three earth drills lie side by side on gravel in front of a sheet pile wall at a construction site, one earth drill lies across

accessories archimedes augers backhoe bit bores cast changeable construction coupler cutting diagonally disc drill drilling drive earth employed energy excavator floor fork foundation foundations geological geology geothermal gravel holes hydraulic hydraulics industry loader machine materials mining oil pile plate predrill principle quick raw semicircular site snail spiral steel tapered tines tips two water well