Experimental investigation of the influence of floodwater due to ship grounding on motions and global loads

High profile collision and grounding incidents show that safety standards for ships need improvement to ensure ship survivability and reduce the potential for loss of life. An experimental investigation into the influence of floodwater, and transient flooding on the motions and structural response of a ship hull following a grounding incident is presented. Results show that floodwater can have a significant effect on the magnitude of ship responses; testing of the transient flooding case provides the opportunity to quantify the magnitude of these changes as well as the time to flood by provision of intact and flooded data during a single test. The movement of the floodwater free surface shows some substantial second order sloshing effects when close to the ship peak response, but little movement in higher frequency waves. Comparisons to classification design rules indicate that there is scope for further assessment of safety margins, including investigation of global responses in conjunction with any local loading due to the presence of floodwater. Future work will look at improving the modelling of the floodwater free surface and carrying out further transient flooding testing in order to better quantify the effect of a ship grounding incident on the survivability of a vessel.