Ключевые слова: bulk, coal, construction, danger, depth, drilling, earth, efficiency, energy, engineering, environment, equipment, excavation, extraction, generator, geology, heavy, industrial, industry, infrastructure, laboratory, landscape, load, machinery, maintenance, material, mine, minerals, mining, moving, operations, operator, performance, power, preparation, processing, production, resources, rugged, safety, seam, site, technology, terrain, track, tractor, underground, vehicles, yellow,