Full-Scale Measurements and Method Validation of Container Ship Wave-Induced Motion at the Port of Fremantle

Abstract

In this article, validation of numerical models of ship wave-induced motions in port-approach channels is carried out. A selected set of high-quality data from recent full-scale trials measuring vertical motions of container ship transits entering and leaving the Port of Fremantle, Western Australia, is used. The measured wave-induced heave, roll, and pitch motions of six example container ship transits are discussed in detail, together with descriptions of in situ wave measurements and wave spectral analysis. A linear strip method, as implemented in the computer code OCTOPUS, is applied to predict the ship wave-induced motions. A comparison is made between measured and predicted ship motion responses to validate the ship motion software, and the measured roll response can be particularly used to assess the suitability of existing roll damping methods at full scale. The method is shown to give predictions of heave, roll, and pitch responses with reasonable accuracy for container ships at full scale in open dredged channels. Large-amplitude long-period roll motions were observed in some cases of the present trials, and unexpected harmonic pitch motions were also observed in other cases. Further research is recommended to study these seemingly nonlinear effects.