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Elk Creek Mine Subsidence Page 14 February 26, 2003 MINING ENVIRONMENT The panel locations, dimensions and overburden thicknesses above the panels are essential for predicting subsidence and strain above the panels. The planned location of the three "IY' Seam longwall panel groups are indicated on Figure 1. All longwall panels are to be 825-ft between the north and south gateroad pillar ribsides, i.e. the sum of the 20-ft width of adjacent gateroads adjacent plus the 785-ft longwall coal block width. The panel mining height is limited to 12-ft by the maximum cutting height of the shearer. The panel mining height is limited by the seam thickness when less than 12-ft and to approximately 8-ft by the minimum cutting height of the shearer. The seam thickness throughout Panel Group 1 equals or exceeds 12.0-ft, as shown on Plate 2. The seam thickness of Panel Group 2 Panels #5 through #7 exceeds 12.0-ft. However, the seam thickness in the set-up rooms and as much as 900-ft of the western ends of Panel Group 2 Panels #8 through #11 is less than 12-f t, as shown on Plate 7. However, the seam thickness in the set-up rooms and as much as 900-ft of the western ends of Panel Group 2 Panels #8 through #11 is less than 12-ft. The seam thickness of major sections of all Panel Group 3 panels is less 12.0-f t, as shown on Plate 12. The seam thickness in the set-up room of Panel #13 is nearly down to 8-ft. The four panels in Panel Group 1 are shown in detail on Plate 1. Plate 1 contains 100-ft overburden thickness contours above the "IY' Seam, Bear Creek that crosses the west ends of Panels #1 and #2 and Elk Creek that is east of Panel Group 1. The seven panels in Panel Group 2 are shown in detail on Plate 6. Plate 6 includes 100-ft overburden contours above the "D" Seam, Elk Creek that crosses the east end of Panel #11 and Bear Creek to the west of Panel Group 2. The eight panels in Panel Group 3 are shown in detail on Plate 11. Plate 11 includes 100-ft overburden contours above the "IY' Seam, Bear Creek that crosses the east ends of Panels #17 through #12 and Hubbard Creek that is west of Panel Group 3. The individual Elk Creek Mine panels are numbered sequentially in the planned order of mining. Longwall mining of Panel Group #1 will proceed northerly, one panel at a time. The 28-ft wide by 9.5-ft high set-up rooms for all panels will be at their west ends. The set-up rooms will be isolated from the 1 West Bleeder Entries by 250-foot wide barrier pillars. Individual longwall panel mining will proceed easterly to the shield recovery rooms at the east end of each panel. The shield recovery rooms will be isolated from the North Mains by tapered barrier pillars, 620-foot wide on the north side and 830-ft wide on the south side of Panels #1 through #3. The -14-