The U.S. Navy has awarded Huntington Ingalls Industries with $58 million in contracts for repair and modernization work on two Los Angeles-class fast-attack submarines.

The Department of Defense on Tuesday announced HII received a $38 million contract for work on the USS Helena, and a $20 million contract for work on the USS Columbus.

The contracts cover repair, maintenance, upgrades and modernization for the vessels, which "is necessary to ensure the submarine is operating at full technical capacity as defined in the availability work package."

Both the Helena and the Columbus are Los Angeles-class nuclear-powered fast attack submarines, which forms the backbone of the U.S. Navy's submarine force.

The Los Angeles-class submarines are used to perform stealth missions such as deploy special forces, minelaying, precision land attacks, or anti-submarine or surface warfare. The vessels have a vertical launch system for Tomahawk cruise missiles and an improved hull design for under-ice operations.

Both contracts call for work to be completed by January 2020.