Centennial MineMines

Mining Moderne

The Copper Empire lasted for over a century and a half – its dominion covering several major periods of American history. It was front in center in the country’s Gilded Age of industry, provided copper for two world wars and the war between the states, limped its way through the Depression, and enjoyed the great excesses of the Jazz Age. It’s longevity endured even into the modern age – an era that was not nearly as excessive as the Victorian ages before it. The modern age was one of effeciency – as the increasingly elusive copper riches of the region afforded far less returns on a company’s investment. To prosper companies did more with less, changing a mindset that had once valued capacity and redundancy towards ideas favoring simplicity and bare bones necessity. This change in approach is most visually apparent in the shiny new surface plants mines like C&H erected in its later years – plants built atop its Kingston, Gratiot, Osceola, and Centennial properties. Surface plants that looked a lot like this:

This is the rock house belonging to the Centennial No.6, a shaft originally opened in the late 1800s but later mined by C&H after it acquired the old property in the late 1920s. With its original workings now abandoned  C&H hoped that the No.6 would provide access to the riches of its great Calumet Conglomerate Lode once again. Towards that end the company invested in a brand new surface plant to accompany the old shaft – the result of which is the towering structure that graces the shaft yet today.  The structure is often refered to as a head frame, but also serves as the shaft’s rock house as inside are a compliment of rock crushers used to break down the rock coming up from the mine into more manageable pieces (click on the “Take A Look Inside” tab above to see for yourself). Skips filled with rock are hauled up the inclined track seen to the right and brought into the upper reaches of the building. From that great height the rock is pulled by gravity through a sorting and crushing process before being dumped into one of two storage silos found at the structure’s base. That rock is later hauled away to either a poor rock pile for disposal or a stamp mill for further processing.

This is no different then any other rock house built for the Copper Empire, except for one important caveat – here the system has been greatly simplified. The building houses six basic components: the sheaves, the skip road, a poor rock dump and bin, a copper rock dump, a pair of rock crushers, and an ore bin. In the past those basic components would have been augmented with grizzlies and other sorting equipment, drop hammers, additional rock crushers, cranes, and a steam engine to power it all. At Centennial rock was either poor or copper bearing with each sent into its own storage bin. By this time in the evolution of copper mining the process had been honed down to only its bear essentials.

Centennial Head Frame
The Sheaves House of the Centennial No.6
The first of those essentials happens to be the reason for the structure’s towering presence – its role as a head frame. A head frame is the truss work which supports a pair of large pulley wheels – known as sheaves – that divert the hoisting rope from the hoist down into the shaft. As these wheels would have to support the weight of anything being hauled up from the underground they are immense and extremely hearty. Those massive wheels would be housed within the very top of the structure – behind the corrugated iron skin seen above. The hoisting cables themselves would have threaded through the small holes seen on the front facade, before wrapping over the top of the sheaves and headed down along the skip road into the shaft.

Shaft House and Dry House at Centennial No.6
Skip Road, Shaft House, and Dry House
That hoisting rope would have then followed the skip road down into the shaft. Today the shaft itself is hidden behind a curtain of shiny steel along the front facade of the shaft house seen above. Atop this road would have travelled the skips – large iron buckets filled with rock from the underground. After leaving the underground they would pass through the shaft house before climbing up the iron roadway towards the top of the adjacent rock house.

Once at the rock house those skips would enter the shelter of an entrance vestibule seen above on the left. Also seen is the first of two chutes those skips could dump their cargo into – a thick wood funnel seen peaking out of the iron framework above the narrow silo. Rock dumped here would be poor rock – rock which contained no copper but was simply removed from the underground during drifting or stoping. The chute would send that poor rock into the narrow silo seen in the right photo – a storage bin used to hold the rock until it could be hauled away.

Discharge Chute at Centennial No.6
The Poor Rock Discharge Chute
At the bottom end of that poor rock silo is this interesting contraption. This is a chute, its maw opened and closed via a pneumatic piston seen attached to the foundation just behind.  A dump truck would have once sat below this chute to receive the poor rock before hauling it over to the mine’s waste pile for dumping. The platform around the chute and attached stairway provided egress to the chute in case of any pinched rock prohibiting it from flowing freely.  This is a further simplification of the system – as older rock houses would have utilized a endless loop tramway atop its own trestle to haul the rock over to the waste piles – another complicated system of its own right consisting of tramways, elevated tracks, and ore cars.

