Impact of propulsion system integration and controls on the vessel DP and manoeuvring capability

Abstract

The paper presents recent insights in the DP manoeuvring capability of a marine vessel. The good integration of the propulsion system with the vessel design enhances the performance of the vessel under many circumstances. In parallel, the integration of the propulsion and engine controls plays an important role. The above is accentuated with the introduction of efficient propulsion unit and engine designs as driven by the current environmental legislation (Tier 3, EEDI, EEOI) affecting the overall vessel performance. The paper will review current advancement in propulsion and engine technologies (high and medium speed). In parallel, a number of test cases will be presented into detail with design specifics: 1) DP for drilling ships and offshore rigs. The importance of the propulsion design on the DP capability of the vessel will be shown based on the determination of the forbidden zones due to unit - to- unit interaction 2) Allowable fast RPM ramp-up of steerable thrusters. The issue is related to the inertia of the water to follow the propulsion unit acceleration and create the required thrust level. 3) Evaluation of manoeuvring of large vessels with tunnel thrusters, esp. with Fixed Pitch Propeller configurations (changing the thrust vector from full port to full starboard)