One such excavator removes enough overburden each day to fill 16,000 semitrailers. To prevent the sides from caving in as the mine goes deeper and deeper, the cut is made to form terraces, or steps.
Lai novērstu karjera sienu iebrukšanu, rakšana notiek vairākos kāpļveida slāņos, uz kuriem tiek veidoti darba laukumi.