Lift, place, slide. Sounds simple enough, unless you’re talking about erecting a series of ultra-heavy deck sections for the self-anchored suspension span (SAS) that will complete the new East Span of the San Francisco-Oakland Bay Bridge.
All photos John Huseby/Caltrans District 4
The first eight of 28 steel deck sections arrived at the bridge staging area at Pier 7 in Oakland by ship from Shanghai in January. After some prep work, they were transferred to barges for the final leg of their trans-Pacific journey—to the job site adjacent to Yerba Buena Island in San Francisco Bay. There, the Left Coast Lifter—a huge crane specially fabricated for this job—has been hard at work hoisting the sections one at a time, and delicately placing them on the temporary trestles supporting the SAS. Each deck section is supported by a cradle that then slides on ski-like appendages toward its final position—an operation that can take 24 to 72 hours per piece.
“We’re beginning to close the final gap toward seismic safety on the Bay Bridge,” said Andrew Fremier, deputy executive director of the Bay Area Toll Authority (BATA), an arm of the Metropolitan Transportation Commission. “The public has waited patiently for this milestone, and the Toll Bridge Program Oversight Committee is excited to start this stage of the construction.” The Committee consists of top staff from BATA, Caltrans and the California Transportation Commission, which together are guiding and funding the monumental East Span project.
The largest bridge of its kind in the world, the dramatic SAS will feature a single main cable that will loop over the top of the tower and be fastened to the deck itself, rather than to an anchorage. The deck sections vary in weight from 559 tons to 1,450 tons, and will be set in place at the rate of about one a week from here on. Deck and tower sections will arrive throughout the year, and the new East Span is expected to be open to both westbound and eastbound traffic in 2013.
All photos Copyright Barrie Rokeach 2010
The largest bridge of its kind in the world, the daring and dramatic SAS will feature a single main cable that will loop over the top of the tower and be fastened to the deck itself, rather than to an anchorage.
