Old Bay Bridge Pier Imploded With Hundreds Of Underwater Explosive Charges
SAN FRANCISCO (CBS SF) -- Caltrans demolished the largest remaining pier of the old Bay Bridge's eastern span Saturday morning using nearly 600 explosive charges over a period of roughly six seconds.
"Everything went according to plan that we are aware of right now," said Leah Robinson-Leach, a Bay Bridge spokesperson, in an interview with KPIX 5's Mark Kelly shortly after the detonation.
The underwater demolition of Pier E3 took place around 7:15 a.m. in San Francisco Bay. Technicians deployed a blast-attenuation system or "bubble curtain" to reduce the impact of the explosions in the surrounding waters by an estimated 80 percent, according to Caltrans officials.
Engineers will be collecting data in the vicinity of the pier's implosion to determine the procedure's impact on the environment and nearby wildlife. That information will be used to choose the best method of demolition for the bridge's remaining piers, according to Brian Maroney, a chief bridge engineer with Caltrans.
"We will get information from that data," Robinson-Leach said. "We don't have it this quickly," she added.
Caltrans may seek approval to implode some or all of the old eastern span's remaining 21 piers, according to the agency.
Traffic was briefly halted on the Bay Bridge during the demolition, and BART trains were temporarily stopped from passing through the Transbay Tube.
November was chosen for the implosion because that's when there is the least impact on fish and mammals because many species, such salmon, herring and nesting birds aren't around, according to Caltrans officials.
Although some fish species were likely killed during the implosion, officials with the San Francisco Bay Conservation and Development Commission said the brief blast would cause less environmental damage than other methods of demolishing the pier.
The explosion may have been successful but it left some onlookers on Treasure Island unsatisfied. The Vides family awoke at 4 a.m. to get a good view but after the event they were as subdued as the placid bay waters.
"I thought it would be bigger. I thought I was going to see something come down," Romeo Vides said, and Blanca Vides agreed.
"I thought it would be more. I mean, it was okay," she said.
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