Rock Bin at Centennial No.6
The Rock Bin and Foundation
As for the rock which did contain copper, its home was the far larger and more impressive iron silo residing just next door. The size differential makes sense considering how the company would insure that most of the rock it hauled up from the surface would be money-making instead of money-loosing. That money-making rock would be stored here until it too could be hauled away, but instead of a waste dump it would instead be taken out the old Ahmeek Mill in Tamarack City. No old dump truck would do for this high class rock either – it would be given star treatment via a scenic train ride through the countryside.

Those train cars would load up in the opening seen to the right above – a space capable of supporting two rows of train cars running side by side. Rock cars within its confines would be filled via a series of chutes lining the roof connected directly with the storage bin sitting above. Those chutes were opened and shut by hand by means of the series of large iron switches dropping down from the roof between the two rail lines. A small catwalk just below the switches provided a work space for the man responsible for opening and closing the chutes. The chutes would be opened until the rock cars underneath were full and then closed. The train would move forward to bring a new set of empty rock cars under the chutes and they would be opened again. The process would continue until all the rock was emptied or they ran out of rock cars to fill.

Rock House Floor at Centennial No.6
The Rock House Floor
 Before the rock would get there, however, it first took a slight detour through the structure’s rock house level – seen above. It’s no coincidence that this level of the building is where almost all of the windows can be found, as it was within here that most of the work was done and its worker’s toiled. Nestled within the floor’s center was a pair of large rock crushers, in which copper rock from the skips would be dumped after arriving into the building. The crushers would work to break down the rock into pieces of a size the mine’s mill could handle. Once that size was achieved the rock would be dumped into the storage bin below to await its turn at the chutes and a trip to the mill.

Together the rock house, bins, sheave house, skip road, and bins are a well honed model of efficiency; an assembly line of rock handling perfected over the decades that culminated in the epitome of modernity seen at the Centennial site today. These head frames are the final stage of the Copper Empire’s technological evolution  – one dedicated not to the boisterous symbols of power and prestige mines like C&H once erected but instead to the efficiency and  simplicity the modern age – and an ailing industry – now demanded.

The Centennial No.6 Rock House - Full View
The Centennial No.6 Rock House – Full View
Taken as a whole the entire structure seems to gleam – even in its current dilapidated state.  Its simple lines and geometric forms combined with the most mundane of material – iron and concrete – exemplify the sensibilities of a modern age. There are no frills here, no Victorian excess or exuberance to be found. Its only excess is in its very antiseptic nature – simplified into single-mindedness  and sanitized into sterility. Yet in a time when profits were scarce and costs were high  such benign characteristics became quite virtuous. This was a symbol not of a Copper Empire at its peak, but one instead in its decline. This was the Copper Empire of the modern age.


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  1. As always, another interesting look into history. Do you plan on writing a book some day? I knoe I would read it and learn.

  2. Another great post Mike, thanks for starting them again. I didn’t realize how close this was when I stayed at the Cent. Cottages a couple years ago. Was this shaft still operating when the mine was finally closed in the 60’s?

  3. Another new year! Love the new layout on the website, a nifty step up (being a fellow map freak, thanks for adding that feature!).

    1. Thanks Craig! Unfortunately I had to remove the map since the plug-in I used to make it turns out to be one of those try once for free and then pay after that deals. So I will have to find another solution. But my plan is to have a map on posts in the future!

  4. 1990, that is more likely when the PCI in Hubbell was trying to reopen it. Homestake tried to run it in the early 1980’s if I remember correctly.

    1. Very much enjoyed the historic review and pictures of the Centennial Mine. Just a small correction of the time period that Homestake reopened the 6 and 3 shafts. I was chief engineer of the project from 1972 thru 1975. During those years we dewatered the Six and connecting Three shaft, deepened the Six from the 36th level down to the 42 level and drove several hundred feet of exploration drifts. We refurbished the Three Shaft for hoisting ore while deepening the Six.

      It was a great project and a beautiful place to live.

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