Energy saving devices called pre-flow stators have already been shown to provide significant fuel savings in ships with fixed pitch propellers (FPP) by optimizing the flow of water into the propeller (see earlier story). Now the technology has been extended to cover vessels equipped with controllable pitch propellers (CPP).
The CPP pre-swirl stator has been developed by Wärtsilä, Netherlands-based maritime research institute MARIN and Italian shipowner Grimaldi as part of the EU sponsored LeanShips project.
According to Wärtsilä, efficiency gains of 3.5 percent have been confirmed by model tests, and subsequent sea trials with Grimaldi’s 165 meter long Pure Car and Truck Carrier Grande Portogallo. This translates into a pay-back period of only 1.3 years.
Gains could actually be higher. Grimaldi says that “the initial noon reports suggest a 5 percent decrease in the fuel consumption, but in order to get a more realistic value we need to record a wider range of data.”
“This represents a major breakthrough in making ships with controllable pitch propellers more efficient, and therefore less polluting. We have earlier established some energy savings for ships with controllable pitch propellers, and now this new technology has been extended in line with the objectives of the LeanShips project,” says Dario Bocchetti, Corporate Energy Saving Manager, Grimaldi Group.
“Wärtsilä continues to collaborate with strategic partners to create greater efficiencies that enable both cost savings and better environmental performance,” says Lars Anderson, Director, Propulsion, Wärtsilä Marine. “The Energy Saving Device developed through the Leanships project is one more example of successful collaboration that results in substantial customer benefits.”