NTSB: Debris Impact Suspected In Barge Breakaway

The National Transportation Safety Board believes debris may have contacted two barges that broke away from an Ohio River dock in high water in 2024, causing an estimated $2.5 million in damage when they hit mooring cells belonging to the TransMontaigne terminal at Mile 794.1.

No one was injured, and no pollution was reported. The barges were recovered with minor damage.

About 11 p.m. April 15, 2024, the crews of towing vessels operated by Evansville Marine Service moored two 297.5-foot-long tank barges, the MPC 644 and MPC 907, in a string alongside the Marathon Petroleum Company terminal dock at Mile 793.8 on the Ohio River’s right descending bank, according to the NTSB report that was released earlier this month. The MPC 644 was carrying about 23,000 barrels of No. 2 ultra low sulfur (MV15) diesel fuel. The MPC 907 was carrying 27,328 barrels of No. 84 conventional blend-grade gasoline. The cargoes were expected to be discharged the following morning.

River conditions were high, with the gauge at Evansville at 38.8 feet and rising. The river peaked four days later, on April 18, at 39.8 feet. The current was about 3 mph. Three lock lines and two winch wires were used to secure each barge.

About 6 a.m. April 16, terminal operations personnel arrived at the terminal and found both barges missing. An investigation showed the barges had broken away overnight. At 6:50, a terminal operations crew found all six lock lines and four winch wires were broken and notified downriver facilities. A review of camera footage showed that the two barges broke from the dock about 4:45 a.m.

Evansville Marine Service reported a drift pile of debris 100 feet by 200 feet in the water about the time of the breakaway. According to Marathon, the camera footage appeared to show a debris pile following the barges after the breakaway.

Evansville Marine Service tugs recovered the barges about 7 a.m. near Mile 802 and returned them to the Marathon dock. “No significant damage was noted to the barges, and all cargo was offloaded without issue,” according to the NTSB report.

The TransMontaigne terminal, located about 1,500 feet downriver of the Marathon terminal, reported damage to its dock structure, which consisted of four mooring cells and a steel access walkway running from shore to mooring cells No. 2 and No. 3. Cell No. 4, located farther upriver “was no longer present.” A sonar survey found the cell piling was fractured at the river bottom and laid in the downstream direction at a 90-degree angle to its original location.

Cell No. 3 sustained “significant damage to the upstream piling structure and concrete pile cap.” Cell No. 2’s concrete cap was fractured. Supports and steps for a spiral access stairway attached to Cell No. 2 were deformed. “The steel access walkway to the mooring cells and associated piping was distorted in the downstream direction,” the NTSB reported. “TransMontaigne estimated the physical damage to the dock structure would exceed $2.5 million.”

In a survey of MPC 907, the tow knee face was set in up to three-fourths of an inch over a 10-inch span on the starboard side. The surveyor found limestone aggregate and concrete fragments which “appeared to be identical to the fill material and concrete cap of cell No. 3 at the TransMontaigne terminal facility.”

Following these events, Marathon Petroleum Corporation reviewed its policies and procedures related to mooring barges at the facility and the process for transfer of custody during barge delivery. “The fleet operator can now only deliver barges in a narrow window of time ahead of transfer operations, and a verbal handoff regarding the barge condition and mooring arrangement must be completed with MPC personnel,” the NTSB said.

In its analysis, the NTSB said that because the mooring lines were not retained for examination or testing, investigators could not determine their condition. However, the lines were inspected weekly, and Evansville Marine Service did not report any issues with the lines when mooring the barges. The number of lines and wires (10 total for the two barges) met MPC’s expectations during high-water conditions, the NTSB noted.

“EMS personnel noted drift piles of debris in the river about the time of the breakaway,” according to the NTSB. “With high water and increased current, debris, such as tree trunks, tree limbs and litter, can collect and drift downstream. Accumulating debris at the head of a barge can lead to an increased strain on its moorings, thus elevating the risk of lines or wires parting. Given the swift river current (3 mph.) at the time, if debris contacted the moored barges, it could have contributed to the failure of the mooring arrangement and the barges breaking away.”