OAKLAND (KRON) — Caltrans is marking a major milestone in the demolition of the old Bay Bridge. The agency on Friday announced the completion of the monumental 80-year-old cantilever section of the bridge’s eastern span.
Construction crews completed the work on Thursday, after they dismantled the structure piece by piece, working in near reverse order of the way the 1936 cantilever east span was erected decades ago, said Caltrans officials.
Early in the process, two sections of the main span cantilevered outward 700 feet from their support piers.
“This careful balancing act was performed hundreds of feet above the Bay and had to deal with the elements and heavy lifts of lead-painted steel, all while adhering to strict environmental safeguards,” said Chief Bridge Engineer for the project, Dr. Brian Maroney.
A big challenge was the well-used Depression-era steel that made-up the old bridge. Caltrans married the World War I steel with modern and sophisticated technology. The process involved advanced computer analyses and construction equipment tailor-made for the historic demolition, officials said.
“California Engineering Contractors Inc./Silverado Contractors, Inc., and the engineers truly deserve credit for a great job,” Maroney said. “This steel was new 80 years ago and technology was basically paper, pencils slide rules and calculations. The steel is now tired fatigued, cracked and rusted. This incredibly challenging work was completed on time, under budget and without loss of life, and that demands our respect.”
The original east span cantilever truss was a half mile span made up of steel elements pieced together in a structural system called trusses servicing the Bay area for eight decades.
Project officials say crews cut the cantilever at its center and dismantled both sides. The 576-foot long suspended span of the cantilever was then removed. Prior to cutting through the cantilever and separating its two halves, preparations were made to reduce structural tension and pull the suspended span on each end toward the rest of the Bridge.
The cantilever demolition began on November 5, 2013. Officials anticipate the final cost for the demolition will be $63.7 million.
This completes the first phase of the demolition process. Now crews will proceed to phase two: dismantling the truss spans that stretch east of the cantilever to the Oakland shore.
