Mass earthmoving --also called “dirt work”—remains one of the biggest sources of employment for operating engineers.  After a field of virgin land is planned for development, operators first strip or “scrape” the top soil using a machine called a scraper.  Once black dirt is removed down to clay or other base material, it is “balanced” by graders and compacted by compactors and rollers.  Holes for foundations and trenches for sewer and water lines are dug with excavators, also called track backhoes.  Bulldozers, “Grade-alls”, and all manner of other specialized equipment move dirt to contour the land to whatever specification is needed.