OAKLAND, Calif. (AP) — Finding a fix for bolts that snapped on the new eastern span of the San Francisco-Oakland Bay Bridge could take weeks or even months, a state transportation official said Wednesday.
California Transportation Commission Chief Engineer Stephen Maller made the comments at a meeting of the Toll Bridge Program Oversight Committee in Oakland, raising concerns that the span won’t be ready in time to open on Labor Day as planned.
The bridge, which is replacing a span damaged during the 1989 Loma Prieta earthquake, is designed to withstand a major temblor. It already is years late in opening and billions of dollars over budget.
Maller said engineers are trying to determine the cause of brittleness in the steel earthquake safety bolts called shear keys that cracked last month after being tightened.
The best explanation investigators have found to explain the brittleness is that hydrogen somehow permeated the steel bolts, making them brittle.
The parts were made in 2008 by Painesville, Ohio-based Dyson Corp., and officials say other parts made by the company on the span’s single tower and another section have been inspected visually and are considered safe.
Those other parts made by Dyson are subjected to far less tension and pressure than the bolts that failed, Tony Anziano, toll bridge program manager for the California Department of Transportation.
Maller said the big question is how hydrogen got into the steel, and that it could take “a few weeks to a few months” to devise a recommended fix.
One possible source of the hydrogen is rainwater, which could have somehow got into the holes the bolts were driven into, which engineers thought were watertight, Maller said. Another possibility is that the hydrogen was introduced at some point during the bolts’ manufacture.
“When it was being designed, nobody thought this would happen,” Maller said. “Water could have collected in these holes, but this may not be the failure mechanism at all.”
While some doubt was cast on the ability to have the bridge open on Labor Day, bridge officials say it’s too early to know for sure.
That rankled Oakland Mayor Jean Quan, who said her city needs timely notification of any possible delay in the bridge’s opening to help avoid impacts to local businesses, particularly hotels.
“There are millions of dollars at stake in hotel rooms. … We need to set a date,” Quan said. The mayor said if people can’t properly plan for a delayed opening, it could “hurt the local economy.”
Steve Heminger, executive director of the Metropolitan Transportation Commission, told Quan it was still too early to set a deadline for a decision on the span’s opening.
“We don’t know enough to say,” he said, adding that officials aren’t sure yet if they’ll have to replace the custom-made bolts or use another option.
“How long will it take to get the new bolts? We can’t just go to Ace Hardware for these. They have to be fabricated,” he said.
All agreed that ensuring the bridge’s safety was the most important goal, even if that means delaying the opening.
“If it means moving the bridge date back, that’s what it means,” said Bill Dodd, chairman of the toll oversight committee. “We’re going to build a first-class bridge here.”
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