On February 27, 2019, about 0704 local time, the towing vessel Chad Pregracke, pushing 30 loaded grain barges down the Mississippi River, was coming out of a bend and lining up to pass under two adjacent bridges in Vicksburg, Mississippi, when the tow set toward the left descending bank and into a pier supporting the Old Highway 80 Bridge. The tow broke apart, one barge sank, and three barges were damaged. The vessel’s nine crewmembers remained on board and began gathering barges. No pollution or injuries were reported. Total damage to the barges was estimated at $800,000.
The 173-foot-long Chad Pregracke was a twin-propeller towing vessel that was powered by two diesel engines that produced a combined 10,000 horsepower. The vessel was fitted with two sets of flanking rudders and two sets of Becker (flap) rudders. The vessel was built in 2016 and operated by Marquette Transportation Company, LLC.
The Mississippi River current at Vicksburg was 4-5 miles per hour (mph), and the river gage was 48 feet and rising (flood stage was 43 feet). The Lower Mississippi River near mile 435 was under an extreme high-water safety advisory from the US Coast Guard Captain of the Port due to “hazardous conditions associated with strong currents, severe out drafts, [and] missing/off- station aids to navigation and diving buoys.” The Coast Guard considers extreme high water to be a rising depth of water measuring at least 40 feet.
The Vicksburg bridges included the Old Highway 80 Bridge, which opened in 1930 as a highway and railroad crossing and still serves as a railway bridge, and the Interstate 20 bridge, which opened in 1973 and was built with piers spaced to match the adjacent and upriver Old Highway 80 Bridge piers. The bridges were located 1.1 miles downstream from a 121° bend in the river. In addition to the cross-currents associated with such a large change in direction of the river, the current from the Yazoo river converged in the bend.
On February 6, 2019, the Lower Mississippi River Committee (LOMRC) activated watchstanders in the Vicksburg Information Center (VIC) to “provide mariners with the most current information related to river conditions affecting transit through the Vicksburg Bridges.” The VIC personnel also were responsible for granting permission for tows to transit under the bridges. VIC personnel verified that each tow met the guidelines for transiting the bridges after discussing the transit with wheelhouse personnel. To receive permission to transit under the bridges, wheelhouse personnel of southbound tows were required to confirm that they were comfortable with their tow configuration and the river state; the tow met the horsepower per barge and max tow size requirements; and all red-flag barges (barges carrying hazardous materials) in mixed tows were placed in inboard strings and not a lead loaded barge in any string.
The Coast Guard also issued a Notice to Mariners on February 6, recommending only daylight operations for southbound tows wider than 110 feet passing under the Vicksburg bridges. On February 25, two days before the accident, the Coast Guard issued another notice, reducing the maximum number of loaded barges from 36 to 30.
4 авг 2020
