Critical Communication Error Leads to Tow Collision Mississippi River

The National Transportation Safety Board (NTSB) has identified a critical error in communication as the cause of a collision between two tows in the Mississippi River last year.

The incident, taking place January 9, 2023, resulted in minor injuries, significant vessel damage, and the release of around 1,380 gallons of ethanol into the waterway.

According to the NTSB, the pilots of the 19-barge Big D tow and the 42-barge Carol McManus tow had agreed to a port-to-port passing arrangement over their VHF radios. This agreement was made approximately 20 minutes prior to their meeting near Fort Adams, Mississippi. The Big D pilot navigated his downbound tow towards the right descending bank as per the agreed plan.

However, the pilot of the Carol McManus incorrectly recalled the arrangement and also directed his upbound tow towards the same right descending bank. Despite noticing the imminent danger and attempting to avoid the collision, there was insufficient time to prevent the accident.

AIS tracklines of the Big D and Carol McManus, with a red X marking the location where the tows collided (left), and the positions of the tows just before the collision at 0152 (right).

The report suggests that the pilot of the Carol McManus might have been more likely to remember the correct maneuver if he had repeated the agreement back.

“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 collision resulted in two minor injuries and caused damage to the vessels estimated at $1.36 million.

NTSB Report: Marine Investigation Report 23-30