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

• Communications, location tracking, and signalling
• Leaky feeder communications systems
• Mine monitoring
• Mine phones

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.