South Africa is one of the largest producers of explosives in the world. The production of explosives is driven by the mines’ need for explosives to produce the commodities needed by the economy. South Africa used to offer a diploma in explosives technology, but this qualification was discontinued in 1996. Currently some qualifications in explosives management are being presented, but these qualifications do not fulfil the industry's need for technical education in explosives. The South African explosives industry reports that they need technical education in explosives. Because the explosives industry is relatively small in terms of personnel numbers, tertiary educational institutions are hesitant to establish a degree in explosives engineering or a similar qualification. The aim of the research conducted was to try and quantify this need as well as to give guidance to the structure of the explosives engineering qualifications. During the study representatives from all the role-players in the industry were interviewed. Further information was gathered by means of a questionnaire. This data were combined and analysed and it was found that there is a definite need for a diploma in explosives engineering, an undergraduate degree in explosives engineering as well as post graduate qualifications in this discipline. The research has shown that there is a good possibility that these qualifications would be sustainable considering the growth in the South African explosives industry, as well as the growth in the African mining market. / MBA, North-West University, Potchefstroom Campus, 2014

The fluid-structure interaction of reacting materials requires computational models capable of resolving the wide range of scales present in both the condensed phase energetic materials and the turbulent reacting gas phase. This effort is focused on the development of a micro-scale structural model designed to simulate heterogeneous energetic materials used for solid propellants and explosives. These two applications require a model that can track moving surfaces as the material burns, handle spontaneous formation of discontinuities such as cracks, model viscoelastic and viscoplastic materials, include finite-rate kinetics, and resolve both micro-scale features and macro-scale trends. Although a large set of computational models is applied to energetic materials, none meet all of these criteria. The Micro-Scale Dynamical Model serves as the basis for this work. The model is extended to add the capabilities required for energetic materials. Heterogeneous solid propellant burning simulations match experimental burn rate data and descriptions of material surface. Simulations of realistic heterogeneous plastic-bound explosives undergoing impact predict the formation of regions of localized heating called hotspots which may lead to detonation in the material. The location and intensity of these hotspots is found to vary with the material properties of the energetic crystal and binder and with the impact velocity. A statistical model of the hotspot peak temperatures for two frequently used energetic crystals indicates a linear relationship between the hotspot intensity and the impact velocity. This statistical model may be used to generate hotspot fields in macro-scale simulations incapable of resolving the micro-scale heating that occurs in heterogeneous explosives.

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In an effort to provide the underground coal mining industry with an understanding of what governs if an explosive is classed as permitted, a preliminary research project was undertaken to investigate the scientific basis of the British Health and Safety Executives Testing Memorandum#2 (TM2). Previous literature indicates that the TM2 standard is empirical and based on comparative testing of the explosive in use at the time, nitroglycerine. Eighty Type I tests were carried out and preliminary findings were that the mechanism that causes ignition is a reflected shockwave which compresses and reheats detonation products. The origin of the reflected pressure wave changed when the primer position was altered within the cannon. With a pressure transducer and pyrometer mounted on the side of the gallery the measurements aided in identifying those maximum pressures and temperatures prior to ignition that are collectively a set of parameters that could be used to identify if an explosive would cause an ignition in the gallery. Additionally numerical modelling was employed to characterise pressure, temperature and velocity profiles within the gallery for blown out and cut off shots. Whilst the pressure and temperature results predicted by the CFD model were 1.5 to 3 times the magnitude of those measured in the field, the modelling results exhibited the behaviour of the shockwaves reflecting off the gallery walls, rebounding, gaining intensity and travelling back towards the centre axis of the gallery. This predicted behaviour reinforced the belief that re-heating of detonation gases by reflected shockwaves is the prime ignition mechanism of the Type I TM2 tests. One hundred and eight deflagration tests were conducted in the Type II cannon. The main finding was that the longer a receptor is subjected to elevated pressures due to confinement the higher the probability of deflagration. Additionally emulsion explosives were found to detonate in the cannon rather than deflagrate raising the question, ???if the explosive is consumed instantaneously, then isn???t the risk of deflagration occurring eliminated???? In reading this thesis it must be noted that all findings are preliminary and many more tests are required to confirm trends and behaviours observed in the testing to date.

