The National Transportation Safety Board (NTSB) has released an investigation report on an incident where the towing vessel Queen City was downbound on the Ohio River in high-water conditions, pushing an 11-barge tow, when the tow struck the Vane Dike at the arrival point for the McAlpine Locks and Dam in Louisville, Kentucky, and broke apart, on March 28, 2023.
Analysis
On March 28, 2023, about 0224 local time, the towing vessel Queen City was downbound on the Ohio River in high-water conditions, pushing an 11-barge tow, when the tow struck the Vane Dike at the arrival point for the McAlpine Locks and Dam in Louisville, Kentucky, and broke apart. No pollution or injuries were reported. Total damages to the barges and cargo were estimated to be $1.98 million.
Background
Owned and operated by C&B Marine Equipment, LLC, the Queen City, built in 1974, was a 103-foot-long, steel-hulled towing vessel. The vessel had
two steering and four flanking rudders, and two 1,500-hp diesel engines each driving a propeller. The US Army Corps of Engineers operates the McAlpine Locks and Dam. The dam’s five upper gates and four lower gates are 22 feet high and 100 feet wide. The Vane Dike is located in a river bend just off the eastern end of the entrance to Portland Channel, which leads to the McAlpine Locks. The dike, measuring 200 yards by 10 yards, extends eastward from the end of Shippingport Island, the northern land boundary of the Portland Channel. A mooring cell is at the end of the dike. The US Coast Guard Lifesaver Memorial Light sits on top of the cell.
The Queen City was not damaged. Nine barges were damaged, with an estimated cost of $1.475 million. There was also about $500,000 of lost cargo (corn).
River Conditions
At the time of the casualty, the upper gage at the McAlpine Locks measured river height at 17.5 feet, and the lower streamgage measured water flow at over
400,000 cubic feet per second. These measurements were nearly the highest compared to readings during the previous 12 months. Waterway users estimate the velocity of currents using the volume of water moving at a given time. Generally, an increased water flow at any point in a river is associated with a faster river current.
Conclusions
Probable Cause
The National Transportation Safety Board determines that the probable cause of the contact of the Queen City tow with the Vane Dike was the pilot not effectively compensating for the strong outdraft while navigating toward the lock channel entrance during a period of high-flow conditions.
Lessons Learned
Preparing for Dam Outdrafts
High currents resulting from high water pose unique hazards for vessels transiting inland rivers. In addition, near dams, greater dam openings in high-water
conditions lead to high flow rates, which can produce outdraft currents near the dam. Mariners should thoroughly assess the potential impact of outdraft currents when entering or exiting locking channels. Vessel horsepower and vessel handling should be carefully considered. Mariners should also consult available resources, such as Waterways Action Plans and company policies, when passage planning.
