Ships that pump it could save fuel

Capital News Service
LANSING — An idea is bubbling in the Great Lakes shipping industry, one that could increase fuel efficiency by 5 percent to 20 percent.
Naval engineers say that injecting air under the bottom of a ship reduces friction, helping it travel faster on less fuel.
“This has been a dream of naval architecture for a long time,” said Steven Ceccio, chair of naval architecture and marine engineering at the University of Michigan.
“If you think about places in the United States where the benefit of fuel savings and reduced emissions would be helpful, it’s the Great Lakes,” Ceccio said.
Great Lakes ships generally have large, flat bottoms – an ideal shape for the technology because air stays underneath the ship instead of bubbling to the surface.
Ceccio and Simo Makiharju, a U of M graduate student, studied the feasibility of an air lubrication technique that requires a blower to inject air under the ship.
The process costs money to run, so they also compared that cost to expected savings from reducing the friction. “From an engineering and energy savings standpoint there’s a benefit, but what we’d need to do with a ship owner and operator is determine the payback time in the cost of retrofitting” each ship, Ceccio said.
Costs of adding a blower depend on the ship. Ceccio said retrofitting old ships with the technology would often be more costly than building it into new ships.
So far no ships in the Great Lakes use air lubrication technology.
“Over the past several years there’s been a great deal of progress,” Ceccio said. “Now in Europe and Japan they’re deploying large ships that use air lubrication to reduce energy use.”
Ceccio predicts that the payoffs from air lubrication will be worthwhile because large companies like Mitsubishi Corp. are using the technology elsewhere.
The shipping industry does have concerns about the technology, according to Glen Nekvasil, vice president of the Cleveland-based Lake Carriers’ Association. The association represents 17 companies that operate U.S.-flag commercial ships on the Great Lakes.
“Certainly anything that could increase our fuel efficiency by 20 percent would be desirable,” Nekvasil said. “Conceptually it’s a wonderful idea.”
However, he said, “We do have to recognize that there are some unique characteristics in Great Lakes shipping.” Among the questions are whether ice formations would affect the air lubrication systems, whether the fuel saved would be worth the cost of generating air and whether the layer of air would be too thick for some shallow ports and channels.
Makiharju presented his research at a Great Lakes Maritime Research Institute meeting in Minnesota. The institute helped fund their work.
“We’re looking for both economic and environmental sustainability for shipping on the Great Lakes, so this ties in with our mission,” said Carol Wolosz, executive director of the institute, which is based at the University of Minnesota-Duluth.
Although Wolosz and other maritime researchers are interested in air lubrication, no ship owners have yet approached Ceccio and Makiharju. However, they hope that demonstrating how lubrication is a good financial choice will generate more industry interest.
“If it were proven that it’s viable and proven to work, it could merit design into future vessels,” Wolosz said.
Carol Thompson writes for Great Lakes Echo
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