Old bridge bumper technology means future oil spills likely
By: John Upton
November 5, 2009
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| The Cosco Busan collision destroyed the bumper on one of the towers of the Bay Bridge. The new bumper cost Caltrans $1.5 million to fix. |
SAN FRANCISCO — Two years after a rigid bumper system on a Bay Bridge tower ripped open two fuel tanks of a wayward cargo ship, the dangerously outdated technology remains in use.
After the Cosco Busan crashed into the Bay Bridge and spilled 54,000 gallons of oil Nov. 7, 2007, the damaged bumper system — which is in place to protect the span’s towers from ships — was rebuilt with the same 1930s technology, despite newer designs being available.
The section of bridge currently under construction will also incorporate the antiquated designs.
The bar pilot steering the Cosco Busan two years ago mistakenly guided the container ship through heavy fog toward a tower of the Bay Bridge instead of through the passage between towers. The vessel avoided directly striking the bridge section, but the bumper system in place to protect the concrete tower gouged an 8-foot-deep, 212-foot-long gash in its hull during the collision.
It was through that massive opening that the 54,000 gallons of toxic bunker fuel gushed into the Bay, causing an environmental disaster.
The spill killed wildlife — including plants, fish eggs, birds and seals — and led to commercial fishing seasons being canceled the following two years.
Such collisions are rare, but they are seemingly inevitable: It was at least the seventh time that a Bay Bridge tower has been struck in 50 years, according to the National Transportation Safety Board. A tugboat, a barge, a ship and a small military seaplane are among vehicles that have collided with a tower.
In the 1930s, fenders were incorporated into the Bay Bridge — which was designed by Caltrans predecessor California Department of Public Works — to protect it from collisions, but they were not designed to protect fuel-carrying ships that might bang into them.
The bumper system crumpled during the Cosco Busan accident, as it was designed to do, and it was rebuilt by Caltrans at a cost of $1.5 million. But newer technology that has prevented Cosco Busan-type oil spills was not used.
Modern bridge bumper systems are designed like modern car bumpers, to absorb and dissipate energy from a collision to minimize damage to a bridge and to a ship. The old style of bumpers simply provide a buffer to protect a bridge tower.
Modern bumper technology is widely credited with averting an oil spill in Maine and minimizing a spill in Boston Harbor.
In September 1996, 170,000 gallons of oil spilled into the waters off Maine after the Julie M, a 560-foot oil tanker, crashed into a bridge.
The span was later replaced with the $130 million Casco Bay Bridge, which was built using $7 million worth of modern fenders that were credited with averting an oil spill in 2002, after they absorbed a blow from an oil tanker, Maine Department of Transportation Senior Engineer John Buxton told industry magazine Professional Mariner following the collision.
The Casco Bay Bridge bumper system is surrounded by gravel- and sand-filled pillars, some as wide as 60 feet, that are attached to the channel floor and coated with slippery plastic to redirect a ship and absorb its energy without necessarily stopping it. The final line of defense is heavy-duty rubber surrounding the bridge’s towers.
Despite evidence that modern bumper systems could help prevent a future oil spill in San Francisco Bay, the western span of the Bay Bridge will retain the 1930s-era bumpers, according to Caltrans spokesman Bart Ney.
Bumpers on the new eastern span will also follow the same general design that was used on the western span, 2003 bid documents show.
Ney said bumper systems exist that are designed to better protect ships, but Caltrans hasn’t made any decisions to redesign the Bay Bridge bumpers, which engineers call fenders.
“Our current fender system adequately protects the bridge,” he said.
The old-fashioned design of the bumper systems has been criticized by UC Berkeley engineering professor Abdolhassan Astaneh-Asl.
“If a ship hits this bridge and spills oil in the Bay, Caltrans should be taken to court,” he said.
SF pilots lack modern tools to navigate, but that’s changing
Capt. John Cota sits in a federal prison in Tucson, Ariz., for his role in the Cosco Busan spill, but his hitherto colleagues are using new equipment that could have prevented such disasters.
