Late last year, the Department of Defense (DOD) delivered a study to Congress on alternatives to the official plans for future Navy fleet architecture. As the new Administration and Congress  debate how best to fulfill their campaign promises to build up the military, the study is receiving renewed interest. It differs substantially from current Navy plans—as well as other proposals from think tanks—and focuses on autonomous robotic integration, electronic warfare, and modularity. The study proposes a ‘distributed fleet’ approach, and works through how such a fleet might be constructed. There are some intriguing and possibly beneficial ideas in the alternative proposal. However, like most things in defense planning, the devil is in the details.

Properly implementing a distributed fleet will require thoughtful integration of its core parts—autonomous robotics, electronic warfare, and modularity—and the avoidance of using those tools just for their own sake. Each of these three pillars of the alternative future fleet platform architecture has its own benefits, but also potential perils. To shift the Navy’s architecture to a distributed fleet approach, the U.S. government must be clear on which specific problems it will solve—and what problems it will introduce.

Unmanned/Autonomous Vessels

One of the main differences between the Alternative Future Fleet Platform Architecture Study and the current plans for the Navy fleet is the study’s focus on unmanned vessels. While the alternative fleet would procure 34 fewer manned vessels than the official U.S. Navy plan, it calls for 128 more unmanned vessels.

This unmanned fleet would consist of 48 unmanned underwater vessels and 88 unmanned fast attack boats. Deploying autonomous vessels would provide several advantages to the U.S. Navy as it navigates contentious waters around the world.

First, the unmanned fleet would allow the Navy to penetrate contested waters with less risk to American sailors. The alternative fleet looks to deploy 80-foot vessels akin to the World War II Patrol Torpedo (PT) boats. PT boats were well armed but easily destroyed. Because of the risk to sailors onboard, their use diminished after the war. Built to operate without men and women onboard, they could become much more useful to the Navy—especially as rival powers seek to deploy systems that put American assets at risk and deter the United States from engaging with them. These anti-access, area-denial (A2/AD) capabilities are a big concern for America’s capital ships, the loss of which would cost billions of dollars and thousands of lives. Small, unmanned ships are a reasonable solution to this dilemma.

There are other potential benefits of autonomous underwater and unmanned attack boats. If designed from the start with autonomy in mind, the Navy could pursue new designs that would be impractical if space for humans onboard needed to be maintained. The production to field timeline could possibly shrink, with replacements for damaged or destroyed autonomous vessels getting out to operations quicker.

But autonomous systems also come with their own problems. Take their use as expendable systems in high-risk environments. High turnover due to loss of vessels is something that the military acquisition system has not had to deal with in a while, particularly in the naval context. Will the Navy be able to produce replacements—with whatever changes that might be required—and deploy them in the timeframe that would make such expendable systems useful? Also tied into this is the budgeting and appropriations system for the military. In a made-to-be-broken world, the need for replacements could become increasingly disconnected from the long and complicated system currently used to fund such replacements. As of yet, it’s unclear that the acquisition system can adapt.

Integrating unmanned systems would also likely require changes to operational concepts. Naval officers will have to be trained to manage both their crews, and a dispersed fleet of unmanned vehicles. The operational systems of unmanned vehicles will not, at least for the near future, be as flexible or creative as trained officers. While the decision may change, the United States has come out strongly against robotic systems making final life-or-death decisions. Keeping humans “in the loop” means that autonomous systems may be less constrained in where they go, but more constrained in what they do. That could have a significant impact on operations. It will also mean that commanders will have to remain more heavily involved in decisions on when unmanned systems should use lethal force.

Reliance on unmanned systems will also complicate the Navy’s need to address electromagnetic warfare. While unmanned systems could help in deploying new electromagnetic warfare capabilities, they themselves could also be vulnerable to electromagnetic attack. Any ship that may require final confirmation on orders—or need to transmit data back to a manned ship—may reveal its location. Depending on development, there will likely be tradeoffs between the costs and production speed of an unmanned vessel and its need for stealth. If costs increase, the Navy will also become more risk averse with the system. The Navy will have to strike a balance between these three factors as it develops its unmanned systems.

