Lockheed Martin Corp.'s first new warship for operating close to shore developed a crack as long as six inches through its hull during sea trials, prompting a U.S. Navy investigation of the design.Glad this made it into open source.
The Navy is analyzing the crack on the USS Freedom, which is homeported in San Diego, to determine if changes are required for future Lockheed Martin hulls, Naval Sea Systems Command spokesman Christopher Johnson said Thursday in an e-mail. This includes reviewing "the design, construction drawings and welding procedures," he said.
During a heavy-weather ocean trial on the USS Freedom in mid-February, he said, sailors discovered a six-inch horizontal hull crack below the waterline that leaked five gallons an hour. Inside the hull the crack measured three inches. It originated in a weld seam between two steel plates.
The ship returned to its home port in San Diego, avoiding rough seas, after the commanding officer judged the leak rate "manageable," Johnson said.
Smaller cracks that indicated welding "defects" showed up in the welds of the vessel's aluminum structure during sea trials last year, Johnson said in his e-mail.