An Operating Engineer operates and maintains various types of power-driven construction machines, such as bulldozers, cranes, pile drivers, power shovels, derricks, earth grinders, and tractors which dig, scrape, and move great amounts of earth or hoist large quantities of building supplies. Some machines require the operator to turn valves, adjust hand wheels, and press pedals to drive the machines and control the attachments. Other machines, such as cranes, require the constant use of both hands and both feet. An Operating Engineer may also be required to service his machines and move the machine from one construction site to another.

All the work is performed in the open, except for a few machine equipped with enclosed cabs. Earth-excavating and grading equipment operators generally work from early spring until the fall freeze and shut down only when it rains.