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Mostly positive inspection for Golden Gate Bridge finds one major fault: the paint job

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Inspectors from Nebraska-based HDR inc. rappel down the Golden Gate Bridge to determine its structural viability in April this year. (Photos Courtesy Golden Gate Bridge, Highway and Transportation District)

The Golden Gate Bridge is the San Francisco Bay Area’s shining icon, but a recent inspection highlighted a problem that can be seen with the naked eye:

The international orange paint job is a wreck.

A regular two-year inspection in April required by federal regulations found the towers of the famous bridge structurally sound, earning what one bridge official called the “highest” marks a water-spanning conveyance can earn.

Yet inspectors from Nebraska-based HDR inc. engineering determined 8.5 percent of the towers’ steel sports peeling paint, while 4.5 percent of the towers’ steel is rusted and corroded. That damage isn’t structural, but still is a priority for the Golden Gate Bridge, Highway and Transportation District to fix.

Most of the bridge was found to be in “good,” condition, which bridge district General Manager Denis Mulligan noted is a top mark.

“Good is the highest you can get,” he told a committee of the bridge district board, Thursday morning. “I know ‘great’ is an inflation in academia, but it doesn’t exist in the engineering world.”

HRD inc. was awarded the $700,000 contract for a full bridge review and performed the death-defying tower inspections, which required its engineers to rappel from the side of the Golden Gate Bridge. Photos and video played by the bridge district during the Thursday committee meeting show inspectors clinging to the bridge’s south tower like Spider-Man, hanging by a web of cables as autos cross above them.

In one video, an inspector hung by cables by the bridge’s base, tapping the concrete foundation with a tool, searching for a dull sound to reveal improper concrete. The tool sounded, “Clink, clink, clink,” as he tapped it against the smooth gray surface. “I find this fascinating in the era of high tech and so on,” Ewa Bauer, chief engineer of the Golden Gate Bridge, told the committee Thursday. Though x-ray and other methods are available, they don’t work nearly as well, she said. “This is the best.”

Seven defects that may be classified as in “fair” condition were found on the bridge, she said, and “very small” non-structural elements were deemed in “poor” condition, she said.

“I’m not saying we don’t have to go and take care of it, but overall the structural evaluation of the tower gets good ratings,” Bauer said.

However, the paint is more of a problem.

It’s rusting, peeling, staining — and, it’s “ugly,” Bauer noted. Fixing it, however, will be an “expensive proposition,” she said.

That’s because the district may need to cloak the entire south tower in scaffolding and “containment enclosures” to catch errant paint. Still, only the south tower of the bridge may need that treatment, she said, since it bears the brunt of the wind and fog. The north tower, on the other hand, is mostly shielded from heavy weather elements by the Marin headlands.

Bauer said the most likely way forward is to fold the paint project in with forthcoming seismic retrofit work on the bridge, which is currently estimated to cost $660 million, according to a bridge district staff report. Still, the committee agreed that repainting the bridge was a necessity.

“People love this bridge,” said Golden Gate District board member Brian Sobl. “They want it to look good — pristine.”

(Photos Courtesy Golden Gate Bridge, Highway and Transportation District)

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