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Christine Johnston, MCC <br />November l9, 1998 <br />Page 9 <br />Ntany of the cracks observed and recorded by CDMG in July 1996 and by Dunrud and Nicewicz <br />in August 1997 show mazked and significant healing. The cracks observed at location CDMG 2 <br />are completely healed. <br />Last, but perhaps most importantly, high flexural stresses and attendant strains commonly occur <br />within the angle of draw of longwall extraction panels, especially at lithologic boundaries. Mine <br />layout design and the location of structures, such as mine access shafts, should be planned so that <br />these structures aze not within the angle of draw. Based on data from Exhibit 60, the angle of <br />draw in this azea ranges from 8 to 21 degrees, as measured from a vertical reference. <br />cc: Jonathan Kelly, WWE <br />D:\831-032\470jmk\Subsidcncc Observations.doc <br />Wright Water Engineers, Inc., 2490 W. 26'" Avenue, Ste. 100A, Denver, CO 80211 <br />Tel. 3031480-1700; Fax. 303/480-1020, e-mail:krwhght(dwrighiwaler.com <br />