The National Transportation Safety Board (NTSB) has released its findings from a significant breakaway incident involving the bulk carrier Sirocco, which occurred on March 27, 2023, at the Convent Marine Terminal, Convent, La.
While loading coal, the Sirocco broke free from its moorings and drifted approximately half a mile down the Mississippi River, ultimately colliding with a barge at the Mosaic Uncle Sam dock. The NTSB report highlighted the urgent need for enhanced mooring safety awareness among vessel crews.
Investigations revealed that the winch brake liners on the Sirocco exhibited severe heat and friction, indicating that the force on the forward mooring lines exceeded the winches' capacity. This slip was exacerbated by strong river currents. The NTSB emphasized the importance of understanding these dynamics during mooring operations.
“To reduce the risk of a vessel breakaway, it is important for vessel crews to understand the forces that act on a vessel when it is moored into a strong current at a dock,” investigators said. “Crews should ensure that slack is taken out of lines as the vessel loads, especially as the forward draft increases and the bow begins to sit lower in the water, exposing more of the hull to the current. Continuously monitoring and taking up any slack from bow lines as forward holds are loaded can help to ensure that the bow does not come away from the dock.”
The NTSB also recommends establishing a breakaway response plan to prepare crews for potential incidents. Vessel masters should consider implementing additional safety measures, such as keeping propulsion systems, thrusters, and steering systems on standby, and ensuring anchors are ready for quick deployment, even if not mandated by the loading facility. Familiarity with the process of requesting tug assistance on short notice is also advised.
The incident resulted in no injuries or environmental damage, but damage to the Sirocco, the barge and the Mosaic Uncle Sam dock was estimated at $5 million.
