Gallery: Hoover Dam Bridge

Strong stomachs and serious suspension

Hoover Dam Bridge Image 1

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.

Hoover Dam Bridge Image 2

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.

Hoover Dam Bridge Image 3

Workers scaled the canyon's walls, digging notches for concrete foundation columns and installing other heavy bridge parts.

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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.

Hoover Dam Bridge Image 5

A head-on view of the construction shows the twin-rib arch of this concrete bridge.

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Until the gap was closed this year, large cables from a separate temporary bridge supported the concrete.

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A rendition of the bridge during construction at night.

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A view from above of the bridge during construction.