Tamping rams and plate compactors pack soil, sand, gravel, and other materials into a stable, level footing that prevents shifting and supports overlays. The rams pummel their foot and the compactors vibrate their plate to flatten and compress loose material before pouring concrete, placing rebar, laying pavers, and performing other site preparation tasks. They also press down asphalt and firm up fill after cable trenching, laying pipe, and installing utility poles, street lights, and fire hydrants.