Laserfiche WebLink
<br /> <br /> 2.04.3(3)(a) <br /> <br /> foot centers with crosscuts also on eighty-four (89) foot centers. <br /> After driving the five (5) entries of each panel to the boundary <br /> parrier, extraction and retreat are accomplished as follows: <br />Extraction is accomplished by partial extraction (slabbing) <br />' of the pillars beginning at the room furthermost from the <br />belt line. <br />' After retreat from the furthermost corner, extraction of <br />the supporting column left hetween the panel being mined <br />and the previous panel is accomplished in the manner <br />just described. <br />' Extraction and retreat from the five (5) initial entries <br />' is accomplished in the same manner. <br /> All extraction and retreat mining proceeds in such a manner <br />' that the nine (9) entries of the panel and removal of the supporting <br /> column between thi s panel and the previous pane] prog resses <br />' uniformly from the boundary barrier back to the main slope. <br /> Upon reaching the main slope, mining in thi s panel is complete. <br />' All mining is being accomplished by means of electric powered <br />t continuous miners and shuttle cars. Belt conveyors, installed <br />in F.ntry P:umber 3 of the panel being mined, are used to carry <br />' coal to the main belt line located in Entry 4 of the main slope. <br />Entries are eighteen (18) feet in width, maximum, on eighty- <br />' four (84) foot center. Crosscuts are indentical to entries <br />at 90° to the direction of the entries. Pillars are sixty- <br />1 six (66) feet square, minimum dimensions, before slabbing. <br />Refer to Figures 2.04.3(3)(a)-1 through-7, for the mining <br />' and posting methods being utilized. Refer to the Operation <br />Plan Map, 2.05.2(1)-1, cohich depicts the existing operation <br />' and the projected scheme of mining. <br />' 26 <br />