The objective of this research was to introduce a workable longwall mining system into the Illinois No. 6 Seam. This appendix contains the results of the premining investigation in which the groundwork was done to select a roof support system. The premining investigation included (1) an analysis of bearing capacity of roof and floor rock in the vicinity of the projected longwall area, (2) a geological study comprising rock strata and faulting information, (3) a summary of previous longwall attempts, and (4) stress analysis on chock-type roof supports salvaged from a longwall face abandoned in 1967. Recommendations from the premining investigation led to the selection of shield-type roof supports. The primary advantage of the shields compared with chock-type powered support is greater stability. Shield-type roof supports are a three-jointed, kinematically determinate system that can easily advance while the canopy is in contact with the roof. All other powered support systems are four-jointed, kinematically indeterminate, and require holding springs or other devices for stability.