Power loss on Dali led to collision with Baltimore bridge: Report

Electrical power loss on container ship Dali led to its collision against Baltimore’s Francis Scott Key Bridge, which collapsed under the impact and claimed six lives, according to a preliminary report by the US National Transportation Safety Board.

The report said that on March 25, about 10 hours before leaving Baltimore port, the Dali experienced a blackout during in-port maintenance. A copy of the report is available with businessline.

On March 26, at about 0129 eastern daylight time, the 947-ft Singapore-flagged cargo vessel Dali was transiting out of Baltimore Harbour in Baltimore, Maryland, when it experienced a loss of electrical power and propulsion and struck the southern pier supporting the central truss spans of the Francis Scott Key Bridge, the report said.

Human toll

A portion of the bridge subsequently collapsed into the river, and portions of the deck and the truss spans collapsed onto the vessel’s forward deck. A seven-member road maintenance crew employed by Brawner Builders — which was contracted by the Maryland Transportation Authority (MDTA) — and one inspector employed by Eborn Enterprises, Inc, a sub-consultant to the MDTA, were on the bridge when the vessel struck it.

The inspector escaped unharmed, and one construction crew member survived with serious injuries. The bodies of the six fatally injured crew members have been recovered. One person among the 23 aboard the Dali was injured, the report said.

Chain of events

Detailing the sequence of events, the report said that at about 0125 hours, the Dali was 0.6 miles — or three ship lengths — from Key Bridge when the electrical breakers (HR1 and LR1) that fed most of the vessel’s equipment and lighting unexpectedly opened (tripped). This caused the first blackout (loss of electrical power) to all shipboard lighting and most equipment, including the main engine cooling water pumps (which controlled engine cooling water pressure) and steering gear pumps.

Generator no. 3 and 4 continued to supply electrical power to the HV bus.

The main propulsion diesel engine was independent of the vessel’s four diesel-driven electrical generators. However, the loss of electrical power to the pumps required for its operation led to the main engine automatically shutting down, and the vessel lost main propulsion — meaning its propeller stopped.

The loss of electrical power halted all three steering pumps and, therefore, the rudder could not be moved. At this point the ship was on a heading of 141.7°, a course over ground of 140.8°, and speed over ground of 9.0 knots, with the rudder amidships (0°).

At 0126:39, the pilots called for tug assist. The Eric McAllister was 3 miles away and immediately answered and headed towards the ship (the tug did not reach the Dali before it struck the bridge).

At 0127:01, the senior pilot ordered an anchor dropped, and the crew began the process to drop anchor. The pilots’ dispatcher called the MDTA Police duty officer and relayed that the ship had lost power. The pilots’ dispatcher then notified the Coast Guard about the Dali’s loss of power.

The Dali crew was able to restore electrical power to the vessel but, when the ship was 0.2 miles from the bridge, a second blackout occurred because DGR3 and DGR4, the breakers that connected generator no. 3 and 4 to the HV bus, opened. This caused total loss of electrical power. Having connected to the emergency bus by this time, the emergency generator provided electrical power to the emergency equipment continuously during the second blackout.

At 0129:10, the Dali’s starboard bow struck pier no. 17 of Key Bridge at 6.5 knots. Six spans of the bridge subsequently collapsed into the water and across the ship’s bow. A Dali crew member, who was on the bow at the time of the accident, told investigators that as he was releasing the brake on the port anchor he had to escape from the falling bridge before he was able to reapply the brake. (Due to ongoing salvage efforts, the amount of anchor chain paid out is still unknown.)

Another crew member sustained a minor injury from the falling debris.

• Also read: Indian seafarers excel; Unfair to question their competency due to Baltimore accident

An official of a ship management company said that until 0124 hours everything was normal in the ship. At 0125 the power failed and at 0129 the ship hit the bridge. Within two minutes the crew responded and restored the power. At least this does not seem to be a case of negligence or human error, he said. The whole thing about Indian crew competence is a ‘hogwash’, he added, referring to reports in the US that raised questions about the competency of the ship’s Indian crew.

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