The Navy's fifth Littoral Combat Ship is the first vessel to receive new waterjets engineered to improve propulsion and fuel efficiency, service officials said.
"The fuel efficiency that we derive is incredibly impressive. We're not talking about one or two percentages – we're talking about 10 percent improvement in efficiency from the waterjet," Rear Adm. Mathew Klunder, Chief of Naval Research told members of the Senate Appropriations Committee's Defense Subcommittee May 14.
Now installed on the USS Milwaukee, or LCS 5, the new waterjets provide improved performance compared to previous waterjet models, said Ki-Han Kim, Office of Naval Research program officer, Sea Warfare and Weapons Division.
The waterjets, developed from 2006 through 2011, improve what's called cavitation performance, the process of creating partial vacuums in a liquid.
"The new waterjets benefit from an improved hydrodynamic design architecture that reduces the size of the waterjet and the damaging effects of cavitation through the use of improved impeller blade design techniques, while maintaining a high propulsive efficiency," Kim said.
Development of the waterjets includes a partnership in funding between the Office of Naval Research, Naval Surface Warfare Center, Carderock Division, and Rolls-Royce Marine, North America. The new waterjets have gone through extensive tests and validations at industry and government testing facilities and also been put through reduced scale at-sea demonstrations, Kim added.
Klunder praised the waterjet development as an example of effective industry-government partnerships.
The Navy plans to add the new waterjets to every Freedom variant of the LCS that is produced, Navy officials said. Each LCS requires four waterjets.
The first units were installed on LCS 5 in the summer of 2013 and full scale units have now been delivered for LCS 5, LCS 7 and LCS 9. Units for LCS 11 and LCS 13 are currently in production. Rolls-Royce won an initial competition to develop the waterjets in 2006 and has since gone on to be awarded a second phase to develop and deliver full-scale waterjets, Kim said.
"During the second phase, more improvements were made to the initial design and intermediate scale testing was performed on a Navy small boat," he explained.