Collins was retained by the Golden Gate Bridge Highway & Transportation District to provide underwater bridge inspection services, including 3-D imaging, for the Golden Gate Bridge in San Francisco, California.
The Collins team performed underwater imaging operations of the South and North Tower Piers of the Golden Gate Bridge. These efforts included multiple 3-D sonar technologies including vessel‐mounted and tripod-mounted (deployed to the channel bottom) applications. Collins fully imaged the submerged portions of the South Tower Pier shaft foundation and its outlying fender construction, and the submerged portions of the North Tower Pier shaft foundation. These efforts also served to obtain contour mapping of the seabed in the vicinity of each pier as well as the bottom of the “moat” between the South Tower Pier and its fender. The results of these imaging operations provided advanced information with respect to expected pier conditions, which were confirmed and further examined through the hands-on diving inspection.
The Collins team performed diving inspection operations for the South and North Tower Piers of the Golden Gate Bridge. The limits of inspection for the piers included the submerged portions of the South Tower Pier shaft within the “moat,” which is created by the protective fender that surrounds the pier, and the submerged portions of the North Tower Pier, which resides on the north shoreline of the waterway under the bridge. The diving inspections were conducted by a five-person, Association of Diving Contractors International (ADCI) certified dive team employing surface-supplied air diving equipment and techniques, with all inspection activities fully captured with real-time video and audio recordings.