The South African rail industry is undergoing a phase of restructuring and much focus is concentrated on re-engineering i.e. optimising the utilisation of available assets and using existing technology in order to improve efficiency; attention shifts to improved heavy haul asset management through train performance models. The computer programs presented in this thesis have been developed to calculate longitudinal in-train forces accruing in long heavy haul trains and their effect on train operations. The model of the train is implemented by dedicated differential equations for the movements of each vehicle. The simulation is menu driven for all input and output decisions using Microsoft Excel while the engine for the dynamic analysis is ACSL (Advanced Continuous Simulation Language). The main program is capable of simulating the operation of any train configuration over any route, including remote operation. The thesis comprises: - • a discussion on the need for alternative train configurations based on the current fleet and the potential of such operating changes; • the comparison of the dynamic response of trains operating with only head-end locomotives, trains operating with both head-end locomotives and remote locomotives and trains operating with different class locomotives in one locomotive consist; • the investigation of the lateral effects in the different train consists as a function of the longitudinal in-train force in the simulation environment; • the advantages of operating with remote locomotives in terms of increased train length, reduced force spectrum on vehicle components and improved energy consumption; • the implications of the optimum position of the in-train locomotive consist on loading and unloading operations; • the implications of different train configurations on driver technique or train handling and the need for an optimum driving strategy to gain maximum benefit from the locomotives. / Thesis (M.Sc.Eng)-University of Natal, Durban, 2000.

Thesis. 1975. Ph.D.--Massachusetts Institute of Technology. Dept. of Mechanical Engineering. / Vita. / Bibliography: leaves 244-249. / Ph.D.

Orientador: Fausto Rodrigues Filho / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-07-25T03:07:16Z (GMT). No. of bitstreams: 1 Martins_SergioRoberto_M.pdf: 8034823 bytes, checksum: 3e3436c2fbc1bce2cd2db72d860250ca (MD5) Previous issue date: 1999 / Resumo: O presente trabalho apresenta um programa computacional para a simulação da frenagem de trem unitário de carga, que são trens compostos por uma grande quantidade de vagões iguais. É feita uma análise das variáveis envolvidas no processo de frenagem, com o objetivo de padronização na determinação destes valores para que haja consistência nos resultados das simulações, permitindo análise comparativa. Finalizando são feitos diversos lotes de simulações, compatíveis com situações reais das ferrovias brasileiras, e uma análise comparativa dos resultados para avaliar a influência das variáveis no processo de frenagem do trem / Abstract: This study presents a computer simulation software to analyse the unit freight train braking process. These are long trains having a great number of equal freight cars. It is made an analysis of the variables involved on the braking process with the purpose of standardization of these values to get consistency on the simulationresults to allow comparative analisis. Endly are made several simulations, according to real situations found in the Brazilian railways and a comparative analysis of the results to avaliate the influence of the variables in the train braking process / Mestrado / Mecanica dos Sólidos e Projeto Mecanico / Mestre em Engenharia Mecânica

Ultra deep mining presents many challenges to the mining engineer, one of which is the logistics to support mining operations quickly and efficiently. Typically, Witwatersrand gold mines operate at depths in excess of 2000 m with stoping taking place to 3500 m and investigations underway to mine to a depth of 5000 m. As mining progresses deeper and further from the shaft, the role of logistics becomes increasingly important if production targets are to be achieved. Access to the workings is often via sub vertical and even tertiary subvertical shaft systems with working faces as far as five kilometers from the shaft. It is inevitable therefore, that distance will negatively impact the working time available at the stope face, material transportation and distribution, as well as the removal of broken ore. Possible solutions to these logistical problems may be found in the use of different transportation systems or by applying sound design and operational principles to transportation systems, both in the horizontal and instope areas. This thesis investigates the challenges of logistics for ultra deep level gold mining in the Witwaterstrand basin for mining layouts planning to mine between 3000 m and 5000 m underground with typical horizontal distances of over 3000 m. The transportation needs analysis recognised that vertical transportation is a wellmanaged and organised system and is mainly the same for both shallow and deep level operations. As a result of this, the thesis only focuses on the logistical issues of the horizontal and in-stope processes. The literature review indicates that the majority of work previously conducted on transportation focused around the area of horizontal transportation with limited inputs to in-stope transportation systems. The review concludes that the traditional locomotive transportation system is the most applicable mode of horizontal transportation. Thus, special emphasis is given to trackbound transportation. An integrated approach is taken towards mine transportation advocating that underground logistics be considered as equally important as any other discipline, Le. rock engineering, ventilation, etc. In addition, the transportation process should consider each area equally important. All to often, the transportation of rock is considered of paramount importance over the transportation of personnel and material. Thus, the planning any transportation system should incorporate personnel, material and rock. To enable this, scheduling, communication and control are important with special attention required for transfer points in the transportation system. As each site has its own particular requirement, thus the final transportation systems must be drawn up based on the specific requirements of each mine. A guideline is proposed for the design of ultra deep level underground transport systems for personnel, material and rock transportation. Thus, providing mining engineers with sufficient information and data to select an appropriate transportation system to meet specific mine requirements. The thesis highlights areas requiring consideration by mine engineers when designing a transportation system from shaft to the working face. / Thesis (Ph.D.)-University of Natal, Durban, 2003.