Conventional diesel tugboats are significant sources of pollution in the world’s seaports, but that is on the verge of change. The Foss Maritime Company is adding a second energy efficient hybrid tugboat to its Southern California fleet. Its first hybrid vessel, the Carolyn Dorothy, was launched in 2009 and at the time it was believed to be the first and only tugboat of its kind in the world.
The new vessel is actually a retrofit of an existing tugboat, for which the California Air Resources Board chipped in a grant of $1 million. It’s just a small part of a major EPA program to reduce pollution in seaport areas all along the U.S. coastlines, which also includes efforts to cut emissions from trucks at seaports.
The basic idea behind Foss’s hybrid tugboat (pdf) is to cut down on diesel emissions related to the considerable time that tugboats spend idling or operating at low power. The vessel’s high tech power management system integrates batteries, generators and the main diesel engines in one system that produces minimal emissions when the tug is idling or stopped. The system also results in lower emissions when the tug is performing tasks that require less than full power. It is expected to result in a 44 percent reduction in particulate matter and nitrogen oxide, along with lower carbon and sulfur emissions. In addition, the hybrid system will result in lower fueling and lubrication costs, and lower lifecycle costs.
Image: Old tugboat by alpha deux cents on flickr.com.