There have been a high number of surface and underground personnel that have been killed or permanently disabled as a result of working near machinery and powered haulage. In surface mining operations, an average of 2 to 3 mine workers are killed each year by being run over or pinned by mobile mining equipment. In underground mining, 33 fatalities were associated with miners getting caught, pinned or crushed by continuous mining machines during the 23-year period between 1988 and March 2011. In most cases the miners are well aware of the dangers, but they become preoccupied with operating their equipment and fail to notice when they or their co-workers stray into or are exposed to potentially hazardous situations. Part of the problem is that the workers attention can be divided among many tasks such as maintaining production goals, watching out for their own safety or that of their coworkers, and processing visual, tactile and auditory information.
NIOSH has developed an active proximity warning system called HASARD (Hazardous Area Signaling and Ranging Device) for warning workers as they approach known dangerous areas around heavy mining equipment and other dangerous work zones. HASARD is composed of a transmitter and a receiver. The transmitter generates a 73-kHz magnetic field using one or more wire loop or ferrite-core antennas. Each antenna is adjusted to establish a magnetic field pattern for each hazardous area. The receiver, worn by the worker, is a magnetic field strength meter. The received signal is compared against preset levels which are calibrated to identify levels of danger. The receiver outputs can include visual, audible, and vibratory indicators and it can also be made to disable machine functions. HASARD was field tested on a Joy 12 continuous miner, a Komatsu 210M Haulpak dump truck, and on a highwall launch vehicle. Slight modifications were made for each application. HASARD provided warnings as designed and proved to be rugged enough to withstand the harsh environment of underground mining.
Related publications:
- An Active Proximity Warning System for Surface and Underground Mining Applications (PDF, 3070 KB, 2001-02)
- HASARD Proximity Warning System Video
- HASARD - An Electromagnetic-Based Proximity Warning System
- Engineering Considerations and Selection Criteria for Proximity Warning Systems for Mining Operations
For more information on HASARD contact NIOSH Mining at OMSHR@cdc.gov.