Dynamic response and impact loads in twin-barge floatover installation

Abstract

Complex impact loads during the floatover installation will threaten the mating operations. This paper presents the experimental investigation on the impact loads and dynamic response in the twin-barge floatover installation. In the model test, two critical loads transfer scenarios were modeled, including 0% and 100% stages in which the topsides are initially connected and separated from the barges. The near-zero gaps between the topsides and the twin-barge are simulated at two stages with the aim of investigating the collision characteristics. The impact loads on mating units, mooring forces, hawser forces, as well as motions of the twin-barge and the topsides were investigated. It is found that the windward barge motions are much larger than the leeward barge in sway, roll and yaw directions. The larger barge sway and yaw motions occurred at the 100% stage compared with the 0% stage. Statistical results indicate that the 100% stage seems to induce the larger impact loads on mating units than the 0% stage. The lateral impact loads were comparable with the vertical loads, in which the maximum lateral impact loads were even greater than the vertical impact loads. The mooring and hawser lines at the 100% stage are subjected to larger loads.