Pilot Misjudged Currents Near Vicksburg Bridge, NTSB Finds
The National Transportation Safety Board (NTSB) released its marine accident brief February 27 detailing its investigation into a February 27, 2019, allision involving the mv. Chad Pregracke, part of Marquette Transportation Company’s river fleet, and the Old Highway 80 Bridge in Vicksburg, Miss.
The allision occurred at about 7 a.m. as the mv. Chad Pregracke, pushing 30 loaded grain barges southbound, was set to pass under the first of two adjacent bridges in the Vicksburg area. The Old Highway 80 and Interstate 20 bridges are less than 400 feet apart. The Old Highway 80 Bridge is a cantilever bridge that opened in 1930. While motor vehicle traffic ceased on the bridge in 1998, the bridge still carries trains from the Kansas City Southern railroad, along with service vehicles. The bridge is listed on the National Register of Historic Places.
At the time of the incident, the Mississippi River in Vicksburg was at 47.92 feet, more than 4 feet above flood stage. According to NTSB, the river was running at between 4 and 5 mph. The U.S. Coast Guard had issued a safety advisory for the area, citing “hazardous conditions associated with strong currents, severe outdrafts [and] missing/off-station aids to navigation and diving buoys,” according to the NTSB report.
The report notes that the bridges cross the river just over a mile below a 121-degree bend and near where the Yazoo River and Mississippi converge, resulting in significant crosscurrents at the bridges. The Lower Mississippi River Committee and Coast Guard had already placed restrictions on southbound tows transiting the bridges, including daylight-only transits and a minimum horsepower-per-barge ratio. On February 25, 2019, the Coast Guard had reduced maximum tow size transiting the bridges from 36 to 30 barges.
On the morning of the incident, the pilot and captain aboard the Chad Pregracke were both in the wheelhouse as the vessel approached the bridges. The vessel made the bend with a speed of 12.1 knots, slowing to 10.8 knots as it steered for the gap between piers 3 and 4 of the bridges. According to the NTSB report, “The pilot told investigators that he experienced the set to the left earlier and harder than he anticipated.” The vessel was moving at 11.5 knots as it allided with pier 3, with the third and fourth barges from the head of the tow striking the bridge.
The tow broke apart, and four barges sustained damage. One sank, another’s bow was submerged, while two others were damaged yet remained afloat. The Coast Guard closed the river following the incident. By 2:50 p.m. that day, the Chad Pregracke crew, aided by other vessels in the area, had retrieved the tow. The crew, along with the 26 undamaged barges, continued south on March 1. NTSB said the closure delayed 26 vessels and 354 barges on the Mississippi River in Vicksburg. According to NTSB, the sunken barge has still not been recovered. Total property damage due to the allision was estimated at $800,000.
The NTSB noted the difficulty of navigating the Vicksburg bridges—especially in high water. In the year preceding the February 27, 2019, incident, the Old Highway 80 Bridge had been hit six times. “The history of bridge strikes at the Old Highway 80 Bridge indicates that the location of the bridge and the geography of the approach make it difficult for downbound tows to pass under the span, particularly in high water,” the report said.
The report concluded that, despite the pilot’s attempt to steer starboard toward pier 4 of the bridge, the crosscurrent force pushing the tow to port was too powerful. Despite meeting all the requirements for transiting the bridge at the time of the incident, “the pilot could not overcome the effect of the current on the tow.” The probable cause, the NTSB determined, was the pilot’s misjudgment of the river’s current acting on the tow as the vessel approached the bridges in high water.