ARLINGTON, Va. — Among the top risks to the critical Columbia-class ballistic missile submarine program is fragility in key parts of the industrial base.
Additive manufacturing, better known as 3D printing, could fix that.
The Navy plans to pair suppliers who cannot keep up with demand with additive manufacturing companies who can print parts around the clock to boost the supply, a Navy program official said this week. This effort would be aimed at the most fragile parts of the submarine industrial base: companies that do castings, forgings and fittings, in particular.
Matt Sermon, executive director of the Program Executive Office for Strategic Submarines, said this would help these companies — some of them the sole sources of components to the Navy — by removing pressure to increase their production rates even as they’re struggling to keep up with the current workload.
The industrial base today builds two Virginia-class attack submarines a year, is working through construction of a single Columbia-class SSBN and helps maintain the in-service submarines in the fleet.
But fabrication has already begun on the first Block V Virginia with a mid-body Virginia Payload Module that increases the construction workload by about 25%. And the Navy will buy its second Columbia SSBN in 2024 and start one-a-year production in 2026, meaning a huge spike in work for the prime shipyards and their supply base. The Navy has started referring to this time of consistently buying one SSBN and two SSNs every single year the “1-plus-2″ years.
If the demand for parts can’t be reduced, then “let’s go additively manufacture the components in that space, such that by the time we get to the 1-plus-2 years, we will have reduced demand signal in castings, forgings and fittings,” Sermon said in his remarks at an American Society of Naval Engineers event.
Today, the Navy certifies individual parts to go on submarines. That part-by-part qualification won’t work going forward, Sermon said, advocating for the Navy to instead qualify materials and processes used for additive manufacturing rather than the parts that result from it.
But the Navy has struggled to do this in the past. For aviation programs, additive manufacturing advocates sought permission to print non-critical parts — but the Navy wouldn’t allow it. Aircraft carrier John C. Stennis hosted the first-ever Advanced Manufacturing Lab onboard, but used the laser scanning and additive manufacturing tools to print parts for the ships in the strike group, not the aircraft.
Putting printed parts on a submarine is as risky a proposition as putting them on aircraft, with both communities having strict safety standards to keep sailors safe in the air and under the ocean. But Sermon said the engineering community is now on board. The technical warrant holders are part of ongoing discussions, and Naval Sea Systems Command’s engineering and logistics directorate has accompanied the program office on site visits to companies that demonstrate additive manufacturing best practices.
“Additive manufacturing gives you a better material, a better steel, than [working with raw materials],” he said. “It is complicated, and microstructures … are complicated and do change some fundamental concerns of ours. We will have to change how we do non-destructive testing in many cases — not because it’s bad, but because it’s different, and we have to understand that.”
The Los Angeles-class attack submarine USS City of Corpus Christi (SSN 705) maneuvers into position to moor alongside the submarine tender USS Emory S. Land (AS 39) to complete repair maintenance actions on Sept. 24, 2015. (Mass Communication Specialist Seaman Zachary Kreitzer/U.S. Navy)
The effort to put printed parts on submarines began in November, and Sermon said the Navy would install the first parts on an in-service submarine this calendar year.
He told Defense News after his remarks the program office has a ranked list of six to 10 components they’d like to print, based on a list of “trouble components” consistently unavailable at the public shipyards when they’re needed for a submarine maintenance availability.
The vendors who make the parts won’t be cut out of the process. Rather, they’ll help with the engineering and have the option to do the printing if they have the capability — though Sermon said most of the companies involved don’t. If the original manufacturer can’t do the additive manufacturing themselves, the Navy will pair them with a small business that can.
Sermon noted during the panel the multiple benefits of embracing additive manufacturing. First, it addresses capacity issues during the 1-plus-2 years, when not having enough parts could put construction or repair timelines at risk.
In the longer run, though, he said working through the processes and the certification of printed parts will enable the Navy and industry to design the next-generation SSN(X) with additive manufacturing in mind — potentially reducing the program’s cost or generating a better or more survivable part.
Megan Eckstein is the naval warfare reporter at Defense News. She has covered military news since 2009, with a focus on U.S. Navy and Marine Corps operations, acquisition programs, and budgets. She has reported from four geographic fleets and is happiest when she’s filing stories from a ship