Ingalls Shipbuilding launched its 30th Arleigh Burke-class guided missile destroyer Ralph Johnson on Saturday.

Ingalls Shipbuilding, a division of Huntington Ingalls Industries, is the largest builder of military ships in the United States, and has built and delivered 28 Arleigh Burke-class destroyers for the U.S. Navy. Guided missile destroyers like Ralph Johnson are designed for both offensive and defensive combat missions, and are able to operate independently or as part of carrier strike groups, surface action groups, amphibious ready groups, and underway replenishment groups.

Four more guided missile destroyers, including Ralph Johnson, are currently in production by Ingalls Shipbuilding division. Ralph Johnson is expected to be christened and undergo sea trials in 2016. Company officials say they were able to launch the vessel ahead of schedule.

"The last week of translating this quality ship across land and then launching it from our drydock is no small task, and our shipbuilders accomplished it in a very efficient manner," Ingalls' DDG 51 program manager George Nungesser said.

Destroyer Ralph Johnson, designated DDG 114, is named for Medal of Honor recipient Pfc. Ralph Henry Johnson, a Marine who served in the Vietnam War. Johnson distinguished himself when he threw himself on an explosive device to save his fellow Marines and prevent the enemy from advancing on their position. Johnson died instantly.

Northrop Grumman to replace U.S. Navy's inertial navigation systems
Charlottesville, Va. (UPI) Dec 16, 2015 –

The U.S. Navy has awarded Northrop Grumman a contract to replace the inertial navigation system used on most of the Navy's combat and support ships.

The contract is valued at $19.8 million with a total potential value of $47.8 million over five years if all options are exercised. The inertial navigation system, also known as INS-R, supports the new Navy Assured Positioning Navigation and Timing architecture currently in development by the Navy. The new system will increase navigation accuracy.

"The INS-R will be the foundation of the assured position, navigation and timing suite for virtually all Navy ships," Northrop Grumman maritime systems business unit vice president Todd Leavitt said. "Our inertial navigation system will provide very accurate position and attitude information for the Navy's combat and support ships to help them accomplish their demanding missions."

Work on the contract, including fiber optic gyro sensor development, will be performed at several Northrop Grumman facilities. Integration into the inertial measuring unit and incorporation of the navigation algorithms will take place at the company's facility in Charlottesville, Va.