By Robert C. Rubel
From the galleasses at the Battle of Lepanto to the aircraft carriers of today, the capital ship has been that ship type that is capable of defeating all other types. That is the general and simplistic definition of the term, but to speculate on the future capital ship, we must understand the underlying characteristics of a capital ship and its role in fleet architecture and design. We will start with the ship itself and then move outward to its context and implications for maritime strategy.
The Core of the Fleet
The adjective “capital” is used because the ships to which it has applied have been the biggest and most expensive of the naval vessels of their day. This was the case due to the armament they carried; the most and biggest guns available and later the most and most capable aircraft. Whether smooth bore cannon versus rams, number of guns available for a broadside or the caliber of rifled guns, the name of the game has been weight of fire and hitting at distance. The protection of capital ships required significant amounts of investment, first in armor, then in escorts. The expense and the difficulty of building capital ships meant that they were the least numerous ship type. However, their number was important in determining overall naval power. Generally, the capital ship inventory of the most powerful navies was in the dozens.
The physical characteristics just discussed had a powerful influence on fleet design and by extension on maritime strategy. The capital ship was the tool by which a nation could contend for command of the sea, either globally or regionally. Thus a nation’s fleet was designed around the capital ship in various ways.
First, they had to be supported by a variety of lesser ship types that performed functions such as scouting and protection. In this sense the capital ship was the pivot of fleet design. Given the existence of other, potentially hostile capital ship fleets, distribution of capital ships was a key issue. If there was a sea invasion threat to the nation, a “home fleet” of capital ships was necessary. On the other hand, depending on the threats to a nation’s maritime commerce, there was frequently a need to deploy capital ships, individually or in small squadrons, to counter or eliminate these threats, but that raised the danger that they would be caught by a larger force and destroyed. The British concept of the battle cruiser, a heavily armed but lightly armored and fast ship, was intended to address this dilemma. As additional threats such as the torpedo boat, submarine, and aircraft emerged, additional protective measures had to be taken such as escorts and design changes including torpedo bulges and dense anti-aircraft secondary batteries.
The capital ship has been the ultimate arbiter of command of the sea, both in war and peace. Command of the sea can be most usefully thought of as the balance of strength among contending navies. The navy with command of the sea is free to disperse its forces to exercise control in various localities and more broadly, has various strategic options open to it that are closed to the navy and nation that has lost command. The expense of capital ships and their consequent relative scarcity, the time required to replace losses and their intimate connection with command of the sea, coupled with the strategic importance of such command, led national leaders and admirals to be cautious about committing their capital ship fleets to the test of battle. Even a small perceived imbalance of power has caused admirals to try and avoid pitched battle; like going “all in” in Poker, one must be very confident of one’s hand.1 Thus decisive naval battles have been rare and most of those that have occurred involved the weaker force being surprised, cornered or forced into battle by their national leader.
Since the age of sail, the capital ship has been the unit of measure for naval power. When a nation seeks great power status, it starts building a powerful navy, this being true even of historically continental powers such as Germany, the Soviet Union, and now China. This has produced naval arms races and wars. The Washington Naval Treaty of 1922 was an attempt to suppress naval arms races by limiting the total tonnage of warships and imposing a hiatus on building capital ships among the U.S., Great Britain, France, Italy, and Japan.
After World War II, the U.S. Navy found itself with near absolute global command of the sea but retained a significant number of its capital ships for the purpose of exercising command of the sea in peacetime. Such exercise consisted of deploying carrier battle groups around the periphery of Eurasia in order to enforce the international order the U.S. desired. In this case the necessary number of capital ships became a function of the combination of deployment demands, maintenance requirements, training, and personnel tempo.
The large deck aircraft carrier has been the capital ship since the start of World War II. Its hold on this status is based on the effectiveness and utility of its embarked tactical aircraft. The question is whether it will retain that status or be replaced by something else. We will take on this question based on the characteristics and factors that have been discussed.
