The Virginia-class attack submarine Minnesota (SSN-783) is under construction at Huntington Ingalls Newport News Shipbuilding. (U.S. Navy photo) 

WASHINGTON — The U.S. Navy has awarded a contract worth up to $18.4 billion to two defense contractors to build two Virginia-class attack submarines and support shipyard improvements.

The contract, awarded to General Dynamics Electric Boat and Huntington Ingalls Industries’ Newport News Shipbuilding division, includes construction of the USS Baltimore (SSN 812) and USS Atlanta (SSN 813) as part of the Block V series.

The Navy did not provide estimated service dates, but previous Virginia-class submarines have taken between four and five years to complete, meaning the new vessels may not be operational for several more years.

In addition to building the submarines, the contract includes funding for upgrades to shipyard facilities, workforce support, and productivity improvements. Of the total amount, about $1.3 billion will go to Newport News Shipbuilding.

The contract includes options that, if exercised, would raise the total value to $18.4 billion. Three other Block V submarines—USS Oklahoma (SSN 802), USS Arizona (SSN 803), and USS Tang (SSN 805)—are currently under construction.