ABSTRACT
The orthodox cutting longwall, which will be taken as a base for considering more highly mechanized systems, is itself a partially mechanized development of hand-got conveyor working, the getting and advancing phases being less mechanized than preparation. Unevenness of mechanization creates a technological disequilibrium in a work system which tends to have deleterious consequences in the socio-psychological dimension; these react back on the economic, and expected results are not obtained (vide p. 263).
