This underwater robot cleans ships to cut emissions and protect marine ecosystems

Imagine a ship making its way across the ocean. It might look elegant as it cuts serenely through the waves. But a look below the water reveals a different picture, with countless aquatic species like barnacles covering the craft’s hull.

It’s been estimated that severe underwater biofouling – as this accumulation of drag-inducing marine life is known – can increase a ship’s fuel consumption by up to 40%, boosting already high CO2 emissions. More than 4,000 marine species have been identified as biofouling organisms.

Maritime transport emits around 940 million tonnes of CO2 annually and is responsible for about 2.5% of global greenhouse gas emissions. It’s been estimated that if global shipping were a country, it would be the sixth biggest polluter, generating more emissions than Germany.

Alien species

This fouling doesn’t just slow ships down. The build-up may include species that can cause severe harm to native species in the new environments they’re transported to. It’s something maritime conservation bodies are increasingly concerned about.

Back in 2017 the bulk carrier DL Marigold became the world’s first biofouling casualty when it was ordered to leave the waters of first New Zealand and then Fiji because it posed an invasive species threat.

Stopping the build-up isn’t plain sailing. Three centuries ago they tried sheathing ships’ hulls in copper. Later, paints made with toxic chemicals were used. After they were banned, coatings were designed to stop plants and marine animals gaining a toehold.

Nothing, up to now, has managed to stop what for ship owners is an expensive problem. In severe cases, there’s been no option but to check the ship into a dry dock for treatment, which can cost anywhere from tens of thousands to several million dollars.

Robotic innovation

So a new robot ship cleaner is being hailed as a breakthrough in the battle against marine fouling. Jotun, a Norwegian paint maker, has produced HullSkater, an underwater machine that cleans a ship's hull and prevents the build-up of fouling.

Holding itself to the ship by powerful magnets, the robot removes marine life before it becomes established. Because it travels with the ship, it can be used every time the vessel is at anchor or in harbour and is designed to work without causing damage or erosion.

Once launched, the robot is operated remotely from central hubs using Internet of Things (IoT) and cloud technology. By inspecting the hull as it cleans, it removes the need for divers, helps avoid that costly dry dock downtime and increases the time ships can spend at sea.

As a fun way of promoting the robot – as well as giving potential owners an idea of what it looks like – Jotun has even produced instructions on how to build one out of Lego. There are 37 steps to build this version.

“Sustainability in the oceans has become more and more important,” said Jotun CEO Morten Fon at the robot’s virtual launch. This latest innovation came about, he added, when the company switched its focus from just “antifouling and paint, to thinking about hull performance”.

“If we were able to deploy this service broadly to ships across the world, we would have a huge environmental benefit,” said Ove Fredheim of telecoms provider Telenor, a member of what he describes as the ecosystem of “technology leading Norwegian companies” behind the project.

In 2019, the World Economic Forum, the Global Maritime Forum and Friends of Ocean Action launched the Getting to Zero Coalition at the United Nations Climate Action Summit, with the goal of decarbonizing the international maritime shipping sector by 2030.

Decarbonizing shipping was also the subject of a session at the Forum’s Race to Zero Dialogues virtual summit in November 2020 – the debate can be viewed on the event’s webpages.

Innovations such as the HullSkater could be an important step in helping to reach that goal.