When Boyan Slat and his team at the Ocean Cleanup Project dragged their 100-m (330-ft) trash-catching boom out to sea in June, the Dutch entrepreneur gave the system a 30 percent chance of breaking. Unfortunately for Slat, these fears have now materialized with the team having to haul the barrier back into shore after it was bent out of shape by the angry Dutch seas.

The damage was inflicted on the boom after around two months at sea, where it was made to endure large waves and winds of up to 45 knots. A recent inspection uncovered damage to two air chambers, which had been bent out of shape and didn't conform to the U-shaped curve of the barrier.

Underwater camera footage revealed that failing shackles connecting the boom to the mooring system were the source of the problem. The team initially sought to monitor the condition of the system while leaving it to conduct its plastic-catching duties, but the problem only grew worse and after almost two months they were forced to rein it in.

While the prototype is currently back on shore for inspection and maintenance, it's all about the bigger picture for the Ocean Cleanup Project. The fact that Slat knew failure was a possibility means he and his team are wasting no time in developing a more robust system that can withstand the forces of the ocean. The North Sea test site was chosen as a testbed for its particularly nasty conditions, where Slat says that minor storms can create more violent conditions than once-in-a-hundred year storms in the Pacific, his ultimate target.

"Based on the lessons we learned from these first two months of testing we will now implement several design improvements to the boom, before reinstalling it at our North Sea test site in the near future," he writes in a blog post. "We will continue to go through these iteration cycles until we are confident the barrier design is capable of lasting in the Great Pacific Garbage Patch for years."

The Great Pacific Garbage Patch is the name of the game for the Ocean Cleanup Project. It plans to install a 100-km (62-mi) floating barrier system between Hawaii and California, which will use the ocean's naturally currents to gather up plastic waste and then funnel it into a central collection point.

But that's a ways off yet. After the North Sea test, the team will install a larger 2-km (1.2-mi) version between Japan and South Korea, with other smaller installations to follow. Slat says that if everything goes to plan, the system can cut the time required to clean up the world's oceans from millennia to mere years.

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