What happened to the bridge in Baltimore?

Could the Baltimore bridge disaster have been prevented? What happens when a ship’s generators fail?

The story so far:

n March 26, a container vessel ran into the pillar of a bridge on the Patapsco River in Baltimore, bringing a part of the structure crashing down together with some people and cars on the bridge. By late March 27, the U.S. Coast Guard had concluded its search in the river for the bodies of the six people who fell. The vessel had an allIndian crew.

OWhat is the timeline of events?

After departing from the port of Baltimore at 12.28 a.m. local time, the 300metrelong vessel Dali was headed for Colombo, Sri Lanka, with several containers of oil and some hazardous material. Less than an hour after its departure, people nearby reported the Dali’s lights flickering. Two minutes later, the ship’s course also started to angle towards two of the bridge’s pillars in the river. At 1.27 a.m. local time, the Dali mowed into the pillar and brought down a segment of the bridge.

A U.S. Coast Guard report said, the Dali’s crew had broadcast a mayday signal seeking help to control the vessel. This signal alerted the Coast Guard as well as prompted local authorities to close the bridge for further traffic. A part of the bridge’s superstructure also fell on the vessel, smashing some containers and leaving them balanced precariously on the vessel.

Maryland governor Wes Moore later declared a state of emergency. With inputs from the Federal Bureau of Investigation, federal officials had by March 28 also virtually ruled out deliberate intent to cause the collision. The Dali belongs to the Danish shipping giant Maersk and flies a Singapore flag. It is managed by the Synergy Marine Group, headed by Rajesh Unni.

What were the casualties?

The Synergy Marine Group said in statements that all crew members were safe.

The bridge’s collapse dropped eight people through 50 feet into the Patapsco River. While two people were fished out soon after, the Coast Guard postponed the search for the other six because of the river’s depth, temperature, lack of light, the presence of sharp objects in the water, and the risk of more parts of the bridge and/or the containers falling in.

Rear Admiral Shannon Gilreath told reporters on March 28 that the team no longer expected to find the six people alive.

What happened to the ship?

The Dali is propelled by a ninecylinder twostroke diesel engine. In the twostroke cycle, fuel is pumped into the combustion chamber, where a spark plug causes the fuelair mixture to explode. The energy release pushes a piston up, rotating the crankshaft. The explosion’s residue (exhaust) is then pumped out of the engine to bring the piston down in the second stroke. Once the engine transfers mechanical power to the crankshaft, it can be further transferred to the propeller directly, via a gearbox or electric motors. It is also coupled with an alternator that converts the mechanical power to electric to supply appliances on the vessel, including lighting. The Coast Guard recorded a statement that at least one of Dali’s engines “coughed” and that “the smell of burned fuel was everywhere in the engine room”, suggesting the vessel’s engine failed. In this scenario, the vessel would have lost its lights and other facilities and, sans mechanical power, deprived its pilots of the ability to steer the vehicle. Onlookers reported the vessel’s lights flickering on later which experts have attributed to a backup generator.

The U.S. National Transportation Safety Board said it would be checking whether the fuel used in the Dali’s engine was contaminated.

In 2023, Chilean authorities reported issues with Dali’s propulsion, although Singaporean ones said it had cleared two inspections at foreign ports the same year.

Could the collision have been prevented?

The Francis Scott Key Bridge — the structure in question — was built in the mid1970s. Colin Caprani, a civil engineer at Monash University, Melbourne, wrote that the protective shielding around the pillars into which the ship moved wasn’t designed to withstand the impact of such a large vessel. Together with the vessel’s speed at the time of the collision, around 15 km/hr, he estimated the impact force to be equivalent to 20,000 tonnes. In 2016, Panama Canal authorities upgraded its locks to allow larger ships to pass through. The Dali‘s design was subsequently modified to increase its container capacity by 10%. Before this, Financial

Times reported, vessels of this size seldom made port along the U.S. east coast — nor did bridges over waterways here have to contend with them.

The Coast Guard suggested the vessel’s engine failed. In this scenario, it would have lost its lights and other facilities and, sans mechanical power, deprived its pilots of the ability to steer the vessle