Introduction to Mobile Cranes Practice Test

The working circle is defined by where the boom sits relative to the crane’s base, so the space around the crane is divided into four areas as the boom moves in front or to the sides and to the rear. These four areas are called quadrants of operation. Each quadrant changes the crane’s geometry, balance, and the available load capacity, so operators refer to the quadrant to select the correct load chart and plan safe lifts with proper clearance and outriggers in place.

Other terms describe different ideas: zones of rotation would focus on turning around the base, planes of tilt relate to the jib’s tilt orientation, and sectors of reach describe how far the jib can reach. But the standard way to categorize the circular working area based on the boom’s position relative to the carrier is quadrants of operation.