Could the Baltimore Bridge Collapse Be Prevented?

A terrible accident in 1980 marked a before and after in the construction of bridges in the United States. On the morning of May 9 of that year, a 185-meter-long cargo ship collided with the Sunshine Skyway Bridge in Tampa, Florida. About 370 meters of the south span collapsed when dozens of vehicles passed through it. There were 35 deaths. The new Tampa bridge, like many others built since then, incorporated defenses to mitigate impacts and protect the piers. The Francis Scott Key in Baltimore, collapsed this week, however, had opened in 1977 and never incorporated adequate protections. The opinions of experts collected by EL PAÍS agree that this could have prevented the collapse of the bridge, which left six fatalities and an imposing economic bill. At the same time, authorities are investigating why the ship lost its way.

“Although events like this are extremely rare, I am surprised that a protection system was not built for this bridge,” Sherif El-Tawil, professor of Civil and Environmental Engineering at the University of Michigan, and an expert in disaster mitigation, tells EL PAÍS. natural and anthropogenic risks, due to earthquakes, explosions and other impacts. “The protection system would have diverted the ship from the piers, protected the bridge, protected the community from the loss of a critical bridge and protected the ship itself,” he explains.

The Francis Scott Key was the pride of the city. Immortalized in some episodes of

The Wire,

the cult HBO series that takes place in Baltimore, it was a lattice steel bridge, with elements joined in triangulations and an arch shape. It was the largest in the city, crossed the Patapsco River and was part of Route 695 and the metropolis's beltway. Its name honored the author of the lyrics of the ubiquitous American anthem,

The Star-Spangled Banner,

a local glory.

The main span, 366 meters, was the third longest in the world. The bridge had a total length of 2,632 meters and was used by almost 12 million vehicles annually, about 33,000 a day.

Since the bridge was built between 1972 and 1977, the size of ships has grown exponentially, according to logistics firm Allyn International. In 1980, the average capacity of freighters was 757 TEU (TEU is the measurement of a standard 20-foot container, 6.1 meters long). Today it has multiplied by six, up to more than 4,400 TEU. And the maximum capacity has gone from 2,961 TEU of

Liverpool Bay

to 24,346 TEU of

MSC Irina,

launched in 2023. There are at least 20 ships with more than 20,000 TEU capacity.

The ship that demolished the Baltimore bridge is almost 300 meters long and 48 meters wide. The capacity of the

Dali,

whose name honors the Spanish painter Salvador Dalí, is 9,971 standard containers, more than triple that of the largest ship at the time the bridge was built. “It is difficult to overstate the impact of this collision we are talking about. It's not just as big as a building. She is really as big as an apple. 100,000 tons all colliding with this pillar at the same time,” said Secretary of Transportation, Pete Buttigieg, at a press conference at the White House this Wednesday. She is about the size of an American Nimitz-class aircraft carrier.

The Singapore-flagged cargo ship cast off after midnight from Monday to Tuesday and embarked on what was going to be a 28-day journey to the port of Colombo, the capital of Sri Lanka, where it was due to arrive on April 22 on behalf of the Danish shipping company Maersk. Managed by two harbor pilots, she lost propulsion as she approached the bridge for unknown reasons and suffered a total blackout. Apparently, the emergency equipment was launched, but it also failed.

The tugs had only helped the ship maneuver at the exit, but had then left it to guide itself. That is another point that experts point out: if the tugboats accompanied the ship beyond the bridge, the accident could also have been avoided. The freighter was adrift for just five minutes, during which it deviated from its course, heading directly towards one of the two pillars of the bridge. The port pilots who were piloting it ordered the anchors to be dropped and declared an emergency by radio. The first did not serve to stop the ship. The second thing allowed traffic to be cut off before the collapse and probably saved dozens of lives.

The force of a rocket

When the freighter approached the bridge pillar, the die was cast. “The ship was so large that the flared bows came into contact with the pillars and applied an enormous load,” explains El-Tawil. “This caused the failure of one of the members of the A-frame pillars. The weight of the bridge caused the other pillar to collapse. Assuming a tonnage of 120,000 tons and a speed of 6-7 knots [between 11 and 13 kilometers per hour] for the ship, I estimate that the force applied is of the order of 30 million pounds, 130 million newtons,” he indicates. That far exceeds the launch force of a rocket. According to NASA, the Space Launch System with which

Artemis 1

was launched was designed to produce 39.1 million newtons of thrust at takeoff.

Roberto T. Leon, professor of Civil and Environmental Engineering at Virginia Tech, considers it unlikely that even a modern and well-designed protection system could have prevented serious damage to the structure due to that enormous momentum that the ship was carrying. “However, it could possibly have prevented the complete collapse,” he notes. “It is imperative that we update our design codes around the world for these types of events, low probability and high consequences, because container ships have become massive,” says Leon.

