Prototype skimmer holds the potential for more effective cleanup of spilled oil

The prototype skimmer that won the million-dollar first prize in the X Prize Foundation's Wendy Schmidt Oil Cleanup X Challenge can clean up almost 5,000 gallons of spilled oil a minute with an 89.5 percent recovery rate, both far in excess of the current industry standards.

But the team that built it said the commercial skimmer that ultimately emerges will probably be a much leaner machine — "a big punch in a small package," said Donald Wilson, founder of Elastec/American Marine, the Illinois-based spill-response company that brought in Glosten Associates of Seattle to help build the winning entry.

The prizewinning design pulls together several technologies. To start with, research at the University of California Santa Barbara showed that using grooved drums instead of flat surfaces optimizes the recovery rate, and Team Elastec multiplied that effect by stacking four rows of grooved discs one behind the other. Any oil the first disc misses can be picked up by the next, and so on.

Then Paul S. Smith at Glosten tackled what he called the Achilles' heel of disc skimmers: their inability to handle waves. "They're excellent stationary skimmers," Smith said. "But their best performance is achieved in a zero-current environment."

To win the prize, the skimmer needed to perform while being dragged through the water at 2-plus knots.

Smith's answer: A short section of downward-facing plate at the mouth of the skimmer that acts like a beach to absorb wave energy, backed up by a plate sloped in the opposite direction that creates a diverging channel and slows the velocity down.

Three induction pumps at the back pull water through the unit so its hydrodynamic signature is almost invisible.

"If those were not running, we'd just be dragging an open box through the ocean," said Smith. "We'd be bulldozing the ocean, which is not terribly effective in oil spills."

The resulting device measures 32 by 10 by 5 feet. And it weighs a ton. Seven tons, actually — it's so heavy, it needs a crane to put it in the water. And that's why a commercial version will probably be scaled down.

"Most customers don't have the infrastructure," said Elastec's Wilson. "I think the majority are going to want something smaller, but they expect the same efficiency. Our goal right now is to go to the industry and say, 'What would you like us to build?'"

Elastec planned to test customer reaction at the Clean Gulf show in San Antonio, Texas, toward the end of 2011.

What made the Deepwater Horizon accident in the Gulf of Mexico so scary, of course, was the magnitude of the blowout. But that was exceptional.

"A lot of our clients have pipelines that may be near shore or underwater, and their exposures are much less than the big guys," said Wilson. "There'll be lots of questions and answers about what our clients would like. And then our challenge is to make it commercially viable and as quick as possible."

By Professional Mariner Staff