How to Print a Ship
One of the most immediate ways 3D printing will impact the Navy is through the design and construction of ships, submarines, aircraft, and everything carried on board. This is due largely to the economic benefits derived from the technology.
The initial cost savings of 3D printing come from the designs allowed by the layer-by-layer process. Senior mechanical engineer Peter Schmehl of MakerBot, a leading producer of desktop 3D printers, says he believes this process has the potential to “radically change ship construction, making designs that might not be possible using conventional techniques.” 1 If the “build volume” is large enough, a manufacturer can print a component as a whole, forgoing the need for further assembly. This means it can go without the brackets, flanges, and surfaces required for handling, bolting, or welding pieces of the component together—thereby saving material and weight. It also means internal systems such as ducting and piping can be designed to maximize fluid-flow efficiency from more rounded shapes, simultaneously eliminating unnecessary system volume and making it lighter still. This is, quite literally, not a pipe dream. As explained in the The Economist , Boeing already uses “a number of printed parts such as air ducts” in the F/A-18. 2
Additive manufacturing’s second cost savings come from the materials used in the process. The traditional production technique, subtractive manufacturing, starts with a “billet” of fill and whittles it down to the desired product, wasting up to 90 percent of the material. When working with the rare and expensive top-grade materials that the military demands in high-performance aircraft and precision weapons, the waste is all the dearer. 3 Researchers at EADS, a major European aerospace company, found that a type of 3D printing using titanium powder could create parts just as strong as traditionally produced items using only 10 percent of the titanium.
The future of design and cost benefits for the Navy could come from trends toward both the proliferation of relatively inexpensive desktop models and advanced 3D printers with increasingly large build volumes. One professor at the University of Southern California is developing a system to construct entire houses out of large printers using concrete or adobe, and naval ship and aircraft assembly could head toward that sort of all-in-one design. 4 The production lines and shipyards of the future could be, in effect, enormous 3D printers that would maximize the economies derived from the additive manufacturing process. As a further benefit, as long as the fill materials and design files were on hand, Pentagon planners would never need to worry about a particular production line shutting down, since it could be started back up at any time with minimal loss of corporate knowledge.
On the other hand, the spread of cheaper 3D printers could lead to the entrance of a whole new field of competition in the defense sector. Jaffe notes that for now, those able to afford the most capable 3D printers are large, well-established companies and design consultancies, but that new, low-cost models are becoming good enough to compete with the expensive versions. For individuals and small firms with good ideas and the requisite design skills, this should lower the barrier to bid for defense contracts. Industry faces many challenges to realize these promised design and construction benefits, but, to the benefit of the Navy, a good deal of effort will be spent overcoming the problems because of the advantages. The most profound change for sailors could be how 3D printers change normal shipboard operations.
Basic Shipboard Use
It might be best to leave to industry the job of exploiting how this process will change manufacturing, but the Navy should explore capitalizing on the transformation of where production can occur thanks to 3D printing. The service would be in good company. In 2012 the Army shipped a 3D printer to Afghanistan as part of its Expeditionary Lab – Mobile, and “NASA has begun projects aimed at creating 3D printers capable of working in microgravity for use in the International Space Station, manned trips to Mars, and even 3D printing of satellites in orbit,” Schmehl says. 5 For the Navy, the greatest immediate potential is in the less-exotic field of logistics.
Augmenting shipboard supply departments with 3D printers can alleviate the need to carry large stocks of pre-manufactured stores. Instead of spending weeks trying to track down a repair part or seldom-used consumable, a repair-parts petty officer could scan the discarded part labeled with a barcode quick response (QR) code, or some other embedded identifier that, once scanned, sends the item’s schematics to queue at the nearest printer.
This simple scenario illustrates many potential benefits. The most obvious is the speed with which a ship could secure a replacement part. This is especially true of rare components or those with low-failure rates not typically carried on board vessels or not in large numbers. “An individual ship has hundreds of thousands of parts,” says Jaffe, “supply can’t stock all of them. For those parts where there are only three in the world a 3D printer would be pretty nice, even if on just one ship in a strike group.” 6
The next improvement is the space and weight saved by not carrying as many of the medium-failure rate items, relying instead on what Schmehl calls the “object on-demand” aspect of 3D printers. Of course fill material will be required, but the Navy can experiment to determine the optimal amount and mix to carry on board to minimize weight. Further, since the materials will be in liquid or powder form, they can be stored in configurations that reduce excess void space from oddly shaped finished pieces and the packaging that protects them.
