Coal Mine Rescue and Survival System. Volume II: Communications/Location Subsystem.

摘要

Volume 2of the Coal Mine Rescue and Survival System covers electromagnetic and seismic equipment for locating and communicating with workers trapped underground either behind barricades,in refuge chambers,or attempting to escape. The electromagnetic (EM) voice downlink and coded beacon uplink were tested and qualitatively and quantitatively evaluated at five different coal mines. In the voice downlink test,intelligible voice transmission was received at each mine using a horizontal wire transmitting antenna terminated in the ground at each end. Coded beacon transmissions also were detectable on the surface. Theoretical and experimental studies indicate that this EM system could be effectively used in rescue operations in about 90percent of all coal mines in the United States provided that these mines were equipped with subsurface EM transmitters and receivers. Further testing,however,was recommended including operation of the Communications/Location Subsystem in a continuing training program. (Author)