February 11, 2010

Soaring Colorado River bridge a magnet for skilled workers

BOULDER CITY, Nev.

Less than a kilometre downstream from one of America’s best-known engineering marvels, the Hoover Dam, a second is taking shape.

A soaring 1,900-foot (579-meter) span across the gorge created by the Colorado River on the Arizona-Nevada border should be completed this fall, eliminating much of a sometimes hourlong bottleneck as traffic creeps over the dam on the key route between Phoenix and Las Vegas.

When it is scheduled to open in November, motorists will cross the longest bridge of its kind in the western hemisphere, with towering concrete columns that rise above a twin rib arch beneath them.

“It’s pretty spectacular,” said Sidney Spears, a 68-year-old retired truck driver from South Dakota, sitting at the dam and admiring the bridge 1,500 feet (457 metres) away. “This day and age, they are only limited by their imagination.”

Construction began on the US$240 million project nearly five years ago and has caught the eyes of many, like Spears, who have driven over the dam for decades.

Visitors to the dam will be able to see the bridge, but the sheer height of the bridge — 900 feet (274 metres) above the river — won’t allow motorists travelling across the span to see the dam. A walkway on the north side of the bridge will give pedestrians a view of both.

Access to the dam also will change with the opening of the bridge.

Tourists no longer will be able to get to it from the Arizona side, instead having to cross the bridge and backtrack, said U.S. Bureau of Reclamation spokesman Bob Walsh. A checkpoint put in place the afternoon of the Sept. 11, 2001 terrorist attacks will remain on the Nevada side, he said.

The new bridge won’t have any such checkpoints, and semi-truck drivers who once had to reroute through Laughlin, Nevada, a 30-mile (48-kilometre) detour, will be able to drive over it.

When crane operator Kevin Raines first heard that a new bridge would bypass the roadway over the dam that his late boss helped build in the 1930s, he said, “I want to be part of it, it’s historical,” recalled the 56-year-old from southern Utah.

For about eight months, Raines teetered on the edge of a steep canyon in his crane, high above the river carrying 20-ton boulders excavated from the canyon walls and the miners who were hired to blast them out. The work was to help support the arches for the bridge.

“It was a real unique one-of-a-kind type job,” said Raines, who has helped build 36 casinos and high-rise buildings in Las Vegas. “Not many people get that chance.”

The projected opening had been late 2007, but work was suspended at least twice when two 280-foot(85-meter)-tall steel construction cranes collapsed amid high winds in 2006 and a worker died in 2008. Nevada’s workplace safety agency investigated the death but determined it was an accident and the contractor, a joint venture of Obayashi Corporation and PSM Construction USA, Inc., wasn’t cited.

Arizona’s job safety agency has cited the contractor about a dozen times since August 2008 for what the agency’s state director Darin Perkins said were minor issues — not inspecting cranes daily before use, lack of handrails or handrails being at the wrong height, for example.

Project director Ken Hirschmugl and project manager Dave Zanetell of the Federal Highway Administration said safety has remained a top priority for workers. More than 1 million work hours have been logged, Hirschmugl said.

Before the project began, Hirschmugl said there was a substantial effort to educate potential contractors so they wouldn’t blindly bid on it. Some of the highlights include the concrete arches that jut out from the canyon walls. Unable to support them from the bottom up, contractors had to hold it in place with cables from above. When they came together late last year, Hirschmugul said they were within three-eighths of an inch.

Zanetell said when the bridge is done, workers have plans to seek out bigger projects.

“We’re not looking to retire on this,” he said. “It would be a great disservice to our industry if we don’t take what we learned here and apply it.”

Associated Press

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