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77.1900 iA)(3) Description of Construction Centennial Development Company P.O. Box 679 12692 S. Redwood Road Riverton, Utah 84065 MSHA I.D. * W-50 The shaft construction method for the shaft is to Co*+struct a shaft collar, drill a pilot hole into the mine, attach the raise bore head and upream to the partial excavation diameter of 5-feet. The muck from the shaft excavation will be removed from the shaft bottom by diesel scoop or continuous miner and teletrams. The operator will not be allowed within B-feet of the shaft wall. Following upreaming, the shaft will be concrete lined while slashing to an inside diameter of 16-feet using the drop form method, proceeding from the base of the collar downward. Adverse shaft wall conditions will be corrected immediately prior to lining by bolting and meshing as needed. At no time will work proceed further than fifteen feet below the limits of the form. The concrete will have a minimum set time of 12- hours between pours; however, if additives are used for quicker set times, the set time may be a minimum of 2 hours between pours if manufacturer recommendations allow this. (Optional) The air sweep(s) at the shaft bottom will be developed during the excavation for the raise head assembly or by using smooth-wall, controlled blasting after the lining has reached the top of the air sweep. Each air sweep will be bolted with 6-foot roof bolts on 4-foot centers with welded wire mesh and covered by a minimum 6-inches of shotcrete. 77.1900 (A)(4) Elevations and Dimensions Diameter (Excavated) - 16 feet Diameter (Finished) - 16 feet Collar Elevation - 6860 feet above sea level Depth to Coalbed - 101 feet 77.1900 (A)(5) Location and Elevation of Coalbed Coalbed - 6750 feet above sea level Elevation(top of Seam) - 6759.5 feet above sea level t Thickness - 9.5 feet f 5 APPRO~-~~U C«S ~ H ~~~ C~~~; 2 ~~ `95