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• <br />Table 83 <br />WIDTH :DEPTH RATIOS FOR MULTIPLE, ADJACENT LONGWALL PANELS - Part 1 <br />Overburden <br />Depth W /H1 <br />Mining Layout (feet) Ratio Classification <br />Longwall Panel No. 1 <br />600 <br />1.00 <br />Super - critical <br />(600 -ft extraction width) <br />800 <br />0.75 <br />Critical <br />1000 <br />0.60 <br />Subcritical <br />1200 <br />0.50 <br />Subcritical <br />1400 <br />0.38 <br />Subcritical <br />1600 <br />0.33 <br />Subcritical <br />2 Longwall Panels <br />600 <br />2.42 <br />Super - critical <br />(1450 -ft extraction width) <br />800 <br />1.81 <br />Super - critical <br />1.000 <br />1.45 <br />Super - critical <br />1200 <br />1.21 <br />Critical <br />1400 <br />0.91 <br />Subcritical <br />1600 <br />0.81 <br />Subcritical <br />3 Longwall Panels <br />600 <br />3.42 <br />Super - critical <br />(2050 -ft extraction width) <br />800 <br />2.58 <br />Super - critical <br />1000 <br />2.05 <br />Super - critical <br />1200 <br />1.71 <br />Super - critical <br />1400 <br />1.28 <br />Critical <br />1600 <br />1.14 <br />Critical <br />