High-performance anti-fouling coatings applied to a vessel’s hull and propeller can significantly increase energy efficiency ratings
Excessive fouling on a ship’s hull and propeller will increase a vessel’s drag, causing poor hydrodynamic performance, raising fuel consumption and producing more greenhouse gas (GHG) emissions. In the age of IMO’s Carbon Intensity Indicator (CII), poor hydrodynamic performance is a non-starter for shipowners; there are clear commercial and environmental incentives for maintaining a clean hull and propeller.
This issue was debated during the bulk carrier roundtable at the Maritime Decarbonisation, Europe Conference, Awards & Exhibition, held in September in Amsterdam. During the roundtable, chaired by Enarete Marine’s Dr Elias Boletis, delegates discussed the need to comply with CII, retrofitting energy-saving devices, applying hull and propeller coatings and undertaking operational changes. While shelving decisions around newbuilds because of legislative uncertainty, most owners are now evaluating or retrofitting environmental solutions, such as hull coatings and air-lubrication systems.
Klaveness Combination Carriers (KCC) operates a fleet of 16 combi-carriers, some of which are CABUs (which transport caustic soda solution, floating fertiliser, molasses and all types of dry cargo) and others are CLEANBUs (which transport clean petroleum products, heavy liquid cargoes, and all types of dry bulk products). The six-year-old Ballard, one of the youngest CABUs in the Norwegian owner’s fleet, was fitted with a raft of energy efficiency technology during dry docking, including an air-lubrication system, shaft generator, Mewis duct, high-speed connectivity and ship performance system to enhance digitalisation. Also noted is the application of silicon paint to improve hull performance and weld seam fairing to reduce the drag caused by welding seams. Seam-fairing solutions for ship hulls can reduce fuel consumption by up to 2.5%, according to one hull coating manufacturer.
“Propeller coatings are part of a portfolio of solutions”
Speaking at the conference in Amsterdam, KCC sustainability and CO2 performance manager, Anders Sørheim, said this was the first of 11 vessels tagged for retrofits. He said the Norwegian shipowner has set “some pretty hairy targets for 2030” with a goal of reducing its carbon intensity by 45%.
KCC anticipates these retrofits will yield a 15% improvement in energy efficiency.
In its 2022 sustainability report, container and multipurpose ship operator Swire Shipping notes that its Scope 1 emissions totaled 754,648 t of CO2 — 99.05% of which was produced by combusting marine fossil fuels in internal combustion engines, both at sea and on land. Swire has implemented S-Insight, a performance management system to gauge the effectiveness of various energy efficiency technologies similar to those used by KCC. Based on its data from 22 owned ships, Swire reported it saved 8,400 metric tonnes of fuel and avoided 26,150 t of CO2 emissions. In a collaboration with Graphite Innovation and Technologies, the shipowner applied XGIT-PROP, a graphene-based, biocide-free propeller coating to the propellers of the 7,756-dwt multipurpose Dili Chief in 2022.
Similarly, fellow Singaporean shipowner Eastern Pacific Shipping (EPS) plans to apply the ultra-low friction foul release coating on 15 vessels in its fleet during dry dockings in 2023 and 2024, to reduce fuel consumption and improve CII ratings for its ships.
Before committing to the programme, EPS tested XGIT-PROP on the propeller of the LPG tanker Quebec.
EPS fleet optimisation manager, Pavlos Karagiannidis, said propeller coatings are part of a “portfolio of solutions to achieve long-term fuel efficiency and reduce emissions.”
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