Examiner Editorial: Bay Bridge bumpers are oil-spill booby traps
November 8, 2009
It has now been two years since the rigid, 1930s-technology protective bumpers around a Bay Bridge tower gouged open two fuel tanks on a container ship that spilled 54,000 gallons of toxic oil into the Bay. That Nov. 7, 2007, Cosco Busan environmental disaster demonstrated how the Bay Bridge bumper system is an oil-spill booby trap waiting to happen. But since then, precisely nothing been has done toward upgrading the bumpers into one of today’s safer new designs.
Caltrans has no future improvements planned either. The bumper system that crumpled by design during the Cosco Busan collision was rebuilt the same way for $1.5 million. Even the replacement eastern span — still under construction 20 years after the Loma Prieta earthquake — will use that same outmoded design concept.
At least seven times in 50 years a Bay Bridge tower has been hit. A tugboat, a barge, a ship and even a small military seaplane are among the vehicles that crashed into a tower.
Bumpers added around the towers after the Bay Bridge opened in 1936 were intended to simply be a buffer protecting the bridge structure. Back then, nobody seemed to think about trying to protect the hulls of ships that might strike the towers and foul the Bay with sticky oil.
Today we know better. Modern bridge bumper systems are designed like modern car fenders. They flex to absorb and dissipate collision energy, which minimizes all damage. This technology is widely credited with averting a major spill in Maine seven years ago and minimizing a Boston Harbor spill.
Maine’s $130 million Casco Bay Bridge replaced an earlier span where 170,000 gallons of oil — three times as much as from the Cosco Busan — spilled during a 1996 bridge crash. The new bridge had $7 million worth of contemporary bumpers that experts credit with averting another 2002 oil spill by safely absorbing an oil tanker’s impact.
Compared to the hundreds of millions in cost overruns for the long-delayed Bay Bridge rebuild of the eastern span, something like $7 million to install the latest bumpers would seem a bargain ecological safeguard. The improved technology is no rocket science. It consists of flexible pillars filled with gravel and sand, backed by heavy-duty rubber and coated with slippery plastic that slides a ship away from breakage.
The Cosco Busan spill killed some 2,500 birds, coated 52 miles of coastline with toxic gunk, cost millions of dollars to clean up and canceled the commercial fishing seasons for the next two years. Busy shipping traffic keeps our irreplaceable San Francisco Bay at high risk of oil spills that would inflict major economic and ecological losses.
Caltrans must use common sense and lower the risk of future Cosco Busan bridge-crash oil spills by investing in proven bumper safety improvements now.