The Petaluma bar pilot, who directed the Cosco Busan into the Bay Bridge in 2007, was sentenced to 10 months in prison after he pleaded guilty to a pair of environmental misdemeanors stemming from the resulting oil spill.
Cota became the nation’s first bar pilot incarcerated for negligently performing his duties. He reported to the Federal Bureau of Prisons last month.
The shipping accident occurred when Cota became disorientated in heavy fog while using onboard navigational equipment, the National Transportation Safety Board said in its findings.
Bar pilots in other harbors carry laptops with all the necessary navigational equipment, but those in San Francisco have traditionally relied solely on the navigational equipment.
Cota abandoned the Cosco Busan’s working radar after it appeared to him to grow distorted, and he directed the ship toward a bridge tower after mistaking symbols on an electronic map for a safe passage space, according to the federal safety agency, which blamed Cota’s use of mind-altering pharmaceuticals for his confusion.
Cota had not previously piloted the Cosco Busan, and his attorney argued that the unfamiliar equipment was confusing and rendered the ship nonseaworthy.
Since mid-2008, the members of the San Francisco Bar Pilots Association have been supplied with and trained on laptops that are equipped with GPS mapping and other navigational software, according to Capt. Peter McIsaac, president of the association.
And recently, the financial burden of the equipment was shifted off the shoulders of the bar pilots. Legislation authored by Sen. Leland Yee, D-San Francisco/San Mateo, to tax shipping companies to provide funds for laptop-based navigational equipment and training for San Francisco’s bar pilots was signed last month by Gov. Arnold Schwarzenegger.
“The Cosco Busan oil spill was devastating for our region and reiterated the need to improve the response to future disasters and to develop the technology to avoid them in the first place,” Yee said in a statement.
Additionally, the San Francisco Bar Pilots Association established a committee after the Cosco Busan spill to ensure pilots use the best technology available, according to McIsaac.
Pleas for brighter-colored bumpers fall on deaf ears
Black plastic pieces that broke off the damaged bumper after the Cosco Busan struck a tower of the Bay Bridge were hazards for ships in San Francisco Bay, but pleas to make the bumpers easier to spot after future accidents have been ignored.
Several pieces of black plastic weighing 15 tons each that were torn from the bumper system during the Cosco Busan collision floated several inches beneath the water, making the navigational hazards difficult for authorities to locate.
One of the pieces, a 20-foot chunk of metal-encrusted plastic, drifted out through the heavily trafficked Golden Gate before floating 20 miles south to Half Moon Bay, where it washed up on a remote stretch of Redondo Beach.
The Army Corps of Engineers, which is responsible for salvaging floating debris in the Bay, appealed publicly after the crash for brighter colors to be incorporated into the replaced bumper system to make the plastic easier to locate following accidents.
Caltrans has so far ignored those pleas.
Bar pilot rules
Changes affecting San Francisco bar pilots implemented after the Cosco Busan spill:
- Use of personal laptops with standardized electronic navigation software mandated to help pinpoint a vessel’s location without relying on onboard devices
- Shipping movements restricted in critical maneuvering areas when visibility falls to less than half a mile
- Third-party medical review and drug testing procedures implemented
- Increased oversight of pilots’ medical fitness instituted by the Board of Pilot Commissioners
- Internal training curriculum committee established to ensure use of the best technology available
Source: San Francisco Bar Pilots Association
Details of the spill
Environmental toll of the Cosco Busan crash:
2,525 Birds killed by the oil spill and recovered by authorities
418 Oil-covered birds rescued and rehabilitated
52 Miles of sandy beach coastline covered in oil
10 Miles of salt marsh coastline covered in oil
54,000 Gallons of fuel spilled
20,000 Gallons of oil recovered from water*
* Doesn’t include oil recovered from shorelines
Sources: Natural Resource Damage Assessment and Restoration Planning for the Cosco Busan Oil Spill (October update), Coast Guard
jupton@sfexaminer.com
Examiner Staff Writer Tamara Barak Aparton contributed to this report.
