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Flintlock Pit cuts range from approximately 3500 feet to over 5100 feet in length. When production requirements <br />are down, the machine in Flintlock Pit becomes afill-in machine. As a result, a single cut may be open for as <br />• long as 18 months. The dragline will strip overburden to M seam at a pit width of approximately 150 feet. Once <br />the M seam has been extracted and the interburden is ri a an shot, the dragline will strip the interburden to <br />O seam from the spoil side. As in all multiple seam pits at Trapper, interburden material that is not needed to <br />build ramps and pads to get up the hill may be spoiled on the second or third spoil row. For this reason, grading <br />closer than three spoil rows from the pit may be subject to additional spoil placement. F~; f t~ ~ .Q Seo-~Q <br />East ~hmore Pit cuts m;ay range from approximately 900 feet to over 2000 feet in length. This is a single seam <br />pit with the dragline stripping overburden to I seam with a simple side cast method. Typically, this pit will cycle <br />quickly, with a cut remaining active for only a few weeks. However, should a significant drop in production <br />requirements occur, a curl could remain open for up to six months. F-~ f} Z sa.t,-,.,.~ <br />ri ~., <br />East Flin~tloc~k Pte' and Gatlin its employ strikeline cuts. A dragline opens box cuts in both of these pits along <br />the s rl~e with lengths ranging from 1800 feet to 3000 feet. Three seams, L, M and O, will be uncovered and <br />mined. Box cut spoils will be placed downhill of the cuts. These materials wi req'll airs widths of up to 1000 feet <br />or more to be left available below the crest of the first cut to allow sufficient room to blend the spoils into the <br />landscape. The box cut areas will be left open for several years until the pits have progressed up the hill a <br />sufficient distance so that regrade operations can begin. Draglines will uncover coal seams from the spoil side <br />stripping along the eastlwest strike. The maximum amount of time that these cuts will be open will be <br />approximately six months. Cast blasting methods will be utilized to aid the dragline in uncovering the top L <br />seam. After L seam is ~incovered, the parting between L and M seam will be shot, the dragline will then walk <br />back to the opposite end of the pit and begin uncovering M seam. O seam will be uncovered in a similar <br />manner with the dragline stripping the parting between M and Q.seams. <br />The final cut in any give pit may be open for as long as 18 months as the need to remove coal to allow for <br />continuous stripping operations is not a factor. Final cuts are a logical area to carry inventory. <br />Due to spoil side stripping techniques employed at Trapper, extra room is needed to effectively place spoils. <br />• Taking into consideration that the shortest cycle time in Flintlock Pit leaves the pit active for 230 days and that <br />the interburden will be cast as far as three previous cuts, it is not possible to regrade the spoils wi in 180 days <br />after coal removal. For Trapper Mine's contemporaneous regrade criteria, grading will progress such that there <br />will be no more than three unregraded spoil rows, including the active spoil row at any one time in each pit. A <br />pictoria view ot^the dcwble pass s ripping operation is shown in Figure 3.5-1. This figure presents a <br />simplification of the Trapper stripping operation and shows graphically why three spoil rows are required. <br />• <br />3-39 Revision• (~ fi. - ~ <br />Appra~J: ~~ <br />