Hempel’s group segment manager for marine drydocking Andreas Glud discusses the ways hull performance can boost both environmental and energy efficiency
Operating as efficiently as possible matters. And this is not just the case for shipping, all industries are looking for new sustainable ways to become more energy efficient, as are people - on a more individual level. We are now very well informed about the damage and threats to our environment and the pressure is officially on, for all of us, to be both cleaner and greener.
For shipping, if we are to strip it down to the very basics, efficiency means using less fuel, which means less harmful emissions are released into the atmosphere. The International Maritime Organization (IMO) has been active in moving towards a greener operating environment and recently ratified a global 0.50% sulphur cap that will enter into force on 1 January 2020. The aim is to significantly reduce the sulphur content of the fuel oil used by ships, and this will be beneficial to both the environment and human health.
This landmark decision by IMO has been widely debated across the industry, as it will ultimately impact more than 70,000 ships, with significant implications for fuel supply around the world. In April 2018, IMO also adopted the Initial IMO Strategy on the reduction of greenhouse gas (GHG) emissions from ships. This historic strategy sets out a framework to reduce the total annual GHG emissions by at least 50% by 2050 compared with 2008 levels.
While these initiatives are ambitious to say the least, the reality is that there are many ways to improve operational efficiency and every little helps towards achieving a cleaner environment. Shipping is one of the most efficient means of transportation for goods by volume transported, but there is plenty more potential to further reduce GHG and CO2 emissions.
“Biofouling can have a massive impact, reducing a hull’s hydrodynamic efficiency by up to 40%”
Simple modifications to the design requirements for newbuilds are already being implemented, and there are plenty of initiatives being adopted by shipowners to maximise efficiency. Slow steaming, reducing port calls and improved voyage planning are just a few of the operational strategies being adopted, but the benefits of technology and science, such as advanced hull coatings, should not be underestimated either.
Hull performance and the benefits of a technologically advanced hull coating can play a vital part in a vessel’s operational efficiency, whatever the type of ship. Biofouling, both micro and macro, has a significant impact on the hydrodynamics of a ship. The growth starts with a bio film, or slime layer of bacteria, that begins to accumulate as soon as the vessel is in water. Once established, other larger organisms can stick to the hull and grow. Macro biofouling includes hard fouling such as barnacles, molluscs and tube worms, while micro fouling covers organisms such as seaweed, algae, slimes and sponges.
Biofouling can have a massive impact, reducing a hull’s hydrodynamic efficiency by up to 40%. The increased drag means a higher fuel consumption is needed to move the ship through the water, which means higher costs and increased fuel emissions. The result is an inefficient and much increased use of energy and power, and this is much more harmful to the environment.
Applying an antifouling coating solution to the hull of a ship is not a new concept, but coatings technology has advanced greatly.
Hempel has been at the forefront of coatings technology for more than 100 years, and in direct response to rising bunkering costs and tightening environmental regulations the company launched Hempaguard in 2013.
Hempaguard is an innovative fouling defence product containing 95% less biocide than traditional antifoulings, but still offering outstanding resistance to fouling during idle periods (of up to 120 days).
Unlike regular hull coatings that, in general, are specified according to a vessel’s speed and activity profile, Hempaguard retains its effectiveness when steaming at slow or at regular speeds; and when alongside in port. This gives shipowners enhanced flexibility over their fleet utilisation.
Hempaguard was the first product to use Hempel’s patented low friction Actiguard fusion technology. which integrates silicone-hydrogel and full diffusion control of biocides in a single coating. It can deliver 6% fuel savings across the entire docking interval and a maximum speed loss of 1.4% over five years.
As the industry changes and markets remain challenging, the focus is on securing enhanced environmental performance, while maximising efficiencies. An advanced coating solution is one step in the right direction for a better future.