The US NTSB issued an investigation report on the contact of towing vessel Rivers Wilson and its tow with Norfolk Southern Railway Bridge on the Tombigbee River, in March 2019. There was one minor injury as a result. The investigation stressed issues associated with poor judgement in high current conditions.
The incident
On 10 March 2019, the towing vessel Rivers Wilson, with 8 crew members onboard, was pushing six loaded barges.
At 0100 local time, the vessel contacted the Norfolk Southern railway bridge near Jackson, Alabama.
As a result, a bridge support was shifted out of position, and the tracks above deflected.
Rail traffic was suspended for 27 hours until temporary repairs were made.
One crew member sustained a minor knee injury in the immediate response. There was no pollution.
Probable cause
NTSB determines that the probable cause of the contact was the pilot’s decision to navigate through a bridge that was poorly aligned with the channel with an unfamiliar towing vessel in high water and strong current.
Analysis
The Rivers Wilson had not been issued a COI, nor was it required to have one at the time of the accident.
Regardless of the vessel’s COI status, the USCG required operators to comply with the remaining requirements in Subchapter M by July 20, 2018, several months before the accident.
Compliance included maintaining the watertight and structural integrity of the vessel.
The numerous watertight and structural integrity deficiencies in the Coast Guard’s postaccident inspection of the Rivers Wilson indicated that the towboat was not adequately maintained.
Meanwhile, the pilot’s statements regarding the dikes and the currents show that he was aware of the high-water conditions and the difficulties presented by the river while transiting the bridge.
Namely, he stated that if he had been concerned about the current [with his 6 barges], he would have tied up below the bridge.
The pilot had the option to leave barges below in the Jackson fleeting area and make several passes through the bridge while pushing fewer barges, but he believed that the Rivers Wilson had adequate speed over ground at his planned abort point to successfully maneuver the vessel through the bridge.
He was not able to accurately anticipate the effect of the high water conditions and the difficulties presented by the relatively new submerged dikes on the direction/strength of the current. His incomplete understanding of the current, in combination with the misalignment of the bridge with the thalweg and the Rivers Wilson’s lower horsepower in comparison to the vessel on which he usually worked, resulted in his belief that the tow had enough speed to overcome the effect of the current,
…NTSB report reads.
Lessons learned
High-current Navigation
Seasonal, high current poses unique hazards for vessels working on and/or transiting inland rivers. Water flowing over normally exposed terrain and obstacles or man-made structures can change the expected current. Mariners should thoroughly assess the impact of high current on local hazards, such as jetties and bridges, and their effect on navigation.
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