Roughest hour – approaches to ship hull fouling management
Doctoral thesis, 2019
The work presented in this thesis aimed at improving current approaches to the management of ship hull fouling, which typically rely on a combination of fouling-control coatings and an in-water cleaning scheme. Knowledge on the adhesive strength of fouling to minimize cleaning forces, on the one hand, and evaluation of the hull condition and hull roughness penalties, on the other hand, are therefore central to the aim of this thesis.
The outcome of performed work supports a preventive approach to hull maintenance, e.g. gentle and frequent cleanings (hull grooming), or an alternative predictive approach, based on vessel performance and condition monitoring for detecting early forms of fouling. Tools are provided with potential to improve hull maintenance practices. These include minimizing cleaning forces applied during in-water hull cleaning through knowledge on adhesion strength of fouling (Papers I, III and IV), and more-accurate determination of the impact of fouling on vessel performance, namely by accounting for hull form effects (Papers II) or using a novel performance indicator that would be applicable in wider comparisons between vessels (Paper V). Seen as a whole, results indicate that the goal of minimizing the environmental and economic risks involved in hull fouling management can only be achieved through continued collaboration between different industry stakeholders, researchers, technology developers, authorities and policymakers, leading to an optimal path in development.
fouling control coatings
in-water hull cleaning
turbulent boundary layer
Chalmers, Mechanics and Maritime Sciences, Maritime Studies, Maritime Environmental Sciences
Matching Forces Applied in Underwater Hull Cleaning with Adhesion Strength of Marine Organisms
Journal of Marine Science and Engineering,; Vol. 4(2016)p. 66-
Effect of ship hull form on the resistance penalty from biofouling
Biofouling,; Vol. 34(2018)p. 262-272
Towards an absolute scale for adhesion strength of ship hull microfouling
Biofouling,; Vol. 35(2019)p. 244-258
Oliveira, D and Granhag, L (–). Ship hull in-water cleaning and its effects on fouling-control coatings. Manuscript submitted to Biofouling.
Oliveira, D, Granhag, L and Larsson, L (–). A novel indicator for ship hull and propeller performance: examples from two shipping segments. Manuscript submitted to Ocean Engineering.
One way to reduce the energy required to propel a ship across the oceans is to ensure underwater surfaces are properly maintained and kept free of biofouling – i.e. marine life attached to the hull and propeller, which contributes to surface roughness. Thus, with reference to a smooth hull, fuel consumption may practically double when a ship reaches the roughest hour, i.e. when the hull is covered with large shells and marine alga.
The present work investigates ways in which in-water ship hull cleaning by professional divers and remotely-operated devices can be improved, through supporting decisions on when to conduct maintenance, and how strong should cleaning forces be. The ultimate aim is to improve shipping’s energy efficiency and its cost-effectiveness, while reducing chemical and biological impact on the marine environment.
Increased energy efficiency in ships through reduced hull fouling
Swedish Energy Agency, 2015-01-01 -- 2017-06-30.
Completing management options in the Baltic Sea Region to reduce risk of invasive species introduction by shipping COMPLETE
Interreg-BSR, 2017-10-01 -- 2020-09-30.
Other Engineering and Technologies not elsewhere specified
Reliability and Maintenance
Chalmers Materials Analysis Laboratory
Doktorsavhandlingar vid Chalmers tekniska högskola. Ny serie: 4691
Chalmers University of Technology
Saga-building, Hörselgången 4, Chalmers Campus Lindholmen, Gothenburg - SWEDEN
Opponent: Dr. Kelli Zargiel Hunsucker (Ph.D.), Florida Institute of Technology, USA