Show New Mining Method Breaking up coal in veins by use of explosives is still standard practice practice practice tice in U. U S. S mining and despite precautions is still hazardous Coal Age described a new method of mining mining mining min min- ing by hydraulic pressure A hole is bored in a coal seam scam a rubber tube is inserted to the bore and the tube is then powerfully e. e expanded by forcing oil into it fracturing the coal Experimental installations broke about 2500 tons of coal each before failing |