A Model Test for Deepwater Lifting and Lowering Operations of a Subsea Manifold

This paper presents an experimental study of the deepwater lifting and lowering operations of a subsea manifold. A series of model tests with an installation vessel, a crane system, and a manifold were performed at the Ocean Engineering Basin of the Korea Research Institute of Ships and Ocean Engineering (KRISO). The lifting and lowering operations during the crane installation of the subsea equipment were tested under both regular and irregular wave conditions. White noise and regular wave tests were first carried out to investigate the vessel motion and wire tension responses during the deepwater lifting operation. The effect of the equipment weight and water depth was also studied. To overcome the limitation of the water depth in the basin, a new experimental technique using a truncated hoisting system was introduced. The effect of the passive heave compensator on the hoisting wire tension was discussed.