- Seven US bridges face Baltimore-like collapse risk
- Bridges include Golden Gate, Verrazzano; pose major safety concern
- Preventive measures crucial; existing regulations may be insufficient
The most recent federal data indicates that at least seven bridges in the United States share comparable dimensions and height to the now-demolished Francis Scott Key Bridge in Baltimore; thus, they, too, are susceptible to a similar catastrophe in the future.
The National Bridge Inventory for 2023, conducted by the Federal Highway Administration (FHA), identified several renowned bridges that comprise “fracture critical members,” or sections of steel where even a single point failure could result in the structure’s total collapse.
The list included well-known structures such as the Golden Gate in San Francisco, the Verrazzano in New York, and the less-recognized St. John’s Bridge in Oregon.
The seven bridges account for an estimated 794,000 daily fatalities among passing vehicles.
Moreover, these seven bridges are all supported by piers, concrete island structures susceptible to the same shipping vessel impact that destroyed the Key.
However, to construct bridge “piers” robust enough to endure the impact of such a container ship, a senior civil engineer stated, “You’ll be constructing a castle in the middle of the river.”
Former chair of the Infrastructure Resilience Division of the American Society of Civil Engineers, Engineer Bilal Ayyub, explained that the alternative safety solution is constructing barriers that prevent ships from approaching a bridge.
Ayyub said, “You cannot design a bridge to withstand the energy associated with a moving object as large as a barge.”
Engineers instead construct steel guide rail-like systems, known as ‘fenders,’ around piers or divert ships away from those vital piers by excavating artificial ‘islands’ around the structure, according to the former chair.
He described the plan: “Essentially, they will raise the submerged ground to the point where a ship is grounded.” “Its primary function was to notify the operator that an object is approaching.”
Although current federal regulations require protective measures such as these “islands” or artificial island barriers called “dolphins,” which are considered “fenders” or “offender” structures, the seven bridges that are in jeopardy predate those governmental regulations.
According to an analysis by The Wall Street Journal of the FHA’s National Bridge Inventory, these seven bridges are comparable to the Key to Merit comparison in dimensions and construction.
And many are sometimes national and sometimes global symbols of their hometown.
However, inconsistencies in the inventory inspection data may indicate that other bridges in the United States are exposed to comparable dangers.
Like the Key, located in Maryland, the Chesapeake Bay Bridge, which spans more than four miles, is presently the subject of consideration for a multibillion-dollar expansion to alleviate traffic concerns.
According to toll data from 2016, the Chesapeake is traversed daily by about 72,000 vehicles, and large container ships pass beneath it.
The majority of bridges in jeopardy are situated in the Pacific Northwest. Among these are the Lewis and Clark Bridge, which connects the states of Oregon and Washington, the Tacoma Narrows Bridge in Washington, and the St. Johns Bridge in Oregon.
Daily, tens of thousands of vehicles traverse these bridges; the Tacoma Narrows Bridge sees over 90,000 vehicles, the St. Johns Bridge has more than 22,000 vehicles, and the Lewis and Clark Bridge has approximately 21,400.
Two additional thoroughfares in the San Francisco Bay area, situated slightly to the south, include the renowned Golden Gate Bridge. These thoroughfares satisfy the risk criteria of magnitude and ‘pier’ design.
One such bridge, the San Francisco-Oakland Bay Bridge, accommodates over 13,000 automobiles during rush hour and between 280,000 and 300,000 commuter vehicles daily.
Constructed in November 1936, marked by the Great Depression, the San Francisco–Oakland Bay Bridge withstood a container ship collision in 2007.
However, notwithstanding its age, that bridge was equipped with fenders to mitigate the impacts.
An official from the state agency overseeing the structure informed SFGate last month that the Golden Gate Bridge has also been reinforced with “the most comprehensive protection system of any bridge on the West Coast.”
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Daily, up to 10,000 cyclists and an average of 89,000 vehicles traversed the strait between the Pacific Ocean and the estuary with the assistance of the Golden Gate in 2023.
However, experts observed that the Key Bridge in Baltimore had completed all inspections. This starkly contrasts with the Key, which was destroyed on March 26 by the 95,000-ton Dali, a 984-foot-tall shipping vessel that demolished an ‘up to code’ bridge.
The Journal designated the Verrazzano-Narrows Bridge in New York City as the seventh significant bridge at risk.
According to the parks department, daily traffic on the structure linking the Brooklyn and Staten Island municipalities is around 200,000 vehicles.
