The U.S. Navy last week announced an overhaul of its troubled Littoral Combat Ship program that will include turning the first four ships into test vessels.

Thursday's announcement came days after the sea service announced an engineering stand-down for LCS crews following an Aug. 29 engineering casualty on the USS Coronado.

That followed a main propulsion diesel engine casualty on the first LCS, Freedom, on July 11.

Under the plan announced Thursday, the Freedom, Independence, Fort Worth and Coronado will become single-crewed testing ships that could be deployed as fleet assets on a limited basis, the Navy said.

Their primary missions will be to satisfy near- and long-term testing requirements for the entire LCS class without affecting ongoing deployment rotations.

Under the plan, the sea service will also abandon its three-crew LCS construct and move toward the so-called "Blue/Gold" two-crew model used in crewing ballistic missile boats, patrol craft and minesweepers.

Twenty-four of the 28 vessels' crews will also merge, train and rotate with mission module detachment crews, organizing as four-ship divisions of a single warfare area, either surface, mine or anti-submarine.

Those 24 ships will form into six divisions, three on each coast, and each having a single warfare focus.

Despite the new organization, the LCS class will retain its modularity between mission modules.

The changes came about after a comprehensive review of LCS crewing, training, maintenance and operations that began in March.

"The findings and recommendations of the LCS review will allow the LCS program to become more survivable, lethal and adaptable as the LCS become regular workhorses of the fleet," the Navy said.

To facilitate these changes, the Navy will eventually homeport Independence-variant ships in San Diego and Freedom-class ships in Florida.

Plagued by cost overruns, design and survivability issues, the planned LCS fleet has been winnowed from an original projected force of 52 ships.

To fill that gap, the Pentagon has announced a multi-mission frigate.

A June Government Accountability Office report recommended that Congress not fund any LCS in Fiscal 2017 while making sure the sea service had an acqusition strategy for the frigate program.