Homyakov V. Improvement of bulk cargo loading methods for low-displacement vessels

The Dissertation is devoted to the decision of a scientific and applied problem of improvement of bulk cargo loading methods for low-displacement coastal vessels, ensuring proper navigability as well as safety of their navigation. It was revealed that the issues of calculating of weight and placing cargo in one hold by several separate stacks were investigated not in full. The weaknesses of modern cargo programs used by navigators for planning cargo operations and calculating the cargo plan were analysed. The work provides consideration of holds configurations of the existing coaster fleet, the features of their loading with individual cargo piles, taking into account certain restrictions. The author has taken into account the modern capabilities and capacities of ports as well as port cargo complexes and terminals in practical calculations of sailing directions and charter conditions on different vessels. Field studies allowed to pin down the necessary solution for the operating objective. The justification of the principal direction of the thesis research, providing for the creation of a «natural separation» method for piles of cargo in case of simultaneous transportation in one hold was provided. The proposed mathematical model that takes into account the configuration of the cargo section and the shape of the volume of cargo piles, uses ship hydrostatic tables and provides functions in the form of approximating polynomials of two variables expressing the light mass and its horizontal moment through two arguments: draft at forward perpendicular and draft at after perpendicular. The model is adapted for engineering calculations and is based on the facts established by the author when performing field studies when loading simultaneously at low-displacement coastal vessels «WILSON BILBAO», «WAVE» and «ELENA» of different batches of bulk cargo and in the different port conditions. The model is implemented using the «Scilab» mathematical calculations package. The «placement method» and the «placement control method» for bulk cargo in a vessel’s hold were developed and patented, including the calculation of the weight distribution of different cargoes according to the amendment for the cargo displacement relative to the trim of the vessel. The method allows calculating the possibility of loading the vessel with various cargoes, preventing their mixing, as well as to calculate the vessel’s navigability using ship cargo programs. The main result of the dissertation is the development of a calculation procedure for the placement of individual piles of cargo at any loading step and any actual trim difference, using «natural separation», which allows improving the bulk cargo loading methods for low-displacement coastal vessels. The results of the dissertation work were applied in the production activities of shipowning companies and on low-displacement boats, as well as were introduced in research works represented at the NU «OMA» and also in the educational process when studying by cadets. In this regard, the results of the thesis work in a form of the developed mathematical and analytical models of operating procedures based on the proposed natural separation method gives the possibility to maximize the use of the load capacity of lowtonnage vessels when transporting several cargo consignments, as well as to increase the safety of cargo transportation. Keywords: coaster (coastal vessel), natural separation method, cargo operations, optimization and loading control of a single-hold vessel, cargo plan of a low-displacement vessel.