Let’s start with weapons. The advent of micro circuitry, new forms of sensing and artificial intelligence have transformed missiles, in all their forms, into perhaps the dominant and decisive type of weapon at sea, both for offense and defense. Most ship types carry them and countries such as China have developed land-based ballistic missiles of very long range that can seek ships. Advanced surface-to-air missile systems now constitute a lethal threat to any aircraft except perhaps those possessing the most advanced stealth technology. Modern anti-ship missiles are increasingly sophisticated and hard to defend against.
All of this has difficult if not dire implications for the continued status of the aircraft carrier as capital ship. Certainly, additional measures can be taken to enhance the defense of both tactical aircraft and the carrier, but these will add to the expense of the total system to the point that it could outweigh the value of the offensive capability it possesses. At that point, according to George Friedman, it becomes “senile.”2 If indeed the missile becomes the key weapon, many different ship types can carry them, for both war at sea and shore bombardment. The question then becomes whether missiles are best concentrated in a large “arsenal ship” or distributed out among a lot of different ships. If concentrated in a few large hulls, it is possible that these “missile battleships” (BBM?) would be the new capital ship. Such concentration would certainly make it easier to coordinate missile salvos.
However, looking beyond the ship itself reveals some factors that militate against concentration. The first is the inherent risk in concentrating offensive firepower in a single ship. Vice Admiral Arthur Cebrowski articulated the concept of tactical stability which states that as we pack more offensive capability into a ship, there is a point at which its defensive capability ceases to increase proportionately. At that point, escorts are needed.3 Moreover, if a task force has a key capability installed on one or a few ships, their loss would neutralize the whole force, and thus it is tactically vulnerable and subject to catastrophic failure rather than graceful degradation. For this reason, the Navy is developing the concept of distributed lethality: mounting offensive missiles on as many ships as possible in order to complicate enemy targeting and reducing the risk of catastrophic degradation to the force as a whole.
Another issue is the distribution dilemma. For today’s Navy, it takes two forms: global and regional. Globally, having only ten available aircraft carriers limits the presence the U.S. can generate in multiple regions simultaneously. Moreover, strategic adjustments to deployment patterns must be made on the basis of carrier groups, which is a rather coarse methodology, sort of like trying to draw a precise, detailed picture with a large-tipped magic marker. Regionally, deploying carrier groups must “starburst” into individually operating ships to accommodate all the Geographic Combatant Commander’s engagement commitments. This prevents routine training to maintain combat readiness skills and of course opens individual ships, especially the carrier, to surprise attack. There is also the risk involved in operating carriers in the threatened littoral. This risk is manifest not only at the tactical level in which attacks are more likely to be successful, but in the strategic risk of losing a precious capital ship. Again, the emerging concept of distributed lethality promises a way to avoid or at least moderate the dilemmas and risks.4
The emergence of the missile as the “weapon of decision” both at sea and ashore has a couple major implications. First, since missiles can be mounted on almost anything, the relationship between ship size and characteristics and weapon power is broken. It would seem to make little difference if a salvo of missiles is launched from a single ship or many. Second, the distribution of offensive power among a lot of different ships promises to reduce both operational and strategic risk in various ways and eases the distribution dilemmas.5 This would seem to spell doom to the capital ship concept, and in this writer’s opinion, it does, at least in the conventional sense of a single ship type.
There is, however, another way to look at the matter. The key capability of a capital ship has been to deliver a superior weight of fire at a longer range than anything else. Certainly, our “BBM” would have plenty of missiles to fire, but that is not enough. Those missiles must be fed targeting information to be of any use. International law doesn’t permit firing missiles down a line of bearing and letting them open up their sensors at a certain point and hit the juiciest-looking contact. That makes them “indiscriminate” and therefore illegal. So, without targeting, the BBM or any missile ship intending to fire over the horizon, is useless.
