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~~- ~~ • • lllllilllllllllllll blue ~•,~ ribaon CO company Mr. 'Pom Gillis Reclamation Specialist Mined Land Reclamation 1313 Sherman Street Denver, CO 80203 Re: Blue Ribbon Mine Request for Minor Revision Your File No. C-047-81 Dear Tom: blue ribbon coal company p.0. bGR b8 delta, coloredo 81416 130') 87475(31 Octobur 29, 1981 -' I1„) Blue Aibbon Mine has been encountering difficult mine roof conditions for more than two months. The five entry development system was narrowed to three entries with the belief that limiting the total mining width to less than the maximum pressure arch could aid roof stabilization. Although the three entry experiment resulted in noticeably less pressure on the coal ribs, little improvement in immediate mine roof control occurred. Mine management has now determined that conditions are not acceptable to continue and that a retreat plan recovering as much coal as is safely possible should be started. This request for a minor modification is based~on our previous phone conversations and speciLicalLy your call. last Friday, October 23, 1981. A belt retraction was completed October 23, 1981 and ventilation changes have been made to allow for room development. Although the minor modifica- tion is requesCed due to an alteration in the timing and sequence of mining coal in the same area (same federal lease, etc.), one significant difference from the Technical Revision (October 15, 1981 was the ML RD approval dale) does follow. That deals with the first date for secondary mining. In order to recover a reasonable percentage of the available coal, a decision regarding secondary minis}; must he made before November 13, 1)81. Blue Ribbon is projecting that dr•veLopment of Urm 5 East rooms will he completed by November 16, 1981. A reduced map, a partial Exhibit C, from the permit application is attached with the modified sequence. An accurate three month projection is very difficult at tl.is time because mining rate will be dependent on the secondarv mining decision. Blue Ribbon Coal proposes the Following: 1. Develop 5 East rooms as projected, 80' x 80' C.L. 2. Perform secondary mining on those rooms and the adjacent chain pillars, leaving proper support in the northern most room entry for adequate ventilation.