Numerical and experimental study on the docking of a dynamically positioned barge in float-over installation

摘要

The float-over installation method has become the best solution to offshore heavy topsides installations due to its flexibility and low cost. Dynamically positioned vessels can accurately keep position and track the predefined path with the help of thrusters, which eliminate the rigid requirements on auxiliary tugboats andmooring system. A precise control strategy is of critical importance to ensure the barge entering the slot successfully while keeping the impact with fenders within an acceptable limit. This paper establishes a time domain method to simulate the nonlinear motions during the docking stage. The barge is exposed to wind, wave and current forces to model the practical installation environment, and interactions between the barge and sway fenders are carefully taken into consideration. A model test is further conducted to validate the simulation results. Comparisons show that the proposed simulation programme can correctly simulate the docking stage of barge and predict the impact force of sway fenders.