Warships whose commissioning is on hold will test a solution to a “class design defect” affecting all the littoral combat ships at Naval Station Mayport, Navy officials have concluded. The Navy decided last month to stop taking delivery of new LCS because of a problem in the ships’ system for merging power from multiple engines to move the vessels at the rapid speeds they’re designed for. The decision left vessels that had already completed Navy acceptance trials — littoral combat ships that were built to be the USS Minneapolis-Saint Paul and USS Cooperstown — waiting at a Wisconsin shipyard while engineers drafted plans to fix a problem in a mechanism called the combining gear.