Brittney Lohmiller / The Natchez Democrat — The Vicksburg District of U.S. Army Corps of Engineers mat sinking crew has between four and five barges full of 950 tons articulate concrete mats delivered a day that is laid along the Louisiana side of the Mississippi River. The mats form a protective overcoat to shield the riverbank from erosion and sloughing caused by current channels. The 320 people working on unit will spend three days laying mats on the banks and bottom of the river.