US Navy Opens the Door to 3D-Printed Parts Across the Entire Submarine Fleet

From one-off exceptions to systematic approval

The US Navy has spent years testing individual 3D-printed parts aboard submarines. That changes now. Vice Admiral Robert Gaucher, the Navy's director of submarine programmes, told a briefing on August 10 that the service is shifting from approving parts one at a time to approving material-process combinations. Once a printer and material combination is certified, any part made with it can be accepted.

"You just have to verify that part is manufactured using the approved print process and material, then if you 3D print it, we can accept it," Gaucher told Janes. That sentence represents the biggest policy change the Navy's submarine maintenance operation has made on additive manufacturing to date.

Why submarines lagged behind surface ships

The Navy has been installing 3D-printed parts on surface ships for years. Submarines are different. The SUBSAFE programme and Level I critical parts requirements create a higher bar for anything that goes into the pressure hull. Every new material or process historically had to be qualified separately, which meant each new part came with its own mountain of paperwork.

That approach kept submarines safe. It also kept lead times long. NAVSEA says the Navy installed nearly 120 additively manufactured parts in 2025, saving more than 1,400 cumulative days of delay. But most of those were on surface ships or in shipyard settings. Underwater adoption moved slower because the approval structure was built around certifying the part, not the method.

What the new framework actually means

The material-process combination approach mirrors how traditional manufacturing works. When a shipyard uses a certified forging or casting house, the Navy does not re-qualify every bracket or flange that comes out of it. The process is trusted, the material is trusted, and individual parts inherit that approval. Gaucher's statement means additive manufacturing is finally being treated the same way.

There are still guardrails. SUBSAFE and Level I parts will carry additional tracking and review requirements. The Navy also needs to update its business accounting systems so that purchased AM parts are recognised as viable inventory. Those are engineering problems with known solutions, not fundamental blockers.

The foundation was already in place

Several milestones paved the way for this shift. In March 2026, Portsmouth Naval Shipyard installed the first welded metal 3D-printed component aboard the attack submarine USS Washington: a copper-nickel flange produced using additive manufacturing and certified for in-service use.

In August 2025, NUWC Division Keyport became the first Naval Warfare Center to receive official NAVSEA qualification for a metal powder bed fusion process, using 17-4PH stainless steel on an EOS M290 system. The seven-year qualification project validated that interrupted builds do not create hidden metallurgical defects, a key concern for any safety-critical application.

NAVSEA has now approved 182 additively manufactured parts for shipboard use, with more than 600 under review, and has published military standards for stainless steel, titanium, and copper-nickel. Six additional materials standards are in development.

Where the bottleneck moves next

The new policy eliminates the part-by-part approval bottleneck. The remaining constraint is industrial capacity. The Virginia-class and Columbia-class programmes need a steady flow of parts, and the organic industrial base still has a limited number of qualified AM machines.

Industry is already scaling up. Lincoln Electric has commissioned four robotic wire arc additive manufacturing systems in Ohio capable of laying 100 pounds of metal per hour. Barnes Global Advisors is building a qualifications database for Inconel 625 and 316L stainless steel aimed at Navy suppliers. Austal USA has launched its Digital SEA platform to give suppliers access to the technical data needed to produce AM components.

The Navy's FY2027 shipbuilding budget request of $65.8 billion includes sustained funding for advanced manufacturing. With the approval framework now aligned to how AM actually works, the next phase is simple in concept and hard in execution: printing enough of the right parts, at the right time, in the right place.