As the Singapore cargo ship Dali shoved off from the Port of Baltimore’s Seagirt Marine Terminal, two tugboats initially helped maneuver it away, then peeled off 20 minutes before the ship crashed into the Francis Scott Key Bridge.

Several pilots and tugboat captains wondered, would two powerful tugboats have been able to push the ship toward the channel and avoid a collision with the bridge in the crucial minutes during which the Dali lost power and black smoke began billowing from the stern.

Cargo ships heading in and out of the Baltimore harbor are guided by tugboats that flank the ship on each side while a Chesapeake Bay pilot on board gives navigational commands to the ship’s bridge and captain.

(Read full coverage of the Key Bridge collapse)

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Ship tracking data from showed the Dali was headed toward the Key Bridge unaccompanied when it crashed into the bridge early Tuesday morning. Two tugboats, both operated by McAllister Towing and Transportation, helped the Dali out of the dock between 12:30 a.m. and 1 a.m. Those tugboats left the cargo ship around 1:09 a.m. The Dali begins veering right and away from the main channel at 1:25 a.m., four minutes and 23 seconds before it struck the bridge.

The tugboats that accompanied it out of the dock, the Eric McAllister and Bridget McAllister, were the first to arrive on the scene after the crash, the ship tracking data showed.

Large ships, like the 984-foot Dali, cannot easily maneuver through the harbor, and need tugboats to guide them away from the shipping terminals. The tugboats can also help push a ship that loses power, as the Dali had, away from the bridge, but experts said it is hard to know whether they could have prevented the accident.

Tugboats are usually mandated by ports to stay with cargo vessels for a specific period of time, according to Capt. Jeffrey Spillane, dean of the School of Maritime Education and Training at SUNY Maritime.

With multiple systems apparently failing on the ship, he said, the presence of tugboats “certainly would not have hurt.”

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“The tugboats are there to get you off the dock, spin the vessel around, and help with precise movement that is difficult for a large cargo ship,” he said. “Once the vessel feels like they are all set, the tugboats get dismissed by the vessel’s pilot.” He said the vessel captain can make a special request for the tugboats to stay for a longer period of time.

Tugboats are not always necessary to escort cargo ships, according to Mike Reagoso, general manager at McAllister Towing. He declined to comment on specific information related to the tugboats operating the morning of the crash, but said environmental factors such as the weather play a role in determining whether tugboats are needed.

Tugboats are usually mandated by ports to stay with cargo vessels for a specific period of time, according to Spillane. Capt. Joseph Ahlstrom, a member of the Board of Commissioners of Pilots of the State of New York, said there may be a push for more tugboat escorts in the industry following the crash.

“Ship owners don’t like tug escorts because you need to pay for them,” said Ahlstrom, who also teaches safety management classes at SUNY Maritime. “But passing under a bridge like this, it may be necessary.”

Kurt Gray, a former tugboat captain, said that many ships are escorted by at least two tugboats running within 30 to 40 feet on either side of the ship as it maneuvered under the Key Bridge. “If the pilot released the assist tugs, as in he didn’t need them anymore, then it seems normal that they peeled off. It is not uncommon. This would be documented in the captain’s log of the ship as well as the captain’s log on the tugs.”

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A Chesapeake Bay pilot would have been on the ship giving navigation commands to the ship’s bridge, or those steering the boat. The ships are too big and waters too unfamiliar for foreign pilots to navigate the bay themselves, said retired Chesapeake Bay pilot, Capt. William Band.

“There are usually a minimum of two tugs that run with them,” Gray said. “They are pulling the ship off the dock,” he said, and then running alongside them under the bridges and then out into the Chesapeake Bay. If the ship gets in trouble or loses power, the tugboats would try to shove the ship back on course, he said.

“That channel is pretty wide. You can have two ships passing underneath the bridge. There is room for everyone,” said Gray. “They would have been able to see the bridge. They will see the lights on the spans.”

A tanker third mate for Crowley’s tank fleet who has sailed through the Baltimore Port repeatedly over the last 18 years said that two, or even one tugboat, may have been able to help a cargo ship of that size, depending on the horsepower of the boats.

It is common for tugboats to peel off ahead of a bridge, such as the Francis Scott Key. The standard notice is for the tugboats to continue the escort if there was a reported mechanical issue with the ship or a recommendation was made by the pilots’ association or the captain of the port due to difficult sea conditions.

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Once the Dali was in the main shipping channel and headed out, he said, it would normally not have taken long to reach the bridge.

“I’m still standing here in shock,” said Band, who worked 41 years as a bay pilot. ”From the video I saw, it looked to me like a steering or engine failure on the ship,” he said. “It looked like there is smoke that came out of the stack of the ship.”

McAllister Towing has responded to a request to support responders at the crash scene. Currently, they have three tugs, the two that escorted the ship early in the morning and the Timothy McAllister, according to their spokesman Jim Lawrence.

The vessel was last inspected in September by the U.S. Coast Guard, which found no deficiencies, according to an online database maintained by Electronic Quality Shipping Information System. Out of the 27 inspections documented for Dali since 2015, two have found deficiencies. In 2016, the ship was found to have hull damage and in June 2023 an inspection found problems with “propulsion and auxiliary machinery.”

Synergy Marine Group, the technical manager for the Singapore cargo ship Dali said in a statement all 22 crew members on board, including two pilots, have been accounted for and there were no reported injuries. The company said it’s unclear what caused the collision and that owners and managers are cooperating with government agencies.

Reporters Liz Bowie and Alissa Zhu contributed to this report.