Investigation on the effects of the number of main engines in sailing yachts in design and engineering perspectives: A case of Bodrum Gulets

Abstract

Yacht design consists of multidisciplinary processes to obtain optimum solution that satisfies the requirements of the users as well as regulations to assure the safety at sea. Following the determination of the yacht type, processes such as preparing the general layout plan in line with the demands and expectations of the user, making hydrostatic calculations and speed-power calculations, determining the hull and superstructure design are followed. In these processes, the main engine selection, which is made depending on the speed and performance expectations, affects not only the engine room, but also many details such as the shaft angle of the boat, the propeller-hull clearance, the placement of the areas adjacent to the engine room. In this research, Bodrum Gulets, which are among the boats unique to Türkiye and produced with custom design and manufacturing processes, are discussed and it is aimed to examine the effects of the number of engines from the design and engineering perspectives. In this context, a total of 46 Bodrum Gulets were examined, and in line with the values obtained, selected parameters have been compared from the design and the engineering perspectives. While the engine room layout plans of the investigated yachts were used for comparison in terms of design, shaft angle was used in comparison in engineering-based evaluation. Moreover, investigated models’ resistance and consequently the power requirements have been compared with the installed engine powers. The results show that models with single main engine are advantageous in terms of requiring less height and consequently less space for the engine room and propulsion efficiency perspectives. The mean value for the ratio between the required height to the height of the engine is calculated as 1.428 for the single engine and 1.982 for the twin engine configuration. Moreover, the results show that the mean value of the shaft angle is 5.29 for single engine and 8.16 degrees for the twin engine configuration. Additionally, the study shows that there is a gap between the calculated power and the installed power, which causes over consumption especially for the twin-engine configuration for the Bodrum Gulets.