In this class, the following term is used with the meaning indicated: "drilling" covers boring and vice versa. This subclass covers: primarily equipment for drilling of earth or rock in their natural formation; similar equipment for drilling of man-made structures in situ, e.g. of road surfaces or concrete structures. This subclass does not cover: hand-held drilling machines, e.g. for domestic use; drilling equipment for manufacturing operations, i.e. where an article is worked, e.g. for further processing; which are covered by relevant subclasses of section B, e.g. ; compositions for drilling of boreholes or wells or for treating boreholes or wells, which compositions are covered by group , e.g. compositions for enhanced recovery methods for obtaining hydrocarbons . Processes using enzymes or micro-organisms in order to: liberate, separate or purify a pre-existing compound or composition, or to treat textiles or clean solid surfaces of materials are further classified in subclass . METHODS OR APPARATUS FOR DRILLING DRILLING TOOLS; ACCESSORIES THEREFOR , ; OTHER EQUIPMENT OR DETAILS FOR DRILLING; WELL EQUIPMENT OR MAINTENANCE Derricks; drilling rods or the like ; , Flushing or cleaning; sealing; heating or cooling , ; ; Valve arrangements; fire-fighting ; Other equipment or details , , OBTAINING FLUIDS FROM WELLS CONTROL; SURVEYING OR TESTING ; CUTTING; SLITTING; DISLODGING General structure of machines , Details , , Other devices , , METHODS OF MINING OR QUARRYING; OPEN-PIT MINING , ; , OBTAINING MINERALS FROM UNDERWATER WINNING MATERIALS FROM EXTRATERRESTRIAL SOURCES This subclass covers methods or apparatus for making or lining tunnels, galleries or large underground chambers, using underground mining methods only, i.e. not involving disturbance of the ground surface. This subclass does not cover underground spaces made by foundation engineering, i.e. involving disturbance of the ground surface, which are covered by subclass . MAKING SHAFTS; LININGS THEREFOR , , , ; MAKING TUNNELS OR GALLERIES; LININGS THEREFOR ; MAKING UNDERGROUND CHAMBERS; LININGS THEREFOR ; WORKING-FACE SUPPORTS OR COVERS , , , SUPPORTS FOR STEP-BY-STEP MOVEMENT SETTING ANCHORING BOLTS VENTILATION , DRAINAGE SAFETY DEVICES, RESCUE DEVICES TRANSPORT; FILLING-UP ; OTHER METHODS OR DEVICES