Big D (top) and Carol McManus (bottom) underway precasualty.

​​ Big D (top) and Carol McManus (bottom) underway before the collision. (Sources: Florida

Marine Transporters, Ingram Barge Company)  

Collision between Big D and Carol McManus Tows

What Happened

​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 on the river. At 0152 local time, the two tows collided at mile 312 near Fort Adams, Mississippi, 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. Damages to the vessels were estimated at $1.36 million.

What We Found

​We determined that the probable cause of the collision between the Big D tow and the Carol McManus tow was the Carol McManus pilot incorrectly recalling the agreed-upon passing arrangement, which resulted in the Carol McManus tow encroaching on the downbound Big D tow.​

Lessons Learned

​Repeating Passing Arrangements via Radio

When mariners are making passing arrangements via radio, several factors may impact each mariner’s understanding of the final agreed-upon arrangement. These factors include garbled radio transmissions, strong accents or an unfamiliarity with the English language, a mariner’s preconceived expectation of the event, fatigue, or distraction. 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 repeat-back also reinforces the agreed arrangement with each mariner.