Data capturing the moments before the container ship Dali struck the Francis Scott Key Bridge has been secured by the National Transportation Safety Board and is being analyzed by the federal agency’s lab, officials confirmed Wednesday.
Large ships are required by international regulations to carry voyage data recorders that, similar to the “black box” found on aircraft, help investigators piece together key decisions and actions.
If the equipment works properly and the data can be verified, it can provide information that serves as a “road map” of what the ship and its crew were doing in the lead-up to, and during, a casualty event, said Lawrence Brennan, an adjunct professor with Fordham University School of Law who teaches a maritime law course.
The bridge collapsed early Tuesday. Six members of a crew repairing potholes on its deck remained missing Wednesday in the Patapsco River and were presumed dead. Searchers continued to look underwater for their remains.
Spokespeople for the NTSB did not respond to an inquiry from The Baltimore Sun about the condition of the Dali’s voyage data recorder and whether it properly captured information.
The NTSB’s chair, Jennifer Homendy, said Tuesday the recorder would be “critical” to the investigation.
A media briefing by the agency is scheduled for 8 p.m. Wednesday.
Data items captured by recorders can include the ship’s position, speed, direction, the audio in work stations, communications audio, radar, the depth of the water underneath vessels, the alarms going off, wind speed and an electronic logbook.
In this case, it could provide details about conversations between the pilot and crew members, the ship’s movement and, potentially, a “mayday” signal that officials say helped prevent more casualties on the Key Bridge by giving police time to close the bridge to drivers. The local pilot was on board to guide the ship through the harbor.
“You know what the watch commander or the captain told the chief engineer,” Thomas Roth-Roffy, a U.S. Coast Guard licensed chief engineer who worked for 18 years as an NTSB investigator, said of such recordings.
Not only can the voyage data recorder help investigators retrace the ship’s path and determine how the crew responded when things went awry, it allows the NTSB to “recreate what’s visible on the ship’s radar,” Roth-Roffy said. “It actually does screen captures every 30 seconds or a minute.”
The data will likely serve as a first step for investigators probing for the reasons why the cargo ship ran into one of the Key Bridge’s support columns — causing the bridge to crumble into the Patapsco River — and whether there was anything defective about the nearly 50-year-old span.
“That’s the primary purpose: Why did the casualty happen?” Brennan said. “Does it range from human error — I doubt it. Is there a mechanical failure? Probably. Are there contributing causes? Is there a failure to respond on the part of the captain or whoever was on the bridge? What could they have done to avoid that?”
Homendy said Wednesday morning that “a few folks” had boarded the vessel Tuesday night and that it was likely NTSB crews would board it again Wednesday.
She said the agency’s focus Wednesday would be “getting on board the vessel, getting the electronic logs or any sort of electronics components that we need to get.” The crews would be seeking “perishable evidence” that would no longer be available when the ship and wreckage was cleared from the waters.
“The focus is: What do we need for our investigation, whether it’s from the vessel or from the highway, from the bridge structure? Identifying those, securing those, before we do any analysis,” Homendy said.
NTSB investigations often take a year or more. Final reports detail the accident and provide an agency analysis and conclusions, along with the probable cause of the event and related safety recommendations.
Homendy said at a Tuesday news conference that investigators could consider whether the bridge should have had additional protective structures and the contents of previous bridge inspections. That examination of past safety deficiencies is a “meticulous process” that could take time, she said.
She also said she was in touch with her counterpart in Singapore, as the Dali was flagged in that Southeast Asian city-state.
She indicated the agency would also be working on a list of who investigators hope to interview, both on the vessel and in the immediate vicinity.
On that list is likely the ship’s entire crew, said Roth-Roffy. Also on board were the pilot and an apprentice who accompanied them.
From those interviews, investigators hope to gain a better understanding of how the vessel was functioning. Given that crews come and go, the NTSB will also examine its inspection history as far back “as they can go, to see if there are any patterns with mechanical failures.”
Built in 2015, the 984-foot Dali was cited for deficiencies with its propulsion and auxiliary machinery during a June 2023 inspection at the Port of San Antonio in Chile, according to the Electronic Quality Shipping Information System, a shipping information website. An inspection by the U.S. Coast Guard in September reported no deficiencies, according to the data compiled by Equasis.
The Dali’s predominantly Indian crew remains aboard and has been “cooperating with what we need,” Vice Admiral Peter W. Gautier of the Coast Guard said during a White House press briefing Wednesday about bridge collapse. “They’re still there and very much engaged in the dialogue and investigation.”
In addition to alcohol and drug testing for everyone aboard at the time of an incident, investigators require crew members to document their work and rest history for the previous 72 hours, Roth-Roffy said.
“Fatigue is a huge issue in a lot of investigations,” he said.
Roth-Roffy said crew conversation as a situation devolves into an emergency can be telling to investigators of mariners’ level of training and adherence to required safety management protocols.
“When you lose a main engine or lose a generator, a lot of the equipment will come on automatically, but some of it may not,” he said. “And you have to be able to quickly identify what you need to get that generator started again or get that main engine started again.”
A local pilot was at the helm of the Dali when it appeared to lose power early Tuesday, causing the ship’s steering and propulsion system to fail, said Clay Diamond, executive director of the American Pilots Association.
The pilot did “everything he could” by contacting authorities and steering the ship’s rudder to the left once its backup generators kicked in, though the ship’s engines were still inoperable, he said. The ship also dropped anchor. Diamond credited those maneuvers with giving authorities the extra time to shut down bridge traffic.
In past cases, the voyage data recorder provided key details.
When the cargo vessel El Faro sank in 2015 near the Bahamas after sailing into the path of Hurricane Joaquin, investigators went to great lengths to find the wreckage and retrieve its voyage data recorder. It was pulled from more than 15,000 feet below sea level on the third attempt. That effort resulted in a lengthy transcript of more than 500 pages.
The chilling account includes a narration of the captain deciding to ring the general alarm to wake everyone up, saying, “We’re definitely not in good shape right now.” Shortly after, a chief mate investigated the situation on one deck and reported water was “chest deep.” Three minutes after the alarm bell rang, the captain said, “Bow is down, bow is down.”
Roughly 10 minutes later, someone called out “I’m gone” or “I’m a goner.” The captain yelled, “No, you’re not.” The audio recording ended less than a minute later.
An earlier NTSB investigation into the Delta Mariner striking the Eggner’s Ferry Bridge in Kentucky in 2012 relied on a simplified voyage data recorder onboard. It captured audio from the pilothouse, as well as location, speed, rate of turn and depth.
The report found that 15 minutes before the impact, someone called out that the vessel was approaching a bridge. It quoted the contract pilot discussing the position of lights on the bridge — saying “I’m thinking the red looks higher,” then moments later asking, “It is, ain’t it?” The transcripted reported that less than a minute later, he said: “Oh [expletive].”
Baltimore Sun reporters Dan Belson and Sam Janesch contributed to this article.
