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Flintlock Pit cuts range from approximately 3500 feet to over 5100 feet in length. When production <br />requirements are down, the machine in Flintlock Pit becomes a fill-in machine. As a result, a single cut may <br />• be open for as long as 18 months. Dozers may be employed to strip to the upper I and L seams in this pit. <br />The dragline will strip overburden to M seam at a pit width of approximately 150 feet. Once the M seam has <br />been extracted and the interburden is drilled and shot, the dragline will strip the interburden to Q seam from <br />the spoil side. As in all multiple seam pits at Trapper, interburden material that is not needed to build ramps <br />and pads to get up the hill may be spoiled on the second or third spoil row. For this mason, grading closer <br />than three spoil rows from the pit may be subject to additional spoil placement. <br />East Ashmore Pit cuts may range from approximately 900 feet to over 2000 feet in length. This is a single <br />seam pit utilizing production dozing in conjunction with dragline stripping to remove overburden to H seam <br />with a simple side cast method. Typically, this pit will cycle quickly, with a cut remaining active for only a few <br />weeks. However, should a significant drop in production requirements occur, a cut could remain open for up <br />to six months. <br />East Flintlock Pit (a.k.a Z pit) employs both dipline and strikeline cuts. In strikeline cuts, a dragline opened <br />box cuts along the strike with lengths ranging from 1000 to 2100 feet. Three seams, L, M and Q, are <br />uncovered and mined. Box cut spoils are placed downhill of the cuts. These materials will require widths of <br />up to 1000 feet or more to be left available below the crest of the first cut to allow sufficient room to blend <br />the spoils into the landscape. The box cut areas will be left open 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 <br />side stripping along the east/west 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. Occasionally, the L seam overburden is removed utilizing production dozing. After L seam is <br />uncovered, the parting between L and M seam will be shot, the dragline will then walk back to the opposite <br />end of the pit and begin uncovering M seam. Q seam will be uncovered in a similar manner with the <br />dragline stripping the parting between M and Q.seams. The dipline cuts in this pit start with a boxcut <br />immediately east of the limit of the strikeline pits. The orientation was changed to dipline to accommodate <br />• the changing structure. The dip of the strata steepens and shifts from a general northward trend to a <br />northeasterly trend. The K, L, M and Q seams are mined in the dipline pits. Production dozing is generally <br />employed to uncover the K and L seams. Dragline stripping is utilized to uncover the M and Q seams. <br />The Kimber (K) Pit is divided into two main blocks, a dragline block, and a truck and loader block. The <br />dragline block is one pass wide, along the ridge top. This block generally runs west to east. The <br />Truck/Excavator pit is further divided into 3 main blocks, A, B, and C. Each block is further divided into cuts <br />with a suitable width for truck and loader benches (avg. 150'). Mining in the truck and loader block will <br />begin in Block B, cut 1. <br />Each cut is further divided into mining horizons. These were developed for a loader with an assumed <br />maximum digging depth of 30'. This is the maximum horizon height. If overburden or interburden is thicker <br />than 30', it is divided into multiple mining horizons, therefore not all mining horizons will end at a coal seam. <br />Additionally, where burdens are thinner, variable depth mining horizons occur. <br />The first step in mining the K Pit will be to mine the K Ridge cut with the dragline. This should be <br />accomplished through sidecast, or spoil side digging, with the spoils being cast into Horse Gulch, lying to <br />the south. This should allow further stabilization of the slide zone by removing any tension that is remaining <br />in the overburden. This will also improve the safety of the truck and loader mining operation as it will <br />remove any excess material from upslope of the operation. This will be the extent of the planned dragline <br />involvement in K Pit. <br />As previously stated, truckand loader operations begin in cut 1B. The first two mining horizons will be <br />moved. At this point, the fleet will move to 26, and begin removing the first horizon. The goal of this <br />sequence is to have multiple faces accessible. This allows shipping to continue unimpeded by coal <br />removal delays. Additionally, this increases the overall highwall angle, increasing the stability of the highwall <br />face. The current sequence continues this staggering until mining is occurring in four pits at one time. <br />• When a lower numbered cut is completed, ie the Q seam is mined out, the next cut in the sequence is <br />opened. This means that cut 5B will not be opened until cut 1 B is complete. Three pits were chosen to <br />minimize surface disturbance. <br />3-39 Revision: ?2- -- <br />Li?-! /,, Approved: