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Wesl E!k Mrne • After a cut of coal is mined, a roof bolter moves in and installs roof bolts Co support the roof. Conventional twin boom roof bolters will provide primary roof support by installing resin- anchored roof bolts, conventional roof bolts, combination roof bolts, or other approved systems. Bolt length and use of plates, mats, and mesh or other supplemental materials are determined by roof conditions. The mine has a roof support plan to provide protection under the anticipated conditions. Roof support practices that may be used include mechanical roof bolts, roof trusses, resin-anchored roof bolts, timbers, resin-anchored cable bolts, steel crossbars, yieldable arches, crossbars, and wire mesh. For support of long-life haulways, air courses, substations, overcasts, track intersections, and other permanent or semi-permanent facilities, supplemental support may be installed if inspections indicate that the roof is weakening. Supplemental roof support is currently utilized in the longwall panel bleeders and tailgates as a matter of practice. The roof support plan also includes provisions for installing supplemental support if a loose or badly sagging top is detected or where abnormalities are discovered. Main Entries & Sub-Main Entries At the West Elk Mine, from five to nine entries currently are mined as main entries. The number of entries depends on mining conditions, ventilation and access requirements. As few as three entries could be driven in special circumstances. The entries are used for intake and • rerurn air ventilation, coal haulage, and men and material transportation. The entries are driven parallel to each other on 60- 100-foot centers. Crosscuts are on 100-to 200-foot centers. The entries are also separated as necessary by stoppings. Room and Pillar Panels In general, the F-Seam room and pillar panels consisted of 6 to 8 entries driven parallel to each other on 60- to 100-foot centers. Crosscuts were on 60- to 120-foot centers. Panel entries consisted of intake and rerurn ventilation, conveyor belt, haulage, and escapeways, separated as necessary by stoppings. During retreat mining of the production panel, additional rooms may have been developed on one or both sides. Sufficient barrier pillars were left to protect the main entries and bleeder entries (if separate bleeders were utilized). During retreat mining, partial or full pillar extraction was used depending on conditions in the panel. Longwall Cate Roads Room and pillar methods are used to develop gate-road entries for the longwall mining equipment. Generally, two to four parallel entries are driven on from 55 to 120 foot centers. Currently athree-entry yield abutment design is used. The size and configuration of longwall gate pillars is based on the regional geology, and depth of cover. Different configurations than those currently in use will likely be used in the eastern portion of reserves as the mine advances into deeper cover. Longwall panel barrier pillars will be left to protect main entries • and bleeder entries. 2. ~5-tg 8/93 Slip. 43 Revised Jan. 1994 PROS; 8/94 TR7l: Revised Jure. 1995 PR06;