The Virginia Tech professor points out that structurally, the bridge was in very good condition, but that in general, in the United States, there are many infrastructures that are poorly maintained and are rarely updated to current codes, because priority is given to repairing the bridges. corroded and cracked bridges versus implementing protection systems.

View from a drone of the freighter 'Dali', which collided with the Francis Scott Key bridge causing its collapse, in Baltimore (Maryland). NTSB (via REUTERS)

Jose Adam, professor at the Universitat Politècnica de València, emphasizes that the usual thing is to protect the pillars or piles in cases of passable channels with a lot of traffic from heavy ships. “These piles were very close to the traversable part, and with inadequate protection,” he says, emphasizing that the problem was not with the bridge as such. “We cannot design bridges and buildings that withstand all types of extreme events such as vehicle impacts, terrorist attacks, explosions, etc. In many cases, it is advisable to move these infrastructures away from the action that could cause their collapse,” says Adam, a specialist in the protection of critical infrastructures.

The professor uses as an analogy what changed after the 9/11 attacks. They did not begin to design buildings resistant to the impact of airplanes, but the solution was to prevent them from being hijacked and crashed into the buildings through security controls, protected cockpits and other measures. “In my opinion, the new bridge should have the piers protected from ship impacts. There are two ways to do it: one, protecting them if they remain in the navigable zone, with breakwaters, protection islands, etc. And another, making a bridge with larger spans, that is, greater separation between piers, leaving the piers closer to the mainland where there can be no boat traffic,” he concludes.

The National Transportation Safety Board (NTSB) is investigating the causes of the Baltimore crash, including the lack of adequate guards. Inspectors have begun to check the condition of the ship, its safety systems and the condition of the crew. They also analyze the quality of the fuel, in case poor fuel had caused a power outage. They have a kind of black box that records the boat's data and radio conversations. The final report may take more than a year to be published.

“It's too early to speculate, of course, about what the NTSB will discover, but if they discover or determine anything that needs to be taken into account in the regulation, inspection, design or financing of bridges in the future, we will be prepared to apply those conclusions. Buttigieg noted.

Inspectors from the National Transportation Safety Board (NTSB) on the bridge of the freighter 'Dali', after the accident.PETER KNUDSON /NTSB/ HANDOUT (EFE)

Latin American victims

Vehicles were traveling on the Baltimore bridge until shortly before the impact. The emergency call

(mayday)

from the ship to the port and from the port to the traffic agents allowed the bridge to be closed. “A ship is approaching that has just lost its way, so until we control it, we have to stop all traffic,” an emergency manager told agents on the ground. One of them, in the radio exchange, warned: “There is a crew on the bridge.” It was too late.

The eight Latin American workers who were repairing potholes on the bridge road did not receive notice in time. Two of them survived the collapse. The bodies of two others were recovered from inside a vehicle that sank with the bridge: Mexican Alejandro Hernández Fuentes, 35, and Guatemalan, Dorlian Ronial Castillo Cabrera, 26. The bodies of the other four have not appeared: Honduran Maynor Suazo, 37 years old, married with two children; the Salvadoran Miguel Luna, aged, married with three children, who had lived in Maryland for more than 19 years, according to the CASA organization; the Guatemalan José López, 35 years old, and a Mexican whose identity has not been revealed.

In addition to the loss of human life, for Baltimore the collapse of the bridge causes significant emotional and economic damage. A landmark of the city is lost, but also an essential communication route, which was part of the city ring road. Some distances have gone from 5 to 45 minutes, and that is not counting the possible collapse of the tunnels that cross the river. Furthermore, trucks carrying fuel and other dangerous goods cannot circulate through them, which will make the detour even greater.

In the short term, the situation is even more serious, as the body of the bridge has created a kind of steel reef that blocks access to the port, the economic heart that keeps the city going. Its terminals handled 52.3 million tons of cargo valued at $80 billion (about €74 billion) last year, a record figure, as announced in February by Maryland Governor Wes Moore. It is the first port in the United States for imports and exports of automobiles and light trucks: around 850,000 vehicles pass through that port each year. Moore estimates that in addition to the 15,300 direct jobs, there are another 140,000 linked to port activities.

“The tragic collapse of a bridge near Baltimore this week has once again brought vulnerability to supply chain risks to the fore,” Oxford Economics analysts noted this week. “The extent of the possible repercussions will depend on the duration of the port disruption,” they added.

Hope now lies in the cranes. To clear the navigation channel of the mass of steel and concrete, several that are already being deployed in the area will be used, including one capable of lifting 1,000 tons. Divers must cut the debris to remove it in an operation reminiscent of the game of Mikado or chopsticks. If a piece is removed from the background prematurely, the whole thing can move.

Follow all the international information on

Facebook

and

X

, or in

our weekly newsletter

.

Subscribe to continue reading

Read without limits

Keep reading

I am already a subscriber

_