A compacting system compacts particulate matter in open-top railroad gondola cars rolling on rails. The compacting system includes a compacting station adjacent the rails and a scanning system that scans the gondola cars as they move along the rails toward the compacting station. The scanning system transmits data of the gondola car to an electronic control system. The compacting station has at least one compaction member, e.g., a plate structure or a roller, configured to contact an upper surface of the particulate matter in the gondola cars. The electronic control system controls the compacting station so that the compaction member engages with and applies force to the upper surface of the particulate matter in the gondola car so as to compress the particulate matter in the gondola. A method for compacting particulate matter in a gondola car is also shown.