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Page 2 <br />2.3.2 Equipment & Methods For Drilling, Loading & Firing Blast Holes. <br />Drilling will be done with hand held jacklegs drilling a 1 1!2" hole X l2 <br />inches deep. Drill pattern will be determined by test blasts performed on <br />the truck dump concrete walls which aze identical to Silo walls. This drill <br />pattern will be within 18 inch spacing by 18 inch bwden and 24 inch <br />spacing by 24 inch bwden. <br />Each hole will be loaded with one cartridge (1 1/4 X 8) of Extra Gelatin <br />80% to which is tied a downline of "Cite Line". This downline along with <br />all holes in its proximity that aze to be feed on the same delay interval <br />will be tied to a coavnon Primacord trunk line (40 grain). <br />Two cross ties of "Shock Star" surface delays will be tied to each <br />Primacord trunk line to provide a 17 ms delay between the firing time of <br />each set of holes. Groups of holes on each side of centerline will be feed <br />simultaneously progressing azound the Silo in both directions on similaz <br />delay times. <br />This results in a wedge cut being formed with the thickest part of the cut <br />(+/- eighteen feet) being centered on the line-of--fall, and opened fast. <br />Drill pattern and blast delays aze planned to continue the forming of the <br />wedge in a sequential pattern so that the last holes to fire aze at the back of <br />the silo where the wedge thickness will be one foot. The eighteen foot <br />high cut on centerline of fall is designed to remove all concrete supporting <br />the two rebaz mats and thus weakening the rebaz mats so that they no <br />longer can act as support for the silo. With this support removed from the <br />front of the silo (on the center line of fall) fast, the direction of fall is <br />established. <br />There will be one blast per silo, each consisting of 400 to 600 holes. <br />Approximately twenty holes will be feed on each of thirty to forty delays. <br />Delay interval is 17 ms and total dwation of blast is six tenths of a second. <br />Each blast is initiated with an electric detonator taped to Lead-in Line that <br />has been strung to a distant point where it is safe to make the connection. <br />Other concrete structwes such as the weigh scale and conveyor-feed <br />hopper will be demolished by blasting, using the basic drill and blast <br />techniques described above. <br />All blasts that may create fly-rock will be covered with blasting mats. <br />Miners Inc. <br />