A year after the collapse of Baltimore’s Francis Scott Key Bridge, an independent agency urged owners of seven California bridges, including the iconic Golden Gate Bridge, to urgently assess the risk of a catastrophic collapse.
In a March 18 report, the National Road Safety Board identified a total of 68 bridges across the United States that have not received a recent ship traffic-based vulnerability assessment. Bridge said it had “an unknown level of risk of collapse due to a vessel collision.”
The report, part of an ongoing investigation into the collapse of the Baltimore Bridge, states that the bridge owners (all built on navigable waterways where marine aviation vessels are frequently visited) may not be aware of the risk of catastrophic collapse from bridge collisions, and there is a potential need to implement measures to reduce the vulnerability of Bridges.
Several California Bridge owners told the Times that assessments were already underway after the Baltimore Bridge collapsed.
The Golden Gate Bridge, Highways and Transportation District said in a statement that it “complies fully with all state and federal regulations, including federal bridge inspection and evaluation requirements,” with the iconic bridge having “one of the most robust ship collision protection systems for any bridge on the West Coast.”
Still, the district said it had hired consultants earlier this year to conduct an assessment of the bridge’s South Tower Fender System’s structural capabilities for ship collisions.
“The results of the study will be submitted to the Federal Highway Administration,” the district said.
Bay Area Toll Service spokesman John Goodwin said he managed all toll revenue from local toll bridges owned and operated by Cartlan, and that his agency began working with Caltrans and other groups last July and began evaluating vessels across the Bay, including waterways that include statewide fee benefits.
“I think it’s wise to assess the vulnerability of all bridges,” Goodwin said. “The risk of collapse is very small, but it’s not zero. There’s no false sense of security there…”
Most of the seven California bridges identified as potentially vulnerable are located in the Bay Area. Richmond San Rafael Bridge, Khakiness Bridge, Benicia Martinez Bridge, Antioch Bridge, San Mateo Hayward Bridge, and Golden Gate Bridge. The only thing in Southern California is the Coronado Bridge in San Diego.
Cartlan, which owns the Coronado Bridge, says the agency is considering recommendations in the report.
“All state-owned bridges were regularly inspected to ensure strict structure safety and seismically modified to the highest national standards,” a Caltrans spokesperson told CBS affiliate KFMB-TV in a statement. “Caltrans is considering recommendations for the National Transportation Safety Board and will respond to the request once the review is complete.”
The NTSB urged owners of seven California Bridges to conduct risk assessments based on guidance established by the US ASSN. More than 30 years ago, state highways and transport personnel, or Aashto.
If the bridge owner determines that the bridge has a high risk level, the agency recommended that it develop and implement a “comprehensive risk reduction plan” identifying short-term and long-term safety strategies.
Experts told the Times last year that California bridges are at a lower risk of collisions with false cargo ships than many bridges across the country.
Still, Robert Dowell, an associate professor of structural engineering at San Diego State University, said the collapse of Baltimore showed how important it is to protect the bridge pier from large container ships by keeping the bridge’s “dolf” completely transparent from the bridge by installing or upgrading large fenders and “dolfs” on the bridge.
“The impact forces from these very large vessels are enormous,” Dowell said. “When you see a large vessel that hits a bridge in Maryland, the top of the vessel leaves from below.
Thirty years after Aashto introduced the guidelines, Goodwin said that vessel traffic has increased both inside and outside the Bay Area, with much larger vessels increasing its waters.
San Francisco Oakland Bay Bridge, the busiest bridge in the Bay Area, has not been identified in the NTSB report. Goodwin said the bridge has already been evaluated and the bridge has been ruled out as a $100 million project will begin after July to replace and upgrade the bridge’s fender system.
Upgrading the Bay Bridge was a regional priority after being attacked by ships in 2007 and 2013, Goodwin said. In both cases, the fenders absorbed and deflected energy, but the 2007 collision damaged the fender and the ship due to a collision with an oil tanker, draining over 53,000 gallons of oil.
Goodwin said the next generation of Bay Bridge Fenders are built of rubber, allowing them to better absorb energy from ship strikes and protect the bridge and ship.
Still, Dowell said all bridges that were evaluated before the collapse of the Baltimore Bridge was reevaluated, even at Bay Bridge.
“You should look at each and every one of them,” he said. “If the assessment was done over a year ago, I’d go back double and look a little more because there was a lot of work done last year since the bridge collapsed in Maryland.”
The freighter Dali attacked Francis Scott Key Bridge in Baltimore on March 26, 2024. (Applications, Maryland National Guard via File)
(Credit/Applications)
On March 26, 2024, a 948-foot-long cargo ship left the port of Baltimore and plunged into the support pier at Francis Scott Key Bridge, losing power, almost immediately crushing the structure. In 25 seconds, the entire bridge plunged into the Patapsco River.
Six members of the construction crew were killed.
The NTSB found that, according to guidelines established by Aashto, the Baltimore Bridge is nearly 30 times above the acceptable risk threshold for important or essential bridges.
The Golden Gate Bridge was built in 1937, but the California bridge, which could be built in the 1950s, 1970s and 1950s, was issued in 1991 for the new bridge in response to an investigation into the collapse of the Sunshine Skyway Bridge in Florida.
In a March report, the NTSB urged the Federal Highways Agency to establish an interdisciplinary team with the U.S. Coast Guard and to establish an interdisciplinary team of the U.S. Army Corps of Engineers to help potentially vulnerable bridge owners assess and reduce the risk of collapse.
The Federal Highways Administration and AASHTO cannot require ship owners to assess the risk of catastrophic failure of the bridge if designed prior to the 1991 guidelines being issued.
The NTSB said in a news release that Aashto recommended it again in 1991 and then in 2009, although the existing bridges were not required to carry out vulnerability assessments. All bridge owners will conduct such assessments on existing bridges to assess the risk of catastrophic collapse.
If the Maryland Department of Transportation, which did not require a vulnerability assessment to assess the Francis Scott Key Bridge, had made such an assessment based on recent vessel traffic, the NTSB said the state agency would have recognized that the bridge exceeded acceptable risks and could take steps to prevent the risk of bridge collapse and death.
Dowell said that an old bridge should be evaluated and upgraded if necessary.
“I think they should be necessary for a detailed assessment,” Dowell said. “And if you follow the laid out procedures and get an evaluation, we will show you[s] That upgrade must or should be done. If you do that, I think you need to do that. ”
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