Experimental investigation on hydrodynamic performance of side-by-side three barges in topsides floatover installation in beam seas

The single barge floatover method faces great challenges when it comes to the gigantic topsides and the substructures lack of sufficient slots. The twin-barge floatover system with large capacities and great flexibilities for various topsides and substructures would be a promising alternative for fixed and floating platforms. This study experimentally investigates the dynamic responses of the floatover system in beam waves with the focus on one of the critical load transfer steps, namely, the topsides transfer operations onto the twin-barge from a transportation barge. Three representative intermediate stages, i.e., 0%, 50%, and 100% stages, were experimentally simulated. Results revealed that the upwind barge experienced larger motions than others, attributed to the shielding effect. Results implied that the in-between fluid resonant may have great influences on the motions. The twin-barge floatover system were subjected to six degree-of-freedom motions in beam random waves because of the unsymmetrical configurations. The impact loads on mating units demonstrated that the lateral loads were quite considerable and they should be paid much attention. The mooring force varied slightly, and the tether lines bear large snap loads at the 0% stage. The critical stage for different components were identified based on comparisons of loads at three stages.