Air conditioned

A few weeks ago, I was talking about a feat of engineering east of Superior called the Claypool Tunnel. There's another amazing work of engineering in (actually, under) Superior: two 140-ton centrifugal chiller units: air conditioning for the Magma Mine. "The First Air Conditioning of the Magma Copper Company Mine" was designated by the American Society of Mechanical Engineers as a National Historical Mechanical Engineering Landmark. This was actually the first air conditioned mine in North America. With the rock temperature at a balmy 102° at the 2000-foot level and the temperature increasing 1.5° per every 100 feet thereafter, the Magma lived up to its name. Air conditioning was needed for both efficiency and safety, and the Carrier Corporation was to provide it. The survey was performed by Dr. Willis H. Carrier himself, and the system was installed in 1937. Two 140-ton units were placed in the deepest level of the mine (3600-foot), and cranked up on July 19 (unit one) and August 3 (unit two).

Sadly, these two historic machines (along with four others that were installed later) were left in the mine, and are now most likely under water.

The photo is of regenerative cooling towers on the exterior of the mine. These were erected in 1941 to provide condensing water to the chiller units. They're visible from US 60 if you have sharp eyes or a big honkin' zoom lens.