NTSB: Failure to Repeat, Faulty Recall To Blame For Tow Collision
A towing vessel pilot failing to repeat an agreed-upon passing arrangement with another vessel, and incorrectly recalling it, led to two tows colliding last year in the Mississippi River, the National Transportation Safety Board said in a February 8 report.
On January 9, 2023, the towing vessel Big D was pushing 19 barges downbound on the Lower Mississippi River, and the towing vessel Carol McManus was pushing 42 barges upbound. At 1:52 a.m. local time, the two tows collided at Mile 312 near Fort Adams, Miss., causing the barges in both tows to break free.
Several barges were damaged in the collision, and about 1,380 gallons of ethanol spilled into the waterway. Two minor injuries were reported. Total damage to the barges was estimated at $1.36 million.
The 6,000 hp. Big D was constructed by Horizon Shipbuilding Inc. in Bayou La Batre, Ala., in 2012. The vessel was owned by the St. Tammany Parish Development District and operated by Florida Marine Transporters (FMT).
The 9,000 hp. Carol McManus was constructed by Gulfport Shipbuilding Corporation in Port Arthur, Texas, in 1969. The vessel was owned and operated by the Ingram Barge Company. At the time of the collision, the Carol McManus was pushing 42 barges. The overall length of the towing vessel and tow was 1,563 feet.
According to the Inland Navigation Rules, when two vessels are meeting or crossing, each vessel shall signal its maneuvering intentions by using the vessel’s whistle or VHF radio, NTSB said. About 20 minutes before the 19-barge Big D tow and 42-barge Carol McManus tow met at the bend near Fort Adams, the pilots navigating the tows agreed over VHF radio to a port-to-port passage.
The Big D pilot maneuvered his downbound tow toward the right descending bank. The Carol McManus pilot incorrectly recalled the arrangement, and also navigated his upbound tow toward the right descending bank. The pilots, noticing the danger of colliding, attempted to maneuver to avoid the collision, but there was insufficient time to do so before the tows collided.
The report stressed the importance of verbal repetition of agreed-upon procedures. “When one mariner proposes an arrangement to another, the other mariner should repeat back the proposed passing arrangement to ensure both parties have a shared understanding of the arrangement,” the NTSB report said. “Verbally repeating or ‘rehearsing’ a piece of information, such as a passing arrangement, serves two purposes: It ensures that both operators understand the arrangement, and it reinforces the storage and maintenance of passing arrangement information in each operator’s working memory until the information is required to be accurately recalled (when the vessels meet). Repeating back a proposed arrangement is critical when there is a long period of time between when passing arrangements are made and when the vessels meet.”
The report concluded that the Carol McManus pilot would have been more likely to recall the agreement and maneuver if he had repeated it back.