In an effort to provide the underground coal mining industry with an understanding of what governs if an explosive is classed as permitted, a preliminary research project was undertaken to investigate the scientific basis of the British Health and Safety Executives Testing Memorandum#2 (TM2). Previous literature indicates that the TM2 standard is empirical and based on comparative testing of the explosive in use at the time, nitroglycerine. Eighty Type I tests were carried out and preliminary findings were that the mechanism that causes ignition is a reflected shockwave which compresses and reheats detonation products. The origin of the reflected pressure wave changed when the primer position was altered within the cannon. With a pressure transducer and pyrometer mounted on the side of the gallery the measurements aided in identifying those maximum pressures and temperatures prior to ignition that are collectively a set of parameters that could be used to identify if an explosive would cause an ignition in the gallery. Additionally numerical modelling was employed to characterise pressure, temperature and velocity profiles within the gallery for blown out and cut off shots. Whilst the pressure and temperature results predicted by the CFD model were 1.5 to 3 times the magnitude of those measured in the field, the modelling results exhibited the behaviour of the shockwaves reflecting off the gallery walls, rebounding, gaining intensity and travelling back towards the centre axis of the gallery. This predicted behaviour reinforced the belief that re-heating of detonation gases by reflected shockwaves is the prime ignition mechanism of the Type I TM2 tests. One hundred and eight deflagration tests were conducted in the Type II cannon. The main finding was that the longer a receptor is subjected to elevated pressures due to confinement the higher the probability of deflagration. Additionally emulsion explosives were found to detonate in the cannon rather than deflagrate raising the question, ???if the explosive is consumed instantaneously, then isn???t the risk of deflagration occurring eliminated???? In reading this thesis it must be noted that all findings are preliminary and many more tests are required to confirm trends and behaviours observed in the testing to date.

In an effort to provide the underground coal mining industry with an understanding of what governs if an explosive is classed as permitted, a preliminary research project was undertaken to investigate the scientific basis of the British Health and Safety Executives Testing Memorandum#2 (TM2). Previous literature indicates that the TM2 standard is empirical and based on comparative testing of the explosive in use at the time, nitroglycerine. Eighty Type I tests were carried out and preliminary findings were that the mechanism that causes ignition is a reflected shockwave which compresses and reheats detonation products. The origin of the reflected pressure wave changed when the primer position was altered within the cannon. With a pressure transducer and pyrometer mounted on the side of the gallery the measurements aided in identifying those maximum pressures and temperatures prior to ignition that are collectively a set of parameters that could be used to identify if an explosive would cause an ignition in the gallery. Additionally numerical modelling was employed to characterise pressure, temperature and velocity profiles within the gallery for blown out and cut off shots. Whilst the pressure and temperature results predicted by the CFD model were 1.5 to 3 times the magnitude of those measured in the field, the modelling results exhibited the behaviour of the shockwaves reflecting off the gallery walls, rebounding, gaining intensity and travelling back towards the centre axis of the gallery. This predicted behaviour reinforced the belief that re-heating of detonation gases by reflected shockwaves is the prime ignition mechanism of the Type I TM2 tests. One hundred and eight deflagration tests were conducted in the Type II cannon. The main finding was that the longer a receptor is subjected to elevated pressures due to confinement the higher the probability of deflagration. Additionally emulsion explosives were found to detonate in the cannon rather than deflagrate raising the question, ???if the explosive is consumed instantaneously, then isn???t the risk of deflagration occurring eliminated???? In reading this thesis it must be noted that all findings are preliminary and many more tests are required to confirm trends and behaviours observed in the testing to date.

In an effort to provide the underground coal mining industry with an understanding of what governs if an explosive is classed as permitted, a preliminary research project was undertaken to investigate the scientific basis of the British Health and Safety Executives Testing Memorandum#2 (TM2). Previous literature indicates that the TM2 standard is empirical and based on comparative testing of the explosive in use at the time, nitroglycerine. Eighty Type I tests were carried out and preliminary findings were that the mechanism that causes ignition is a reflected shockwave which compresses and reheats detonation products. The origin of the reflected pressure wave changed when the primer position was altered within the cannon. With a pressure transducer and pyrometer mounted on the side of the gallery the measurements aided in identifying those maximum pressures and temperatures prior to ignition that are collectively a set of parameters that could be used to identify if an explosive would cause an ignition in the gallery. Additionally numerical modelling was employed to characterise pressure, temperature and velocity profiles within the gallery for blown out and cut off shots. Whilst the pressure and temperature results predicted by the CFD model were 1.5 to 3 times the magnitude of those measured in the field, the modelling results exhibited the behaviour of the shockwaves reflecting off the gallery walls, rebounding, gaining intensity and travelling back towards the centre axis of the gallery. This predicted behaviour reinforced the belief that re-heating of detonation gases by reflected shockwaves is the prime ignition mechanism of the Type I TM2 tests. One hundred and eight deflagration tests were conducted in the Type II cannon. The main finding was that the longer a receptor is subjected to elevated pressures due to confinement the higher the probability of deflagration. Additionally emulsion explosives were found to detonate in the cannon rather than deflagrate raising the question, ???if the explosive is consumed instantaneously, then isn???t the risk of deflagration occurring eliminated???? In reading this thesis it must be noted that all findings are preliminary and many more tests are required to confirm trends and behaviours observed in the testing to date.

