VALLEJO — A Chinese company supplied hundreds of thousands of bolts of the wrong size for the seismic retrofitting of a San Francisco Bay Area bridge, according to a California Senate report.
The 250,000 incorrectly sized bolts were made by Shanghai Zhenhua Heavy Industry Co. Ltd. for a retrofit of the Carquinez Bridge to Vallejo, the report says.
The bolts for the Carquinez Bridge were rejected and remade, but they the led to “a near disaster,” according to the report.
An after-hours call to Shanghai Zhenhua was not answered. Bay Bridge spokesman Andrew Gordon said the bolts were never used on the span. “We made sure that the correct bolts were installed,” he said.
Matt Rocco, a spokesman for the California Department of Transportation, said he wanted to reiterate that the bridges are safe. The report, released Wednesday, focuses on the construction of the new eastern span of the San Francisco-Oakland Bay Bridge, raising questions about the quality of workmanship used to build the $6.3 billion span. The problems with the Carquinez Bridge are mentioned in a footnote that says they led the California Department of Transportation to have quality-assurance specialists perform an audit of Shanghai Zhenhua before allowing the company to take on deck and tower work for the new Bay Bridge.
James Merrill, an engineer who headed the audit, said Caltrans was taking a great risk in letting Shanghai Zhenhua do the work, according to the report.
Merrill’s staff subsequently found hundreds of cracks in bridge welds done by the company, the report says.
Caltrans has said that the weld cracks in question were repairable and have been mostly fixed and that the bridge is safe.