Mariners making a tow A towboat approaching a curve pushes 20 fully loaded barges. Mariners use the expression “making a bridge” to talk about navigating their tow beneath the roads that cross the rivers. A barge filled with scrap metal to be recycled Smaller fleeting vessels help move barges in and out of tow. Specially fitted tanker barges transport chemical liquids. A towboat's propellers work hard to push thousands of tons of cargo through the water. Liquid cargo barges transport petrochemicals, liquid fertilizers, pressurized products, and other fluids. A typical tow stretches 1,000 feet, longer than two football fields, and carries the equivalent of 1,050 large tractor-trailers. A towboat navigates the Mississippi River bridges in Memphis, Tennessee: the Harahan, the Frisco, and the Memphis-Arkansas Memorial Bridge carrying Interstate I-55. Towboats operate night and day in all kinds of weather. Icy waters beneath a drawbridge in Peoria, IL. Like international cargo ships, towboats move containers, too. Two mariners walk on the cover of a loaded barge. Mariners harness sheer manpower for their work. A lock raises and lowers boats between stretches of water of different levels on river and canal waterways. Mariners use lines to lash barges together. Communication is critical between crew members. The rolled-back cover of this barge reveals its contents. Mariners do not yield to the elements, working rain or shine.