Missiles are getting smarter, but there are a couple of reasons that it is tactically and operationally inadvisable to just light off a salvo with incomplete targeting and identification. First, if facing sophisticated defenses, the salvo must be timed precisely to saturate or at least confuse defenses so that at least some missiles get through. Second, missiles themselves will likely be at least somewhat scarce resources and so must be used efficiently. To achieve both objectives, an area-wide network of sensors, processing and decision making must exist beyond the hulls of the fleet. Granted, individual ships will have their own targeting capabilities, but these likely will not be sufficient for getting full kinetic range from their missiles.
Merging Capital Ship and Networked Force Concepts
Putting it all together, it seems useful to regard the fleet battle force network as the future equivalent of the capital ship. It and it alone allows the delivery of a useful weight of fire at long range in a naval fight. The application of the capital ship term may not be absolutely necessary, but it does confer some useful organizational effects.
First, if the network becomes the pivot of fleet design, certain new perspectives emerge. A key one is a fresh understanding of how existing and potential ship types relate to each other. There isn’t room in this essay to tease out all of these threads, but there are several insights that can be mentioned.
First, since the network consists of physical nodes and connectors (sensors, communication relays, etc.) it must receive physical as well as cyber protection. This is an important potential new role for aircraft carriers. Using a new air wing composition, the carriers can provide air superiority over distributed lethality forces and protect airborne assets like P-8s and Tritons, provide communications relay in the event that satellites are knocked out, and perhaps provide targeting services to missile ships. Thus, carriers would become escorts for the network. An advantage of this new function is that they would not have to operate as close in to the enemy shore as they would if their air wings constituted the key offensive strike capability and the risk to aircraft is reduced. This would allow carriers to remain viable and useful for the foreseeable future.
Second, since physical concentration would not be necessary for combat effectiveness, the risks associated with the regional distribution dilemma would be substantially avoided. Globally, since combat power would be distributed among a larger number of ships, a finer strategic distribution picture could be drawn, assuming that each forward fleet has its own battle force network established.
A network-enabled distributed lethality force would also mitigate the strategic risks associated with the traditional capital ship concept, especially in an era of renewed naval competition. A fight for command of the sea using such a force would not necessarily entail an “all in” decision, providing some strategic decision making flexibility for fleet commanders. Crises or perhaps limited conflicts that occur within the range arcs of major power denial systems could produce a risk dilemma for the U.S. if its offensive power remains concentrated in traditional capital ships. This is precisely what, for instance, the Chinese hope to create if conflict breaks out over any of their contested island claims or even war on the Korean Peninsula.
Missile technology appears to give a decisive edge to the tactical offensive at sea – the historically normal state of affairs. In the early years of the Pacific War, aircraft carriers dealt with this condition by attempting to strike effectively first, the paradigm being the Battle of Midway. However, if the enemy’s offensive power (missiles, say) is dispersed and hidden, then such a remedy is unavailable. Thus capital ships, in attempting to intervene in some littoral conflict would be excessively vulnerable; that is, their loss would be incommensurate with the strategic gains promised by the operation. Capital ships should only be risked when the potential strategic gain, usually command of the sea, is worth such risk. The point is that in the emerging world it may not be worthwhile to employ traditional capital ships even when regional command of the sea is at risk, as they could be lost without prospect of meaningful gain. Network-enabled flotillas would substantially obviate the dilemma.6
Without going into the murky world of cyber warfare, it is worthwhile to point out that the network has offensive and defensive potential beyond supporting missile warfare. Offensive cyber attacks can disrupt enemy command and control and targeting. It would make sense to have such capabilities inside the lifelines of a fleet battle force network in order to achieve effective coordination with missile and other forces. In terms of network design, we may yet be in the “pre-Dreadnought era” awaiting that breakthrough concept that makes all other approaches obsolete. Applying the capital ship framework to the battle force network may help us develop or at least recognize that breakthrough when it comes along.
