The dramatic footage of a huge cargo ship colliding with a bridge near Baltimore and causing it to collapse like a scene from a Hollywood disaster movie riveted people around the world Tuesday.
In the Bay Area, where dozens of large cargo ships, oil tankers, cruise ships and other vessels sail in and out of San Francisco Bay every week, the calamity raised the question: Could it happen here?
Ships have occasionally hit several of the eight major bridges that cross San Francisco Bay over the decades. But for a variety of reasons, the chances of a bridge collapsing are very low, experts said Tuesday.
“It would be ridiculous to say it could never happen here,” said Scott Humphrey, chairman of the San Francisco Bay Harbor Safety Committee, a state organization of industry, government, and nonprofit maritime organizations that meets monthly to improve shipping safety. “But it’s extremely unlikely that anything of that magnitude could happen here.”
All of the major bridges that cross San Francisco Bay, including the Bay Bridge and the Golden Gate Bridge, have concrete buffers, called fenders, that surround the columns supporting the bridge near the water line.
If a large ship loses power or steering and hits one, it glances off, said Bart Ney, a spokesman for Caltrans, which owns most of the bridges spanning the bay.
“The bridges are designed for it,” he said. “The strategy is that if you get a vessel that is going to collide with the bridge, you want to keep it from touching the bridge. All of our bridges have a robust fender system that are designed to absorb energy. The bridge does more damage to the ship than the ship does to the bridge.”
The Francis Scott Key Bridge in Baltimore did not have the same fender system, he said.
Further, the Bay Area is known for earthquakes. All of the major bridges across San Francisco Bay have undergone an extensive earthquake retrofits in the past 20 years, Ney said. They have been fitted with seismic dampening systems — joints that allow bridges to flex and move in earthquakes, along with huge hinges, and other features that not only help them survive earthquakes but avoid collapse in ship collisions, he said.
Khalid Mosalam, a professor of civil engineering at UC Berkeley, watched the video Tuesday of the Baltimore bridge collapse frame-by-frame.
“It’s a very classical mode of failure. It was breathtaking,” he said. “You study these things and learn about them and teach them to students, but you rarely see it happen, which is good thing.”
Many of California’s bridges are more resilient than bridges in other parts of the world, he added.
“Because of earthquake designs, the columns in West Coast bridges tend to be a lot stronger, a lot bigger,” he said. “If an accident like this happened here, I doubt it would lead to destruction like we saw in the video.”
But accidents do happen.
Last year, 2,874 large ships arrived and departed San Francisco Bay, sailing under the Golden Gate Bridge carrying everything from oil from Alaska to steel shipping containers full of electronics and clothes, according to the Marine Exchange of the San Francisco Bay Region, an organization that tracks ship movements. Expert harbor pilots board the ships and help them navigate when they are entering and leaving the Bay.
On Nov. 7, 2007, the 901-foot Cosco Busan, a cargo ship headed from Oakland to South Korea, sideswiped a Bay Bridge support column protected by a fender in dense morning fog.
The incident ripped a 211-foot-long gash in the ship and dumped 53,000 gallons of bunker fuel into the bay. No people were injured or killed, but the spill oiled 69 miles of shore. Roughly 6,800 birds were killed.
An investigation by the National Transportation Safety Board found that the ship’s pilot, John Cota, of Petaluma, had a “degraded cognitive performance from his use of impairing prescription medications.” Cota, the investigation concluded, had a history of alcohol abuse and prescriptions for at least nine medications for pain, depression and sleep disorders.
Other causes of the Cosco Busan incident included a lack of communication between Cota and the ship’s Chinese captain; inadequate crew training; and a failure by the Coast Guard to warn Cota by radio that he was heading for the bridge.
The bridge fender suffered only minor damage. The Bay Bridge itself was not damaged.
The Cosco Busan’s owner, Regal Stone Ltd., and its operator, Fleet Management Ltd., both of Hong Kong, paid $44 million to settle the civil case with state prosecutors.
Not long afterward, in 2013, another ship, the Overseas Reymar, a 748-foot-long oil tanker, struck the Bay Bridge in heavy fog. A state investigation found that the pilot, Capt. Guy Kleess of San Francisco, made a risky last-minute change in course and “lost awareness of what was happening around him.”
The oil tanker was empty, having offloaded its cargo at a refinery in Martinez the night before. No oil was spilled.
The accident caused $1.4 million in damage to the fender but did not structurally damage the bridge, Caltrans reported. The ship sustained $220,000 in damage.
After the incident, the harbor safety committee passed guidelines recommending large ships not sail under the Bay Bridge in heavy fog.
There are still some areas of concern. State law requires oil tankers to have tug boat escorts so they can be pushed away from danger if they lose power or steering. But tug boat escorts are not required for cargo ships moving in and out of San Francisco Bay. In 2004, following a series of Mercury News stories exposing the risk, state lawmakers passed a bill to require tug escorts for chemical tanker ships in San Francisco Bay, but Gov. Arnold Schwarzenegger vetoed the bill after the shipping industry raised cost concerns.
Early reports indicate that the ship in Baltimore reported it had lost power before colliding with the bridge. In April 2022, the Wan Hai 176, a 564-foot container ship, lost engine power and drifted seven miles off the coast of Point Reyes with 21 people aboard. It was intercepted by tug boats and towed into San Francisco Bay without incident. The Singapore-flagged vessel had more than 700 containers on board and 39,000 gallons of fuel.
“We have seen accidents in the Bay Area involving large ships in the past,” said Ben Eichenberg, an attorney with Baykeeper, an environmental group. “If a ship loses power, taking out a bridge isn’t the only disaster that can happen. It can run aground. It can leak oil. This Maryland accident should get us to review all of our safety procedures. There is going to be some soul searching here.”
Source: www.mercurynews.com