Two Caltrans engineers in 1995 decided on their own to check X-rays of welds from a seismic safety project on a San Diego freeway viaduct.

The project had already passed the inspection of private contractors, but when the Caltrans engineers took a look they found that half the welds were bad, requiring $5 million in corrective work.

That's just one example of how private inspection work could have allowed disastrous defects on highway projects in California, according to a group that represents state-employed engineers.

Now the group is charging that Caltrans could be headed for further trouble with the $5.6 billion new Bay Bridge project by contracting out inspection work.

"The examples of faulty inspections in the past have always been by private inspectors," said Bruce Blanning, executive director of Professional Engineers in California Government, which represents 13,000 engineers, architects and other professionals working for the state.

Contracting out such work, he added, unnecessarily jeopardizes safety when such work could be done by state employees.

Caltrans, the state transportation department which isbuilding the bridge and gearing up for nearly $20 billion worth of bond-funded transportation projects, says it would never compromise on safety and that the contracted inspection help will actually make the bridge safer.

"Safety is not compromised, regardless of who is on the job," said Rick Land, Caltrans' chief engineer.

Moreover, only about 10 percent of inspection work is contracted out for Caltrans projects statewide, while the rest is done by Caltrans staff.

The Bay Bridge may be getting a higher percentage, however, because it involves types of construction that the agency's engineers don't have much experience with. The $1 billion skyway span used precast concrete segments, and the adjoining $1.4 billion self-anchored suspension span will be the largest of its kind in the world, so both projects needed additional expertise to design the spans and check the work, said Brian Maroney, Caltrans deputy toll bridge program manager.

"We value safety, we value efficiency, and one way to get those things is to make sure the team has the best toolbox," Maroney said, "with all the capability and all the experience that we need."

But Blanning's group argues that recent history is littered with examples of private contractors failing to adequately watch over the quality of work done by private contractors.

Last year, for example, shoddy work on Boston's "Big Dig" project is alleged to have led to the collapse of a tunnel roof that crushed a woman in a car to death.

"The issue really was (general contractor Bechtel/Parsons Brinckerhoff) was responsible for its own construction oversight," said Glenn Briere, spokesman for Massachusetts State Auditor A. Joseph DeNucci. "After the tragedy last year, the turnpike authority was taken to task for not properly overseeing Bechtel."

In the San Diego case, Caltrans gave an award to its engineer for catching the bad welds already inspected and found acceptable by a private firm.

Another case, in which one weld was

X-rayed repeatedly and the results passed off as different welds, led to the 1998 criminal conviction of a radiologist hired to ascertain the quality of work on Bay Area freeways retrofitted after the Loma Prieta earthquake.

"The main difference is that the public inspectors work for the public, that's who employs them," Blanning said.

His group has been embroiled in a recent fight between Gov. Arnold Schwarzenegger's administration, which is seeking more private engineering help to build $43 billion worth of infrastructure financed by November ballot measures and the state Legislature, which voted to hire 600 more state engineers instead.

But veteran engineer Carl Monismith, who is in charge of pavement research at the University of California, Berkeley, had worked with some of the contractors Caltrans uses and finds them to be just as dedicated as public engineers.

"That doesn't mean that in making money that they're going to shirk their responsibilities and do a shoddy job," Monismith said. "I don't see why you couldn't hire a contractor to check the work if you don't have the staff to do it in-house."

Caltrans officials note that the engineering group's examples are somewhat dated, and its current contracting regime incorporates contract workers in teams that work alongside Caltrans engineers.

That's just as true where parts of the new self-anchored suspension span are being fabricated, in China, Japan and South Korea, as they are at the base of the bridge in Oakland, Maroney said.

"Everybody has their work checked for quality through a well-designed supervisory team," he said.

Contact Erik Nelson at enelson@angnewspapers.com or (510) 208-6410. Read his Capricious Commuter blog at InsideBayArea.com.