| Ship turnaround time at a marine containerport is an important measure of the port's efficiency and attractiveness. Both the speed and quality of load planning affect the length of turnaround time considerably. Past attempts at computerizing the load planning function have been unsatisfactory and have not reflected the port's objective of optimally utilizing its facilities and equipment. The computerized model developed through this study generates optimum feasible load plans that minimize yard material handling of containers while meeting all ship stability and loading restrictions. The model is particularly addressed to containerports with transtainers as prime yard movers.;;*All degree requirements completed in 1981, but degree will be granted in 1982.;Minimization of yard handling is accomplished through formulation of the transtainer routing problem as a dynamic programming problem. The set of shipboard container-cell assignments is then checked against the constraints. Pairwise exchanges of assignments are made to meet any violated constraint so that the yard handling increase is minimized. The model has been tested using data for five actual ship loadings at Port of Portland. It yielded feasible load plans that were better than those manually generated showing an average 3.2 percent less material handling requirements. The model can be easily implemented at containerports with medium-to-large computers with some adjustments. The success of this study not only provides a way of increasing port productivity, but also makes available an important software component for a port automation system. |
