Cargo Ships Keep Getting Bigger, and Infrastructure Is Racing to Keep Up

A massive container ship hit Baltimore’s Francis Scott Key Bridge this week, calling attention to the demands that ever-growing shipping vessels are placing on ports, canals and bridges

a large container ship in a river with ruins of a truss bridge on top of it
The container ship Dali hit Baltimore's Francis Scott Key Bridge on March 26, 2024, causing the entire structure to fall within seconds. Kena Betancur / Getty Images

Early Tuesday morning, a cargo ship lost power and crashed into the Francis Scott Key Bridge, a 47-year-old interstate transportation route over the Port of Baltimore. In a matter of seconds, the entire structure collapsed into the Patapsco River.

The enormous ship was Dali, a nearly 1,000-foot-long and 160-foot-wide vessel that was headed to Sri Lanka. When the ship lost power, its crew sent a distress signal to shore, allowing officials time to stop traffic on the bridge and save lives during the ensuing crash.

Baltimore’s bridge was “up to code” for when it was built in 1977, but experts have noted that massive vessels like Dali would not have existed when the bridge first opened. The size of container ships has ballooned over the last half century, and the nation’s infrastructure is now racing to keep up.

“Worldwide, bigger ships means that when you have an incident, the negatives that come out of that incident are often expanded,” retired Rear Admiral Stash Pelkowski of SUNY Maritime College tells E&E News’ Francisco “A.J.” Camacho.

Despite its seemingly large scale, Dali is an average-sized container ship. It can carry 10,000 TEUs, or 20-foot equivalent units, the global measure of a ship’s container capacity. The term derives from the standard 20-foot containers used to transport cargo.

For comparison, Philadelphia welcomed the largest vessel to visit the East Coast on March 8: the CMA CGM Marco Polo, which has a container capacity of 16,000 TEUs. And the world’s largest container ship, the MSC Irina, is more than 1,300 feet long and 200 feet wide, with a capacity of 24,000 TEUs.

Aligned end-to-end, the Dali, Marco Polo and Irina would equal the length of ten football fields. But cargo ships did not always look like the monster vessels of today.

In April 1956, the first commercially successful container ship set sail from Newark to Houston: Called the SS Ideal X, it was a modest size—a 524-foot-long and 30-foot-wide vessel with a cargo capacity of approximately 800 TEUs. North Carolina businessman and trucking magnate Malcom McLean created the ship by fitting a former World War II T2 tanker with equipment to carry containers on deck. He saw it as a significant opportunity to improve long-distance trade and shipping. Immediately, the Ideal X became a more cost- and time-efficient choice, and port equipment such as cranes scaled to meet its size.

a long container ship
The SS Ideal X had a similar structure to the T2 tanker pictured here from August 1943. U.S. Navy via Wikimedia Commons

Then, the race to construct increasingly larger ships began. With each passing decade, the size of cargo ships grew substantially. In less than 70 years—from the very first cargo ship to today’s largest—the vessels have ballooned in cargo capacity by 2,900 percent.

As ships enlarged, infrastructure developed to keep pace with their demands. Ports that expanded their facilities and equipment were often rewarded with economic success. For example, the Port of Seattle bought into the container ship revolution in the mid-20th century, with investments in containers, cranes and a redesign of its terminals. At the time, the decision was risky; cargo ships were still fairly new to the maritime shipping industry. But, partly due to its infrastructure modifications, the port experienced “steady increases in trade volume beginning in 1963 and continuing through the 1970s,” wrote HistoryLink’s Kit Oldham in 2020.

Today, as this race for scale continues, infrastructure is often playing catch-up. Port and civil structures are usually constructed for a lifespan of over 50 years, while that number is only 20 to 30 years for a ship, says Thomas McKenney, an expert in naval architecture and marine engineering at the University of Michigan, to Smithsonian magazine.

“By the nature of their engineering system, you always have this gap in lifetimes that needs to be considered,” McKenney says. “Which means that, to some degree, there will always be some lag between ship size and next versions of port and bridge infrastructure.”

Larger ships don’t necessarily translate to more accidents, but this week, Dali’s size enabled its forward momentum toward the Key Bridge’s support pillar. Before the crash, the ship’s pilot ordered crews to drop its anchor, but Dali continued advancing, dragging the anchor along with it.

Experts say the Key Bridge had no chance of surviving the Dali impact, but a lack of modifications to accommodate today’s container ships may have put the structure at a higher risk of disaster.

“Despite meeting regulatory design and safety standards of the 1970s, the Baltimore Key Bridge may not have been equipped to handle the scale of ship movements seen today,” Toby Mottram, an emeritus engineer at the University of Warwick in England, says in a statement from the Science Media Center.

Similar concerns emerged in 2021, when the Suez Canal was blocked for almost a week by the Ever Given, a container ship with a capacity of around 20,000 TEUs. In response, the Suez Canal Authority announced it would widen and deepen the canal to prevent such a crisis in the future.

Companies and governments overseeing other waterways, too, are under pressure to expand port infrastructure and equipment to accommodate bigger ships—or risk losing business.

In 2016, the Panama Canal finished its largest-ever expansion, a $5 billion operation that doubled its cargo capacity. The Port Authority of New York and New Jersey finished a $1.6 billion project in 2017, which raised the Bayonne Bridge roadway by 64 feet to accommodate larger ships passing below. Across the United States, many other waterways have completed or are planning dredging projects to accommodate today’s cargo ships.

Bayonne Bridge Construction Time-Lapse

Although infrastructure challenges persist worldwide, cargo ships may continue to grow. “From a design perspective, there’s kind of no [ship size] ceiling that you could see,” McKenney says. “But on the port side, they need to do their own assessments of the types of ships that are coming in and out and the ability to accept them.”

Today, about 90 percent of globally traded goods are carried across oceans, and maritime trade volumes are set to triple by 2050 as demand increases. With these trends showing no signs of abating, the race for infrastructure to accommodate the evolution of cargo ships appears far from over.

“Improved resilience should be on everyone’s mind as aging infrastructure is rebuilt,” Rick Geddes, an infrastructure policy expert at Cornell University, tells the Guardian’s Oliver Milman. “Enhanced protection against ship-bridge collisions will certainly become more salient.”

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