Electromagnetic Warfare

Electronic warfare capabilities are another pillar on which the distributed fleet rests. Assured communications will be needed to fully connect a dispersed fleet. The benefits of investments in more secure datalinks, communications, and offensive electromagnetic warfare capabilities are evident from current conflict zones. China has been investing in new radar installations in the South China Sea. Russia, which has been using electromagnetic signals to target Ukrainian positions and disrupt Ukrainian communications, has demonstrated how important spectrum dominance is on the modern battlefield.

But, while the United States has been investing in new electromagnetic capabilities, there are still concerns that it may have lost its edge (or be behind) near-peer competitors in both developing these capabilities and integrating them into operations.

The implementation of the distributed fleet will require regaining the advantage in the electromagnetic spectrum. Otherwise, unmanned systems and dispersed assets may be more of a liability than benefit. The U.S. military does not have a great track record in developing distributed systems. The Army’s Distributed Common Ground System has long been criticized as a very expensive yet ineffective system. In 2015, a report released by the Center for Strategic and Budgetary Assessments argued that the Navy did not have the operational guidance to use its newest electromagnetic technologies to the greatest effect.

If the Navy is then to use systems that require even more reliance on the spectrum for communications and coordination, the DOD is going to have to fix how it develops and acquires its electromagnetic warfare capabilities. This may mean allowing more competition between the individual branches to develop systems, and then distributing the best ideas out among the entire military. It may mean reforming intellectual property rules to allow more engagement by the private information technology sector. Acquisitions for these types of systems, though, have long been an Achilles’ heel for the DOD.


The third pillar the distributed fleet rests on is modularity. The plan for the distributed architecture includes both explicit modularity—a common hull auxiliary multi-mission platform—as well as implicit, with different unmanned ships designed for different missions.

Modularity has its benefits. For individual platforms, it allows adaptability and relatively quick upgrades. The B-52 bomber, for example, which is best described as a “flying box,” has allowed its lifetime to be dramatically expanded. Once the system is designed, focus on modules for that system can also lead to reductions in costs across missions.

However, misused modularity can cause significant problems. The Littoral Combat Ship’s anti-submarine module was plagued with problems, in part because that specific mission did not mesh well with the overall capabilities of the ship. While not modular in the traditional sense, the general-purpose approach to the F-35 Joint Strike Fighter led to delays and cost overruns because the variants wound up only sharing 20 percent of their parts. The Future Combat System was also built on shared platforms, and wound up being cancelled for being too costly. Focusing on modularity can also produce a system that is a jack-of-all-trades but master of none. Changes in computer chips—with more focus on optimizing chips for specific purposes—may also diminish the benefits of modularity, at least as it comes to the electronics within systems.

If the distributed fleet is to work, its architecture needs to avoid the pitfalls of modularity. For specific systems, such as the common hull auxiliary multi-mission platform, the range of missions should be clearly laid out before development. The Navy should avoid adding missions further into development or procurement, and should ensure that the designated missions should have overlap in system-level capabilities—such as ship speeds, range, etc.

The same is true  for autonomous vessels. Applying modularity to unmanned systems can be beneficial if the overall mission remains the same. Changes in missions, however, can stress systems undesigned for them. Adding on missions in development will inflate costs, which will defeat the purpose of low-cost, expendable unmanned systems. It may be hard to avoid tacking missions to a system that’s approved and being acquired, but it will be a must. Otherwise, unmanned systems may go the way of the littoral combat ship, a vessel that was supposed to be expendable but became too costly to risk.  

Distributed Calculus

Shifting towards a distributed fleet could address some of the threats challenging the Navy today: A2/AD systems keeping large capital ships at bay, the proliferation of drones, swarm technology, and the spread of precision stand-off weapons. Spreading out American forces to reduce targets for enemy forces, connecting disparate capabilities, and deploying unmanned systems all seem like beneficial ideas. Like everything in the defense world, though, the process of application will be key to success.