Recently, WorkBoat technical editor Bruce Buls visited Foss Maritime's Rainier Shipyard on the Columbia River to get a look at the tug Campbell Foss as it undergoes conversion from traditional propulsion to hybrid technology. Buls got a chance to speak with VP Susan Hayman and project manager Rick McKenna about just what the conversion entails for this Dolphin-class tug, similar to the Carolyn Dorothy, which was purpose-built as a hybrid. Essentially, the Campbell Foss will now use the appropriate power supply for the appropriate duties, only engaging the main engines when necessary, and using the batteries for idling and the generators for transit, for example. This, said Hayman, would result in as much as 25 percent fuel savings and 30 percent maintenance cost savings.