Possible design flaw in littoral combat ships under investigation

Dec. 16 (UPI) -- A potential major design flaw recently discovered on the U.S. Navy's 10 active littoral combat ships could prompt expensive repairs and leave the ships in port.

The Navy disclosed problems with propulsion systems on the USS Detroit and USS Little Rock, The National Interest reported.

Clutch bearings within combining gear, which connects gas turbine and diesel engines to the propulsion shafts allowing the ships to travel through the water, may be fundamentally faulty, according to officials.

"The government is investigating a material defect with the combining gear of USS Detroit and USS Little Rock, both Freedom-variant littoral combat ships," the U.S. Navy Seas Systems Command told Defense News on Wednesday.

"A joint Navy and Lockheed Martin team with RENK AG, the original equipment manufacturer, are conducting a root cause analysis of this defect," Navy officials said.

The two ships have recently seen repeated failures linked to the bearings in the transmission. All littoral combat ships could be affected by the flaw. The Navy has 10 Freedom-class LCS at sea, with six more planned or under construction.

The information comes after numerous problems were reported in the LCS fleet.

Three required engine overhauls after seawater penetrated their engines and ruined gaskets, and one had driveshaft damage. Both the Freedom- and Independence-classes of ships have also seen major cost overruns.

LCS ships, which are 378 feet long and are required to operate in a variety of shallow water and open sea situation, have stringent design requirements, notably the ability to travel at 40 knots [46 miles] per hour in open seas.

The high speed requires sturdy and complex transmissions, the subject of the most recent reported problem.