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FIRST-HALF 2005 SUBSIDENCE REPORT <br />I. Survev Data• <br />During the first-half of 2005, subsidence survey data was collected from mid-January <br />through mid-April on established monuments on the Union Pacific Railroad spur (UPRR) <br />in areas underlain by gate-roads or panel centers during periods of mining in the 17-Right <br />(Panel No. 17) longwall panel. In eazly August, mining in the 17-Right panel was <br />approximately 11,300 feet past the point on the raikoad where the longwall face/track <br />intersects the tailgate entry. Along with mining under the UPRR, the panel passed <br />underneath Fish Creek. As reflected in the data and on the attached subsidence map, the <br />17-Right longwall panel did not directly undermine the Walcott, Hayden-Gore Pass, or <br />Western Area Power Administration powerlines. <br />The data and frequency for the survey monuments along the UPRR aze presented in the <br />attached Table No. 1. The survey of Fish Creek will be completed in August 2005 and <br />will be submitted along with the second-half 2005 subsidence report. <br />II. Structures: <br />No structures other than the UPRR were affected during the first-half of 2005 reporting <br />period. As noted above, in August 2005 mining in the 17-Right panel was approximately <br />11,300 ft past the point on the UPRR where the longwall face/track intersects the tailgate <br />entry. <br />Visual inspections of the UPRR by UPRR personnel were conducted from January 26, <br />2005 through February 13, 2005. Daily surveys and observations of the UPRR over <br />Panel 17-Right were also performed by Twentymile Coal Company (TCC) personnel <br />from January 19, 2005 through Mazch 11, 2005. Follow-up reports on the survey data <br />and observations were submitted to UPRR personnel on a daily basis. <br />Panel No. 17 is the last panel in the North Mining District to undermine the UPRR. Final <br />re-leveling of the rail-line to the postmining tazget level will be performed by the UPRR <br />in the summer/fall of 2006 on an as-needed basis. A follow-up survey will be performed <br />at that time and a final report, reflecting final survey data, will be submitted to the UPRR. <br />Structures remained essentially unaffected during the reporting period, with the exception <br />of the predicted impacts to the UPRR and Fish Creek from first-half 2005 mining. No <br />adverse impacts, i.e. imminent failure of structures, were evident with regazd to these <br />structures. No repair work, beyond the future minor realignment noted above, will be <br />required on the UPRR to address subsidence resulting from TCC's mining activities. <br />2005_IstHaltSubReport.doc Page 1 of3 7/21/2005 <br />