A snub-nosed boat with push knees used for pushing barges. A small towboat (called a push boat) may push one or two barges around the harbor. A large towboat is used to push from 5 to 40 barges in a tow is called a line boat. From the Port of New Orleans, line boats deliver cargo to Mid-America via the 14,500-mile waterway system flowing through the Crescent City.