Simulation is used to study the effectiveness of mine avoidance sonar (MAS) use on safe minefield transit by a ship. A MAS is able to detect mine-like objects but currently cannot classify the detected object as a mine or a non-mine mine-like bottom object (nombo). The tactic is to avoid all detected objects. The minefield is represented by a finite grid of fixed width and length. The representation of ship maneuvering in the simulation is similar to that of a wall tracing algorithm for a computer mouse going through a maze. The simulation results indicate that the use of the mine avoidance sonars can increase the probability of successful transit. The probability of successful transit increases as the probability of detection increases for minefield object densities less than 50% of the field. However, the probability of successful transit is sensitive to the mine and NOMBO (NOn-mine Mine-like Bottom Object) density. The probability of successful transit can be increased if the density of mine-like objects is decreased. Some suggestions on mine avoidance tactics are made from the results obtained to show the limitations and effectiveness of the MAS with regards to the open waters, narrow channels, ports and harbors.

A low cost Cook-Off experimental facility has been established to provide a convenient method of ranking explosives in their response to Cook-Off by the time to event under two widely different heating rates and at two different scales. This thesis describes the literature review undertaken as preparation for the purposed study and all the experimental work developed comprising the design of the trials vehicles, the demonstration of their suitability for Fast and Slow Cook-Off trials with confined explosive systems, the preparation of the samples and test vehicles to be trialled as well as the set-up of adequate facilities to undertake the scheduled firing programme. Results are reported for Cook-Off tests on TNT, RDX, and their mixtures. The emphasis of the study is on time to event, and temperature at event, and in addition a qualitative assessment of the violence of the event was made by examination of the fragments of the vehicles, although it is accepted that the relatively light and low cost design of the vehicle may lead to variable confinement in the early stages of the explosive event, and hence to a wider spread of responses than would be obtained from a more heavily confined and more costly vehicle. The test vehicles give results, which differentiate between the various explosives and explosive mixtures trialled and between the scales. More experiments are required to establish the reproducibility of the measurements. The design of the equipment makes this a relatively inexpensive undertaking. The experiment was modelled using published kinetic data, but the calculated time to event differed from that observed to different extents at the two scales. It is hypothesised that the mechanism may change over the prolonged heat soaks and that quantitative scaling is not possible with the available information. Further work is also suggested using a different type of Cook-Off test vehicle, which will in our opinion reduce even further the cost of Cook-Off testing, due to reduction in man-hours of preparation involved and manufacture cost of the Cook-Off test vehicles, and consequently of ranking of explosives.

A low cost Cook-Off experimental facility has been established to provide a convenient method of ranking explosives in their response to Cook-Off by the time to event under two widely different heating rates and at two different scales. This thesis describes the literature review undertaken as preparation for the purposed study and all the experimental work developed comprising the design of the trials vehicles, the demonstration of their suitability for Fast and Slow Cook-Off trials with confined explosive systems, the preparation of the samples and test vehicles to be trialled as well as the set-up of adequate facilities to undertake the scheduled firing programme. Results are reported for Cook-Off tests on TNT, RDX, and their mixtures. The emphasis of the study is on time to event, and temperature at event, and in addition a qualitative assessment of the violence of the event was made by examination of the fragments of the vehicles, although it is accepted that the relatively light and low cost design of the vehicle may lead to variable confinement in the early stages of the explosive event, and hence to a wider spread of responses than would be obtained from a more heavily confined and more costly vehicle. The test vehicles give results, which differentiate between the various explosives and explosive mixtures trialled and between the scales. More experiments are required to establish the reproducibility of the measurements. The design of the equipment makes this a relatively inexpensive undertaking. The experiment was modelled using published kinetic data, but the calculated time to event differed from that observed to different extents at the two scales. It is hypothesised that the mechanism may change over the prolonged heat soaks and that quantitative scaling is not possible with the available information. Further work is also suggested using a different type of Cook-Off test vehicle, which will in our opinion reduce even further the cost of Cook-Off testing, due to reduction in man-hours of preparation involved and manufacture cost of the Cook-Off test vehicles, and consequently of ranking of explosives.