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Doc Date:12H1/2001 111 IIIIIIIIIIlII III • • l'/~ • 3. 3 OVERBQRDSN RSlIOVI-L NST8OD8 3.3.1 EQIIIPE~SNT The primary piece of stripping equipment used at the Edna Mine was a Bucyrus Erie 1260-W, walking dragline. This machine was equipped with a 40-cubic-yard bucket and was capable of digging up to 120 feet in depth. The 1260-W used a variety of stripping methods including standard area stripping and side-cut Stripping. Standard area stripping was performed from the highwall side, whereas side-cut stripping was performed either from the highwall or spoil side of the active pit. The Edna Mine employed only a single dragline operation and typical methods are shown in Exhibits 3.3-1 and 3.3-2. The Edna Mine used three types of secondary stripping equipment. These included the DeMag H-111 backhoe type loader, rubber-tired scrapers and track type dozers. The DeMag H-111 backhoe was equipped with an eight-cubic-yard bucket and was capable of stripping 18 feet deep in a single pass. This machine was used to strip shallow overburden and/or interburden. Methods of stripping included standard area stripping, side-cut stripping and possibly truck-shovel. The rubber-tired scrapers were generally used to remove and replace topsoil, however, when necessary, these machines along with the tractor type dozers were used in shallow overburden to supplement our primary stripping equipment. They employed standard area stripping and side-cut stripping methods where applicable. When material was encountered which was inappropriate for scraper or tractor type dozer mining, a truck-shovel method was used. 3.3.1 !lI NINO 88QII8NC8 As described in the Geology Section (Section 2.1), the Edna Mine is on the eastern limb of the Twentymile Park Syncline. Thus, the surface minable coal was found on the ridges running generally north-south to the east of Trout Creek. • Renewal-3 3.3-1 October 21, 1996