Thứ Ba, 7 tháng 5, 2013

On the Rise

[Image: A Galveston house on stilts, courtesy of the Galveston County Museum, Galveston, Texas, via Science Friday].

Following the catastrophic hurricane of 1900, the city of Galveston, Texas, was vertically raised up to 17 feet from its original ground level using "hand-cranked janks and mules," NPR's Science Friday explained last week.

In order to "protect itself from future storms," Dwayne Jones of the Galveston Historical Foundation told the radio program, the city set about constructing a defensive seawall. "And the city began to be raised behind it," he adds, "so everything was lifted up... Houses, out-houses, sidewalks, fences—everything was raised."

[Image: "One hundred men worked to raise the church, one-half inch at a time, for 35 days. Once the correct height was reached, a new concrete foundation was poured." Image courtesy of the Galveston County Museum, Galveston, Texas, via Science Friday].

The whole town, in effect, was "lifted up and put on blocks," including huge masonry structures, such as Galveston's St. Patrick Catholic Church. The church was held off the earth by nearly 700 separately hand-operated jacks. The church was kept level as it was raised only one half-inch a day for 35 days, lifted off the ground as if you were changing its tires.

The description brings to mind the truly extraordinary photographs of North Moore High School being moved across Los Angeles, posted here back in 2011.

[Images: Moving Fort Moore High School in Los Angeles, 1886; photos courtesy of the Title Insurance and Trust/C.C. Pierce Photography Collection, USC Libraries].

Commenting on the seven-year time span of the overall town-lifting operation, Jones describes how the soil there in Galveston is "all sand." These soft ground conditions meant that the engineers could "put canals through, and they had barges and pumps that took the soil or the fill from Galveston Bay and pumped it underneath the properties. So they would go kind of block by block, lift the properties up in that block, pump underneath it, and keep going across the island." The city dredged itself.

In any case, the short but interesting radio segment goes on to discuss contemporary structure-moving operations in New Orleans, Chicago, and beyond, with the ultimate implication that perhaps the inhabited coastal periphery of the greater New York City area might also someday see itself on the rise.

(Thanks to Ed Porter for the tip!)

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