Conveyance monitoring to improve mine hoisting safety

Technology to enhance safety during mine hoisting is being investigated by researchers at the Spokane Research Center National Institute for Occupational Safety and Health, USA. The objective is to test sensor technology and engineering controls to prevent injuries and fatalities related to vertical movement of personnel and materials in mine shafts. Improved monitoring and inspection technology will provide operational data on the mine shaft conveyance to a hoist operator in real time and warn of potentially dangerous situations. Assessment of current technology determined what conditions and equipment should be monitored and the availability of appropriate sensors. A state-of-the-art hoisting facility was constructed, and new sensors and data acquisition interfaces were developed. A computer-based system controls the hoisting motor, material loading and dumping and related hoisting functions. A new sensor was developed to determine conveyance loads and slack and tight rope conditions. Data on wire rope tension, conveyance position and guide displacement are acquired with a custom-designed data acquisition board. Data transmission up the shaft has been successful for a distance of 600 m (1800 ft) via 2.4 GHz, spread-spectrum modems when using a directional antenna. Data are received with a patch antenna and transmitted to the serial port on a personal computer and processed with a Visual C++ computer program.