The container ship that caused the deadly collapse of Baltimore’s Francis Scott Key Bridge has been refloated and is moving back to port.

The Dali has remained at the collapse site in the US state of Maryland since it lost power and crashed into one of the bridge’s supporting columns on March 26, killing six construction workers and snarling traffic into Baltimore Harbour.

The ship appeared to start moving shortly after 6am local time (11am BST) as crews started to manoeuvre it out of the wreckage. It started and stopped a few times before slowly backing away from the collapse site.

Maryland Bridge Collapse
Six construction workers died after the collision (AP)

Officials said the vessel would move at about 1mph on the roughly 2.5-mile trip, a fraction of the speed it was travelling at when it lost power and crashed into the bridge.

Pieces of the bridge’s steel trusses protruded from its bow, which remained covered in concrete from the collapsed roadway.

Officials have said they plan to unload the ship’s containers and complete some short-term repairs while it is docked in Baltimore.

Crews conducted a controlled demolition on May 13 to break down the largest remaining span of the collapsed bridge.

The Dali experienced four electrical blackouts within about 10 hours before leaving the Port of Baltimore for Sri Lanka and hitting the bridge, according to a preliminary report issued by the US National Transportation Safety Board.