HOW DATA-DRIVEN HULL MAINTENANCE LOWERS EMISSIONS AND COSTS

With the recent news of shipping giant Maersk declaring their commitment to be completely CO2 neutral by 2050, and their recent tests of carbon-neutral vessels, it is clear that the way forward is towards a lower-carbon future, not just to protect our oceans, but also to optimize costs.

One of the simplest and easiest ways to reduce maritime emissions is to focus on preventative and pro-active maintenance techniques, utilising data-driven solutions and advancing tech.

INDUSTRY MOVEMENT TOWARD LOWER EMISSIONS

Industry leaders ABS, A.P. Møller – Mærsk, Cargill, MAN Energy Solutions, Mitsubishi Heavy Industries, NYK Line and Siemens Energy have partnered together to create the new Center for Zero Carbon Shipping in Copenhagen, with the end goal of creating a cleaner and greener future for the shipping industry and maritime space. The topic of lowering emissions is abuzz all over the maritime arena – and the question needs to be posed – what exactly can vessel operators do today to lower emissions, and why should we even bother?

SIGNIFICANT FUEL REDUCTIONS THROUGH HULL MAINTENANCE

Lowering vessel emissions isn’t simply just a way to help reduce pollution and help protect our maritime environment, it’s also a pathway to saving costs. One of the simplest ways to cut down on emissions is to cut fuel consumption, which in turn cuts bunker costs. It’s common knowledge that you can cut fuel consumption by slowing your vessel – but a far more convenient alternative is to cut fuel consumption via a well-maintained hull.  

Hull roughness slows ships down due to drag, and that same drag drives fuel consumption upwards. JOTUN’s recent whitepaper on the topic states that “Poor hull and propeller performance alone is currently estimated to account for around 10% of the world’s fleet energy cost and corresponding greenhouse gas emissions.”

The rough average number, supported by the International Maritime Organisation, is that a well-maintained and regularly cleaned hull can increase vessel efficiency by about 10%. This increased vessel efficiency translates directly into lower fuel consumption and lower emissions. Of course, a hull’s fouling growth rate and rate of corrosion will vary depending on the vessel’s working environment and conditions – and this is where data-driven solutions come in.

ADVANCED TECHNOLOGY DRIVES QUALITY DATA

3D map of an underwater harbour pile-wall (captured with the BAR15 ROV)

Underwater automation and robotics technologies are advancing at a rapid rate, as well as methods of collecting and organising operational data in order to create data-smart vessels, optimizing performance and fuel efficiency.

An example of a useful maritime technology is Blue Atlas Robotics’ BAR15 automated robot, which can be deployed into the water to scan hulls at a quick rate of 15 square meters per minute, capturing a detailed 3D hull model and HD video footage. 

Data can be collected from such scans to track which organisms are clinging to a hull, how quickly those organisms are growing, and how fast slime is producing, in order to tailor anti-fouling solutions to your vessel’s specific needs and predict the most cost-effective time for cleanings. The tool can also be utilized to track how well your anti-fouling is performing in different seasons and conditions and confirm if spot-repairs and anti-corrosive measures are succeeding or failing, in order to guide future maintenance decisions. All of this results in more effective maintenance planning and less vessel downtime.

DATA BRINGS CONFIDENCE TO SAVINGS

Although we have a general energy-saving figure of 10% to run by, it remains to be said that gaining a perfectly accurate number on how much money a clean hull will save you is a little bit hard to pinpoint, due to vessels experiencing many variables on the water which can skew results – such as wind speed, sea conditions, and trim.

However, a recent study from The Journal of Bioadhesion and Biofilm Research simulated the efficiency losses of a poorly maintained hull, by comparing steel plates covered in varying concentrations of artificial barnacles.  The steel sheets were towed through a pool of water, which remained a constant. The experiment was successful in controlling for external factors and focussed solely on the effects of fouling on levels of frictional resistance. The resulting data showed that for a containership of 230m, at a speed of 24 knots, if even only 10% of the hull was fouled with small barnacles (less than 2.5mm in height), the frictional resistance increased by 27%, which creates a critical amount of drag and an additional power increase of 17.5% needed to make up for said drag. Additionally, if 10% of a hull was covered in medium-sized barnacles (less than 5mm in height), the frictional resistance increased by a whopping 49%, requiring a power increase of 31% in order to compensate.

New studies such as mentioned above are showing that a well-maintained hull is the way to go to save fuel and cut emissions. Additionally, with data-driven blue economy technologies such as the BAR15, you gain the ability to no longer only rely on wider tests and studies, but to see precisely how your vessel is being affected by its specific working environment, as well as which maintenance techniques and timings produce the greatest performance and cost-efficiency.

With Maersk and other industry leaders pushing toward reducing emissions, it is expected to see a trend of vessel operators utilizing more data-driven maintenance techniques, to ensure peak performance, cost-savings, and a lower-emission future.