The Hoover Dam Bridge [updated]
The Hoover Dam is one of the most impressive human constructions on the planet. (Yes, yes, I know it was a government make-work project, but still ... )
Perhaps one of the few things to top it is this, the new 1,060 foot twin-rib concrete arch bridge over the Black Canyon, about 100 feet south of the Hoover Dam, due for completion in December.
If swearing at sheer awesomeness was ever justified, this bridge would be it.
The pics are from a series of Bridge Folios by Jamey Stillings of the bridge under construction that you should really examine in depth.
While listening to Bob Mould.
And he links to the description of the bridge’s construction at Popular Science:
Temperatures upward of 115°F, winds capable of felling cranes, an 890-foot drop below: ‘Inhospitable’ doesn’t begin to describe conditions at the Colorado River’s new Mike O’Callaghan–Pat Tillman Memorial Bridge.
A 1,900-foot span designed to divert traffic from the narrow, switchback-laden road across the Hoover Dam, it will be the longest concrete arch bridge in the Western Hemisphere when it opens next fall, with 106 segments of ultra-high-strength concrete forming a twin-rib arch. Workers scaled the canyon’s walls, digging notches for concrete foundation columns. To construct the 1,060-foot-long arch, they cast 24 feet of concrete at a time, while a separate, temporary cable-stayed bridge held up the unfinished ends until the gap was closed this year.
It’s that cable-stayed temporary bridge that gives the new bridge so much of its drama.