Mining Publication: A Communication and Monitoring System for an Underground Coal Mine, Iron Ore Mine, and Deep Underground Silver Mine

Advanced communication and monitoring systems were developed and demonstrated in three underground mines representing different mining techniques, geographical areas, and material mined. The first was a large coal mine in western Pennsylvania using room-and- pillar techniques and continuous mining methods. The system developed provided private telephone channels, environmental monitoring, and control of underground equipment, all on a single coaxial cable, with all system operations under the direction of a minicomputer. The second was a magnetite ore mine in eastern Pennsylvania that used block caving mining techniques. A radio system was developed that provided two-way communications between trackless vehicles and roving personnel. A unique system of UHF-VHF repeaters combined with a "leaky-feeder" transmission line offered operational and emergency features not previously found in mine communication systems. The third was a deep silver mine in the cour d'Alene District of Idaho. This system utilizes a single wire pair to provide up to 14 voice channels. A combination of pbx, telephone carrier systems, and intercom offered private conversations, selective signaling, and emergency backup communications.