ARLINGTON, Va. — The aircraft carrier construction team at HII’s Newport News Shipbuilding faced a key deadline in March 2022.
The team was on the hook to move a block of the keel for the future Enterprise weighing hundreds of tons into the dry dock.
Shipbuilders outfit these pieces, known as superlifts, in the final assembly platform on the pier, installing the piping and wiring into these massive Lego blocks and then crane-lifting them into place in the dry dock.
But, a single component threatened to throw off this complex activity, Brian Fields, the vice president for Enterprise and sister ship Doris Miller, recently told reporters.
In November 2021, the team learned one cast metal part — a critical but sensitive component Fields declined to name — would not be available until late June or early July.
“I needed to put that huge superlift into the dry dock,” he said. “It was one part, and I had to have it installed in the final assembly platform.”
Waiting and installing it later “would have been significantly risky and a big cost impact,” Fields added.
Instead of choosing between a schedule delay or the added expense, the shipbuilder and the Navy worked together to design, qualify and 3D print the part in just four months, meeting the March superlift deadline.
Though the circumstance was unusual, the Navy and its suppliers are hoping it will one day be the default, instead of the dated casting procedure.
Top Navy officials have repeatedly pointed to challenges in the submarine industrial base in particular, as well as its aircraft carrier and surface ship industrial base. The number of suppliers is dwindling even as the service would like to increase its production rate.
In the case of the Virginia-class attack submarines, for instance, industrial base concerns are the sole reason the government is not boosting its procurement rate from two a year to three.
Matt Sermon, the executive director for the Program Executive Office for Strategic Submarines who oversees submarine industrial base issues, said the Navy isn’t pursuing additive manufacturing as a novelty, but rather “we are doing this because we have to.”
It’s “the path” to getting to on-time submarine construction and repairs, he added.
Long-standing production challenges
Sermon said Jan. 30 at an American Society of Naval Engineers conference that the industrial base struggles the most to keep up with the required capacity of heavy metal parts and components. These include castings, forgings, valves, fittings and fasteners.
In fact, he said, the Navy looked at 5,500 parts that have presented schedule challenges for new construction and maintenance availabilities for submarines and ships; six materials account for 70% of late deliveries, he said. Additive manufacturing could get more of these parts to construction and repair yards faster and more reliably.
These parts have always been a challenge to the industrial base, as the fundamental metallurgy is complex and can lead to flaws. But there are fewer companies making these components today than in past decades, and that smaller base is struggling to keep up with growing demand.
The Navy has developed a plan to mature the metals, printing machines and processes associated with those six materials this year, such that by March 2024 they can be printed in volume and put on submarines, Sermon said.
Vice Adm. Bill Galinis, the commander of Naval Sea Systems Command, told Defense News Jan. 12 NAVSEA is working with its warfare centers and with the Naval Nuclear Propulsion Program to advance the sea service’s understanding of and comfort with additive manufacturing technology and processes.
“We don’t have that process fully matured to the point where we’re able to scale additive manufacturing like I think we need to,” he said. “We can do the one-off parts, and frankly, even for a reactor component, we’ve built some fairly complex parts using additive manufacturing, but we haven’t gotten to the point where that’s scalable.”
Columbia-class ballistic missile submarine construction has already begun but will continue to grow in the coming years, even though the industrial base is already struggling with the current workload. Galinis said additive manufacturing as an alternate to castings and forgings will help industry keep the Columbia program on schedule and get the Virginia-class program back on track.
“What you’d like to be able to do is to identify high-volume, high-usage parts, and you have a printing capability that allows you to print those on a pretty regular basis. There’s elements of private industry out there that have done some of that,” he said. “Our challenge right now is, one, quickly coming through the certification process, codifying what that’s going to look like, and then being able to scale additive manufacturing.”
That’s exactly what Fields is trying to do at Newport News.
He said castings are particularly tough for the yard, and there’s a long list of cast metal parts he’s struggling to procure on time and in good quality.
Fields said the company can do the metal casting, but once employees start to machine it down to the right shape, any flaws in the metal call for either repair via welding or a restart of the whole part. These flaws aren’t always visible early on, so re-casting a piece can be an unwelcome surprise to the ship construction schedule.
“All of our suppliers are struggling to get castings on time to support the ship schedule,” he said. “First-time quality is a lot better from a 3D printed part, and the cost is significantly less.”
He used a JP-5 manifold as an example. This piece helps move jet fuel around the aircraft carrier and includes a cast metal part with fabricated flanges on the ends.
“They’re really hard to get made properly. I’ve got 28 of them right now that I’m waiting for that have been cast, and every time you hydro them, they turn into sprinklers because the casting is hard to get right. And now we’re weld-repairing them,” Fields said. “That example of all the time and money spent trying to get those parts to me so I can get them installed on the ship on time is where I see 3D printing being able to really move the needle.”
Sermon said additive manufacturing could shorten the production timeline for certain metal pieces by an average of 80%, depending on the printer’s efficiency.
HII signed an agreement in 2017 with additive manufacturing specialist 3D Systems to help explore potential printing opportunities at Newport News for aircraft carrier and submarine construction and repairs.
Mike Shepard, the vice president for aerospace and defense at 3D Systems, told Defense News that while the company has its own printing hubs, the goal is not to print parts for Newport News Shipbuilding but rather to help the company integrate cutting-edge printing technology into its processes.
3D Systems’ particular copper-nickel alloy is one area of collaboration between the two companies today. Traditional methods like casting and forging can create flaws in copper-nickel parts that slow down the production.
With 3D Systems’ direct metal printing process, “we’re getting better properties than either conventional forgings or castings. We don’t have any of the porosity issues with the [printing] approach. That means we are cost-competitive with casting and have a much lower lead time,” Shepard said.
Shepard added that the volume of parts 3D Systems is helping Newport News print is growing, “but we are just skimming the surface of the overall opportunity.”
For Sermon and Naval Sea Systems Command’s director of maritime engineering Doug Arnold, these types of industry collaborations help match new technologies to gaps in industrial capacity — but the Navy needs to ensure its rigorous engineering standards are applied.
Sermon said the aviation community and academia have already invested in significant research into additive manufacturing with certain metals, and in those cases the Navy can move forward pretty quickly. But in metals specifically geared to naval applications, including copper-nickel and some steel alloys, more research is needed on what happens when these materials are used for printing, particularly how it affects the metals’ fatigue and corrosion properties.
Arnold said the Navy and vendors could start using these materials to print components where these second- and third-order properties aren’t as relevant — using copper-nickel for components not exposed to water and where corrosion isn’t a big concern — to learn lessons printing low-risk components and buy time for researchers to better understand the finer details of using these metals in additive manufacturing.
Fields said HII must be especially careful with parts going on submarines, due to the added technical requirements.
But, he said, the Navy and its industry partners need to find a path forward if they want to continue or increase today’s submarine production rate.
“One of the pressures for the dam breaking is the customer at the end screaming ‘I need this.’ So I think that’s starting to accelerate” considering printed parts for submarines, Fields said.
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