As California transportation officials vow to increase frequency of inspections on the troubled San Francisco-Oakland Bay Bridge, they had no firm estimate of when federal inspectors would okay its reopening to traffic. For the second time in two months, crews have worked non-stop to install an emergency eyebar repair on the critical crossing, which usually carries 280,000 daily vehicles. The original fix made over Labor Day weekend consisted of a steel saddle brace wrapping around a broken beam of the steel truss. That brace snapped during the windy Oct. 27 evening commute, dropping a 5,000-lb crossbeam and steel connectors into traffic. No one was injured and the bridge is closed indefinitely.
As of the morning of Oct. 30, crews with North Highlands, Calif.-based MCM Construction Inc. were replacing all four support rods, installing damping devices to keep the new ones in place, and gouging out connecting welds, deepening them to structural welds. MCM is also adding straps to further support the four tie bars. The new design enhancements are based on the theory that vibrations from high winds caused the failure, and will focus on reducing vibration and therefore fatigue, says Caltrans spokesman Bart Ney. “Tying off the rods will ensure that if there is a failure, pieces won’t fall down,” Ney adds. Metallurgists are currently testing the damaged pieces to determine if the failure was due to design, material quality or installation.