The Navy awarded General Dynamics NASSCO a $13 million, one-year contract modification to turn out preliminary designs for a new amphibious-landing ship.

The Pentagon announced the deal June 26.

The Navy plans to replace its current dock landing ships with a new ship called the LX(R), which could carry 500 U.S. Marines and their landing craft, and would eventually replace the current Harpers Ferry and Whidbey Island classes.

The Navy wants to procure its first LX(R) in fiscal 2020, according to a Congressional Research Service report posted on the Federation of American Scientists website.

According to the Pentagon announcement, work under the $13 million deal may cover systems engineering, marine engineering, naval architecture, cost estimating and computer modeling. “The early industry involvement contracts will enable the shipyards to investigate ship designs and production cost reduction opportunities and to participate in the preliminary design evolution and reviews,” the announcement said.

NAVSEA, the Naval Sea Systems Command of Washington, D.C., awarded the deal. Two-thirds of the work will be done in San Diego, and another 12 percent in Bath, Maine — home to another General Dynamics (NYSE: GD) naval shipyard.