The US defense department has awarded General Dynamics NASSCO a $1.6 billion contract for the construction of the sixth and seventh ships of the Expeditionary Sea Base (ESB) program.

The contract provides $1.08 billion as a fixed-price-incentive modification to a previous contract for the design and construction of the two ships, with an option for the third that, if exercised, would bring the total cumulative value to $1.63 billion.

Work on the two new ships of the ESB program is scheduled to begin in the first quarter of 2020 and continue to the second quarter of 2023, providing the opportunity to sustain and grow the workforce along San Diego’s working waterfront.

“We are pleased to be building ESB 6 and 7 for our navy,” said Kevin Graney, president of General Dynamics NASSCO. “ESBs have proven to be affordable and flexible, and as the fleet has gained experience with the platform, we have worked with the Navy and Marines to develop even more capabilities and mission sets.”

GD has so far delivered four ships in the class while the fifth, USNS Miguel Keith (ESB 5), is to be delivered later this year.

The first two ships, USNS Montford Point (T-ESD 1) and USNS John Glenn (T-ESD 2), are configured with a vehicle staging area, vehicle transfer ramp, large mooring fenders and up to three Landing Craft Air Cushion (LCAC) vessel lanes to support its core equipment transfer requirements.

Follow-on ships are optimized to support a variety of maritime based missions including special operations force (SOF) and airborne mine counter measures (AMCM). They include a four-spot flight deck and hangar and are designed around four core capabilities: aviation facilities, berthing, equipment staging support, and command and control assets.

In August 2017, the third ship in the class, USS Lewis B. Puller was redesignated from a Military Sealift Command ship into a commissioned warship with the aim of providing the navy with greater operational flexibility.