied, a 42% (+/-) occupancy rate.  Not really a stellar performer. 

Perhaps the low  overall occupancy ratio (6 of 55 million sq ft)  provides a cushion to their air quality issues?

 

FWIW, I've been in cautious disbelief over how well lit the pictured areas have been in their leasing info. I just found the following image that appears to be more typical of what I would expect to be the case:

 

https://en.wikipedia.org/wiki/File:Subtropolis_02.JPG