SAN FRANCISCO — It’s back to the drawing board for engineers at the ambitious Ocean Cleanup, a Dutch non-profit that in October launched a plastic cleanup system meant to rid the world’s oceans of plastic pollution. They say they hope to have it back up and running by early summer.
The system failed in late December when a 60-foot length of the device deployed in the Great Pacific Garbage Patch between Hawaii and California broke off. That necessitated towing the entire 2,000-foot device back to Hawaii for testing and inspection.
Several weeks of analysis found that material fatigue caused a piece of three-inch thick high-density polyethylene pipe to crack and break, spokesman Alan Dunton said Thursday.
“The team hasn’t determined the exact fix yet,” he said.
They believe the action of the waves causing the device to rise and fall in the water resulted in over 1.5 million load cycles on the material. Each load cycle is a time when the plastic flexed. That, combined with a local stress concentration from a weld, caused the pipe to fracture, they believe.
The Ocean Cleanup is a passive system involving a 2,000-foot floating series of connected four-foot diameter pipes that make up a boom, which forms a giant horseshoe on the surface of the ocean.