Two additional advantages come from combining this manufacturing process with information systems. The first, as discussed earlier, is the preservation of knowledge. There need be no worry about the loss of knowing how to build a widget when its maker goes out of business; that data can be simply stored as a design file. However, the Navy may need to experiment with determining the appropriate type of business contract for items when it is no longer purchasing a finished product. Should the design be bought outright? Or should a per-use licensing arrangement be reached, with a clause either securing the rights or paying a company’s creditors in the event of bankruptcy?
The second benefit of 3D printers working with existing information systems is the ability to deliver rapid design upgrades to the Fleet. If a critical vulnerability is fixed or new capability introduced, a physical upgrade is possible without waiting to return to port or for a drawn-out supply-chain delivery.
Room for Experimentation
Printing replacement parts also highlights what should be one of the first goals of experimentation: determine which items it makes sense to print. For the foreseeable future, mass-producing things such as high-use consumables will remain less expensive. There are also limitations on what can currently be printed, and how quickly. For these reasons, it is unlikely sailors will soon line up next to a 3D printer every time they need a roll of toilet paper or fluorescent light tube.
One factor to consider when determining the proper mix of fill materials to carry on board is that every ship and sub may not need the rare-earth metals required to create permanent replacements for higher-end pieces of equipment. But an emergency swap-in that gets a system to 90 percent in the meantime, built from common materials, could be invaluable.
This points to another major initial goal: establishing a process for quality assurance. The Navy will need to determine who verifies that a printed copy meets military specifications, and how. Could a part’s design file be preapproved for all copies, or would each copy need individual approval? Would every printer require separate approval to print each type of part? The Navy will need to ensure the 100th copy is just as up to spec as the first. And for those emergency swap-ins, the Navy could explore using a form of the approval process for departures from specifications (DFSs) to set how long and under what conditions the part can be used.
Other questions the Navy must examine include determining the types of printers to procure, how large they should be, where they should be installed on ships, whether every ship needs one, who will create and maintain the parts design files, and what skills are needed to operate and maintain the printers or to assemble printer-produced components to make complete items.
Redesigning the Logistics Tail
The answers to the questions 3D printers pose will continue to evolve over the years as challenges are overcome and new possibilities and opportunities arise. While the near-term supply scenario sketched here may seem radical, the potential mid- to long-term uses will appear even more so.
Advances in printing and robotics indicate how shipboard additive manufacturing may be useful beyond simple repair parts. Already researchers at the University of Southampton have successfully printed an entire working unmanned aerial vehicle, except for the engine. 7 Meanwhile, this year scientists at the Naval Research Laboratory will start testing on the ex-USS Shadwell of the Autonomous Shipboard Humanoid (ASH) firefighting robot, meant to be able to “walk in any direction, keep its balance at sea, and go through narrow passageways and up ladders.” 8 The Navy has also funded a similar project at the Georgia Institute of Technology for a “MacGyver Bot” that can solve complex problems and assist in dangerous situations by using whatever it finds nearby. 9 If these trends are a clue, the future could hold the ability to print complete replacements of the robotic crew members, weapon systems, and remotely piloted or autonomous vehicles that fight the ship and project power.
For human crew members, 3D printers might also bring radical changes. Scientists have successfully printed living tissue, and biomedical engineers “in about a dozen major university and corporate laboratories” are working to advance the ability. 10 The result could be extraordinary new emergency medical capabilities available in a ship’s sick bay or strike group, including custom-made replacement skin, organs, and bones, with no risk of host rejection by repurposing and replicating a patient’s own cells.
Additive manufacturing might even shake up galleys and repair lockers. Specialty printers can create chocolate cupcakes and could in the future displace the 21-Day Menu with on-demand orders. The ability to make custom items could likewise be ideally suited for the demands of shoring and patching during damage control.
Undergirding these advances is the potential to move the point of production from a factory to somewhere much closer to the sailor who needs it. These new printers still rely on a logistics tail to supply their fill materials. Yet even resupply could be augmented or supplanted by machines refilling material stocks from shipboard recycled waste, or the developing concept of biomining—harvesting resources from the surrounding seas or ashore—perhaps with purpose-built 3D-printed vehicles.
These longer-term possibilities will drive more questions and room for Navy experimentation. Conveniently, they also bring the discussion back to thoughts of ship design. Should printers be integrated into it, or should open space be left for embarking the best models? And should systems that support the printers be built into the ship? We need to know whether 3D printers can take advantage of modularity, on which ships it makes sense to include special medical printers, which vessels should have material-harvesting or waste-recycling capabilities, and whether new classes of supply vessels should be dedicated to biomining.
