The new Bay Bridge East Span is finally opening for business. Nearly 25 years after the 1989 Loma Prieta earthquake damaged the original 1936 span, the Bay Area public will be able to drive on a contemporary and seismically safe new bridge designed to ride out an earthquake of a magnitude predicted to strike only once every 1,500 years.
© 2013 Barrie Rokeach
By Brenda Kahn
Published: September, 2013
The new Bay Bridge East Span is finally opening for business. Nearly 25 years after the 1989 Loma Prieta earthquake damaged the original 1936 span, the Bay Area public will be able to drive on a contemporary and seismically safe new bridge designed to ride out an earthquake of a magnitude predicted to strike only once every 1,500 years.
The new bridge is as beautiful as she is strong, accenting the natural and built environment and redefining what a suspension bridge is all about. Designed into the monumental structure are several architectural references to other iconic structures. The tapering, 525-foot tower was inspired by the shape of the Apollo missions’ Saturn V launch rocket, while the bridge’s asymmetrical triangular profile and brilliant white color are a nod to the distinctive white shipping cranes that define the Port of Oakland’s busy container operation.
Under construction for more than a decade, the new East Span was erected in two main phases: first the Skyway, a streamlined, curving concrete causeway that stretches from Oakland to a midpoint in the Bay, and then over the last several years, the focus was on the more complex steel self-anchored suspension span that closes the gap between the Skyway and Yerba Buena Island. Whereas the old East Span is double-decked, the new bridge features side-by-side roadways, a design that will enhance earthquake resistance while opening up new vistas to motorists.
From the start, much of the focus has been on the self-anchored suspension span that will carry traffic over the deep shipping channel near Yerba Buena Island. Accounting for just 2,047 feet of the nearly 2.8-mile new East Span, this element has been the most challenging in terms of engineering and fabrication, but also the most dramatic portion visually. The SAS, as it is referred to in engineer’s shorthand, shares some suspension DNA with the 1936 West Span of the Bay Bridge as well as the 1937 Golden Gate Bridge and the 2003 westbound Carquinez Bridge, and forms another link in the necklace of suspension bridges ringing San Francisco Bay.
During construction, the fine bones of the SAS centerpiece were somewhat obscured by ever-present scaffolding on the tower and falsework underneath the deck. In the spring of 2013, the SAS’ massive load was successfully transferred to the newly completed suspension cable system, and workers were able to remove the underpinnings and scaffolding as well as the catwalks, for the first time fully revealing the SAS’ profile and delicate-appearing but sturdy web of cables.
It was at this point that the bridge hit a major snag that threatened to derail the planned 2013 Labor Day weekend opening: problems with high-strength bolts holding down seismic gear at the east end of the SAS. The Toll Bridge Program Oversight Committee — made up of the Bay Area Toll Authority, Caltrans and the California Transportation Commission — sprang into action, investigating the root cause of the bolt problem and engineering a fix. And when it became apparent that the fabrication and installation of new parts to compensate for the failed bolts would stretch into December 2013, a team of independent experts recommended an interim fix that put the Labor Day weekend opening back on track — albeit without the much-anticipated public celebration.
Officials hope to reschedule the celebratory trans-bridge walk, bike ride and run at a future date, and in the meantime, the public will be able to experience the new East Span up close via the bicycle-pedestrian path, which will open close to the same time as the traffic lanes (although the bike-ped path won’t extend the full length of the new East Span until the old bridge is removed).
In mid-August, Caltrans tested the nighttime roadway lighting system, a marvel of architecture and engineering in itself. Bathed in the glow from the LED light fixtures and set against San Francisco’s golden skyline, the new Bay Bridge East Span showed her true colors, a debutante in sparkling white ready to join the other icons on the Bay.
The bike-ped path along the new East Span is set to open as well, although it won’t extend the full length of the new span yet. Photo by Martin Chandrawinata
In place of the double-deck configuration of the old East Span (shown to the right in the middle and left photo), the new East Span will feature side-by-side decks and wide-open vistas. The canopy of cables — shown in all three photos — will create a cathedral-like feeling as drivers pass underneath. 1st image by Noah Berger, 2nd and 3rd images by Tom Paiva.
