Independent Review of MSHA's Actions at Crandall Canyon Mine

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technical guidance from someone experienced with the program, the Crandall Canyon pillaring proposal would be difficult for the first time LAMODEL user to analyze. The engineer stated that he attempted to run LAMODEL but that he encountered problems and abandoned his effort. Furthermore, although the LAMODEL program was available to District personnel, the AutoCAD ® program that facilitates creating the mine grid for LAMODEL was essentially unavailable. (Only one copy of AutoCAD ® existed for the entire District office, and it was installed on a computer that was not readily available to the Technical Programs group.) The District’s review of the LAMODEL portion of the supporting data was, in essence, reduced to a comparison of the input parameters that the consultant used, to those suggested by the default values of the program. No independent verification of the modeling was obtained, and no in-depth analysis was conducted by District 9. The second AAI report submitted by the Company contained an ARMPS analysis which the engineer was able to evaluate. ARMPS was developed in 1995 by the former U.S. Bureau of Mines (now NIOSH) and is widely used within the mining community to aid in designing pillars for room and pillar retreat mines. As mentioned before, ARMPS is an empirical program, based on more than 250 case studies, and is very user-friendly. The user simply inputs basic parameters such as overburden thickness, mined height, entry width, and basic mine geometry. The program determines a stability factor by comparing the load-bearing capacity of the pillars to the estimated applied load. The stability factor can then be compared to the case studies in the program’s database, or against site-specific areas within the mine being analyzed. ARMPS also calculates a stability factor for barrier pillars between the active workings of the mine and gob areas. As part of his evaluation of the ARMPS analysis conducted by AAI, the engineer also ran his own evaluation using ARMPS. Neither the District ARMPS analysis, nor the one conducted by AAI, examined the stability factor of the barrier pillar between the longwall gob area to the north and the new entries developed into the North Barrier of Main West. Research conducted by the developers of the ARMPS software concluded that barrier pillars are especially important in bump-prone, deep cover areas. The ARMPS program resource files include a paper entitled, “Deep Cover Pillar Extraction In The U.S. Coalfields” that states: “Barrier pillars are an essential element in deep cover retreat mine design. Traditionally, barrier pillars have been employed to isolate active panels from adjacent gobs as a stress control technique. As the cover deepens, it becomes more important to isolate the active panel from side abutment loads transferred from the adjacent mined out workings by employing barrier pillars. An important design issue is just how wide the final remnant or inby barrier pillar (after rooming and/or slabbing) should be. This topic is a critical and life threatening design concern in highly stressed environments because of the historically high occurrence of bump incidences during 18
partial and full barrier pillar extraction.” 2 The NIOSH researchers found that when the barrier pillar stability factor is greater than 1.9, no bumps occurred. The ARMPS “help file” on stability factors states that “the use of substantial barrier pillars also increases the likelihood of success.” Despite such a recommendation, the District 9 ARMPS analysis did not examine barrier pillar stability in any way. Furthermore, the District did not question the mine operator about why the AAI analysis did not discuss barrier pillar stability factors. The importance of the barrier pillars can best be understood by examining the report prepared by NIOSH for the United States Senate, in which the August bounce events at Crandall Canyon were analyzed. 3 The ARMPS analysis conducted by NIOSH concluded that the Barrier Pillar Stability Factor (BPSF) for the remnant barrier pillar that remained after the development of the four entries in the North Barrier was 0.95. Likewise, NIOSH calculated a BPSF of 0.91 for the remnant barrier that was left to the south after the fourentry development into the South Barrier. Both remnant barrier stability factors were less than half of the NIOSH recommended BPSF of 2.0 for deep cover, bump-prone areas. The NIOSH report concluded, “that the two remnant barrier pillars were probably the key elements in the Crandall Canyon pillar design,” and that, “the ARMPS program indicates that an elevated risk of bumps was present in the Crandall Canyon West Mains area, due to the deep cover and the low barrier pillar stability factors of the remnant barrier pillars.” In addition to the failure to examine the barrier pillar stability factors, the District 9 ARMPS analysis only evaluated the proposed mining in the North Barrier section. No independent analysis was ever conducted by District 9 for mining in the South Barrier section. Davis and Knepp are ultimately responsible for approval of plans in District 9. Both were aware that mining was being proposed for the barrier pillars at Crandall Canyon. Mining barrier pillars between gobs under deep overburden was not a typical mining technique, and Davis and Knepp should have provided oversight during the review process for this request. However, neither questioned Owens on his evaluation of the plans for mining the North and South Barriers at the Crandall Canyon Mine. Conclusion: District 9 failed to conduct a comprehensive review of the supporting data submitted by the mine operator in order to justify mining in the barriers to the North and South of Main West. The District reviewers did not adequately analyze the LAMODEL report, nor did they recognize the importance of Barrier Pillar Stability Factors. 2 Deep Cover Pillar Extraction In The U.S. Coalfields, Proceedings, 21st International Conference on Ground Control in Mining, Frank E. Chase, Christopher Mark, and Keith A. Heasley. 3 Evaluation and Control of Coal Bumps, Office of Mine Safety and Health Research, NIOSH, September 28, 2007. 19