There are other capital ship-related concepts such as staying power7 that could be useful when applied to the design and operation of battle force networks. Capital ships were built to take hits and still fight. Obviously no ship can endure multiple hits indefinitely, so the notion of staying power helped designers figure out how much protection was needed and make the necessary tradeoffs with armament, speed, sea keeping, magazine capacity, etc. How long the ship needed to hang in there was a valuable determination and so it might be with the network. Staying power might not be measured in minutes as it was with battleships, but some other criterion such as confidence or available bandwidth might be adopted.
This article does not advocate reducing the number of aircraft carriers or for constructing any new class of ship; the designation of the battle force network as the modern instantiation of the capital ship is a way of establishing a new logic that underpins fleet design. If fleet design is regarded as the prerequisite and precursor to fleet architecture, the logic of network-enabled missile warfare will clarify what kinds and numbers of ships the Navy should have.8 There are, of course, many other considerations and influences on fleet architecture, but achieving institutional focus via the network as capital ship concept would go a long way in helping the Navy rapidly enhance its offensive lethality and use its available resources efficiently.
Emerging technology and shifting geopolitical conditions are changing how naval warfare will be conducted in the future. The U.S. Navy must adapt or find itself strategically outmaneuvered. Effective adaptation will require more than updates to current ship types; it will require totally new approaches to fleet design. Instead of thinking outside the box, it might help the Navy to think outside the hull.9 Adopting the network-as-capital ship idea is one way to do that.
Professor Emeritus Rubel is retired but serves as an advisor to the CNO on fleet design and architecture. He spent thirty years on active duty as a light attack and strike fighter aviator. After leaving active duty he joined the faculty of the U.S. Naval War College, serving as Chairman of the Wargaming Department and later Dean of the Center for Naval Warfare Studies. In 2006 he designed and led the War College project to develop the concepts that resulted in the 2007 Cooperative Strategy for 21st Century Seapower. He has published over thirty articles and book chapters dealing with maritime strategy, operational art and naval aviation.
1. Alfred Thayer Mahan, Lessons of the War With Spain and Other Articles, (Boston, Little, Brown and Co., 1899), p. 31. Mahan discusses the effect of the loss of a single ship on the naval balance with Spain before the war.
2. George and Meredeth Friedman, The Future of War, (New York: St. Martin’s Griffin, 1996), p. 26 and Chapter 8, “The Aircraft Carrier as Midwife,” pp 180-204.
3. Wayne P. Hughes Jr, Fleet Tactics and Coastal Combat, (Annapolis, MD: US Naval Institute Press, 2000), pp. 286-291. Prof. Hughes influenced Admiral Cebrowski’s thinking, and the discussion of massing for defense on the cited pages provides a more in-depth look at the logic of instability.
4. Robert C. Rubel, “Deconstructing Nimitz’s Principle of Calculated Risk,” Naval War College Review, Autumn 2015, (Newport, RI: Naval War College Press), pp. 31-45. The article contains a detailed discussion of the various risks and distribution dilemmas inherent to aircraft carriers using the Battle of Midway as a case study.
5. Hughes. Chapter 11, “Modern Tactics and Operations,” pp. 266-309. Prof. Hughes offers a detailed and mathematical discussion of modern missile combat through the lens of operations research.
6. Rubel, “Cede No Water: Naval Strategy, the Littorals and Flotillas,” Proceedings, September 2013, (Annapolis, MD: US Naval Institute), pp. 40-45.
7. Hughes, pp. 268-274.
8. Hughes, “The New Navy Fighting Machine: A Study of the Connections Between Contemporary Policy, Strategy, Sea Power, Naval Operations, and the Composition of the United States Fleet” (Monterey, CA: Naval Postgraduate School).
9. Rubel, “Think Outside the Hull,” Proceedings, June 2017, (Annapolis, MD: US Naval Institute), pp. 42-45.
Featured Image: USS Yorktown (CV-10) Crew stands at attention as the National Ensign is raised, during commissioning ceremonies at the Norfolk Navy Yard, Virginia, 15 April 1943. (Photographed by Lieutenant Charles Kerlee, USNR. Official U.S. Navy Photograph, now in the collections of the National Archives)