America’s largest military shipbuilding company, Huntington Ingalls Industries announced on Friday that its Ingalls Shipbuilding division has received a $1.5 billion fixed-price-incentive modification to a previously awarded contract for the procurement of the detail design and construction of amphibious transport dock LPD 31.

The ship will be the 15th in the San Antonio class and the second Flight II LPD.

“In building this 15th LPD, Ingalls experienced shipbuilders will continue this hot production line of great amphibious warships for our Navy/Marine Corps team,” Ingalls Shipbuilding President Brian Cuccias said. “We are all proud to be building these great ships, and will continue to deliver the most survivable and affordable ships possible for our customers and our nation.”

Ingalls’ LPD Flight II program vendor base consists of more than 600 manufacturers and suppliers in 39 states, including 387 small businesses. More than 1,500 shipbuilders work on each LPD. Ingalls has delivered 11 San Antonio-class ships to the Navy, and it has three more under construction.

The San Antonio class is a major part of the Navy’s 21st century amphibious assault force. The 684-foot-long, 105-foot-wide ships are used to embark and land Marines, their equipment and supplies ashore via air cushion or conventional landing craft and amphibious assault vehicles, augmented by helicopters or vertical takeoff and landing aircraft such as the MV-22 Osprey. The ships support a Marine Air Ground Task Force across the spectrum of operations, conducting amphibious and expeditionary missions of sea control and power projection to humanitarian assistance and disaster relief missions throughout the first half of the 21st century.