Students Learn About Construction of Bay Bridge East Span

Why is a new East Span of the Bay Bridge being built? Simple – it’s missing a piece, said kindergartners in Autumn Ayllon’s class at Shore Acres Elementary School in Bay Point during a presentation by the East Span outreach team.

The youngsters were looking in 3-D through old-fashioned viewfinders at a picture of the San Francisco-Oakland Bay Bridge that depicted the deck section on the East Span that fell during the Loma Prieta earthquake in 1989. 

From there, it was only a viewfinder-click away to introduce construction of the new, seismically safe East Span, scheduled to open during the 2013 Labor Day weekend. After viewing pictures of the new skyway, the Left Coast Lifter (a special crane built to lift the 700-ton deck segments into place), the 15-1/2 foot bike/pedestrian path from Oakland to Yerba Buena Island and the new self-anchored suspension system, or SAS, the kindergartners were ready to tackle a special Activity Booklet on bridge facts.

The fifth-grade class of Denise Nunally got to hear even more bridge facts during theviewfinder presentation. They learned that the bridge is asymmetrical, and that each wire in the main cable of the SAS is strong enough to hold up a military-grade tank (137 bundles of 127 wires make up the main cable). And they got to actually tackle an engineering task – putting together a model of the East Span that was created by the Lawrence Hall of Science. The model kit includes two road pieces, a base, the tower, three crossbeams, the main cable with magnets for counterweights, and falsework. It was quite a challenge for the fifth-graders to get their bridge models ready for load transfer, when the falsework was removed and the bridge deck was held up by the cable alone.

“I’m going to be an engineer,” one student proclaimed after his group had achieved the load transfer.

Outreach to students from kindergarten through college on the building of the new East Span is presented by the San Francisco-Oakland Bay Bridge Seismic Safety Projects, comprised of Caltrans, the Bay Area Toll Authority and the California Transportation Commission.  School groups can arrange a visit to Pier 7 in Oakland for a presentation that includes a walking tour of one-to-one scale models of the tower and an actual tire from the straddle carrier that is 12 feet in diameter and weighs 2,000 pounds. Contact Steve Padilla, Public Information Officer, atspadilla@bayareametro.gov or (510) 286-7167. Tours will be offered through July 2013 and later in the year sometime after the Labor Day Weekend bridge opening.

For a detailed description of the actual load transfer on the East Span of the Bay Bridge, completed in November 2012, visithttp://www.mtc.ca.gov/news/current_topics/11-12/sfobb.htm.

—Georgia Lambert

Lawrence Hall of Science Bay Bridge Exhibit Now Open

The Bay Bridge is featured in an ongoing exhibit, “Ingenuity in Action,” at the Lawrence Hall of Science. The Bay Bridge Viewer is an interactive four-screen exhibit powered by a Kinect controller. It gives visitors a choice as to which area they’d like to explore through photos and other media. Two models are on exhibit; in addition to the simple model pictured on the right, a second, more complex model features roadway sections made out of metal. And a new exhibit, “Design Quest,” opening June 1, 2013, will feature the engineering design process, highlighting (via videos and photos) engineering feats and challenges that developed during construction.

The Lawrence Hall of Science is located at 1 Centennial Drive in Berkeley.