Redridge Dam

“Steel dam construction was flirted with only temporarily at the turn of the century, a time which the Redridge Dam owes for its existence. By 1900 the wood crib dam that had been built on the Salmon Trout River to supply water to the nearby Atlantic Mill had proved inadequate in performing the same function to both it and the new Baltic Mill. A new larger dam was needed – and fast. This time constraint together with a lack of conventional materials nearby, the decision was made to try a different approach. The Wisconsin Bridge and Iron Company would build a new steel dam at Redridge – under the direction of engineer J.F. Jackson.

Its been said before that the Redridge Dam is one of a kind, and it truly is. First, the Redridge dam joins only the Ash Fork (Arizona) and Hauser Lake (Montana) as the only three steel dams ever built on the continent. Second, since the Hauser Lake’s failure and subsequent destruction in 1908, the Redridge is now only one of 2 still standing. And third, unlike its sisters, Redridge was not a structural dam. Both of her sisters relied on the truss work to transfer the load of the impounded water directly to bedrock, and it was the bedrock itself that supported the dam and the water. Due to the lack of any solid rock at Redridge (the rock here is brittle sandstone), a large concrete foundation had to be built to play the role of the bedrock. It is this foundation that sets Redridge apart from all others.”

A Monument of Iron and Concrete

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As the new century dawned the great Copper Empire had taken dominion of the rugged peninsula at its feet, transforming what was once a remote wilderness into an industrial megalopolis of almost Babylonian proportions. It was a landscape no longer dominated by the natural world, its prehistoric DNA shaped and altered instead by …

A Fall Walk in the Clouds

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That time of year… all the colors… This is one of those things I’ve missed living out west for too many years and it’s a damn fine sight to see again. We piled into the van last Sunday and dithered our way over the old A&LS rail line that has …

A Few More Items of Interest

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Before moving on from our exploration of the old Redridge dams, I’ve decided to take a final look at a few more details of the old steel dam that we’ve failed to note in our previous installments. We start up at an old plaque found at a roadside parking area …

In the Shadow of Greatness

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The lands south of the Portage were nothing but empty wilderness when the Atlantic Mine first appeared on the scene in 1872. Before the Atlantic took residence only a handful of inconsequential mines had made feeble attempts at success among the rugged hills, all of them failures. Unlike its predecessors, …

Postscript

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The steel dam at Redridge was completed in November of 1901, and became only the second steel dam in the United States. It was preceded by the Ash Fork Dam in 1898 and followed by the larger Hauser Lake dam in 1907. The Hauser Lake dam was subsequently destroyed by …

Anatomy of a Steel Dam (p3)

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As you progress along the foundation of the Redridge Dam, you drop level after level via a series of concrete staircases built into the floor. It’s about 30 feet from the gorge rim where the dam’s wing sections are, to the river level where the main center section sits. As …

Anatomy of a Steel Dam (p2)

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In its simplest form, the Redridge dam is a steel wall built across a ravine – 464 feet wide and 74 feet high. This wall is built from a series of steel I-beams set on 8 foot centers that support a layer of 3/8″ thick concave plates. Near the bottom …

Anatomy of a Steel Dam (p1)

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Steel dam construction was flirted with only temporarily at the turn of the century, a time which the Redridge Dam owes for its existence. By 1900 the wood crib dam that had been built on the Salmon Trout River to supply water to the nearby Atlantic Mill had proved inadequate …

The Spillway

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Flood waters pose a serious threat to most dams steel or otherwise. Dams are built with a specific load limit and water height in mind, and once that is exceeded the dams fate becomes perilous. The other steel dams of its time were designed so that those flood waters would …

A New Danger

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The dangers that a spring thaw once meant for the Redridge dam included the possibility of a dangerous over-topping. The water level in the reservoir would get so high as to flow over the top of the superstructure itself, spilling down onto the dam’s foundation and threatening to wash away …

Supply Lines

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The Redridge Steel Dam was built not to supply power, but to supply water. The Atlantic and Baltic stamp mills that relied on the dam required over 25 million gallons of water each day to operate. The reservoir created by the dam held over 600 million gallons of water, enough …

Behind the Dam

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There are in actuality two dams on the Salmon Trout River. The first and older dam was built before the turn of the century, and was a classical style of dam construction used heavily up to the time. The second dam – the steel one currently in place – was …

The Second Dam

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There are actually two dams built on the Salmon Trout River. When there was but one stamp mill on the red-ridged shores of Lake Superior, a smaller and less technically advanced structure was used to dam the river. When the newer dam was built years later, the old dam was …

Into the Superstructure

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looking down the concrete foundation under the dam As we quickly dropped down into the river gorge the roar of the river ( and the rumble under our feet ) became more pronounced. The light of the day disappeared as we arrived at the bottom, and as we walked forwards …

Steel Dams

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Steel dams were an experiment in dam construction that had a very short life in the United States. Steel dams work under the premise that steel construction offers substantial savings in material and labor costs compared to concrete or masonry construction. The Redridge dam was relatively cheap to build, costing …

The Trestle

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The side road that we had turned onto turned into a parking area for a historical marker that we found overlooking the gorge. The marker denotes the dam as a steel dam, built in 1901, and nothing else. It was only later that we learned this dam’s true claim to …

From the Road

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The Keweenaw was a land tamed by steam. The rise of steam power in the nation corresponded with the rise of the copper mines in this region, resulting in a celebrated use of these technological beasts of burden. Steam engines were used in all aspects of the industry. They were …