A tanker collision with a military pier at Joint Base Charleston earlier this year is the second such incident in two years involving large commercial vessels navigating the Cooper River, according to a National Transportation Safety Board (NTSB) report.
The 604' Hafnia Amessi, under the control of a Charleston Branch Pilots Association pilot, struck Pier B at the Naval Weapons Station on Jan. 14, 2024, after getting too close to the eastern riverbank. The contact caused an estimated $8.1 million in damages to the vessel and pier. No pollution or injuries were reported.
The tanker sustained damage to its side hull plating. The NTSB investigation found that as the vessel made a right turn at a bend in the channel, the pilot began favoring the eastern side of the channel in preparation for the next bend to port. That position brought the vessel into the influence of bank effect, a hydrodynamic phenomenon that pushes the bow away from the bank and pulls the stern toward it.
Despite rudder and engine corrections, the pilot could not compensate for the forces acting on the vessel. The bow was also affected by flood current as it exited the shelter of the eastern bank, further compromising maneuverability. The vessel was unable to complete the turn without striking the pier.
The NTSB drew parallels between this incident and a 2022 contact between Pier B and the Bow Triumph, another tank vessel under pilotage that came too close to the same bank.
“These incidents demonstrate the risks associated with bank effect and strong currents in confined waters,” the NTSB said. “Had the Hafnia Amessi approached the left turn in the more open water to starboard, it would have reduced bank effect on the port side and provided better positioning to counteract the flood current.”
Following the two pier strikes, the U.S. Coast Guard Captain of the Port for Charleston issued new safety requirements. All vessels over 10,000 gross tons or with drafts greater than 25 feet are now required to use a tethered two-tug escort when transiting between Pier B and Snow Point.
The NTSB report emphasized that even experienced pilots can be challenged by hydrodynamic forces in shoaling-prone channels. Squat and shallow water effects reduce rudder effectiveness, and unexpected shoaling can further exacerbate these conditions. The agency recommended that vessel operators consider risk factors and use tugs, speed adjustments, or transit delays as needed to ensure safe passage.
Marine Investigation Report 25-11 is available on the NTSB website.
