Page 18: of Maritime Reporter Magazine (August 2022)

The Path to Zero

Proactive In-water Cleaning

Microfouling and the f rst step to decarbonization n the April 2022 edition of Maritime Reporter & Engi- indicating that a thin layer of slime, half a millimeter thick neering News, Armach Robotics discussed how its au- covering approximately half the hull, can increase emissions tonomous robot could operate on a ship’s hull, but only as much as 20-25%. With an IMO goal of a 40% reduction in

I touched on the value this technology can bring. Armach’s GHG emissions by 2030, addressing microfouling alone can hull crawling autonomous robot (named the Hull Service Ro- move vessels closer to achieving that goal, lessening the criti- bot, or HSR) was developed to proactively address biofouling cality of other complex emissions reducing technologies. on ship’s hulls. To minimize the impacts of microfouling, the growth needs to be removed early and often. The challenge has been how to

But Why? do this in a way that is economical, non-disruptive to the ship’s

Simply put, biofouling is a problem. And the earlier it can be schedules and not detrimental to the ship’s coating system. addressed, the better. The maritime world has known biofoul- More frequent use of traditional cleaning methods is not fea- ing to be a problem for over a thousand years, and has been sible, as the cumulative cost is very high, would require taking steadily evolving how to deal with it. The focus has largely time away from the operational schedule, and since traditional been on macrofouling - barnacles, weeds and grasses - the re- cleaning methods are targeted for macrofouling and are very ally easy to see ugly stuff. Modern approaches include the use aggressive, they risk signi? cantly damaging the paint if used of anti-fouling and fouling release coatings, as well as reactive regularly on microfouling. cleaning methods. These coatings can be effective in slowing Armach’s HSR is designed to overcome these challenges. It the appearance of macro-fouling on vessels, and when their is purpose built for proactive cleaning. Its small size and auton- effectiveness is diminished, reactive cleaning takes place. But omy greatly reduce the infrastructure necessary to deploy and these established practices fail to address the issue of micro- operate the system, reducing operating costs when compared fouling, or the earliest, slimy, stages of fouling development to traditional systems. In fact, multiple HSRs can be deployed on the vessel. simultaneously, and be overseen by only one operator, allow-

Microfouling will start to appear on a surface within hours of ing for complete coverage of the hull during a typical in port immersion, and will increase over the coming days and weeks period. The small topside footprint required minimizes disrup- until, if left alone, it eventually becomes macrofouling. The tion on the pier and will enable cleaning operations to occur rate at which this happens is highly dependent on numerous concurrent with other import activities. factors - water temperature, sunlight, nutrients in the water, Armach’s HSR is speci? cally designed for removal of mi- coating system, currents, vessel speed etc - but the reality is crofouling - the soft brushes it uses are engineered to remove there is going to be some level of microfouling present. And slime without damaging the coating system. Long term testing microfouling matters. has shown no damage or accelerated wear to coatings, and in

Microfouling increases drag on the hull. It may be slimy and some instances has resulted in a smoother coating system than slippery, but it is less hydrodynamic meaning greater fuel con- at application, improving hydrodynamic ef? ciency. sumption and more greenhouse gas (GHG) emissions than a The bene? ts of a proactive cleaning approach extend be- clean hull. The IMO recently published a preliminary report yond the emissions reductions and not-insigni? cant fuel sav- 18 Maritime Reporter & Engineering News • August 2022

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