NTSB Releases Report On May 2019 Ship Collision On Lower Mississippi River
The National Transportation Safety Board has released a marine accident brief detailing its investigation into the May 16, 2019, multi-vessel collision involving the tanker American Liberty on the Lower Mississippi River near Reserve, La.
Shortly after 8:40 p.m. that night, the American Liberty got underway at Mile 140.2, with the bridge team losing control shortly thereafter in the extreme high river and swift current. Along a 1.2-mile stretch of the river, the ship “made contact with moored vessels, barges and wharfs along the left descending bank,” according to the report. The incident caused a reported $40.5 million in damages to vessels and terminals between Miles 139.5 and 138.7. Three people were injured in the incident.
The NTSB found that the likely cause of the incident was “poor bridge resource management and miscommunication between the pilot and the master, which led to the bridge team’s delay in carrying out an engine order and caused a delay in the vessel attaining sufficient speed to conduct an undocking maneuver in high river conditions.” NTSB investigators added that a decision to release assist tugs too early was likely a contributing factor.
On the night of the incident, the 601.3-foot American Liberty was fully loaded and moored at the Marathon Petroleum facility in Garyville, La., on the left descending bank, with its bow pointing upriver. With a river pilot on board and two assist tugs, the Josephine Anne and Vera Bisso, on hand, the pilot began issuing commands to the tugs and the American Liberty’s bridge crew for the ship’s bow to come around, then head downriver.
At 8:33 p.m., the ship had begun to swing around, with the stern well clear of the terminal. By 8:36, the ship was moving downriver, but with the stern nearer to the bank than the bow. At that time, the vessel’s stern was nearing a moored articulated tug barge, the Teresa-Acadia. The pilot ordered, “Give me whatever you can give me, Cap … and get a little speed here,” according to the NTSB report. The bridge master increased the engine order telegraph (EOT) to half ahead. Rather than report the move, the master replied, “We should be good.” At 8:37, the master stated, “We’re at full,” but when the pilot responded with “Full?” the master then increased EOT to full ahead.
According to the NTSB retelling of the bridge interactions, the miscommunications aboard the American Liberty continued. At 8:38, the pilot ordered engine stop, with the master responding, “We need the engine. We need to go.” The pilot then ordered engine slow ahead, but neither the master nor the mate responded. Instead, EOT at shortly after 8:38 was increased to fully ahead without any communication with or order from the pilot.
At 8:39, the master ordered rudder hard left, but the pilot countered with rudder hard right. The miscommunications continued through the 8:40 minute: “At 2040, the pilot ordered engine stop then engine full astern, which was not acknowledged by the master or the mate, but at 2040:14 the EOT was slowed to dead slow astern and two seconds later increased to half ahead without communication of the action to the pilot. The pilot repeated the order for engine full astern, again with no response, and at 2040:16, the master ordered, ‘Hard left, full ahead, don’t listen to the pilot.’”
During this time, the American Liberty narrowly cleared the Teresa-Acadia and the tug Miss Caroline. With the vessel still out of control, the American Liberty made contact with two vessels at the Cargill Terre Haute Grain Terminal, then the crane barge Don D, with impacts to the African Griffon. Afterward, the pilot ordered the ship to drop anchor. Still moving downriver, the American Liberty went on to impact the ADM fleet, including the Ever Grace and four barges. The ship finally came to a stop against the Port of South Louisiana’s Upper Globalplex Reserve wharf.
In its report, NTSB noted that good bridge resource management (BRM) “states that only one officer can have the conn at a time, so the helmsman and EOT operator need to know who has the authority to give wheel and engine commands.” The report also stated that bridge commands “must be brief, five words or less” and that the helmsman or EOT operator are required to repeat the commands word for word.
“During the accident, both the master and pilot gave commands,” the NTSB report stated. “The helmsman told investigators that there was a lot of ‘commotion and confusion’ on the bridge, and that he wasn’t sure if the pilot or the master had the conn because they were telling him ‘conflicting things.’ The mate told investigators that the master had ‘filtered’ the commands given by the pilot.”
Concluding its report, NTSB offered the following guidance for safe and effective bridge resource management: “The pilot and the bridge team should share the same mental model for the maneuver and fully understand the planned tasks. Communications should be open, involve discussion of the intended maneuvers and should continue throughout the evolution. Clear orders and commands should be acknowledged and carried out promptly.”