EFFECTIVENESS HARBOUR TUG FLEET: PROBLEM FORMULATION AND METHODOLOGY OF ITS SOLUTION

The article deals with the current problem of improving the effectiveness of the harbour tug fleet. The methodology of the selection of optimal structure of the tug assistance has been suggested. It is based on the methods of statistical modelling, the queuing theory and the theory of the ship design, as well as algorithms developed by the authors. The method of calculating forces, which act on the ships during their movement to the port berths, and the transfer of these forces to the required total bollard pull of tugs is described. The method for calculating the economic performance of the harbour tugs used in harbour towage is considered. The algorithm for the development of the order with the determination of the required number of tugs to carry out towing operations in the current hydrometeorological conditions of the port is suggested. The model of the functioning of the harbour tugs is developed. The optimization problem of the determination of the required structure of the harbour tug fleet is formulated and solved. The findings of the study results are suggested for the optimization of the existing or renewed tug assistance of the port, selection of the design characteristics of harbour tugs on the conceptual stages design