The Littoral Combat Ship (LCS-1) USS Freedom’s ship service diesel generators (SSDG) continue to give the vessel fits, recently causing the LCS to lose propulsion briefly while heading out to participate in at-sea exercises off the coast of Singapore and forcing it to return to port, the U.S. Navy says.

“Freedom departed Changi Naval Base July 19 to participate in the at-sea phase of Carat (Cooperation Afloat Readiness and Training) Singapore, which begins July 21 and continues through July 25,” says U.S. Navy spokesman Lt. Cmdr. Clayton Doss. “The ship lost propulsion briefly July 20 while making preparations for a vertical replenishment. Freedom never lost power, the crew restored propulsion, and the ship completed the vertical replenishment.

“Initial assessment on the loss of propulsion is that the (number) 2 Ship SSDG overheated and shut down,” Doss says. “The crew determined turbochargers in (number) 2 and (number) 3 SSDGs had exhaust leaks and needed to be replaced. Turbochargers increase SSDG efficiency and power by forcing more air into the combustion chamber. Freedom also experienced problems load-shedding between online generators that will require further troubleshooting by maintenance technicians in Singapore.”

Freedom’s commanding officer decided to return to port to accomplish repairs with available spare parts, Doss says, and to allow the crew and maintenance technicians to continue troubleshooting the electrical plant as required.

“While it is general policy not to discuss specific maintenance timelines or operational schedules, technicians are working quickly to repair the problem,” Doss says. “If repairs are accomplished soon, Freedom will return to sea and join other U.S. Navy units along with Republic of Singapore Navy ships to participate in the sea phase of Carat Singapore.”

During transit through the Pacific, the ship also experienced power outages due to problems with diesel generator power disruptions.

Doss acknowledges the SSDG problems appear related to power losses reported on the ship in March, and notes electrical plant issues are under review by the LCS program.

Adm. Jonathan Greenert, the chief of naval operations, suggests some modifications may be needed to better pinpoint the problems and potential solutions for the complicated LCS propulsion system.

“It’s very integrated,” Greenert said of the system during a media May briefing aboard the Freedom at Singapore’s Changi Naval Base. “We need to look at that. I don’t know if we can change that much, but when you get so integrated, when something fails, everything has to kind of stop.”

Greenert says the Navy needs to figure out how to isolate and more quickly repair problems in such a system. “What can we do to decouple and as appropriate repair more quickly? We have to look at that.”

Doss says that “despite challenges that are not uncommon for any U.S. Navy ship on deployment, let alone a first-of-class ship that has never deployed overseas before, the Freedom crew continues to perform well as they capture valuable lessons learned that will inform follow-on rotational deployments as well as the LCS program.”