ABSTRACT
In order to discover whether contrasting types of face group organization have any relationship to the level at which production is maintained, two longwalls—one organized on conventional and the other on composite lines—were compared. Both faces were in the same seam, at pits in the same neighbourhood. Geological conditions were alike as regards the nature of the coal, the type of roof and floor, and the dry and level character of the face areas, though minor differences existed in seam section and in amount of band (cf. p. 125). Both were double-unit panels with 80-yd faces either side of a mothergate. The same cutting technology was used and the haulage was similar. The primary task in both cases was the daily completion of a scheduled production cycle, and winding arrangements fixed the same relationship of tasks to shifts, with coal being filled off at specified times, alternating between foreshift and backshift.
