An experimental study on determining the best operating condition of an automated underwater biofouling cleaning tool

Efficiently removing marine biofouling from ship hulls is essential for maintaining asset integrity. This study explores the application of a rotating brush mounted on an automated system designed for cleaning plates under controlled conditions. Two experiments were conducted: one to evaluate geometric combinations - attack angle and tool standoff - for effective coating removal and another to determine optimal parameters - attack angle, tool standoff, time over surface, and number of sweeps - for marine life removal. Using statistical methods including ANOVA and Tukey's test, four potential coating removal combinations were identified: (60 degrees, 130 mm), (45 degrees, 100 mm), (45 degrees, 160 mm), and (60 degrees, 100 mm). However, the maximum coating thickness removal did not exceed 127 mu m under worst-case conditions. In the second test, employing a Taguchi L9 matrix (3(4)) for experimental design, the best parameter combination - 60 degrees, 160 mm, 18 s, 2 sweeps - outputted a cleaning rate of 86.1% on a plate immersed for 498 days. A discrepancy was observed in a plate reserved for validating Taguchi predictions, which remained immersed for 555 days, potentially attributed to the presence of a new species. These findings provide valuable insights into enhancing ship maintenance practices, aiding the development of improved cleaning strategies, and ensuring long-term asset integrity.