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Monday, May 18, 2020 

According to maritime performance optimisation data company GreenSteam, vessel owners, operators and charterers reacting to a sharp reduction in demand due to Covid-19 are soon to face an additional operational challenge in the form of accelerated hull fouling as more and more vessels lie idle at anchor or provide floating storage for petroleum products.

Some sectors currently have between 15-100% of vessels lying at anchor. Bulkers were the first to be hit as raw material cargoes to China softened and the economy contracted. With customers affected by faltering demand, empty supply chains and falling requirements, container ships have been forced to cancel routes or slow-steam leading to around 14% of global TEU capacity lying idle. And as a result of the recent oil price crash, demand for floating oil storage rocketed from 75 million barrels in February to 160 million in April. But it is cruise ships that are suffering the most, with almost every cruise ship anchor.

GreenSteam, a Castrol partner company, says we are now starting to understand and quantify the knock-on impact of so many stationary vessels when it comes to hull fouling. The growth of organisms on a hull can, if left unchecked, increase fuel costs by over 20% as well as shortening coating life which necessitates early docking. Vessels lying at anchor are subject to accelerated hull fouling. This means that, once the shipping industry has successfully navigated the effects of COVID-19 and looks to return to business as usual, many owners, operators and charterers may be subject to increased fuel bills as a result of this excess hull fouling.

Simon Whitford, COO, GreenSteam said: “Fouling follows an S-shaped growth curve. After the rate of fouling starts to accelerate it can soon pass a point of no return for in-water cleaning as the hull surface gets saturated by plant then animal organisms. Cleaning before this point is usually reversible – we can turn back the clock on hull fouling. After this point it becomes increasingly difficult to clean without damaging the coating. Damaged coatings lead us to a future of expensive and ever worsening performance until the next dry dock and re-coating, Despite this S-shaped growth curve, a recent survey during a GreenSteam webinar found 78% of attendees with hull cleaning responsibilities did not use a monitored condition-based strategy, preferring to clean the hull at fixed 'rule of thumb' or 'based on experience' periods, or 'reactively' after a manual inspection or when fuel consumption spikes."

Alternatively, some owners and operators have used legacy non-machine learning methods which rely on a 2016 ISO 19030 standard for hull fouling measurement. This differs from GreenSteam’s machine learning software which uses valid ship data to build a very accurate picture of fouling - making it possible to establish an optimal cleaning schedule.

GreenSteam’s Head of Performance Management, Jonas S Frederiksen, said: “it is now possible for the industry to get ahead of the curve and move to a monitored condition-based strategy, which protects expensive coatings whilst reducing emissions. GreenSteam’s machine learning software uses both historical and live data to create a vessel performance model and applies this in conjunction with real-time and historical metocean data to build a complete picture of hull fouling. This allows a monitored, condition-based predictive strategy lowering both fuel and maintenance costs.”

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