The Chinese company hired to build key parts of the San Francisco-Oakland Bay Bridge had never built a bridge.
Shanghai Zhenhua Port Machinery Co. Ltd., after all, was a manufacturer of giant cranes for container ports.
The California Department of Transportation agreed to contract with the company known as ZPMC in 2006 because it had established a reputation as fast and cost-effective, offering savings of about $250 million compared to the competing bidder.
Bridge officials were racing to finish the span, pushed years behind schedule and billions of dollars over budget by political squabbles and construction delays. Fearful that the old bridge might not survive a major quake, they wanted speed and savings.
Caltrans asked an outside expert to assess whether ZPMC could do the job, and Jim Merrill, a senior materials contractor for the bridge project, gave the company a "contingent pass." He also labeled it "high-risk." Among other problems, ZPMC didn't have enough qualified welders or inspectors, the audit noted, and routinely welded in the rain, a basic error that often causes defects. Undeterred, Caltrans signed off.
The company later boasted of "zero defects" in a news release. Brian Maroney, chief engineer for the bridge, said in a recent interview the audit's "contingent pass" heightened vigilance to head off problems.
But Caltrans' decision to hire an inexperienced Chinese company, unaccustomed to the rigor of American construction rules, to fabricate the suspension span's signature tower and roadway partly explains why costs ballooned to $6.5 billion and misgivings persist about the quality of the bridge. Caltrans continued to bet on ZPMC by relaxing U.S. standards when the firm couldn't finish fast enough.
Caltrans overrode bridge welding codes and near-universal requirements for new bridge construction when it deemed many cracks in welds produced by ZPMC inconsequential and left them in place to hurry construction along, Caltrans documents show.
Maroney said ZPMC's automated welding process produced excellent results. Caltrans documents show that it also paid hundreds of millions of dollars to fix problems of ZPMC's making, even as it delivered a bridge riddled with cracked welds.
If ZPMC couldn't build the bridge to the required quality, "it should have been taken away from them and built someplace else," Doug Coe, a high-level Caltrans engineer in China during much of the job, said at a California Senate committee hearing in January.
"The race for time" created overwhelming pressure to keep moving as planned, he said. "But there's no excuse for building something defective like that because we are in a race for time."
The litany of Bay Bridge problems exposed in recent years includes suspect foundation concrete, broken anchor rods and rust on the suspension span's main cable. Yet beyond those investigative findings, bridge engineers say, the decision to hire ZPMC will haunt the new span and the public for generations to come.
Incorporated in 1992, ZPMC is one of the world's leading builders of port machinery. ZPMC officials did not respond to requests for comment.
In an investigation of the welding issues, The Sacramento Bee reviewed more than 100,000 pages of construction records and emails by bridge officials, interviewed technical experts and examined testimony at the Senate hearing.
The state Senate Transportation and Housing Committee and the California Highway Patrol are investigating how the weld problems were handled. (In a written statement, Caltrans declined to comment on the CHP probe.)
At the Senate hearing, bridge officials dismissed quality concerns as baseless. "It has been a winding road to get here, but we are here. We have achieved seismic safety for the bridge," said Caltrans Director Malcolm Dougherty.
But committee chair Sen. Mark DeSaulnier, D-Concord, suggested that Caltrans had tried to cover up serious problems with "a deliberate and willful " attempt to obfuscate."
His comments were echoed by experts inside and outside Caltrans -- some of whom supervised the welding and warned of serious flaws. They said the state bought a bridge likely to require extraordinary and costly maintenance.
Caltrans' prime contractor on this part of the bridge was ABF, a joint venture of American Bridge Co. and Fluor Enterprises Inc. ABF, with Caltrans' approval, hired ZPMC as a subcontractor. In choosing a Chinese firm, Caltrans gave up federal money and angered U.S. labor advocates and steelmakers.
In December 2006, ZPMC began making roadway "box girders." These box shells, flat on top for the roadway, would be shipped to Oakland and welded together there to form the suspension span's 2,047-foot roadway.
But after a month, the work already was going sideways. A Caltrans inspector caught ZPMC employees using the wrong radiation source from the wrong direction to check steel plates for flaws. ABF didn't catch the lapse.
Caltrans recorded the episode in a "nonconformance report," a technical memo detailing contract violations and specifying corrections. The reports, many citing multiple errors, averaged one every day or two -- adding up to 965 in less than five years. ZPMC welders made errors, and the firm's inspectors overlooked those flaws.
In early 2008, at a meeting with Caltrans and ABF, the Chinese firm showed open defiance, according to a Caltrans memo about welder performance. "ZPMC stated that they, as the fabricator, will decide whether or not they will adhere to the agreed upon (quality-test) procedures. To this date, ABF has not provided the department with ZPMC's decision."