Increasing the Speed of a Cargo Vessel by Main Components Selection and Propulsion System Adjustment

One of the major concerns in designing and redesigning the vessel’s propulsion system is adjusting its main components including the engine, gearbox and propeller. Components mismatch leads to overload or overspeed in engine. In this research, a method is presented for selecting a propeller and matching it to a full displacement vessel’s propulsion system, and related calculation for increasing the speed, has been done. The suitable engine and gearbox are selected after the vessel’s power and resistance has been calculated by MAXSURF software for 10 knots. The selected engine has 478 KW power at 2150 RPM and the reduction ratio for gearbox is 3.05. The calculated fixed pitch propeller was from B -Wakening series and had a diameter and pitch of 1.13 meters and 80 cm, respectively. It also had 4 blades and 70% area ratio. The results show that the selected propeller is fully matched with the engine and also the propeller power consumption curve is well suited to the engine’s propeller theoretical power. The value of propeller’s produced thrust is about 45.6 KN at 704 RPM which confirms the situation of having two propellers, 0.2 thrust deduction factor and 73 KN vessel resistance at 10 knots speed. The propeller torque value at final RPM is 6125 N.m which leads to an increment of 4 knots in the vessel’s speed. In this research, the performance of selected propeller in different engine RPMs has been well analyzed.