Speed bump: USN focus on speed in littorals created engineering headaches

Naval engineers have described the Freedom-class propulsion plant as the most complex non-nuclear plant in the US Navy fleet. (Janes)

The US Navy (USN) is restarting Freedom-class ship deliveries, however, propulsion plant issues have curtailed vessel operations.

Perhaps no one stated the difficulty in solving the propulsion plant design flaws on the Freedom-class Littoral Combat Ships (LCSs) more than Admiral Michael Gilday, the chief of naval operations. Summing up the design problem, he said, “The issue with the combining gear is probably the most challenging engineering problem that we've seen on any class of ship since I've been in the navy.”

“We really forced industry to go back to the drawing board with respect to the fidelity of their engineering work, to do significant and rigorous shoreside testing before we approve that final [re]design,” Adm Gilday told reporters on 17 November.

Navy engineers who have studied the plant, operated the ships, and dealt with the issues that have sidelined some Freedom-class operations have told Janes thatthe plant is the most complex non-nuclear set-up in the USN – designed and developed specifically to sate the navy's need for speed in the littorals.

Officially, the USN acknowledges LCSs can top 40 kt, however, Janes was aboard Freedom when the ship reached nearly 50 kt.

In that speed quest, the USN jettisoned any extra weight it could find – often in the form of weapons or ship-survivability design and systems – and approved a propulsion plant design that surged the ship in a higher gear.