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A field study is presented, conducted at Sonepur Bazari open-cast coal mine, West Bengal, India, to determine the machine operating parameters, namely depth of cut (DOC), cutting speed (CS) and drum speed (DS), and rock parameters, i.e. compressive strength, tensile strength, Poisson’s ratio and Young’s modulus, for investigating thermal behaviour of conical picks during cutting by a 2.2-m-drum-width surface miner. Using an experimental design based on a Taguchi L16 orthogonal array, the cutting performance of the surface miner is studied with respect to the machine operating parameters. The results indicate that the experimental cutting-temperature value is 277 degrees C for the optimum combination of machine operating parameters, DOC of 0.24 m, CS of 18 m/min and DS of 80 rpm, which provides optimal cutting-power utilisation, maximum production value and minimum pick consumption. Analysis of variance (ANOVA) shows that the contributions of DOC, CS and DS to cutting-pick temperature are 53.37, 44.70 and 1.93%, respectively. The development of empirical models using the Taguchi method, multiple linear regression (MLR) and artificial neural network (ANN) to predict the optimal temperature for cutting picks is described. In confirmation tests, the optimum experimental temperature (277 degrees C) is compared to the predicted values obtained by the Taguchi method (276.68 degrees C), MLR (274.90 degrees C) and ANN (270.93 degrees C) and the errors between the experimental and predicted temperatures are 0.12, 0.75 and 2.19%, respectively., A field study is presented, conducted at Sonepur Bazari open-cast coal mine, West Bengal, India, to determine the machine operating parameters, namely depth of cut (DOC), cutting speed (CS) and drum speed (DS), and rock parameters, i.e. compressive strength, tensile strength, Poisson’s ratio and Young’s modulus, for investigating thermal behaviour of conical picks during cutting by a 2.2-m-drum-width surface miner. Using an experimental design based on a Taguchi L16 orthogonal array, the cutting performance of the surface miner is studied with respect to the machine operating parameters. The results indicate that the experimental cutting-temperature value is 277 degrees C for the optimum combination of machine operating parameters, DOC of 0.24 m, CS of 18 m/min and DS of 80 rpm, which provides optimal cutting-power utilisation, maximum production value and minimum pick consumption. Analysis of variance (ANOVA) shows that the contributions of DOC, CS and DS to cutting-pick temperature are 53.37, 44.70 and 1.93%, respectively. The development of empirical models using the Taguchi method, multiple linear regression (MLR) and artificial neural network (ANN) to predict the optimal temperature for cutting picks is described. In confirmation tests, the optimum experimental temperature (277 degrees C) is compared to the predicted values obtained by the Taguchi method (276.68 degrees C), MLR (274.90 degrees C) and ANN (270.93 degrees C) and the errors between the experimental and predicted temperatures are 0.12, 0.75 and 2.19%, respectively.

In a labour intensive sector, some of the factors in the work environment which impact the health of vehicle operators include: Whole-Body Vibration (WBV) and Hand-Arm Vibration (HAV). The vibrations transferred from the dumpers are harmful to the operators; hence a study was carried out to measure the vibration from dumpers and its effect on operators in Indian opencast mines. Dumper is a vehicle designed to transport bulk material and used extensively in the construction and mining industries. For the measurement, dumpers with the different capacities were selected from the opencast mines. Vibration measurements were carried out in accordance with ISO 5349-1 for the measurement of HAV and ISO 2631-1 for the measurement of WBV. The obtained WBV exposure result shows that the problem of musculoskeletal disorder was significantly higher with respect to VDV(8) (69 %) in the exposed population as compared to A(8) r.m.s. acceleration (46 %). Moreover different capacity dumper vehicle hand transmitted vibration through steering wheel, A(8) r.m.s. acceleration observed in the range of 1.91 m/s2-4.28 m/s2. As per EU DIRECTIVE 2002/44/EC, specified Exposure Action Value (EAV) 71 % measured A(8) value falls within EAV limit. However, despite of the result operator experience problem of hand arm vibration syndrome. Hence there is a need of ergonometric deign enhancement on dumpers vehicle’s seat and steering wheel.

In this paper an experimental investigation is performed on a range of transverse gap ratios (0.5≤T/D≤4.5) between the cylinders arranged in side by side configuration. The pattern of the test cylinder motion, spectral diagram and amplitude are used to analyze the vibration excitation at different conditions such as free stream velocity, natural frequency of the test cylinder. From the results, for the spacing ratio of T/D= 0.5 it is observed that the cylinders gets excited beyond the critical velocity and vibrates in a spiral pattern with the line dominated spectrum, which implies that by having a similar frequency along with a phase shift, the characteristics behavior of the cylinder is observed to be like an oscillator with the cross wise and stream wise response. Besides that, it is also observed that the cylinders at higher spacing ratios (T/D= 4.5) producing minimum oscillation when compared to the smaller spacing ratios.

In this paper an experimental investigation is performed on a range of transverse gap ratios (0.5≤T/D≤4.5) between the cylinders arranged in side by side configuration. The pattern of the test cylinder motion, spectral diagram and amplitude are used to analyze the vibration excitation at different conditions such as free stream velocity, natural frequency of the test cylinder. From the results, for the spacing ratio of T/D= 0.5 it is observed that the cylinders gets excited beyond the critical velocity and vibrates in a spiral pattern with the line dominated spectrum, which implies that by having a similar frequency along with a phase shift, the characteristics behavior of the cylinder is observed to be like an oscillator with the cross wise and stream wise response. Besides that, it is also observed that the cylinders at higher spacing ratios (T/D= 4.5) producing minimum oscillation when compared to the smaller spacing ratios.