3D Printing Drone Swarms, Part 13: Autonomous Submarines

As we discuss in our ongoing 3D Printing Drone Swarms series, additive manufacturing (AM) will play an increasing role in the production of all manner of semi-sentient robots. This has been demonstrated by unmanned aerial vehicles (UAVs), which are now being made in part with 3D printing for lightweight, custom designs. For this reason, we expect AM to be used for other drone-style bots as well, often for military purposes. We are also not advocating for the use of 3D printing for the manufacturing of weapons or military equipment, but are highlighting this as a likely inevitability. 

As covered in our last post, we can expect missile production to incorporate 3D printing at an increasing rate. We can also would anticipate that planners and weapons designers will turn to additive manufacturing (AM) to make the bodies of submarines.

Composites 3D printing will certainly be used, but, given the high costs of submarines, metal printing could very well play a part on future vehicles as well. Optimized structures and weight saving will also become more important. Currently, subs carry crew to man sensors, arm weapons, look at sonar stations round the clock, and to cook food. Reducing the staff to zero would have huge impacts on what is possible and what future submarines would look like. Additionally, getting rid of all of the equipment to manage human waste; dispose of, cool, and store food; provide and recycle water; scrub oxygen, and all those other annoying human things will greatly reduce the excess space and energy on a sub.

Whereas an unmanned aerial vehicle (UAV) is more expendable overseas, and a dog-like robot can help you carry a bigger machine gun, the impact on submarine warfare will be even more significant. Yes, UAVs can fly longer because remote pilots can be swapped out and go home to sleep. They can also take more Gs and be radically redesigned. But, in comparison, the submarine world will be altered even more fundamentally.

U.S. nuclear subs can now pretty much stay below the surface for years. It’s only the food and the needs of the crew that cause them to return to base periodically. So, the vision of a completely shoreside sailor submarine force is a very compelling one. Now, I’d probably want a mechanic or two aboard a nuclear missile sub. Indeed, maybe we’d need some staff to turn the keys, just to make sure that a Windows update doesn’t bring about the end of the world. But, everything else will be apt to change.

Hunting subs are often focused on patrols, protecting convoys, and finding friendly ships primarily through finding and sinking other subs. Newly trendy subermisibles, such as Sweden’s Gotland, have air-independent propulsion (AIP) and have accomplished amazing feats, such as sneak up on an aircraft carrier and pretend sink it during war games. In other exercises, the Gotland class outfoxed surface ships.

Imagine the performance of that sub with fewer people on board—or perhaps none. Through the use of AIP, this conventional submarine is quieter, more difficult to detect, and does not need air to run its power system, meaning it can be submerged for longer. The sub is diesel, but combined with AIP, it can do 10 knots for two weeks submerged. The AIP development is already significant and redraws the battle lines considerably. The Gotland class still needs 24 men or so to run it.

Saab, the maker of the Gotland class, now also produces the more contemporary Blekinge class. This is still 1,900 tonnes and features about 18 crew, but it now lasts 18 days under water. This craft is due to be delivered somewhere in 2028. At the same time, electrification looms over the submarine world, as well. Just like AIP, a pure battery technology could fundamentally change submarines.

So, submarine warfare itself is at a crossroads with regards to power generation. At the same time, machine learning and other technologies must loom large. There’s a problem, however, and it’s a problem that relates to communication.

As it stands, submarines intermittently communicate with the shore. The culture, systems, rules of engagement, and people have been selected and hardened to be resilient and independent. This is due to the fact that there is no lifeline, no help, no cavalry. Any problem is their problem. And because they’re aboard something not meant to float but remain below the sea, a lot of simple problems may turn out to sink the ship.

This self-reliance and independence has been an important quality that submarine services have fostered. Checking in with the bosses and phoning home is also something that may get you killed. Signals—any signals—can be tracked, as can any energy.

For this reason, automating a full-scale submarine will be tempting. However, any kind of remote pilot type craft may be difficult because a live communication home to connect the distanced controller to the vehicle will be difficult. A non-state actor may not have the ability to track or disrupt or trace the signal powering a Predator drone (usually). In contrast, China or Russia could track, disrupt, and listen to a signal like that, especially if the communication needed to be persistently beamed from satellites to seamlessly communicate with a sub beneath the water. This seems complex and fraught with risks.

So, if we can’t automate nuclear missile subs or the kinds of craft we’re used to, we may need to think of very different vehicles. Just as in the air we’re seeing a plethora of new vehicles with unique capabilities and above the water we’re seeing the first forays into novel boating vessels, we could also begin seeing a real departure in the submarine world. Underwater gliders use buoyancy to very quietly propel themselves underwater for months at a time. Liberdade class gliders have tracked subs for half a year and have been deployed as mobile sensor networks.

This is a relatively dumb craft that really changes things. Imagine arming something so low-cost and persistent. Other designs are derived from torpedos or towed mine location devices, as shown above. Devices like the Bluefin above are widespread. The Autonomous Underwater Vehicle Application Center has over 200 different underwater drones from all kinds of countries, used for all sorts of purposes.  Some include soft robotics with biomimetic designs, such as Festo’s AcquaJelly.

Across these different platforms, a radically reduced form factor seems to herald an era in which we must completely rethink what submarine warfare means. Governments sent humans to risk their lives beneath the oceans so that they could kill other humans. Sinking ships was the foremost goal, deterring the other side’s supplies from reaching distant shores. Now, with 3D printing and new propulsion technologies, perhaps a smaller, sleeker, and far more numerous fleet of unmanned vehicles could rule the seas.