On March 27, 2023, about 0208 local time, the bulk carrier Sirocco broke free from its moorings at the Convent Marine Terminal, located at mile 160.9 on the Lower Mississippi River in Convent, Louisiana, drifted downriver, and at 0249 collided with a barge moored at the Mosaic Uncle Sam dock at mile 160.4. There were no injuries, and no pollution was reported. The Sirocco, the barge, and the Mosaic Uncle Sam dock sustained damage totaling about $5 million.
We determined that the probable cause of the breakaway of the bulk carrier Sirocco from the Convent Marine Terminal dock and the subsequent collision with moored barge MEM 5087 was the bow coming off the dock during cargo loading in the forward holds, exposing more of the vessel’s underwater hull to the strong river current, resulting in the brake-holding capacities of the ship’s mooring winches being exceeded and the lines paying out until the vessel broke free from the dock.