Analisis Perubahan Sistem Propulsi dari Azimuth Thruster ke Fixed Pitch Propeller pada SPOB 2999

Abstract

The Self Propelled Oil Barge (SPOB) with a Gross Registered Tonnage (GRT) of 2999 was analyzed before and after modification, particularly focusing on the propulsion system and hydrodynamic characteristics. The resistance of the existing vassel based on the holtrop manual method was 128,506 kN, while the maxsurf simulation yielded 117,4 Kn. After the modification, the resistance increased to 135,249 kN (manual) and 124,3 kN (maxsurf). The main engine power requirement per unit rose from 621,057 kW to 649,964 kW with the twin screw propeller configuration. CFD fluent simulation results for the existing propeller showed a thrust coefficient (K_T) of 0,202, a torque coefficient (K_Q) of 0,0341, and efficiency of 0,32. The new propeller, type B3-50, with a diameter of 2,76 meters and a rotation speed of 225,102 Rpm, demonstrated a higher efficiency of 0,475. Cavitation evaluation showed that the calculated cavitation number (?c burril) of 0,1873, indicating the propeller is safe from cavitation risk. The engine-propeller matching analysis showed an absorbed power of 86,02% (clean hull) and 90,32% (rough hull) at 100% Rpm. The attained EEDI value of 16,20 gr-CO₂/T-mile is lower than the required EEDI of 17,25 gr-CO₂/T-mile, indicating that the post-modification vassel design complies with energy efficiency standards.