SAN FRANCISCO, Aug 28 (Reuters) - The eastern span of a Depression-era bridge connecting San Francisco to Oakland was retired on Wednesday night, 24 years after it partially collapsed during a major earthquake.
But the big party once planned for next Tuesday, when a majestic $6 billion replacement bridge is scheduled to open, has been canceled - fitting for a project that was six years late, cost five times initial estimates and suffers from broken seismic safety bolts that some critics say render it unsafe.
Four California governors oversaw the planning of what will be the world's largest self-anchored suspension span. Two of them, Pete Wilson and Arnold Schwarzenegger, lobbied for a simple concrete viaduct. Bickering over everything from the exact location to whether or not to include a bicycle path (it does) delayed the project for years.
East Bay politicians including Governor Jerry Brown, who as Oakland's mayor at the time had pushed hard for a landmark structure that might move the workhorse Bay Bridge - second-busiest highway bridge in the country - out of the shadow of the glamorous Golden Gate.
They got one. With its single 525-foot (160-meter) white tower, the span rises up as a breathtaking sight. Eastbound motorists, who were caged on the lower deck of the old gray bridge, will now take in wide-open views of the bay and hills.
But the cracked fasteners discovered in March have sparked questions about whether the connector, which will carry up to 280,000 vehicles a day, could withstand the next big earthquake.
A temporary retrofit is supposed to take pressure off 32 fractured bolts, some as long as 25 feet (7.6 meters), until a permanent fix can be installed on the 2.2-mile (3.5-km) span in December. But fears about the integrity of another 2,268 bolts linger, along with questions about the quality of Chinese steel used in construction and concerns about visible cracks in welds at the base of the tower.
For Abolhassan Astaneh, a professor of bridge engineering at the University of California at Berkeley, the cracked bolts are only one piece of what he sees as a fundamentally flawed project. He has been warning about the dangers of the self-anchored suspension bridge since designers first proposed it in 1998.
"It looks like this bridge was designed in the 16th century when no one knew anything about bridge engineering," he told Reuters. "This is going to go in the textbooks on how not to build a bridge."
Transportation officials went back and forth on whether to delay the opening after the broken bolts were discovered, but after the Federal Highway Administration signed off they decided to press ahead.
"The existing bridge is the one folks ought to be worried about," Steve Heminger, executive director of the Metropolitan Transportation Commission said at a news conference. "We've got two structures out there side by side. And there is no contest between which one is safer."
The old bridge closed at 8 p.m. Wednesday, and the new one is scheduled to open at 5 a.m. Tuesday, leaving Bay Area residents without an essential roadway link for five days.
The 1989 earthquake shook loose a 50-foot (15-meter), 250-ton section of the eastern span's upper deck, which buckled and fell onto the lower deck. The collapse following the 6.9 quake killed one driver, shut down the essential connector for a month and exposed the fragility of the bridge, hailed by the American Society of Civil Engineers in 1955 as one of the "seven modern wonders of the world."
Now it will be dismantled piece by piece at a cost of $300 million, nearly four times what it cost to build, said Randy Rentschler, a transportation commission spokesman.
Unlike the old bridge, the new span was built to sway along with an earthquake rather than to resist it. Investigative reports in the Sacramento Bee and the San Francisco Chronicle newspapers, however, called into question whether the new bridge would perform as designed.
Two engineering firms and the Federal Highway Administration examined the bolts and deemed the bridge safe. Engineers believe the fasteners cracked during manufacturing, during exposure to the bay's moist environment, or both.
But Berkeley's Astaneh and other engineers continued to warn about a possible catastrophe. He said he would take the train from his East Bay home to San Francisco and never drive on the bridge.
It is impossible to predict when the next major earthquake will strike the Bay Area and test the span, but area residents can predict the state of regional traffic with the Bay Bridge closed over the Labor Day weekend.
They are braced for gridlock. (Additional reporting by Jonathan Weber; Editing by Lisa Shumaker)