Carrier 2.0: The Drone Carrier Revolution
A Wayne Hughes Salvo Equation Analysis of Emerging Drone Carriers
Drones have become a mainstay of modern battlefields, changing tactics, and operations — driving a new wave of defense tech focused on gaining advantage in this new domain. The most prescient examples are the Ukrainian and Syrian conflicts. However, the use of this disruptive technology has not been exclusive to ground conflict; Houthi rebels have employed one-way attack drones throughout their ongoing sea-denial campaign in the Red Sea. Yet the impacts on Naval combat and tactics must be fully developed and understood. This article examines a novel naval capability several nations are investing in, the drone carrier.
The work of Wayne Hughes and his salvo equations further demonstrates the importance of massing fires in naval combat. Recent battlefield evidence suggests that the massing of one-way attack drones can successfully overwhelm an adversary’s defenses in a cost-efficient manner. It follows that a drone carrier could be an effective way to mass fires with one-way attacks and pose serious survivability challenges for naval and littoral targets.
This article assesses scenarios of carrier-launched long-range, one-way attack swarms against naval surface targets. This baseline analysis of how appropriately massed carrier-launched swarms could impact surface action group (SAG) formations helps contextualize where and how these flashy flat decks might operate. The defensive capability and staying power of the SAG is based on an Arleigh Burke-class destroyer, and the drones modeled have the payload of a Shahed-136. This modeling effort indicates carriers must mass 50 or more drones to successfully sink vessels in an adversarial SAG. Though, regardless of specific vessels and drones, the ability of a drone carrier to mass large swarms is a critical component of its value in surface combat.
Hughes’ Salvo Equations
Captain Wayne Hughes’ salvo equations for modern missile combat are utilized as the foundation of this modeling effort. In this case, salvos are drone swarms rather than cruise missiles. The original equations are adapted to the single Force B equation below.
The impact of a Force A drone swarm, resulting in Force B casualties, is assessed as a function of B’s staying power and defensive power.
As an illustration, imagine a drone salvo of 10 attacking a SAG with a staying power of 5 drones and a defensive power of 10 drones. The variables and equation would be as follows:
The negative and zero values illustrate that no vessels were lost in the salvo. A negative number represents excess staying power or defensive capacity depending on the ship's characteristics. Alternatively, if defensive power is reduced to 1 drone while all other variables remain the same, a slightly different result is observed.
In this scenario, Force B experiences a 1.4 vessel loss during the salvo. Practically speaking, 1 to 2 vessels become casualties due to the exchange.
Drone Carrier Salvos
In the notional scenarios assessed, a drone carrier launches a single drone swarm against a three-ship SAG. The size of the swarm, staying power, and defensive power of Force B’s ships are varied to contextualize how each characteristic impacts Force B’s casualties.
The individual drone and drone swarms are assumed to be one-way attack drones similar in design to the Shahed-136 used by the Russians in the Ukraine War. These drones have a nominal range of ~2000km and carry up to a 100lb warhead. While relatively small and slow compared to antiship ballistic missiles, the objective of the drone swarm is to overwhelm the SAG’s countermeasures systems.
Conversely, the SAG must be able to counter the drone swarm and absorb some of the attacking drones in the exchange. While multiple defensive power values are assessed, it can be expected that the SAG vessels will be capable of countering at least 10 Shahed-like drones. In October 2023, the USS Carney reportedly shot down 15 Houthi drones and multiple cruise missiles in a single day of engagements. While the USS Carney’s engagement does not precisely capture the exact nature of the simulated drone swarm, it does provide evidence that a SAG vessel has the tactics, weapons, and magazine capacity to counter sustained drone attacks.
If countermeasures fail, a ship must be able to absorb several drone strikes without sinking. Using the assumptions outlined by CAPT Anthony Cowden, USN (ret.) in Distributed Maritime Operations: A Salvo Equation Analysis, we assume that the vessels in the SAG, each with at least an 8000-ton displacement, can absorb roughly 1,320 lbs of modern warhead explosive or 14 Shahed-like drones before becoming a casualty. For the analysis below, we vary a ship’s staying power between 5 and 30 drones.
Staying Power Analysis
Modern staying power depends on robust vessel design characteristics, which may include modular power systems, redundant combat systems, and damage control processes. In the scenario below, we assess growing swarms of 10 to 100 drones, assuming each vessel in the SAG has the defensive power to counter 15 drones.
The swarms assessed produce decreasing Force B casualties as the SAG’s staying power increases. In this scenario, the drone swarm must mass at least 50 drones to inflict casualties on the SAG. A swarm of fewer than 50 drone lines produces a negative 𝚫B, which indicates (as in the previous example) that Force B possessed excess staying power or defensive capability. These lines are omitted in the plot above. Conversely, the SAG is completely destroyed in the largest swarm (denoted by the black point in the above chart) when the staying power is 19 drones or less. When the staying power is the previously discussed 14 drones, the SAG can repel and absorb drone attacks without casualties until the 50 drone swarms. The inverted blue triangle, plotted at the 14-drone staying power line, denotes the 0.4 casualties the SAG can reasonably expect against a 50-drone swarm.
