The NTSB released the timeline after boarding the ship on Wednesday to gather perishable, factual evidence. The agency also revealed 56 containers with hazardous materials, some of which were breached.
The U.S. Coast Guard recovered approximately 6 hours of voyage data recorder (VDR) data from the DALI on the morning of the accident and provided it to the NTSB. The data covers the period from 00:00 to 06:00 EDT on March 26, 2024. The NTSB is continuing to obtain the remaining 30 days of data that the VDR is required to record.
The VDR data, which includes audio from the ship’s bridge and VHF radios, varies in quality due to background noise and alarms. Further analysis will be conducted at the NTSB’s lab to enhance the audio clarity. All information is preliminary and subject to final validation and change.
The VDR also recorded limited system data such as ship speed, engine RPM, rudder angle, ship heading, and some alarm information.
The times expressed below are as recorded by the VDR and converted to local eastern daylight time, as shared by the NTSB:
The VDR recorded the ship’s departure from Seagirt Marine Terminal at approximately 00:39 EDT, recorded the ship’s transit outbound in the Fort McHenry Channel, and the striking of the Francis Scott Key Bridge (1-695).
By 01:07 EDT, the ship entered the Fort McHenry Channel.
By 01:24 EDT, the ship was underway on a true heading of approximately 141 degrees in the Fort McHenry Channel at an indicated speed over ground of approximately 8 knots/9 miles per hour.
At 01:24:59 EDT numerous aural alarms were recorded on the ship’s bridge audio. Around the same time, VDR ship system data ceased recording, however, the VDR audio continued to be recorded using the VDR’s redundant power source.
Around 01:26:02, the VDR resumed recording ship system data. During this time, there were steering commands and rudder orders on the VDR audio.
Around 01:26:39 the ship’s pilot made a general VHF radio call for tugs in the vicinity of the DALI. MDTA data from around this time indicated the pilot association dispatcher phoned the MDTA duty officer regarding the blackout.
Around 1:27:04, the pilot commanded the DALI to drop the port anchor and issued additional steering commands.
Around 1:27:25, the pilot issued a radio call over the VHF radio and reported the DALI had lost all power approaching the Key Bridge. Around this time, MDTA data shows the following occurred:
• MDTA duty officer radios two units already, one on each side of the bridge, to close the bridge.
• All lanes are shut down by MDTA.
Around 1:29:00, the ship’s speed over ground was recorded as just under 7 knots/8 miles per hour. From this moment until approximately 1:29:33, VR audio recorded sounds consistent with the collision with the Key bridge. Additionally, around this time, an MDTA dash camera shows the bridge lights extinguishing. Additional analysis of the VR audio and comparison of other time sources will be needed to determine the exact time of contact between the DALI and Key Bridge.
At 1:29:39 the pilot reported the Key Bridge down over VHF to the USCG.
