The demolition of the 78-year-old original eastern span of the Bay Bridge is proceeding on schedule in a methodical, piece-by-piece manner, a Caltrans spokeswoman said Thursday.
During a media tour of the old eastern span, which went out of service when the new eastern span opened up a year ago, Caltrans spokeswoman Leah Robinson-Leach said the dismantling of the old section is taking place in the reverse order from which it was built.
The first phase was to cut the suspended span of the cantilever truss at its center in order to begin removing it, Robinson-Leach said. There is now an 800-foot gap in the middle of the cantilever span, which is visible to drivers on the new eastern span.
Robinson-Leach said demolition has also begun on the temporary detour near Yerba Buena Island known as the S-curve. The second phase will involve removing the five truss spans and the truss causeway and the third and final phase calls for removing the underwater foundations for the old span, she said.
The demolition work began last year and isn't scheduled to be completed until 2018, Robinson-Leach said. One of the challenges for workers is keeping the old span stable while it is demolished. One way to accomplish that is by installing temporary support trusses, she said.
Another complication is that many of the large number of cormorants who have nested under the old eastern span for many years have refused to leave their spots and move over to the new span, according to Robinson-Leach. Workers have tried to deter the cormorants and attract them to the new bridge by installing netting and spikes on the old span but the effort "has not been as successful as we had hoped," she said.
One of the challenges for the new eastern span has been problems with some of the bolts that secure earthquake shock absorbers to its deck. In March 2013, about one-third of the initial batch of 96 bolts that secure the shock absorbers to the deck failed when they were tightened.
But Caltrans officials figured out a temporary solution that allowed the new eastern span to open on schedule on Labor Day in 2013 and completed a permanent fix in December. Recent tests have shown that most of the bolts are safe and Robinson-Leach said a final report on the bolts will be released at next Tuesday's meeting of the Metropolitan Transportation Commission's Toll Bridge
Program Oversight Committee, which oversees Bay Bridge construction.