As the name suggests, a cable-tow system is pulled through the field by a steel cable and a wench. One end of a flexible hose connects to the gun cart, while the other end connects to a riser pipe. This hose is dragged as the big gun moves across the field. The polyethylene hose is attached to a large diameter reel and the reel is mounted on a carriage. Once the big gun and hose are pulled away from the carriage, the reel slowly revolves and pulls the big gun back toward the carriage.
Water pressure is an important issue when using a big-gun sprinkler for irrigation.
If the pressure is too low, the water will stream out of the nozzle and not breakup into droplets. At the design pressure, the stream of water will cascade into droplets and apply water all along the entire length of the trajectory. Remember that this is the pressure at the big gun, not the pressure at the pump. When using a traveling gun, often the pressure at the pump must be 140 psi or greater to account for friction in the pipe and for changes in elevation. A irrigation designer or engineer can assist you in selecting a pump to supply your system.