Date:2013-05-31 15:20
More than 100 feet below the roiling waters of the Bay lies BARTs Transbay Tube, one of the regions most impressive engineering feats a path that acts as a portal for nearly 200,000 passengers travelling each day between the East Bay and San Francisco.
Tucked neatly into a protective trench on the floor of the Bay, the tube is nonetheless exposed to the elements of corrosive saltwater, and, more troubling, an occasional misplaced ship anchor.
To arm the tunnels exterior against the harmful effe