Heavy equipment or heavy machinery refers to heavy-duty vehicles, specially designed for executing construction tasks, most frequently ones involving earthwork operations or other large construction tasks. Heavy equipment usually comprises five equipment systems: implementation, traction, structure, power train, control and information.Heavy equipment has been used since at least the 1st century BCE when the ancient Roman engineer Vitruvius described a crane in De architectura when it was powered via human or animal labor.
Heavy equipment functions through the mechanical advantage of a simple machine, the ratio between input force applied and force exerted is multiplied, making tasks which could take hundreds of people and weeks of labor without heavy equipment far less intensive in nature. Some equipment uses hydraulic drives as a primary source of motion.
The term "plant" is used to refer to any mobile type of heavy machinery.