Page 1: Independent Review of MSHA’s Acti
Page 4 and 5: Protective Ground Support Used Duri
Page 7: Location of March Bounce Last Known
Page 10 and 11: EXECUTIVE SUMMARY The Federal Mine
Page 12 and 13: • Persons who could have contribu
Page 14 and 15: There was no lack of hard work and
Page 16 and 17: BLM INSPECTIONS OF CRANDALL CANYON
Page 18 and 19: oxygen and dust into the fresh air
Page 20 and 21: MSHA’S ACTIONS PRIOR TO AUGUST 6,
Page 22 and 23: that the proposed retreat sequence
Page 24 and 25: On February 23, 2007, District 9 re
Page 28 and 29: District management’s oversight w
Page 30 and 31: elieved that a higher stability fac
Page 32 and 33: questions were asked in an attempt
Page 34 and 35: offset between crosscuts 139 and 14
Page 36 and 37: To determine the validity of the in
Page 38 and 39: disapproval to the District Manager
Page 40 and 41: amendments for the South Barrier re
Page 42 and 43: The following table contains certai
Page 44 and 45: The Price Field Office did not inve
Page 46 and 47: The inspector stated that this even
Page 48 and 49: conducted every seven days. However
Page 50 and 51: Recommendation: MSHA should establi
Page 52 and 53: DIRECTION AND ACTIVITIES DURING THE
Page 54 and 55: 111-8, which was in effect at the t
Page 56 and 57: MSHA Person-In-Charge of Mine Rescu
Page 58 and 59: Davis stated that when Stickler and
Page 60 and 61: There was also no verification that
Page 62 and 63: employee stated, “Everybody got f
Page 64 and 65: Underground Phone Communication Sys
Page 66 and 67: PROTECTIVE GROUND SUPPORT USED DURI
Page 68 and 69: equipment to tram in and out of the
Page 70 and 71: Top of Rockprop Bottom of Rockprop
Page 72 and 73: Canyon the inby end of the ropes wa
Page 74 and 75: educed to writing and served to the
Page 76 and 77:
planned to film the underground res
Page 78 and 79:
Stickler stated that family members
Page 80 and 81:
Conclusion: MSHA failed to enforce
Page 82 and 83:
Later on August 6 th , a mine rescu
Page 84 and 85:
anybody sit down with the MSHA peop
Page 86 and 87:
EXPLORATIONS During the underground
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since the ribs could not further ex
Page 90 and 91:
DRILLING OF BOREHOLES Boreholes pla
Page 92 and 93:
pump for a period of time, the meas
Page 94 and 95:
After this hole was drilled, MSHA
Page 96 and 97:
The borehole showed there was no vo
Page 98 and 99:
RISK VERSUS VALUE In all rescue and
Page 100 and 101:
stoppings to crosscut 95 would also
Page 102 and 103:
section were equipped with Self-Con
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data, the idea was not pursued any
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for an hour and one-half and then w
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sampling equipment to their truck a
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Agency. The handbook consisted of 9
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updates and briefings on the rescue
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Utah Governor Jon Huntsman, Jr., MS
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Stickler contradicting or correctin
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trapped miners should, to the exten
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Conclusion: The MSHA person-in-char
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An attachment to the policy sets fo
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air and water waiting for us to com
Page 126 and 127:
Davis did clarify that there was no
Page 128 and 129:
the family and press briefings, and
Page 130 and 131:
emergency with role-playing by all
Page 132 and 133:
MINER ACT AND MINE EMERGENCY EVACUA
Page 134 and 135:
Post-Accident Communications The MI
Page 136 and 137:
Recommendation: The Agency should d
Page 138 and 139:
At the time of the accident, the ER
Page 140 and 141:
locations, and along normal travel
Page 142 and 143:
CMS&H STAFFING AND RESOURCE UTILIZA
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CMS&H STAFFING LEVELS District staf
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In addition to the decreased levels
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completion rate decreased dramatica
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Other specialists had limited inspe
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ALLEGATIONS OF INFLUENCE BY THE MIN
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GENERAL CONCLUSION Internal Reviews
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APPENDIX A LIST OF PERSONS INTERVIE
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Moore, III, Clarence W. ...........
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List of Ground Control Panel Member
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Event Number Activity Code Genwal R
Page 171 and 172:
Borehole #3 Location: #4 Entry, X-c
Page 174 and 175:
Oxygen Content of Air: Sign and Sym
Page 177 and 178:
EFFECTIVE DATE: 12/22/2006 EXPIRATI
Page 179 and 180:
Act, Pub. L. No. 109-236, June 15,
Page 183:
APPENDIX G PROGRAM POLICY LETTER NO
Page 186 and 187:
2006. The MINER Act requires that t
Page 188 and 189:
The above table is based on the 199
Page 190 and 191:
2. Inflatable shelters or equivalen
Page 193:
APPENDIX H PROGRAM INSTRUCTION BULL
Page 196 and 197:
I. Quantity of Breathable Air. In d
Page 198 and 199:
What is MSHA's authority for this P
Page 201:
NORTH BARRIER Last Known Location o
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Independent Review of MSHA's Actions at Crandall Canyon Mine

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