The container ship that knocked down Maryland’s Francis Scott Key Bridge in March lost power several times before the accident, investigators said Tuesday.
The Dali first experienced a blackout during in-port maintenance at the Seagirt Marine Terminal in Baltimore Harbor Mar. 25, about 10 hours before departing the port, according to the Marine Investigation Preliminary Report on the accident released Tuesday by the National Transportation Safety Board (NTSB). During the maintenance work, “a crewmember mistakenly closed an inline engine exhaust damper” which ultimately caused the ship’s engine to stall, the report revealed. One of the ship’s alternating current (AC) generators then automatically started.
Insufficient fuel pressure from the generator triggered a second blackout, and another AC generator automatically came on, according to the report.
The first blackout after departure occurred at about 1:25 a.m. Mar. 26 with the ship being 0.6 miles from the bridge. Two electrical breakers that fed most of the ship’s equipment and illumination tripped. All lights on board went out and most of the vessel’s equipment lost power.
The loss of power to the engine cooling water pumps shut down the main engine and the ship lost propulsion. The loss of power to all three steering gear pumps stopped the rudder from working. The vessel’s voyage data recorder momentarily stopped recording the vessel system data but still recorded audio.
The crew began to drop anchor, notified the Maryland Transportation Authority Police and the U.S. Coast Guard of the outage, and called for a tug, which immediately responded, the report further revealed.
The crew restored power in less than three minutes but a second outage ensued as two other breakers working with two other AC generators tripped. A third AC generator automatically started, and the emergency generator also started supplying power to emergency equipment.
The main engine, however, remained shut down, as the emergency generator could not restart the engine without all four AC generators. The ship thus could not regain propulsion, according to the report.
One of the pilots issued warnings to all waterborne traffic and the MDTA ordered the closure of the bridge to all traffic, while the crew partially restored power. Maintenance workers remained on the bridge.
The ship remained without propulsion, and at about 1:29 a.m., just over three minutes after the first post-departure blackout, the ship struck the bridge before the tug arrived. (RELATED: Ship That Knocked Down Baltimore Bridge Had Previous Accident, Past Hardware Issue)
Six of the bridge’s seven maintenance workers died and the seventh survived but with serious injuries, the NTSB said. An inspector working with the maintenance crew narrowly escaped unscathed, making it to the nearest surviving span of the bridge just before the collapse, and one of the 23 crew members aboard the Dali was injured from falling debris, according to the report.
The NTSB reportedly was not aware of any other blackouts in the Baltimore port or the previous ports where the Dali had docked. The Dali had docked in Newark, New Jersey Mar. 19 and in Norfolk, Virginia Mar, 21, before arriving at Baltimore Mar. 23, according to the report.
The Dali had experienced a propulsion-related fault during a port inspection in Chile in Jun. 2023 and had allided with the berth at the Port of Antwerp in Belgium back in Jul. 2016.