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<br /> <br />JOHN F. ABEL, JR. <br />MINING ENGINEER <br />310 LOOKOUT VIEW COURT <br />GOLDEN, CO 80401 <br />303-2794901 <br />FAX 2788163 <br />JFADet]®HOme.com <br />November 8, 2000 <br />Tom Anderson <br />Oxbow Mining Inc. <br />P.O. Box 535 <br />Somerset, CO 81434 <br />REFERENCE: Safety benching above D Seam portal <br />Dear Tom: <br />A safety catch bench is essential at the base of the lower <br />sandstone bed at the top of the slide mass. The safety catch bench <br />will help protect the crew excavating part of the up slope slide <br />mass from rolling rocks. The safety catch bench can, if access is <br />maintained and the bench periodically cleaned, provide rolling <br />rock protection of the D Seam portal area during the life of the <br />mine. <br />The shortterm purpose of this catch bench is to prevent <br />blocks of sandstone that may detach from the two sandstone beds, <br />and could otherwise roll uncontrolled down the slide area, while <br />the cut slope is being excavated. Without a catch bench at the top <br />of the cut slope the men working on the slope will be at risk. The <br />purpose of the slope excavation is to enhance the stability of the <br />slide mass by reducing the driving force on the slide surface. <br />Part of the excavated slide material will be used to load the toe <br />of the slide which will increase the sliding resistance of the <br />slide mass. <br />The long-term purpose of the recommended catch bench <br />immediately below the lower sandstone bed is to prevent blocks <br />that may detach from either of the two sandstone beds outcropping <br />above the slide area from rolling down toward the D Seam portal <br />area. It will be necessary to periodically remove the debris that <br />will collect on the catch bench in order for the catch bench to <br />function effectively throughout the active life of the D Seam <br />portal. Access will have to be maintained to the catch bench <br />which will necessitate continued maintenance of the pioneer road <br />up the cut slope until the D Seam mining is complete. <br />A catch bench is most effective, i.e. will retain the maximum <br />volume of debris, and, therefore, will last longer if it slopes <br />inward toward the slope and includes a berm along the outer edge. <br />