Surging water from the Mississippi River led to a 2023 barge strike on a gate at Algiers Lock in New Orleans, the National Transportation Safety Board said Thursday.
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.
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.
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.
The crew of the Kitty described a 3–6-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 feet.
“The effects of water displacement from a deep draft vessel’s wake can increase when that water pushes into and recedes from narrow and/or smaller water bodies, such as shallow areas and lock chambers,” the report said.
Source: National Transportation Safety Board (NTSB)
