Posts tagged with "quarry":

Placeholder Alt Text

How marble from a small town in Georgia built America’s top monuments to power

In the United States, the architecture of power manifests itself in the stone edifice. Like the Roman and Greek precedents that gave rise to home-grown neo-Classical examples, stone is the material of choice for the monument. Marble, to the Western world, appeals to the upper echelons of society due to its ability to connote the democratic ideals Greek and classical architecture represents. "More marble was used in building in the United States in the years 1900–1917," wrote Marcus Whiffen, "than... in the Roman Empire during its entire history." Emphasizing the U.S.'s love of the eternal material, Whiffen continued: "Nowhere outside the United States were the classical orders... drawn up in so many parade formations." Of course, this is not to say that the style, or indeed use of marble, has come to an end. With typologies such as state capitols, courthouses (a phenomena well chronicled in Courthouses of the Second Circuit by the Federal Bar) and other governmental buildings that require a certain grandiose scale and presence, marble will be in demand for a long time to come. The thirst for marble nevertheless continues and the supply may lie in the sleepy rural town of Tate, Georgia. Located upstate, two hours north of Atlanta, Tate has an established white marble pedigree. Now run by Polycor, the huge quarry has been mining marble for over 180 years, supplying much of the U.S. with its white and gray marble which has been used for many national landmarks and emblems of power, notably the New York Stock Exchange, Lincoln Memorial, and the U.S. Capitol. Now, it is also used for the vast majority of U.S. military gravestones. Polycor has pioneered advancements in marble manufacture, developing a new 3/8" (1cm) thick marble slab. This equates to being one third of the weight of a normal slab that is three times as thick, meanwhile the application of a proprietary composite backing increases the strength of the stone ten fold. https://www.youtube.com/watch?v=U6VXi1TVSQI This development means that marble can now be used effectively in cladding systems. A notable failure of marble being used for cladding in the past can be seen with the Aon Center tower in Chicago (formerly the Amoco building). Once built, the Amoco building was the world's tallest marble-clad building, utilising 43,000 slabs of Italian Carrara marble. While construction was still underway, however, on December 25, 1973, a 350-pound marble slab fell from the facade, puncturing the roof of the adjacent Prudential Center, an unwanted Christmas present. Now, thanks to the new stronger and thinner marble slabs, the material may once again be considered for such uses and indeed many more.
Placeholder Alt Text

LACMA Prepares its Giant Rock

If all goes according to plan, sometime in early October an enormous boulder will leave a Riverside, California quarry and a couple of weeks later roll onto the grounds of the Los Angeles County Museum of Art, to become an installation called Levitated Mass. In 1968, Michael Heizer, the artist behind Levitated Mass, made a drawing of a rock he hoped would one day emerge from the quarry he had been visiting. Decades later in 2007, the boulder he’d been looking for tumbled out of its granite escarpment.  The 21½-foot-tall rock came to rest several yards from the quarry face. “It was quarried up top, and they pushed it with 2 bulldozers and a Caterpillar loader 300 feet. That’s how we pulled it off the mountain. But when it became a work of art, they had a big cradle and crane to move it,” remarked Stephen Vander Hart, the head of Stone Valley quarry, who seems both pleased and anxious to see the boulder leave his custody.  It has taken nearly five years of fundraising and engineering to work out how to move the rock the 85 miles to Los Angeles. To get from quarry to museum, the 340-ton chunk of granite will be slung on thick cables suspended between two 127-foot-long steel beams and hauled at a snail’s pace by a Kenworth truck in front and an Oshkosh military transport from behind.  Each truck is capable of producing 550 to 600 horsepower.  The entire rig, front to back, will be 273'-10" inches long.  LACMA says the rock is the “largest monolith moved since ancient times," a lofty claim no one could really prove or disprove. Still, toting the 670,000-pound boulder requires Emmert International (the firm building and driving the rig) to construct a transporter consisting of two hollow beams of welded and gusseted T-1 laminated steel.  Each beam is roughly 2 feet wide, tapering from 40” up to a height of 6’-9”.  The beams, which have been pieced together on site around the boulder, are made up of five sections that will be drawn together by bolts along vertical seams.  When closed, the seams push against each other, like the keystone in an arch, becoming stronger because they are in compression.  When completed, the beams will be connected by cross members and trusses, forming a 26’-7” wide saddle that will sit on 22 dollies with remote control steering.  A total of 196 tires will bear the load. Empty, the rig will weigh nearly a half-million pounds; fully loaded about 1.1 million pounds.  It will lumber, by night, at an average speed of five miles per hour.  “It’s just a big rock,” said Rick Albrecht, Emmert’s supervisor for the move.  “I’ve seen most of the route so far. We’ll do it,” he added flatly.