The Road Ahead
Most of these ideas are visions of the future, in some cases quite far off, should they ever really come to pass. Along the way there are many challenges for industry and the Navy to overcome to take full advantage of additive manufacturing.
As noted, the most capable machines, such as those that can print titanium alloy objects, are, according to Schmehl, “quite expensive and quite large,” and increasing the speed of printers is “daunting.” However, the competitive effects highlighted by Jaffe should drive down both costs and printing time. Schmehl predicts that “printers will continue to get faster and faster,” moving ever-closer to providing true “object on-demand” capabilities. 11
The costs of fill materials can be similarly prohibitive. This has been due in large part to the proprietary nature of the fill materials and requirements for interfaces with the machines, “just like inkjet and laser printers,” says Schmehl, in what Jaffe calls “the razor and shaving blade” model. Movement toward common technological standards and competition will help bring these costs down too—trends toward which MakerBot and other inexpensive 3D printers are pushing.
Printers can’t yet build with every material. Jaffe reels off a list of accomplishments-to-be: “Flexible plastics, polymers, rubbers, wax, translucent materials, and different types of metals.” 12 He also notes that one of the biggest prizes is being able to combine various materials, mixing mediums all at once or in one machine, to produce more useful and complete items such as motors and circuitry.
Jaffe explains that objects created layer by layer rather than through a traditional casting or molding process are different at the molecular level. This allows designers to develop intricate internal structures that yield stronger-than-normal materials and equipment. But it also leaves some of the cheaper products, like those made with plastics, weaker, because they were not created as individual pieces. This need not remain the case, but it is so now.
Just as Gutenberg’s press helped disseminate information more widely, 3D printing brings to America’s competitors the same opportunities it brings to the Navy. It introduces new security challenges in efforts to prevent proliferation. In late June 2012, a Wisconsin engineer made headlines when he used a 3D printer to fashion a working receiver assembly for a firearm modeled on the AR-15. 13 Although it was only a portion of the weapon, the project to create a complete gun continues with new supporters. It is not difficult to imagine the attraction of such a capability for some not-so-nice state and non-state actors.
As the Navy introduces 3D printers into the Fleet, it will need to secure them against cyber threats as it does other information systems.Unique vulnerabilities exist from the same 3D printers that are opportunities for our own cyber efforts. For example, a printer could be hijacked to create a self-destructing weapon or an infiltrating robot. Exploitable, unnoticeable design flaws could be introduced, or a crucial supply capability could simply be shut down.
It will take years, likely decades, to overcome all these challenges. But they will not stop the development and evolving opportunities afforded by 3D printers. One of the biggest tasks for the Navy will be to evaluate each new breakthrough’s impact on the shifting economic calculus of consigning any one of the thousands of shipboard parts to print-on-demand status. Better understanding of the link between printer developments and new capabilities will allow the Navy to focus research resources to achieve them. The potential cost and capability benefits are enormous. Let the great experiment begin.
2. “Solid Print,” The Economist , 21 April, 2012, www.economist.com/node/21552892  .
4. Rebecca Boyle, “Giant 3D Printer to Make an Entire House in 20 Hours,” Popular Science , 9 August 2012.
5. Zach Walton, “The Army Is Deploying 3D Printers to Afghanistan,” WebProNews, 12 August 2012.
6. Telephone conversation between Cheney-Peters and Brian Jaffe, 25 October 2012.
7. Clay Dillow, “UK Engineers Print and Fly the World’s First 3D-printed Aircraft,” Popular Science , 28 July 2012.
8. Al Kamen, “Of Machines and Men, and Fires and Fastballs,” Washington Post , 10 October 2012.
9. “U.S. Navy Funds ‘MacGyver’ Robot that Can Create Tools,” BBC News, 10 October 2012, www.bbc.co.uk/news/technology-19902954  .
10. Robert Lee Hotz, “Printing Evolves: An Inkjet for Living Tissue,” Wall Street Journal , 18 September 2012.
11. Cheney-Peters interview of Peter Schmel.
12. Telephone conversation between Cheney-Peters and Brian Jaffe.
13. Andy Greenberg, “‘Wiki Weapon Project’ Aims to Create a Gun Anyone Can 3D Print at Home,” Forbes , 23 August 2012.
Lieutenant (j.g.) Hipple is the executive officer of PC Crew India and director of the NEXTWAR blog at the Center for International Maritime Security. He is a graduate of Georgetown’s School of Foreign Service. This article evolved from their series of blog posts at the Center for International Maritime Security ( http://cimsec.org/category/future-tech/3d-printing-future-tech/  ) and a subsequent article on the USNI News and Analysis website, “3D Printers Are Here, Are the Sea Services Taking Advantage?”