2025-05-05_PERMIT FILE - C1981010 ‎(32)‎

• Permit No: C1981010
• IBM Index Class Name: Permit File
• Doc Date: 5/5/2025
• Doc Name: Inwall HWM Sequence Analysis
• Section_Exhibit Name: Appendix X-II 534-61
• Media Type: D
• Archive: No

Tonia Perkins
July 31, 2024
Page 4
Agapito Associates, Inc.
Figure 2(a). Web Pillar Design Table and Chart for the M Seam in N-Pit
Design
Depth of Cover, ft 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8
80 2.3 2.4 2.6 2.8 3.3 3.7 4.0 4.4 4.8 5.3 5.7 6.0 6.4
95 2.4 2.7 2.8 3.0 3.3 3.7 4.0 4.4 4.8 5.3 5.7 6.0 6.4
110 2.8 3.0 3.2 3.3 3.5 3.7 4.0 4.4 4.8 5.3 5.7 6.0 6.4
125 3.0 3.3 3.5 3.8 3.9 4.1 4.3 4.4 4.8 5.3 5.7 6.0 6.4
140 3.3 3.6 3.8 4.1 4.3 4.5 4.7 4.8 5.0 5.3 5.7 6.0 6.4
155 3.5 3.8 4.2 4.4 4.7 4.9 5.1 5.3 5.5 5.7 5.8 6.0 6.4
170 3.8 4.2 4.5 4.8 5.1 5.3 5.6 5.8 6.0 6.2 6.3 6.5 6.7
185 4.0 4.4 4.8 5.1 5.4 5.7 6.0 6.3 6.4 6.7 6.8 7.1 7.3
200 4.3 4.7 5.1 5.4 5.8 6.1 6.3 6.7 6.9 7.2 7.4 7.6 7.8
215 4.4 4.9 5.3 5.8 6.1 6.5 6.8 7.1 7.3 7.7 7.9 8.2 8.3
230 4.7 5.2 5.7 6.1 6.5 6.8 7.2 7.5 7.8 8.1 8.4 8.7 8.9
245 4.9 5.4 5.9 6.4 6.8 7.3 7.6 7.9 8.3 8.6 8.9 9.2 9.5
260 5.1 5.7 6.3 6.7 7.2 7.6 8.0 8.3 8.8 9.1 9.4 9.8 10.0
Coal strength, psi 766 Mining width, ft 11.50 No. web pillars 9
Pillar widths in italics have width-to-height ratios of 0.8
Mining Height, ft
0
2
4
6
8
10
12
0
20
40
60
80
100
120
140
0 50 100 150 200 250 300 REQUIRED WEB PILLAR WIDTH, ftREQUIRED WEB PILLAR WIDTH, in DEPTH OF COVER, ft
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
Mining
Height,
ft