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.
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