Waste’s End
There are two types of rock underground – the type of rock that makes money and everything else. Copper may be more abundant here then anywhere else, but even here it’s a minority. Within the lodes that it calls home, Copper is scattered about in small pockets and thin veins largely outnumbered by the value-less rocks around it. In conglomerate lodes (like the one Centennial worked) copper exists as pebbles. In amygdaloid lodes it was more like flakes. Mines were lucky to get a pound of copper for every 100 pounds of rock mined.
Unfortunately mines only made money with copper. For all the rock they had to remove to get to that copper, they lost money. The “poor rock” - as it was called – was a thorn in a mines side. The least they had to deal with it the better. The rock-house’s job was to remove as much as this poor rock from the copper as possible, before transporting the copper rock to mills and smelters. The resulting waste rock would be removed and sent to a nearby dump.
At Centennial we followed the skip road towards the Rock house’s rear end – literally. For here was the poor rock bin and chute, used to remove waste rock from the building and transport it to the dump nearby. It consisted of a long metal tube, on the bottom of which was an opening to a short chute. Originally a wooded tramway would leave from this point and run out to the dump. (oops, see comments…) Now only the chute remained.
Getting closer we could see the chute door was open. The opening in the tube was curtained by a series of chains, possibly to slow the pieces of rock down as they left the holding bin. Above that was a platform for the workers, used to dislodge any jams in the bin or chute. Below the chute we could make out the pneumatic piston used to operate the chute door.
Looking up the bins length to the top, the rock house structure loomed overhead ominously. ( View Panoramic >) We could see at the top of the bin where skips would dump their cargo into it, probably a loud process as the rock bounced down the bin towards the chute. We decided to move along, towards the building’s other bin – the copper rock bin just in front of us.
At most of the newer head frames such as Centennial, Kingston, Osceola, etc. there was no tram way, or even a rail spur under the poor rock chute. You would just pull a dump truck under and drive the rock to the dump.
Joe Dase | February 5, 2007
Joe - Well that does make more sense. I had seen photos (at Gratiot for instance) that show a tramway heading off to the poor rock pile so I had assumed the same would be true here (my bad). It would make more sense of course that in the modern age a dump truck would be used since it probably would be cheaper (less maintenance and low start up costs) then building an elevated tramway…. Thanks for the catch!
explorer | February 5, 2007