Surging water from the Mississippi River led to a 2023 barge strike on a gate at Algiers Lock in New Orleans, according to a new report from the National Transportation Safety Board (NTSB).
The Algiers Lock connects the Mississippi River to a network of inland waterways. On July 4, 2023, the towing vessel Kitty was pushing two loaded tank barges into the Algiers Lock during low water conditions. NTSB said the tow surged within the lock chamber and the lead barge struck one of the lock gates. The contact did not result in any injuries or pollution. Damage to the lock gate was estimated at $2 million.
The NTSB found the surge was likely due to wake effects from deep draft ships transiting the Mississippi River adjacent to the Algiers Lock forebay during extremely low water conditions, which moved water in and out of the forebay and lock chamber, causing the vessels in those areas to surge.
NTSB noted that before the contact, three loaded ships had transited near the lock within about 10 minutes’ time. NTSB investigators determined the size and the speed of the three ships transiting near the lock within a short time span likely would have produced wakes that affected the forebay and lock chamber.
Kitty's crew members described a three-to-six foot change in water level in the lock chamber while transiting. The NTSB studied the water-level variations in the Algiers Lock based on footage from the Kitty and found the minimum change in lock water level during the casualty to be 3.4'.
The NTSB report highlighted how water displacement from deep-draft vessel wakes can intensify when funneled into narrow or confined spaces, such as shallow waterways and lock chambers. This phenomenon can create significant operational challenges, particularly in low water conditions.
Marine Investigation Report 25-01 is available online.
