Abstract:
The main objective of this study was to develop and incorporate an electrically-controlled system into the existing gantry crane and to modify the gantry to improve its performance with respect to rigidity and functionality. Soil-bin Investigations of three pairs (sharp and dull) model tillage tools were also carried out in loose and compacted loamy sand soil at rake angles 30° and 45° to evaluate the effects of the tools’ parameters on draught and soil disturbance. The modified gantry crane test was also conducted. The loamy sand soil experimental design was a 3 ₓ 2 ₓ 2 factorial experiment with three replicates. Analysis of the results were carried out using Excel (2007) software packages. Graphical representations were made and statistical models were established. The modified gantry crane has been mechanized and effectively reinforced with respect to rigidity and functionality with the horizontal (trolley) and the vertical (hoist) velocities reduced to 0.3 m/s and 0.001 m/s respectively. The magnitude of the width of crescent failure is higher than the rupture distance for all the model tillage tools except the VEE dull tillage tool where the width of crescent failure was less in magnitude to its rupture distance at both rake angles and the cone index range of 3.03 kPa to 226.95 kPa and 4.63 kPa to 256 kPa for loose and compacted loamy sand soil respectively. Optimum tillage is obtained at rake angle 30° (maximum throw of loamy sand soil by the tillage tools with less energy requirement). At rake angle 30°, the highest degree of soil diturbance (ridge-to-ridge) was 388.3 mm for the semi circular sharp followed by 383.3 mm for the semi circular dull model tillage tools with corresponding draught of 276.7 N and 353.3 N; the least magnitude of ridge-to-ridge was 276.7 mm while the highest magnitude of height-of-ridge was 43.7 mm , and the corresponding magnitude of depth-of-furrow was 66.7 mm in loose loamy sand soil with penetration resistance of 3.03 kPa to 226.95 kPa. At rake angle 30°, the R2 value of 0.779 shows strong correlation between the draught and the width and depth of the model tillage tools while the R2 values of 0.805, 0.534, and 0.911 and at rake angle 45°, the R2 values of 0.911, 0.958, and 0.763 show strong correlation between the soil disturbance parameters, and the width and depth of the model tillage tools. Therefore, the soil/tools interaction evaluation parameters are significant parameters to determine the draught and soil disturbance parameters in loamy sand soil. The required draught by the six model tillage tools increased as the rake angle increased from 30° to 45° in loose and compacted soil.
