PARIS – The collision of a container ship that brought down a busy Baltimore bridge has cast light on the role of local pilots whose job is to manoeuvre giant vessels in and out of the world’s ever busier ports.

The 95,000-tonne Dali had two pilots on board when it issued a mayday call early on March 26 warning that it had lost power, moments before smashing into a pier supporting the Francis Scott Key Bridge.

“Each ship engaged in foreign trade coming to Maryland ports is required to take on a local ship-handling specialist, known as the pilot, to navigate the vessel safely into port,” the website of the Association of Maryland Pilots said.

Pilots also handle the ship as it leaves port.

“They are the experts about currents, danger points and traffic, they must know it all by heart,” Mr Francois Mayor, from the French pilots training centre, said.

Baltimore is the largest city in the state of Maryland, and the ninth-busiest US port, set on a complex network of waters in the Chesapeake Bay.

Besides ports, pilots also manage ships as they approach river estuaries or traverse narrow chokepoints, such as the Suez and Panama canals or the Bosphorus straits in Turkey.

The pilot guides the ship’s captain on the proper routes to take and how to handle the local conditions, the French Federation of Maritime Pilots says on its website.

The job can be dangerous. The pilots arrive and leave the ship by a long hanging ladder – called a “Jacob’s ladder” – from a small boat, or by winch from a helicopter.

When there are two pilots on board, as was the case with the Dali in Baltimore, it is because the navigation is particularly complicated.

One generally manages the electronic navigation, while the other passes instructions into the crew, said Mr Mayor.

The presence of pilots aboard does not relieve the captain of his obligations. The captain remains responsible for the ship’s security, according to international maritime codes.

In Maryland, port pilots must have a college degree from a maritime academy and at least 10 years of seagoing experience. Then they must serve a further five-year apprenticeship before being fully licensed, according to Maryland’s public television station.

With many thousands of dockings a day worldwide, accidents do happen. And the increasing size and speed of container ships makes navigating the world’s ever more crowded shipping lanes ever more difficult.

The obstruction of the Suez Canal by the Ever Given container ship in March 2021 was caused in part by misunderstandings between the two Egyptian pilots and the ship’s Indian captain, according to a report published in 2023 by Panamanian authorities. AFP