Boyan Slat‘s vision became reality a few months ago. It’s been five years since Slat, just nineteen, left his studies in aerospace engineering to focus on his mission, cleaning the oceans of plastic. After establishing the NGO Ocean Cleanup, Slat conceived a device to collect plastic garbage from the sea using ocean currents.
After a feasibility study and successful fundraising campaign, the machine – called Ocean Array Cleanup – sailed from San Francisco to the Pacific Trash Vortex, the largest plastic island floating in the Pacific Ocean, between California and Hawaii: «The cleanliness of the world’s oceans is around the corner» said Slat.
Behind the Ocean Array Cleanup there is a simple but brilliant idea: the device exploits sea currents to ensure that plastic garbage accumulates in the platforms and the sea clean itself alone. The system consists of a chain of two-kilometer floating barriers placed in favor of current, without nets, which convey the plastic towards platforms that act as funnels. It was a great idea, but – after two months – Ocean Cleanup will have to completely remake the System 001 floating barriers: the device in Great Pacific Garbage Patch needs a redesign. Actually, two months after the launch of their massive trash-collecting device to the middle of the Pacific Ocean, they had to renovate the plan they’ve been working on for years after it turned out to have some complications.
«The journey toward a clean ocean is certainly not an easy one» said Lonneke Holierhoek, the Ocean Cleanup’s Chief Operations Officer from her office in Rotterdam. Also the Ocean Cleanup’s CEO talked about some problems in his blog: Boyan Slat, in fact, wrote that the device deployed in the Great Pacific Garbage Patch, in October was having trouble holding on to the plastic garbage it was created to corral. The action of the currents and waves was expected to push trash into the system‘s center while the pieces of plastic garbage were caught by the barrier. But, from Slat’s words seems that the device was only retaining the floating plastic pollution “for a relatively short time”. Unfortunately, the System 001 is moving too slowly at times to keep the plastic inside the device, allowing it to float out again. Sometimes the plastic even moves faster than System 001, outrunning it.
The group’s engineers and scientists have been studying the problem since it first became evident, but there are problems that you can fix only with the experience in the field. «During the process of the design and the engineering there were a lot of points were we said Is this assumption we’re making correct? Can we test it? How can we verify it? We probably ended up with about 50 assumptions that we decided we couldn’t verify anywhere but in the field» said Holierhoek.
The Ocean Cleanup team isn’t sure why things are going in a different way, even if they have a few theories. One is that the force of the wind against the system might be making both extreme ends of the floating pipe oscillate back and forth like a fish’s fin: that motion could slow the system down. «It is also possible that the vibrations in the ends of the U-shape could be creating a type of ripple-force field that repels the plastic away from as it nears the mouth of the system» wrote the CEO.
While the main ship is working its way back to the Garbage Patch, a small crew of six is staying with System 001 in a guard ship. System 001 is meant to be the first of as many as 60 such devices the group hopes to deploy to clean the world’s oceans of plastic garbage. In his post, Slat said it «Must work before we can look to scaling up, so there is no time to waste».