Hazard Evaluation Methodology for Computer-Controlled Mine Monitoring/Control Systems

A summary of results of the development of a methodology for identifying safety hazards inherent in underground monitoring and control equipment will be given. Under a US Bureau of Mines contract, a methodology has been developed for determining the inherent design items that affect safety hazards. Though serious consideration has already been given to the normal intrinsic safety and explosion-proof characteristics of a system, the problem may be the system itself rather than the more immediately noticeable system components. In monitoring or controlling items located in underground coal mines, the hardware reliability of a system is seldom recognized as a potential safety hazard. The software or program operating such a system is never considered as a potential safety hazard because it is, in many cases, located outside the hazardous area. In reality, electronic technology is outstripping the industry's normal view of safety and is quickly growing unseen potential safety problems. These unseen problems are a combination of hardware and computer software that must be identiried and analyzed. The methodology developed for analyzing electronic and computer-based hardware/software systems and the results of analyses completed by the West Virginia University (WVU) research team are presented. A WVU-designed distributed microprocessor-based mine environmental monitoring/control system and two other commercially available systems have undergone detailed analyses. As a result of the developing methodology, a set of design guidelines has been developed to ensure that known system design difficulties can be identified from the outset for designers of new mine monitoring/control systems.