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Memorandum to Ryan Sweetwood and Kathy Welt <br />August 2, 2010 (Revised February 1, 2011) <br />Page 3 <br />A review of the information summarized in Table 1 shows that the smallest angle of draw calculated <br />is at Station 57 and the largest is at Station 101. However, survey information in the vicinity of <br />Stations 37 and 57 are difficult to evaluate because there is no clear definition of the effects between <br />the longwall panel extraction and development mining of the chain pillars. Therefore, these <br />calculated values have less certainty than values calculated at Stations 10, 80 and 101. Excluding <br />Stations 37 and 57 results in a mean angle of draw value of 16.3° and a range of 14.0°-18.4°. <br />The predicted angle of draw for the E-seam presented in Exhibit 60E ranges from 15° to 17° and <br />was based on the subsidence monitoring data from MCC's B-seam longwall mining. The E-seam <br />subsidence data predominantly conforms to this predicted range with one exception (Station 101) at <br />18.4°. All other data from the B-seam and E-seam show angles of draw less than the maximum <br />predicted value of 17°. However, considering the measurement at Station 101, WWE recommends <br />that the maximum predicted angle of draw for the E-seam be increased to 19° for the South of <br />Divide and Dry Fork mining areas. <br />ZAProject Files\72-99\831-032\831-032.792\Engineering\Angle of Draw\Angle of Draw Memorandum 020211.docx