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West Elk Mine feet, where the extraction thickness is 12 feet, and from 8.4 to 11.2 feet (0.6 to 0.8t), where the extraction thickness is 14 feet. • Panel E9. This panel trends about N10°E and is of supercritical width. 1. Maximum vertical displacement above the chain pillars in this shallow overburden is expected to range from 1.2 feet (O.lt), where the extraction thickness is 12 feet and from 1.4 feet (O.lt), where the extraction thickness is 14 feet. 2. Maximum subsidence is projected to range from 8.4 to 9.6 feet (0.7 to 0.8t), where extraction thickness is 12 feet, and 9.8 to 11.2 feet (0.7 to 0.8t), where the extraction thickness is 14 feet. Maximum Tilt Maximum tilt (Mm) was calculated from differential vertical displacements at the West Elk Mine monitoring network in terms of the ratio of maximum vertical displacement to overburden depth (5,,,/d in dimensionless units L/L). Tilt values at West Elk Mine range from 0.014 to 0.021 dimensionless units (L/L). Maximum tilt in four different mining areas of the Western United States ranges from 2.5 to 5'(S m/d). fiche Rocks Minin Area -Based on analysis of the current West Elk Mine subsidence monitoring network, and using an average value of 2.7 (5,,,/d), tilt above the eastern panels is projected to range from about 0.006 in the southern flank of West Flatiron to about 0.027 near the head of Sylvester Gulch. TIlt above the western panels, for E Seam mining only, is projected to range from 0.017 on the higher ridge areas to about 0.048 in the lower areas of Horse Gulch. Following completion of E and B Seam mining, filt is projected to range from about 0.033 on the higher ridges to 0.085 in Horse Gulch. Box Carryon Mining Area -Maximum tilt, based on analyses of West Elk Mine subsidence measurements, is projected to range from 0.004 beneath West Flatiron to 0.035 above the northernmost panel beneath Box Canyon. South of Divide MininQArea -Tilt above the nine longwall panels (panels El-E9) within the South of Divide mining area is projected to range between 2.2 and 2.3 Sm/d for coal extraction thickness ranging between 8 and 14 feet. These values are based on subsidence measurements at West Elk Mine (Table 1, and Figure 5 of Exhibit 60B). As represented in Table 2 of Exhibit 60B, the overburden depth ranges from 400 to 1,425 feet. • Panels El to E8. Maximum tilt in these panels is projected to range from 0.007 to 0.037 (0.7 to 3.7 percent) where 8 feet of coal is extracted, from 0.013 to 0.044 (1.3 to 4.4 1.05-//6 Revised November 2004 PRIG