Engineers have designed, built and installed a fiber-reinforced polymer composite tailcone on the USS Mississippi.

This new tailcone replaces a traditional metallic unit. It's less expensive to build, install and maintain, and it reduces the ship's overall weight, the Navy said Thursday.

Mississippi (SSN 782) is the Navy's ninth Virginia-class submarine.

Engineers at the Naval Surface Warfare Center Carderock Division, in conjunction with the Office of Naval Research, Program Executive Office Submarines and industry, were responsible for the innovation.

"Through years of research and development, we've identified a process where we can build tailcones for new submarines using composite materials, which weigh less and are more resistant to corrosion," said Craig Madden, an ocean engineer at NSWC Carderock Division. "The lighter, less expensive composite materials have significant potential savings in total ownership cost for the Navy."

The tailcone of a Virginia-class submarine extends aft from the propulsor hub. It traditionally has been made from metallic materials that require extensive cutting, shaping, welding and machining. That process could take up to a year to complete.

The new tailcone took less than seven months, and now with a mold, future composite tailcones could be made in four months, the Navy said.