Model Study of the Wave-Driven Impact of Bergy Bits With a Semi-Submersible Platform

Abstract

This paper describes model bergy bit/semi-submersible impact tests conducted in the 58-m wave tank at Memorial University. The objective of the tests was to develop a method to accumulate statistics on the locations and velocities of wave-driven iceberg/structure impacts. We used a single irregular sea state and conducted 30 trials in each test series to accumulate the desired statistics. During each run, a camera system tracked the motions of both the bergy bit and the semi-submersible. We transferred this data and the geometry of both bodies to a CAD facility, which then recreated each test by redrawing the positions of the two bodies at each time step. In this manner, we determined the impact locations and times without the obstruction of the water surface, and computed automatically the desired impact velocities and kinetic energies. This paper describes the test and analysis techniques, and presents results for one test series. It also describes a new method to estimate impact kinetic energies using only open-water velocity data.