Air lubrication a possibility for Great Lakes ships
An idea is bubbling in the Great Lakes shipping industry, one that could increase fuel efficiency by 5 percent to 20 percent.
“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.
Naval engineers believe injecting air under the bottom of a ship reduces friction, helping them travel faster on less fuel.
“If you think about places in the U.S. where the benefit of fuel savings and reduced emissions would be helpful, it’s the Great Lakes,” Ceccio said.
Great Lakes ships tend to 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 graduate student at the University of Michigan, studied the feasibility of air lubrication. The technique requires a blower to inject air under the ship. That costs money to run, so they also compared that cost to the 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 on 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 expects the payoffs of air lubrication are worthwhile because large companies like Mitsubishi are using the technology.
Makiharju presented his research at a Great Lakes Maritime Research Institute meeting in Minnesota in September. 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 Great Lakes Maritime Research Institute.
Although Wolosz and other maritime researchers are interested in air lubrication, no ship owners have approached Ceccio and Makiharju. They hope proving lubrication is a good financial choice will generate more interest.
“If it were proven that it’s viable and proven to work, it could merit design into future vessels,” Wolosz said.