The Bay Bridge’s eastern span is rising to new heights — albeit slowly — as the fourth piece of the iconic tower is installed this week.
The latest section will make the tower 480 feet high. It will take five days for the piece to be put in place, according to Caltrans, the state agency that oversees the bridge.
Caltrans spokesman Bart Ney said crews will work around the clock through Friday to put the piece in place.
Check out a slideshow of crews installing the Bay Bridge's newest tower segment.
“It looks like one big piece of steel traveling in the sky,” he said. “We’ll be working around the clock. Everything has to be in line before we move forward.”
Installing this next piece means the tower is nearly complete. But getting to this point has been very slow.
The replacement of the 1.2-mile eastern span, from Yerba Buena Island to Oakland, is more than a decade overdue and comes in at hundreds of millions of dollars higher than its original cost estimates. The project currently stands at $6.2 billion.
Discussions to replace the span began in the early 1990s following the 1989 Loma Prieta earthquake, which shook loose a section of the bridge.
Following years of discussion and political fighting, the new eastern span is “on schedule” to open in 2013, according to Ney.
Most suspension bridges around the world have two or more towers. The Bay Bridge will have the longest span supported by a single tower.
With work moving forward, this fourth piece will put the new tower 100 feet above the existing bridge’s elevation.
Because work is taking place on the new span, high above the deck of the existing bridge, Ney said, traffic should not be affected during work.
The final piece, roughly 45 feet high, is expected to be lifted in to place in early April, according to Ney.
Seismic upgrades to the Bay Bridge have been in the works since 1992, after the 1989 Loma Prieta earthquake collapsed a section of the bridge.
- October 1989: Loma Prieta earthquake kills motorist on the east span of the Bay Bridge.
- September 1992: UC Berkeley team estimates retrofit of east span would cost up to $200 million.
- December 1996: Consultant report recommends replacement over retrofit. It estimates the cost at $843 million for a bridge that includes a single tower. Two Caltrans panels recommend building a new eastern span, saying it will be safer and more economical than a retrofit.
- June 1998: Metropolitan Transportation Commission approves bridge design.
- January 2002: At eastern span project groundbreaking, Caltrans says span will open in 2007.
- March 2003: Caltrans increases eastern span cost estimate to $3 billion, citing the unique scale and complexity of the project.
- May 2004: Single bid received to build a self-anchored suspension bridge at a cost up to $1.8 billion, which is double Caltrans’ $730 million estimate.
- August 2004: Eastern span cost estimated at $5.1 billion, with $1.3 billion in overruns blamed on self-anchored suspension bridge.
- December 2009: Eastern span cost estimated at $6.3 billion, including $2.3 billion for self-anchored suspension bridge.
- January 2010: First shipment of steel parts arrives 18 months late for self-anchored suspension bridge. Delay blamed on complexity of design.
- July 2010: First section of the tower of the self-anchored suspension span is bolted to the Bay floor, the beginning of the 525-foot structure set to be the centerpiece of the new span.
- February 2011: Construction crews begin to lift into place the fourth section of the span’s self-anchored suspension tower. Current projections have the entire self-anchored suspension span to be completed by late 2013.
Sources: Caltrans, California State Library, staff reports
Self-anchored suspension on the eastern span of the Bay Bridge:
Length of the fourth section
Weight of the fourth piece
Height of the tower after the fourth piece is in place
Height of tower at completion
Height of original Bay Bridge span