The 7 bridges in the US that are at risk of a Baltimore

Release time：2024-05-21 07:09:35 Source：Earth Enquirer news portal

There are at least seven bridges in the US with similar size and reach of Baltimore's now-collapsed Francis Scott Key Bridge, making them vulnerable to a similar future tragedy, according to the latest federal data. 

The Federal Highway Administration's (FHA) National Bridge Inventory for 2023 identified several iconic bridges that contain 'fracture critical members,' which means damage to just one steel component could collapse the entire structure.

Household names like San Francisco's Golden Gate and New York's Verrazzano are among those on the list, as was Oregon's lesser known St. John's Bridge.

Taken together, the seven bridges are responsible for motorist lives inside approximately 794,000 passing vehicles each day.

More worrisome still, these seven bridges are all supported by concrete island towers, or 'piers,' vulnerable to the kind of shipping vessel impact that felled the Key.

But, to build bridge 'piers' strong enough to withstand a blow from such a container ship, as one senior civil engineer told DailyMail.com last week, 'You'll end up just building a castle in the middle of the river.' 

Seven bridges with the size and reach of Baltimore's now collapsed Francis Scott Key Bridge are vulnerable to a similar future tragedy, according to the latest data from the US Federal Highway Administration. All seven (pictured above) are older than the Key bridge

First completed during the Great Depression, the San Francisco–Oakland Bay Bridge (above) actually managed to withstand a collision with a container ship in 2007. But this bridge, unlike Baltimore's Francis Scott Key Bridge, had fenders in place to absorb the strikes

Engineer Bilal Ayyub, the former chair of the American Society of Civil Engineers' Infrastructure Resilience Division, explained that the alternative safety solution is to create barriers that keep ships coming near a bridge in the first place.

'You cannot design a bridge to withstand the energy that comes with a moving object as large as a barge,' Ayyub told DailyMail.com.

Instead, the former chair said, engineers construct steel guiderail-like systems, called 'fenders,' around piers, or redirect ships away from those crucial piers by dredging man-made 'islands' into existence around the structure. 

'Basically, what they will do is they will make the ground [underwater] elevate higher so that a ship will be grounded,' he explained. 'It was designed to basically alert the operator that you know you're approaching an object.'

While federal guidelines in place today mandate safeguards like these 'fenders.' 'islands,' or slightly more distant man-made island barriers, dubbed 'dolphins,' the seven at-risk bridges predate those government rules.

A Wall Street Journal analysis of the FHA's National Bridge Inventory identified these seven bridges as being being similar in size and construction to the Key to merit comparison. 

And many are local, and sometimes international, icons of their home city.

But inconsistencies have been found in the inventory's inspection data, which could mean there are other US bridges that face similar risks.

The over four-mile-long Chesapeake Bay Bridge (above), which like the Key is in Maryland , is currently being eyed for a multi-billion-dollar expansion in advance of traffic worries

The over four-mile-long Chesapeake Bay Bridge, which like the Key is in Maryland, is currently being eyed for a multi-billion-dollar expansion in advance of traffic worries.

The Chesapeake sees about 72,000 vehicles cross it daily, per 2016 toll data, and also has large container ships pass underneath it.

Most of the at-risk bridges are located in the Pacific northwest, including the Tacoma Narrows Bridge, Washington; the St. Johns Bridge, Oregon; and the Lewis and Clark Bridge, which connects Oregon to Washington state.

These bridges are also main traffic arteries that see tens of thousands of vehicles each day: over 90,000 vehicles for Tacoma Narrows, more than 22,000 vehicles per on St. Johns, and roughly 21,400 vehicles travel across the Lewis and Clark.

Roughly 21,400 vehicles across the Lewis and Clark bridge (above) between Washington state and Oregon each day

Each day, the Golden Gate helped an average of 89,000 vehicles cross the strait between the Pacific Ocean and the bay, and as much as 10,000 cyclists, in 2023.

A little ways down south in the San Francisco Bay area there are two more thoroughfares, including the iconic Golden Gate Bridge, which meet the size and 'pier' design parameters for risk. 

One, the San Francisco-Oakland Bay Bridge, is responsible for supporting as many as 280,000 to 300,000 commuter vehicles per day, or above 13,000 automobiles during a peak traffic hour.

First completed during the Great Depression, November 1936, the San Francisco–Oakland Bay Bridge actually managed to withstand a collision with a container ship in 2007.

But that bridge, despite its age, did have a fenders in place to absorb the strikes.

Similarly, the Golden Gate Bridge in has been also been fortified with 'the most robust protection system of any bridge on the West Coast,' a spokesperson for the state agency that manages the structure declared to SFGate last month.

The Golden Gate helped an average of 89,000 vehicles cross the strait between the Pacific Ocean and the bay, and as much as 10,000 cyclists, each day in 2023. 

But as experts noted, Baltimore's Key bridge had passed all of its inspections — a strong indication that massive shipping vessels like the 984-foot, 95,000-ton Dali, which destroyed the Key on March 26, could wreck even an 'up to code' bridge.

New York City's Verrazzano-Narrows Bridge was the seventh of the large, at-risk bridges identified in the Journal's analysis.

The structure, which connects the boroughs of Brooklyn to Staten Island averages approximately 200,000 vehicles in traffic daily, according to the parks department.

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