The plastic pipe and screen project called Ocean Cleanup is about to head back to sea with a redesigned marine litter removal system to be smaller, lighter, more modular, and hopefully better able to withstand the harsh conditions of the Great Pacific Garbage Patch.
The Netherlands-based nonprofit group plans to test its upgraded design and return the second-generation ocean sweeper to the gyre between California and Hawaii, an area believed to be the largest accumulation zone of trash on the planet.
The U-shaped system consists of a 2,000-foot high density polyethylene floater pipe and a tapered polyester screen for corralling and collecting plastic. The most obvious change to it involves the screen, which extends 10 feet below the water's surface. The screen has been brought forward and is no longer attached to the underside of the pipe, which is the backbone of the contraption.
In the first version of the system, a stress crack developed at a welding point for the screen and caused a 26-foot end section to break away in late December after only about two months at sea. The new design uses a new connecting system reduce the chances of fatigue fractures, according to Boyan Slat, founder of the Ocean Cleanup, said in a May 24 online update.
The new design also eliminates the need for heavy stabilizers, which prevented the first system from toppling over because of all the electronics on the top of the pipe.
"We made the electronics much simpler, much smaller, so we can get rid of the stabilizers, which obviously didn't help with the loads on the pipe," Slat said.
To improve the Cleanup's speed, the group has two plans. At first, the creators thought the system had to move faster than the plastic, but Slat now says it can move slower and still do the job.
"The key is consistency," Slat said. "What you want is for the system to always go faster than the plastic or always go slower."
To maintain a consistent speed, the group will put six inflatable buoys on the front side of the system.
"[They] kind of tow the system forward, propelled by the force of the wind," Slat said.
If the buoys don't work, the group will try a "massive" 20-meter diameter parachute.
"This would actually turn the system around, and rather than always wanting to go faster, this should allow it to always go slower than the plastic. So, let the plastic float into the system," Slat said.
The next Ocean Cleanup system also will be smaller "by a factor of three" for several reasons, including faster parts procurement, assembly and towing, Slat said.
In addition, the redesigned system is more modular to make operations and maintenance of riggings and screens easier at sea.
Slat called the group's "mitigation approaches" interesting but uncertain.
"That's why it's so key we get out there as soon as possible and put these things to the test and continue learning as we go," he said.
If it ever works, the system is expected to remove about a ton of debris per week. When it is full, the plastic will be hauled to shore and recycled.
Skeptics have doubts about the system's ability to harvest ocean plastic and some argue that the Ocean Cleanup, which raised about $35 million from donors and sponsors, is taking valuable attention and money from other more viable plans.
Italian environmentalist and TV presenter Cristina Gabetti is among the latest critics. She points out that the garbage patch is more of a garbage soup than garbage island, which complicates cleanup efforts.
Gabetti recently told architecture and design magazine Dezeen, "I'm not saying it's a hoax; rather [it's] a dream that seduced many people and donors. And we all fell for it."
Plastic recycling expert Arthur Huang suggests another use for the money in the May 23 Dezeen story.
"Scooping out trash in ocean is good so the project could never be declared a failure conceptually," he said."[But] we could use $30 million and install a series of fishing nets to trap trash from going into the ocean in any polluted river in China. That will have way more impact and collect way more ocean trash."