NTSB Determines Cause of Tow Collision Report highlights importance of repeating passing arrangements


Big D (top) and Carol McManus (bottom) pictured before the collision.

​Big D (top) and Carol McManus (bottom) pictured before the collision. (Source: Florida Marine Transporters (top), Ingram Barge Company (bottom))

​​WASHINGTON (Feb. 8, 2024) — A towing vessel pilot incorrectly recalling the agreed-upon passing arrangement led to tows colliding last year​ in the Mississippi River, the National Transportation Safety Board said Thursday.

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. About 20 minutes before the 19-barge Big D tow and 42-barge Carol McManus tow met at the bend near Fort Adams, Mississippi, 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.

​“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 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 Carol McManus pilot would have been more likely to recall the agreement and maneuver if he had repeated it back. 

Two minor injuries were reported and barges in both tows broke free. About 1,380 gallons of ethanol spilled into the waterway. Damage to the vessels was estimated at $1.36 million.

Marine Investigation Report 23-30 is available online. ​

To report an incident/accident or if you are a public safety agency, please call 1-844-373-9922 or 202-314-6290 to speak to a Watch Officer at the NTSB Response Operations Center (ROC) in Washington, DC (24/7).