Defensive Power Analysis
Modern naval vessels have a straightforward augmentation path for counter-drone defensive power compared to staying power. While staying power must be built into the ship’s design, defensive power can be reinforced through self-contained munition launchers, jammers, or other bolt-on combat systems. In the scenario below, the SAG’s defensive power, interpreted as counter-drone capability, varies between 10 and 35 drones. The model in this scenario assumes each vessel has a staying power of 10 drones, slightly less than the 14-drone casualty threshold identified earlier.
In all swarm scenarios, there are predictably fewer Force B casualties due to increasing defensive power. Assessing the same defensive power displayed by the USS Carney, 0.5 SAG casualties are produced, denoted by the inverted blue triangle on the 50 swarm line. Understandably, vessels prefer countering all rather than absorbing any of the carrier’s swarms. From the SAG’s perspective, this sentiment requires vessels to invest in high-capacity counter-drone magazines to minimize risk. Tracing the same 50-drone swarm line right, Force B casualties continue to decrease, intersecting the zero-casualty line once the vessels’ counter-drone magazine increases over 17 drones. Alternatively, in a 100-drone scenario, the SAG is completely destroyed, denoted by the black point, when the vessel’s defensive power falls below 23 drones.
The Drone Carrier’s Future Value Proposition
It is clear that if drone carriers are intended to attack capable modern surface vessels the ability to mass large swarms with sufficient payloads is paramount. It is unclear if or when drone carriers will be able to launch 100 or even 50-drone swarms, and have the requisite command and control to guide such a swarm to a target.
Further, there is the issue of the staying power of the drone carrier itself. Part of the value of drone swarms is the relatively inexpensive method of overwhelming defenses and in the case of ground combat having distributed and survivable launch sites. If a drone carrier is easily targetable, with little staying power you have a design paradox where you lose the initial intended value of the drone swarm. In the case the carrier is a one-of-one asset with low survivability, its value proposition lies solely in the ability to fire first and with sufficient swarm size to defeat the adversary. Individual drone carriers and their associated concepts of employment should be evaluated in this context.
Based on this analysis and some of the challenges identified, it is possible that navies investing in this capability imagine different use cases other than attacking an adversary surface fleet. A drone carrier’s value may be more evident when focused on attacking dispersed land targets, conducting sea control along sea lines of communication (SLOC), and providing persistent intelligence, surveillance, and reconnaissance (ISR) coverage. In the analysis above, the SAG effectively defends against swarms of fewer than 50 attack drones. For sea denial, the drone carrier’s fires may be better suited for targeting less-defended assets, such as individual surface combatants or merchant vessels. The drone carrier’s magazine capacity could also enhance a friendly SAG’s ability to harass and deter shipping along SLOCs, similar to Houthi drone attacks in the Red Sea. Finally, the drone carrier’s real value may lie in launching and massing ISR drones to achieve widespread coverage. Instead of massing 50 or more one-way attack drones, 10 long-endurance drones over an area of interest in support of persistent coverage could provide inexpensive high-resolution collections compared to satellites or manned flights.
Current Drone Carriers
Drone carriers built by Iran, China, and Turkey have captured the world’s attention, but are they to be disruptive naval assets? The ships, either adapted from existing platforms or purpose-built, are being outfitted with special drone-specific packages, control stations, and launch configurations. While these ships have ample deck space to launch and recover large UAS systems, it is still unclear if these vessels will play host to exquisite and expensive airframes or less expensive expendable drones. There is some speculation that Iran’s Shahid Bagheri could use containerized cruise missiles or stacked one-way attack drone launchers. Understanding the minimum defensive and staying power necessary to counter swarms should motivate necessary investments in counter-drone combat systems, the development of counter-drone tactics, techniques, and procedures, and an analysis of surface vessel staying power against swarm formations.
Conclusion
New forms of mass and attrition in the form of relatively low-cost drones are changing warfare. These capabilities are coming to the maritime domain as countries experiment with new drone carriers. While still a nascent capability, navies around the world should pay attention and posture themselves accordingly. Whether attacking with drone swarms or defending against them the insights from Wayne Hughes' work hold, that the advantage will go to the side that can mass effective fires and fire first.
The views and opinions expressed on War Quants are those of the authors and do not necessarily reflect the official policy or position of the United States Government, the Department of Defense, or any other agency or organization.
Agree on Drones and Drone swarming.
Not navy, but are we restricted to surface warfare? An Arleigh Burke cruiser is 8000-9700 tons, at $2.2B apiece.
They could conceivably be sunk for $2 million.
To move beyond ships;
Have you heard of RAPID DRAGON? Palletized missile launch system.
Any cargo aircraft just became a bomber with standoff.
https://youtube.com/shorts/YyCp1mTMI88?si=sc4twKwqWSY1eb1T
We might be better incrementally adjusting platforms and tactics while mass producing and let Joe figure it out. He’s highly motivated, people are trying to kill him.
Currently we incrementally produce all systems and for that matter soldiers, sailors, airmen while massively adjusting doctrine… and massively producing papers.
I agree on all major points.
HNY