The cargo ship Dali had an electrical outage the day before the March accident that resulted in the collapse of Baltimore's Francis Scott Key Bridge according to a preliminary report released Tuesday by the National Transportation Safety Board (NTSB).
Why it matters: The NTSB said it is still investigating if the prior outage contributed to the two blackouts that occurred just minutes before the vessel slammed into the bridge.
The latest: Salvage crews collapsed part of the bridge on Monday and freed the wrecked cargo ship.
- As of Tuesday, the ship remains on the Patapsco River as crews conduct safety assessments and surveys. Once those are complete, the plan is to use tugboats to pull the ship to the pier and clear the channel, the Coast Guard said Monday.
- The accident, which has been classified as a major marine casualty event by the Coast Guard, has led to reduced shipping traffic to and from the Port of Baltimore.
What's inside: The NTSB said the prior outage occurred on March 25 while the ship's crew conducted in-port maintenance 10 hours before leaving the Port of Baltimore.
- It occurred while a crewmember was working on the ship's diesel engine exhaust scrubber system and accidentally closed an inline engine exhaust damper.
- This caused the engine to stall and caused at least two blackouts. The crew had to reconfigure the ship's electrical distribution system to recover from the outages, the NTSB said.
Zoom in: The first outage on March 26, the day of the Key Bridge accident, was caused by two electrical breakers opening unexpectedly, which cut power to shipboard lighting and most equipment, including the main engine cooling water pumps.
- The loss of the cooling pumps further caused the main engine to shut down, which cut the ship's propulsion and steering abilities.
- The crew restored power but the ship again lost power from breakers tripping when it was just 0.2 miles from the bridge.
Zoom out: The report said a seven-person road maintenance crew and one inspector were on the bridge when the Dali struck a support pier.
- The inspector survived by running to the nearest span of the bridge that remained standing after the collision.
- Six other workers were inside vehicles and fell with the bridge, and only one freed himself from his truck before being rescued. The bodies of the six construction crewmembers who were killed have since been recovered.
- One of the 23 crewmembers aboard the Dali was injured.
The big picture: The board said it plans to investigate the design and operation of the Dali's power distribution system and will continue analyzing the damage to the ship after it is cleared from the river and moved to a facility.
- The NTSB said it's also working with the Maryland Transportation Authority and other entities to assess whether bridges around the country need additional pier protection systems.
Go deeper: Baltimore crews use explosives to free collapsed bridge from Dali ship
