Experts weigh likelihood of Bay Area bridge failure similar to Baltimore
OAKLAND, Calif. - The catastrophic collapse of a major bridge in Baltimore has drawn attention to the structural integrity of Bay Area bridges and the potential for a similar incident locally.
Early Tuesday morning in Baltimore, a cargo ship lost power and collided with the Francis Scott Key Bridge, causing it to collapse into the river within moments.
Experts said that a similar incident could happen in the Bay Area, where the protection of the region's bridges has been somewhat compromised by the presence of mega-ships that ply the ocean's shipping lanes and ports.
See it: Satellite images show Baltimore bridge before and after collapse
Maxar satellite images show the Francis Scott Key Bridge above the Patapsco River taken before the devastating crash. Photos taken around noon on Tuesday show the container ship under parts of the collapsed bridge and the search efforts underway around the crash site.
In 2013, the 751-foot-long Overseas Reymar, an empty oil tanker, brushed against the fender bumpers of one of the Bay Bridge's western span towers. Similarly, in 2007, the 902-foot-long Cosco Busan, a container ship, also made contact with the bridge.
The hard, but glancing blows to the fender system at the tower bases kept the ships from damaging the bridge towers.
Bart Ney, a spokesperson for Caltrans, the agency responsible for the bridge, said, "All of our bridge columns are surrounded by extremely robust protection systems that absorb the energy of the ship before it can actually touch the bridge. Our fenders actually do more damage to the ship than the ship has done to the bridge in the past."
However, unlike the situation in Baltimore, neither of the Bay Area collisions directly struck a tower.
Retired UC Berkeley engineering professor and consultant Robert Bea disagrees with Caltrans, suggesting that Bay bridges would face similar risks.
"Our Bay bridges would be in the same trouble," said Bea.
He said if a vessel was to hit a Bay Area bridge while moving at 7 to 8 knots, the same speed the Baltimore ship was at when it struck the Francis Scott Key Bridge, it could cause serious damage.
"Either failure or near failure," he said.
Caltrans adds that Bay bridges are fortified to withstand earthquakes.
"The seismic systems would also dampen some of the impact," said Ney.
Internationally renowned earthquake engineer Peter Yanev recognizes the differences in earthquake loads but suggests that the increasing size of modern ships necessitates a reevaluation of bridge protection measures.
"What has changed to change our protection?," asked Yanev.