Reopened Bay Bridge Called ‘Inadequate’ : Quake recovery: More redesign work is needed, a government agency says. Although the span is at least as strong as before, it poses ‘serious threats’ in a larger temblor.

As the first cars crossed the repaired Bay Bridge on Friday night, a governmental agency warned that the structure may not withstand an earthquake similar to the one that hit Oct. 17.

At 11:19 p.m. Friday, a month to the day after the quake sent a 50-foot section of the upper deck collapsing onto the lower deck, Caltrans removed orange freeway cones, thus reopening the bridge to traffic.

Motorists escorted by California Highway Patrol cars indulged in the event by honking their horns, hollering and giving the thumbs-up sign as they edged their way toward the toll plaza.

Throughout the day on Saturday, traffic was light on both sides of the bridge. CHP reported there were no back-ups or accidents.

Even with the opening of the bridge, officials say more work will have to be done before the most heavily used bridge in the nation’s fourth-largest metropolis can withstand another major earthquake.

Sen. Quentin Kopp, a San Francisco independent who chairs the Senate Transportation Committee, said he was virtually certain that the state will spend the funds for the additional work.

Meanwhile, a panel of the San Francisco Bay Conservation and Development Commission said that the repaired bridge is at least as strong as it was before the temblor. But major quakes closer to the bridge, or of the magnitude of those in 1906 or 1868, will likely cause “failures involving more serious threats to life safety.”

“I’m not sure the public at large realizes that the criteria used for the original (Bay Bridge) design is inadequate,” said Alan Pendleton, executive director of the planning and regulatory agency, which must grant Caltrans a permit to complete any large-scale retrofitting.

“While this criteria was appropriate to 1930s,” Pendleton added, “it is not appropriate for the 1980s.”

Pendleton noted that engineers can redesign supports to ensure that the bridge can withstand even stronger, closer quakes. But the expense would easily dwarf the estimated $4 million that the reconstruction has cost.

The tone of the agency’s statement contrasted with comments of Abolhassan Astaneh, engineering professor at UC Berkeley who is studying the bridge with funds from the National Science Foundation.

“There’s nothing weak about that bridge,” he said last week.

Astaneh did, however, add a qualification. He said the span’s seismic safety features were “30 years ahead of its time” when it was built. Now, 53 years after the bridge’s opening on Nov. 12, 1936, the design is “20 years behind the times.”

Last week, dignitaries praised Caltrans, contractors and crews for the repairs that were done and for getting the bridge back in service so quickly.

“We’ve beaten the bureaucracy on this one,” Transportation Secretary Samuel Skinner declared in a visit to the bridge last week.

The reconstruction involved such feats as shifting the eastern end of the bridge--10 million pounds of steel and concrete--westward five inches. In all, 150 tons of new steel was used in the reconstruction, nearly all of it fabricated on barges in the bay below the bridge. Given the bridge’s importance, time was of essence.

“I never had a budget. They said, ‘Fix the bridge.’ This was a marching army,” said Denny A. McLeod, 63-year-old founder of Rigging International, one of the main subcontractors.

McLeod had taken on big jobs before. In 1963, he helped figure out how to hoist a Japanese airliner that had belly flopped into San Francisco Bay. He and his firm helped build sections of the Alaskan pipeline, nuclear power plants and container facilities at ports in Long Beach and San Pedro.

“This took all the experience we could muster,” he said. “There was nothing in the book that says what you do with a broken bridge that has been shook by an earthquake.”

For many of the ironworkers, it was the job of a lifetime.

“A lot of guys really wanted to get on this job,” ironworker Joe Kroll said after a month of 12-hour-a-day shifts. “It was a challenge, you might say. There aren’t too many bridges being built these days.”

Kroll, 34, was among the first workers to arrive on the bridge the morning after the quake. At the time, the broken 50-foot section was teetering. With aftershocks coming without warning, the lower deck could have slipped. If it gave way, the upper deck would have followed--perhaps taking with it hundreds of feet of bridge.

Workers lashed the lower deck together with wire rope, three-fourths of an inch and an inch thick. Hard-hatted workers resembled mountain climbers as they prepared the collapsed section to be hoisted away. They clutched ropes as they scampered up and down the steeply tilted roadway.

With the five-lane decks secured, workers cut the slabs using diamond-tipped saws on the concrete and torches on the steel. Once the slabs were halved, the general contractor, Smith Rice Co., moved in with a barge and crane. The northern piece was lashed to a giant orange hook that hung down from the crane.

After 4 1/2 days of painstaking preparations, the first section of the upper deck was ready to be removed. The crane lifted the concrete-and-steel slab section, swung the 100-ton structure around and gently deposited it onto the barge. The procedure was repeated until all the sections of the 50-foot upper and lower deck were removed.

While new steel for the bridge was forged, workers prepared the damaged section to receive the replacement parts. Old rivets, 4,000 to 5,000 of them, were busted out. As big as that job was, it paled compared to the job of moving the bridge back into place.

By the time the earthquake had stopped shaking, the bridge was 5 1/2 inches to the east and about an inch to the north from where it had been.

Engineers know from experience how much pressure is needed to move steel that is resting on steel. But McLeod noted that they could not be “dead sure what it would take” to move the out-of-plumb sections of the bridge.

“The surfaces had been scuffed. There was paint and debris,” he said.

Engineers groped, calculated and finally concluded that two jacks exerting 200 tons of pressure each could shift the bridge back into place. Crews built platforms for the jacks and braced them to a pier of the bridge. Two bridge towers had been knocked out of alignment to the west, and that helped, because the steel was elastic. When the towers snapped back, they helped pull the bridge into place.

“It worked slick as hell. It was a sophisticated, homemade scheme and it worked,” McLeod said, adding: “Just think of it as shortening your commute.”

A CHP traffic spokesman attributed Saturday’s light traffic flow to people using the mass transit systems.

An elated Sgt. Kevin Kelley, who led the 30-m.p.h. procession across the upper deck Friday evening, said: “It was my first time getting over to Oakland in the past month. It’s a great feeling to have the bridge back in operation.”

Times staff writer Victor Zonana contributed to this story.