Could protective barriers have prevented Baltimore bridge collapse?

The collapse of the Francis Scott Key Bridge in Baltimore on Tuesday has raised serious questions about what safety or protective mechanisms might have prevented the disaster and the loss of six lives.  

It is still unclear what caused a massive 985-foot long cargo vessel to apparently lose control and strike a pier, also known as a pylon, a critical part of the structure that keeps the deck of the bridge in place.

But could the bridge have been better protected to safeguard against a large vessel striking a key part of its infrastructure?

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The cargo ship Dali sits in the water after running into and collapsing the Francis Scott Key Bridge. Questions are being raised as to how much protection the bridge had. (Tasos Katopodis/Getty Images)

From 1960 to 2015, there were 35 major bridge collapses worldwide due to ship or barge collisions, with a total of 342 people killed, according to a 2018 report from the World Association for Waterborne Transport Infrastructure. 

Eighteen of those collapses happened in the U.S., including in 1980 when a 609-foot freighter slammed into the Sunshine Skyway Bridge in the Tampa Bay area of Florida.

The freighter, Summit Venture, was navigating through the narrow, winding shipping channel when a sudden, blinding squall knocked out the ship’s radar. The ship sheared off one of the bridge's supports, dropping a 1,400-foot section of concrete roadway into the water during the morning rush hour. 

Seven vehicles, including a bus with 26 aboard, fell 150 feet into the water. At least 35 people died.

Following the tragedy, a replacement bridge was constructed, and its piers were protected by several circular sheet pile cells known as dolphins. The protective infrastructure is also known as a fendering system. The area around the larger piers was also buffered with concrete and rocks for added protection, while the shipping lanes for vessels to pass through were widened. 

On April 29, 1987, the day before the new bridge was scheduled to open, the new bridge's protective bumpers were hit head-on by a 74-foot-long shrimp boat. The bumper sustained minor damage – but the bridge was not affected and was opened at a later date. The shrimp boat took on water and was towed out of the channel into shallow waters, where it sank.

The Sunshine Skyway Bridge in Tampa has several barriers in place for protection. (Thomas Bender/Herald-Tribune/USA Today Network)

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The Francis Scott Key Bridge, which was built in 1977, does not appear to have any protective barriers in place, and the pier that was struck was not surrounded by any barrier or buffer-like structures, according to photos and videos from the scene. There are some small circular-shaped structures in the water, but it is unclear if they are barriers that serve another purpose. A spokesperson for the National Transportation Safety Board (NTSB) did not respond to Fox News Digital's request for comment about whether the Baltimore bridge had a bumper system or protective barriers in place.

Ron Harichandran, Ph.D., dean of the Tagliatela College of Engineering in Connecticut, told Fox News Digital that protective barriers – if they were there – may not have been enough to stop the Dali, given its sheer size and weight. The Singapore-flagged container has dead weight tonnage, or total tonnage, of nearly 117,000 tons. 

"Most of those protections systems that they have directly around the pier would probably not have been able to protect this particular incident because of the size of the cargo ship and the weight," Harichandran said. "It was just too big."

"The only thing that might have worked is if they had sort of an island around the piers and that's not done often," Harichandran added. "It basically involves filling up an area of the river and building an island, so the ship would hit the island and not the pier. That's what you would have to do if you wanted that level of protection, but obviously, that's quite expensive."

"It should really have been done at the time the bridge is built and not retrofitting it," he added. 

The Francis Scott Key Bridge in Baltimore on May 7, 2017. A bridge support was struck by a container ship, causing a catastrophic collapse. (Rick Brady)

Jennifer Homendy, the chair of the National Transportation Safety Board, said at a Tuesday press briefing that protective structures would be a part of the investigation into the collapse of the Maryland bridge. 

"There’s some questions about the structure of the bridge – protective structure around the bridge or around the piers to make sure there isn’t a collapse," she said, responding to a reporter’s question. "We are aware of what a structure should have. Part of our investigation will be how was this bridge constructed? It will look at the structure itself. Should there be any sort of safety improvements? All of that will be part of our investigation."

At least six construction workers who were on the bridge at the time of its collapse are presumed dead at the time of this report.

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Harichandran said other more cost-effective systems can be used to alert bridge users.

"You could have trip wires and have more sophisticated warning sensors that would warn of approaching the bridge much earlier," Harichandran said.

"For those kinds of remote sensing approaches, you could potentially have given an earlier warning of a disaster that could have gotten people out of the way. I know there was a warning because of the radio call, and it helped stop traffic and so on but an earlier warning might have warned the authorities sooner," Harichandran added. "Think of a trip wire that is set up a mile before the bridge and if a ship is not to going the way it is supposed to it would set it off and warn people that something is amiss, and you could close the bridge."

The Associated Press contributed to this report.