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An investigation into various elements influencing cycle times, payloads and utilization; the three key factors determining overall Heavy Mining Equipment efficiency.

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Research shows miners can be exposed to foot-transmitted vibration (FTV) when operating various pieces of underground mining equipment, and case reports suggest workers are experiencing symptoms similar to those of hand-arm vibration syndrome in their feet. A field study was conducted to measure and document FTV exposure associated with operating underground mining equipment, and probable health risks were determined based on both ISO 2631-1 (1997) for WBV and ISO 5349-1 (2004) for HAV. Seventeen participating operator’s also reported musculoskeletal discomfort. Seventeen male participants ranging between 24-61 years of age, with an average height and mass of 175.0cm and 88.2kg volunteered for the study. Seventeen pieces of equipment were tested; 1 locomotive, 1 crusher, 9 bolter drills (4 scissor platforms, 2 Maclean, 2 Boart/basket, and 1 RDH), and 6 jumbo drills. Including all seventeen pieces of underground mining equipment, the vibration acceleration ranged from 0.13-1.35m/s2 with dominant frequencies between 1.25-250Hz according to ISO 2631-1. According to ISO 5349-1 vibration acceleration ranged from 0.14-3.61m/s2 with dominant frequencies between 6.3-250Hz. Furthermore, the magnitude of FTV measured on the jumbo drills with grated platforms (#5 and #6) was less than FTV measured from the jumbo drills with, solid metal surfaces. Additionally, twelve of the seventeen equipment operators indicated a complaint of discomfort in their lower body (specifically at the level of the knee or lower). The health risk analysis based on ISO 2631-1 indicated that one operator (bolter drill #9) was exposed to vibration above the criterion value, while the health risk analysis based on ISO 5349-1 indicated iv that two operators (jumbo drill #1 and bolter drill #1) were exposed to vibration above the criterion value. Operators reported very severe or severe discomfort; however, the same operators were not the operators of the equipment with FTV exposure levels above the ISO standards, leaving evidence to suggest that the standards are not properly assessing injury risk to vibration exposure via the feet. Future research is needed to develop a standard specific for FTV and to determine the link between early musculoskeletal injury reporting and the onset of vibration white foot. To do so, a better understanding of the biodynamic response of the foot to FTV is needed. A laboratory study was conducted to 1) measure and document transmissibility of FTV from (a) floor-to-ankle (lateral malleolus), and (b) floor-to-metatarsal, during exposure to six levels of vibration (25Hz, 30Hz, 35Hz, 40Hz, 45Hz, and 50Hz) while standing, and 2) to determine whether independent variables (vibration exposure frequency, mass, arch type) influence transmissibility (dependent variable) through the foot. A two-way repeated measures analysis of variance (ANOVA) was conducted. There was a significant interaction between transmissibility location and exposure frequency (λ = 0.246, F (5,25) = 15.365, p = 0.0001). There were significant differences in mean transmissibility between the ankle and metatarsal at 40Hz [t(29) = 4.116, p = 0.00029], 45Hz [t(29) = 6.599, p = 0.00000031], and 50Hz [t(29) = 8.828, p = 0.000000001]. The greatest transmissibility at the metatarsal occurred at 50Hz and at the ankle (lateral malleolus) transmissibility was highest from 25-30Hz, indicating the formation of a local resonance at each location. v Future research should focus on identifying resonance frequencies at different locations on the feet. This information is needed to develop an exposure guideline to help protect workers from exposure to FTV, and to develop personal protective equipment capable of attenuating harmful FTV exposure frequencies.

M.Com. (Business Management) / Background Best cost country sourcing is a relatively new concept and not many organisations are utilising this specific process nor are they optimising this as their sourcing strategy. Best cost country sourcing is one of the most profound sourcing processes available, and it has the ability to increase an organisation’s efficiency and effectiveness if implemented correctly. Purpose The purpose of this study is to determine if best cost country sourcing should be used as an alternative to local sourcing. It includes aspects of the best cost country sourcing process as well as its risks and advantages. Research method The dissertation analyses the process of best cost country sourcing and the effect it has on an organisation’s sourcing strategy. To achieve this understanding it is necessary to do a qualitative investigation, which is the reason a qualitative research was used as the research methodology in this dissertation. Conclusion Pursuing the process of best cost country sourcing requires a lot of dedication and implementation time. It is a complicated process and no two situations will be alike. Each organisation would need to determine the advantages, risks and challenges which they will encounter with best cost country sourcing. Organisations would also need to determine the best cost countries, as well as the criteria they would need to use in selecting potential suppliers.

The object of this thesis is to establish the necessary design criteria for a number of special feedback networks which were required to allow the final development of the Strip Mining Industry's first Automatic Crowd-Hoist Regulator. The introduction considers the purpose and needs for such a regulator by briefly outlining the present manual dipper loading operation. Section IV and Appendix 1 presents the analytical system requirements which are basically determined from an analysis of the system's inherent mechanical oscillatory frequency. Section VA is concerned with the development of the hoist and crowd motion transfer functions which are necessary to accomplish the stability analysis of the system. A general determinantal solution is obtained based on linear analysis to allow expression of the motion transfer functions as a factored polynomial. In section VB, the development of the necessary Crowd-Hoist feedback circuits is accomplished in terms of the system parameters defined from the analysis of the oscillatory mechanical system. Section VIA outlines the procedures to be followed in going from the basic mechanical system parameters to the specific control system hardware. The general requirements for a Bode analysis of the system GR is defined in section VIB, including the general procedures to follow in the utilization of the two lead compensation circuits provided. / M.S.

A self-contained self-rescue unit is a device that is used in the mining industry in case of fires or release of toxic gases that depletes or contaminates breathable oxygen in the surrounding atmosphere. These units are the first line of defense by providing oxygen in a closed breathing cycle, allowing personnel to get themselves to safety. The goal of this project was to design a unit that is more comfortable to carry during the daily operations in and outside the mines. A unit that is easier to done and less likely to damage the users and/or surrounding mining equipment. It is developed in close collaboration with Atlas Copco, as the main sponsor, as well as Dräger and personnel working at Zink Gruvan Mining.  The result is a unit with an operational time of twenty minutes and a reduced size and weight. It’s position can be adjusted to be worn around the waist or the chest, depending on the tasks the user performs, as well as simplifying the donning procedure.

M. Tech. Industrial Engineering / The Reconfigurable Vibrating Screen is a newly designed beneficiation machine to be used for mineral particle separation in mines and quarries with adjustable screen capacity and structure in order to respond to changes in production and quantity demand required by the customers. In order to increase the durability, availability, reliability and maintainability of a reconfigurable vibrating screen, an effective method is required to functionally appraise and improve its working condition. The aim of this study is to develop a tool for functionally assessing reconfigurable vibrating screens and existing vibrating screens.

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