Studies of Development Methods for Improving Mining Equipment and Processes with Case Histories from Hard Coal Mining.

The limits which a number of machines and devices currently used with great success in hard coal mining have reached are illustrated by the example of longwall mining with fully mechanized operational equipment. A new methodological procedure for developing substitute technologies for coal mining as quickly and purposefully as possible and with minimum risk is proposed. Three examples of the successful use of this procedure are presented - namely, the development of a flexible anchoring device, a bent drilling process, and a new type of chain.