The investigation into the bridge collapse in Baltimore is ongoing

BALTIMORE (AP) — The power outages experienced by the container ship Dali before it left the port of Baltimore were “mechanically different” from those that led to the deadly collapse of the Francis Scott Key Bridge hours later, a report says Testimony before Congress on Wednesday.

“Two of these were related to routine maintenance work at the port. “Two of these were unexpected circuit breaker trips on the accident journey,” said Jennifer Homendy of the National Transportation Safety Board.

The Dali was on its way to Sri Lanka, loaded with shipping containers and enough supplies for a month-long voyage. Shortly after leaving the port of Baltimore early on March 26, the ship lost power and propulsion and struck one of the bridge’s support columns, killing six construction workers.

Homendy’s comments came the day after the safety agency released its preliminary report on the bridge collapse. Your full investigation could take a year or longer.

According to the report, the ship’s first power outage occurred after a crew member accidentally closed an exhaust flap while performing maintenance in port, causing one of its diesel engines to stall. A backup generator automatically turned on and continued to run for a short time – until it started again due to insufficient fuel pressure, resulting in a second power outage.

While recovering from those power outages, crew members made changes to the ship’s electrical configuration, switching to a different transformer and a different set of circuit breakers, according to safety investigators.

“Changing circuit breakers is not unusual, but it could have affected operations as early as the next day on the accident trip,” Homendy testified Wednesday morning before the U.S. House Transportation and Infrastructure Committee.

She said the board is still gathering more information about what exactly caused the various power outages. The FBI has also launched a criminal investigation into the circumstances that led to the collapse.

When the breakers tripped as the Dali approached the bridge, the ship’s emergency generator kicked in, according to Homendy. This generator can power the ship’s lights, radio, and other functions, but it cannot restore propulsion.

“Without the propeller turning, the rudder was less effective,” Homendy said. “They were essentially drifting.”

Although redundancy is built into the ship’s systems, it is no different than other ships in terms of emergency generator functions and other factors, she said. She said investigators were working closely with Hyundai, the manufacturer of the Dali’s electrical system, to determine what went wrong after it left the port of Baltimore.

“We are still on scene evaluating everything about this accident,” Homendy said.

She also reiterated another finding from the report that testing of the marine fuel did not reveal any concerns about its quality.

The safety agency began its investigation almost immediately after the collapse, in which six members of a road construction team fell to their deaths. Investigators boarded the ship to document the crime scene and collect evidence, including the ship’s data recorder and information from the engine room.

The preliminary report details the chaotic moments before the bridge collapsed as crew members struggled to resolve a series of power outages that occurred in quick succession as disaster loomed.

At 1:25 a.m. on March 26, when the Dali was just over half a mile from the bridge, the circuit breakers powering most of the ship’s equipment and lighting unexpectedly tripped, causing a power outage. The main propulsion diesel engine automatically shut down after its cooling pumps lost power and the vessel lost control.

According to the report, crew members were able to temporarily restore power by manually closing the tripped circuit breakers.

The ship was less than a quarter mile from the bridge when a second power outage occurred due to additional circuit breakers tripping. The crew restored power, but it was too late to avoid impact with the bridge.

A last-minute emergency call from the ship allowed police to stop traffic, but they didn’t have enough time to alert a team of construction workers who were filling potholes on the bridge. A man was rescued from the water. A road inspector also survived by escaping to safety shortly before the bridge collapsed.

The final bodies of the six victims were recovered from the underwater wreckage last week.

On Monday, crews conducted a controlled demolition to tear down the largest remaining span of the collapsed bridge, which landed across the bow of the Dali. The ship is expected to be refloated and returned to the port of Baltimore early next week, officials said Wednesday.