Have a regime when the current’s abeam. Ensure adequate maneuvering space!
The U.S. Coast Guard in New Orleans has issued a Marine Safety Alert (Safety Alert 03-19) for towboats to beware of strong currents following three recent accidents on the lower Mississippi River where high water was believed to have been a factor.
In all three marine casualties, the towing vessels sank after becoming pinned in strong current. One of the casualties resulted in a fatality.
While the three cases are still under investigation by the Coast Guard, preliminary findings indicate that there are some similarities between the incidents. According to the Marine Safety Alert, in all three cases towing vessels became pinned against another object in an aspect that exposed the vessel broadside to very strong currents. Once in that position, the vessels could not recover and sank.
“The high water conditions on the Mississippi River present numerous risks for towing vessels, including unusually strong river currents and dynamic eddies,” the U.S. Coast Guard says in the alert. “These river currents are often different from one section of the river to another; therefore it is absolutely essential that vessel operators 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. Additionally, the faster the current, the greater the forces acting on a vessel when it’s pinned against a stationery object.”
As a result, the U.S. Coast Guard strongly recommends the following to towing vessel owners, operators, and other responsible parties:
- 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.