The U.S. Navy announced it will not take delivery of littoral combat ships like the USS Little Rock, pictured, until a transmission design flaw is corrected. Photo by MCS2 Delvin Bowser/U.S. Navy
Jan. 20 (UPI) -- The U.S. Navy has halted receipt of Freedom-class littoral combat ships from Lockheed Martin, citing a design flaw with potentially disastrous outcomes.
At issue is a major design flaw in the combining gear of the ship's transmission, a complex set of gears transferring power from its engines to its propulsion system.
The problem was disclosed last year, when the Navy Sea Systems Command acknowledged problems with the USS Detroit and the USS Little Rock.
The two ships have recently seen repeated failures linked to the bearings in the transmission, with all littoral combat ships could be affected by the flaw, according to USNI News and Defense News.
The Navy has 10 Freedom-class LCS at sea, with six more planned or under construction.
Lockheed Martin designed the heavily armed ships, which specialize in speed and shallow-water use, and they were built by Fincantieri Marinette Marine. The gear in question was designed by the German firm RENK AG.
"A joint Navy and Lockheed Martin team with RENK AG, the original equipment manufacturer, conducted a root cause analysis and determined a class design defect exists with the high-speed clutch bearings," Naval Sea Systems Command said this week, USNI reported.
"A design fix has been developed and is in production, to be followed by factory and sea-based testing. The Navy is determining the plan to install this fix on ships in the fleet," officials at the command said.
The Navy will not receive additional ships from Lockheed Martin until the design flaw is fixed.
Two LCS vessels, the USS Minneapolis-St. Paul and the USS Cooperstown, completed acceptance trials in 2020 but will remain at the Mariette, Wis., shipyard where they were built until the gear issue is resolved.
With the understanding of what needs to be fixed, the method of repair could include penetrating ships' hulls to access the combining gear, but Lockheed Martin is investigating a method by which the gear is lifted with jacks and then rotated.
The Navy regards the problems as a "latent issue," indicating that Lockheed Martin is expected to pay for the repairs.