While we’re all excited over here at SFBay for the new $6.3 billion span of the Bay Bridge to open in September, we’re not exactly looking forward to the long timeline for deconstructing the old span.
Since each section of the existing eastern span needs to be carefully taken apart, it will likely take years until the earthquake-vulnerable structure disappears from The Bay’s skyline.
Brad McCrea, regulatory director of the Bay Conservation and Development Commission, recognizes the difficult process that still lies ahead after the new span is built. He told CBS-SF:
“Taking the old Bay Bridge down is as practically as big a project as putting the new one up.”
Basically imagine how they constructed the behemoth bridge in the 1930s and then go in reverse order. McCrea explained:
“They have great documentation about how this old structure was built in the 1930s. So they will use the architectural drawings from the 30s, they’ll use all of the photographs they have from the 30s, and they’ll use that as a road map to un-doing what was done 75 years ago.”
Caltrans spokesman Bart Ney told KTVU the only recent comparable dismantling project is when the old Carquinez Bridge between Vallejo and Crockett took over two years to take apart once it was replaced.
The Bay Bridge, though, is a different kind of beast altogether, as it’s twice as big as the Carquinez Bridge and much more complex.
Workers will first demolish the main portion of the bridge which sits precariously close to the new span. Then they get down to the nitty-gritty and dig the marine foundations out from 175 feet of mud. However, McCrea suggested:
“If you use micro charges all throughout them, you could effectively have them fold into themselves, in theory, and have it work down and all the debris would actually just collapse down into the bay mud itself. And they would just leave it there.”
Once dismantled, the scrap metal can’t simply be recycled as most of it is coated in toxic lead paint.
One small piece of steel is sure to survive the destruction: The Bay Bridge Troll, installed secretly by 1990 workers when they fixed part of the bridge following the Loma Prieta earthquake.
Some argue it should go behind glass in a museum, others want it to continue to usher cars safely across the span as it’s done for years before.