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West Elk Mine <br /> <br />2.05-8 Rev. 11/04- PR11; 03/06- PR10; 07/15- MR413; 07/18- PR15, 01/24-TR152 <br />transportation out of the mine. After a cut of coal is mined, a roof bolter moves in and installs <br />roof bolts to support the roof. Conventional twin-boom roof bolters provide primary roof <br />support by installing resin-anchored roof bolts, conventional roof bolts, combination roof bolts, <br />or other approved systems. Bolt lengths and use of plates, mats, and mesh or other supplemental <br />materials are determined by roof conditions. <br /> <br />The mine has a MSHA-approved roof control plan to provide protection under the anticipated <br />conditions. Roof support materials that are allowed under this approved plan include mechanical <br />roof bolts, roof trusses, resin-anchored roof bolts, timbers, resin-anchored cable bolts, steel <br />crossbars, yieldable arches, crossbars, wire mesh, concrete props called “cans” and other <br />commonly used mine roof support means. For support of long-life entries, air-courses, critical <br />ancillary installations, overcasts, and other permanent or semi-permanent facilities, supplemental <br />roof support may be installed, if inspections indicate that the roof is weakening. Supplemental <br />roof support has also been utilized in the longwall panel bleeder and tailgate entries. The roof <br />control plan also includes provisions for installing supplemental support if a loose or badly <br />sagging top is detected or where abnormalities are discovered. <br /> <br />Main Entries & Sub-Main Entries <br /> <br />At West Elk Mine, from five to ten entries are typically mined as main entries. The number of <br />entries depends on mining conditions, and ventilation and access requirements. As few as three <br />entries could be driven in special circumstances. The entries are used for intake and return air <br />ventilation, coal haulage, and men and material transportation. The entries are driven parallel to <br />each other and are generally on 100 to 200 foot centers. Crosscuts are also generally on 100 to <br />200 foot centers. The entries are separated as necessary by stoppings. <br /> <br /> <br />Room and Pillar Panels <br /> <br />F Seam room and pillar panels generally consisted of 6 to 8 entries driven on 60 to 100 foot <br />centers and with crosscuts on 60 to 120 foot centers. During secondary mining of the room and <br />pillar panels, additional rooms may have been developed on one or both sides of the initial <br />development. Sufficient barrier pillars were left to protect the main entries and bleeder entries (if <br />separate bleeders were utilized). During secondary mining, partial or full pillar extraction was <br />completed, depending on conditions in the panel. <br /> <br />Longwall Mining Methods <br /> <br />MCC uses longwall mining technology to mine the B and E Seams. Longwall panel layouts <br />consist of gate-roads driven by continuous miners, a longwall face about 1,100 foot wide, and <br />necessary ventilation and conveyor entries, and barrier pillars. <br /> <br />After the ventilation and gate-road entries are completed, a longwall set-up or start room is <br />driven at the far end of the panel. Longwall equipment is moved in and assembled. Once <br />equipment is ready, the longwall system mines the panel in a retreat fashion until it reaches the <br />main entry barrier pillar. The equipment is then disassembled and moved to another panel.