Bay Bridge Boat Tour

(For more photos click on the photo above.)

By Jordan Lebovich, JBL Photography

With perfect weather and an eager group we set off to tour the new bay bridge that will link Oakland with Yerba Buena Island.  To start the tour we were shown a short video about the bridge and the progress to date.  The numbers that were covered are colossal.  From the tons of steel, rebar and concrete to the miles of cable to the dozens of companies and countries that are involved, it’s hard to comprehend the effort that has gone into the design and building of this bridge. 

The eastern span replacement of the bridge has been under construction since 2002 and is scheduled to open by Labor Day Weekend in 2013 at a cost of $6.3 billion. The replacement span is engineered to withstand the largest earthquake expected over a 1500 year period and is expected to last at least 150 years with proper maintenance. The Self-Anchored Suspension (SAS) tower was completed in 2011 and all 28 deck segments on the span are in place.

Workers have completed the challenging task of pulling and installing the last of the 137 strands of the nearly 1-mile-long main SAS cable. Each strand consists of more than 17,000 individual high-strength steel wires. The SAS’s single, nearly 1-mile-long cable is anchored into the east end of the roadway, traveling up and over the single tower to wrap around the west end before traveling back up and over the tower to anchor back into the east end; in other words, the 2.6-foot-diameter cable acts like a giant, unbelievably strong sling. The cable’s diameter is the largest for a self-anchored suspension span and at nearly a mile-long, the cable is also the longest looped suspension cable in any bridge. The cable features 118 miles of 2 1/2-inch steel strands and more than 17,000 5mm wires, each of which can support the weight of a military grade Hummer. The cable weighs 5,291 tons or nearly 10.6 million pounds. Anchoring the main cable in the deck itself puts the span into compression and enables it to remain standing.

The new East Span of the Bay Bridge features a unique single tower suspension bridge, connecting to a mile-long elevated viaduct, or Skyway. The parallel roadways of the new span will provide motorists with sweeping views of San Francisco Bay. Each deck will accommodate five lanes of traffic and include 10-foot-wide shoulders to help keep traffic moving. The Skyway has massive pilings reaching deep into bay and seismic safety devices that will enable the road decks to move rather than buckle in the event of an earthquake. The Skyway’s decks are comprised of 452 precast concrete segments, fabricated in Stockton and transported by barge to the project site. These are the largest segments of their kind ever cast. They are lifted into place by winches, which were custom-made for this project.

These are just some of the features of the new bridge, but there were other considerations like the wildlife habitat that the bridge spans. The Bay Bridge and other Toll Bridge projects are global leaders in developing ways to reduce underwater noise caused by construction activity.   In addition, since birds have been roosting on the original Bay Bridge for years, the team designed special platforms (a.k.a., “Cormorant Condos”) under the Skyway to provide nesting habitat in the same area. The project will provide opportunities for the creation and/or enhancement of shorebird roosting habitat in the East Bay. The team regularly monitors birds in the area, such as the Peregrine Falcon, Least Tern, California Brown Pelican, Double-crested Cormorant and Western Gull, to ensure they are not disturbed by construction activities. 

For more information about the bridge project go to http://baybridgeinfo.org/