The new green-and-white tug, named the Carolyn Dorothy, can do the same work as a traditional tug -- assisting huge freight ships move safely in and out of the harbor -- but with 44 percent less pollution.
The Port of Long Beach was one of Foss' two funding partners, contributing $500,000 toward the building of the $8 million vessel, as part of the Technology Advancement Program under the San Pedro Bay Ports Clean Air Action Plan.
"The world's first hybrid tug is exactly the type of technology-advancing project that will help the Port of Long Beach achieve its clean-air goals," said Richard D. Steinke, Executive Director of the Port of Long Beach.
Under an agreement with the ports of Long Beach and Los Angeles, the Foss tug will undergo six months of tests and evaluation of the vessel's operational and environmental performance. After that, the tug will be operated in both ports for at least another five years.
Foss developed the hybrid tug with an eye toward retrofitting existing tugboats with the diesel-electric power plant.
Based on the typical port workload, hybrid technology should be well suited for tugboats. The hybrid power plant on the Green Dolphin is able to provide the enormous power the tug needs when she needs it, but can also switch to low-emission mode for the times when it's cruising the harbor on its own or idling.
