Recently there were three marine casualties that resulted in the sinking of towing vessels on the Lower Mississippi River, with one resulting in a fatality.
These cases are being investigated by the US Coast Guard, but the preliminary fact finding shows some similarities between the three incidents. In all cases towing vessels became pinned against another object in an aspect that exposed the vessel broadside to very strong currents. Once they got in that position, the ships could not recover and sank.
The high water conditions on the Mississippi River raise several risks for towing vessels, including unusually strong river currents and dynamic eddies.
These river currents are often different from one section of the river to another. For this reason, it is vital for vessel operators to provide a wide berth when maneuvering around any other vessel or object.
For reference, when a river current is flowing at 1 knot, the water is moving at 1.7 feet per second, or approximately 100 feet per minute. This means that in a 6 knot current, the water is moving about the length of a football field in just 30 seconds. What is more, the faster the current, the greater the forces acting on a vessel when it’s pinned against a stationery object.
The US Coast Guard strongly recommends that towing vessel owners, operators, and other responsible parties take the following actions:
- Avoid transiting between two anchored vessels, between two barge fleets, or between any other set of stationary objects;
- Minimize the number of operations which require the vessel to be positioned beam-to the river current;
- Establish minimum distances between the towing vessel and another vessel/object prior to conducting any operation that requires the vessel to be positioned beam-to the current;
- Recognize the risks involved in operating under high current conditions and weigh those risks before attempting to cross in front of stationery objects or attempting an operation that requires the vessel to be positioned beam-to the current.