Design and Full-Scale Experimental Results of a Semi-Active Heave Compensation System for a 200 T Winch

Lifting and lowering a load on the ocean can be a dangerous task but can be made easy and safe by adopting heave compensation (HC) devices. The design and full-scale experimental results of a 3000-m semi-active heave compensation (AHC) system for a 200-T winch are presented in this paper. First, the design requirements are given and the semi-AHC mechanism is chosen. An integrated cylinder with one passive chamber and two active chambers is designed. Then, the capacities of the passive and active chambers are determined. The hydraulic and electrical systems and the control strategies are introduced subsequently. Finally, full-scale factory tests at different sinusoidal wave periods and amplitudes show that the semi-AHC system has a displacement compensation efficiency of 92.9% met the design requirements. In-depth power analysis further shows that the active and passive chambers contribute 20.5% and 72.4% displacement compensation efficiencies, respectively. The efficiency of the passive chamber consists with the 68%-80% passive compensation efficiency from Oceanworks Company and Rexroth Company.