United States naval technology has reached a tipping point. The Navy must reconsider the feasibility of high-cost/low-capacity missile technology and begin pursuing low-cost/high-capacity capabilities through new developments in naval gunnery, specifically railguns.
Naval warfare and technological developments have always been interconnected. The navy that dominated was the one best able to expand and incorporate advanced technologies into its fleet.1 Naval technology undergoes a predictable pattern of growth: fleets adopt a technology and build their ships and tactics around it until a new concept overshadows the previous way of employing ships. A naval arms race develops until the technology is rendered obsolete or becomes cost-prohibitive.
Since naval strategists recognized the obsolescence of the ramming bow and fielded the first practical ship-based guns in the 16th century, the naval gun reigned supreme as the dominant weapon until the second half of the 20th century.2 Admirals understood the defining factor in classifying a ship was not her speed or survivability but how much firepower she could bring to the fight. Ships began to be classified based on how many guns they could carry and were designed to accommodate more. Naval tactics evolved in response to those technological developments, and the line of battle was developed to maximize the effectiveness of a fleet’s total armament. As guns became larger and more powerful, naval architects recognized they were approaching the point where they could not put any more guns on a ship and still consider her seaworthy.
Transitory Improvements
The race to cram more guns into a single hull peaked in 1852, with the 131-gun steam-powered HMS Duke of Wellington, after which a noticeable decline began in the number of guns per ship as the exploding shell and moveable turret shifted the focus from quantity to quality. Those developments prompted ship designers to think of new ways to defend against them. Ironclads became the new standard. The naval gunnery and armory race continued for almost another 100 years, culminating in World War II with the massive 18.1-inch guns and 26-inch armor on the Yamato-class battleships. As evidence of the transient nature of naval technology, the Yamato and her sister ship, the Musashi, were both sunk by torpedoes and aircraft-delivered bombs.
As that war came to an end and naval weaponry developed, it became apparent that further research in gun technology was a poor investment.3 The limited use of battleships in the Atlantic and Pacific theaters and the emergence of the aircraft carrier and submarine demonstrated that naval technology made possible the shift from capacity to capability. Advances in radar, propulsion, and computer technology offered further capability over capacity. Missile development began to dominate naval strategists’ thinking.
This shift was illustrated in 1955 when the USS Boston (CA-69) was recommissioned from “heavy cruiser, attack” to the world’s first guided-missile cruiser (CAG-1). Appropriately, her aft 8-inch gun was removed to allow for the installation of an antiaircraft missile system. The race intensified to develop more capable missile systems, and developments began to occur so rapidly that older systems were quickly outmoded. In 1968, due to the obsolescence of her missile armament, the Boston was reconverted to an attack cruiser and decommissioned two years later.
Just as more powerful guns led to the development of the ironclads, increases in missile technology spawned the development of defensive systems, such as jamming, chaff, and hard-kill missile defensive systems. In each case, as the capability increased, so did the cost. Today, missile development has reached a similar point on the cost-benefit curve as guns did in the postwar period. Further investment, while necessary to keep pace with other missile-based threats and missile defensive systems, has reached a point of diminishing returns.
The Navy has fielded, and in many cases is using, third- or fourth-generation upgrades to missile systems purchased decades ago. These upgrades have been at increasing cost and decreasing quantities. The Navy purchased the Harpoon Block I antiship cruise missile in 1977 for $475,000 per unit and later upgraded to the Blk IC. The Blk II was developed during the late 1990s at a per-unit cost of $1.2 million, but the service chose not to purchase the upgrade. In 2006, the Navy considered upgrading the Harpoon Blk IC to the Blk III, which would add a global positioning system unit and data link in an attempt to modernize a 30-year-old weapon for the 21st century. The program experienced cost growth and schedule delays, and the Navy determined the relative increase in capability to be cost-prohibitive and canceled the program. By that time it had already spent more than $110 million in development alone, a number that limited the upgrade to only a fraction of the total Harpoon inventory. The Navy is conducting an analysis to determine the next-generation long-range antiship cruise missile capable of meeting 21st-century requirements. Cost estimates are measured in the billions of dollars—before the Navy purchases a single combat-ready weapon.
Too Rich for the Market
Increased costs result in higher per-unit costs, which drive down procurement numbers. When the Harpoon was first developed, the Navy purchased thousands. Procurement estimates for a replacement system are measured in terms of hundreds. Often this is a result of cost growth and lower budgets.
The same trend can be seen in other defense areas. For example, the Navy canceled the upgrade to the antiaircraft SM-2 Blk IV missile (itself a multigenerational upgrade) in favor of developing the SM-6, albeit at reduced levels. The Navy continues to fund the Tomahawk and its multiple upgraded variants but is also initiating an analysis of a future land-attack weapon. The SM-3 Blk IA ballistic-missile interceptor is due to be replaced by the SM-3 Blk IB, which in turn will be followed by the SM-3 Blk IIA and IIB.
Each successive upgrade or, in some cases, entirely new concept, results in higher development costs, higher per-unit costs, and lower overall procurement numbers. These relatively small inventories force war planners to use expensive and limited weapons only against higher-end targets; the high costs simply make them unsuitable for use against lower-end threats. This has created a gap in the Navy’s ability to economically engage lower-end threats such as cruise missile-equipped patrol boats, near-shore undefended land targets, or relatively simple ballistic missiles, all of which could be more economically serviced by a low-cost gun round than by a missile.
Missile technology has evolved rapidly at the expense of cheaper gun systems. The largest naval gun currently in service is the Mk 45 5-inch gun, fitted out on Ticonderoga-class cruisers and Arleigh Burke-class destroyers starting in 1971. While capable of performing multiple missions, the gun’s range is limited to 13 nautical miles, rendering it useful only for self-defense or naval surface fire support. The Navy has attempted to increase the range of the Mk 45 through multiple upgrades as well as the extended-range munitions program, but that was cancelled after technical problems, cost hikes, and a series of failed flight tests. The result is 40 years of negligible increases in gun capability.
The Navy is currently developing the Advanced Gun Systems (AGS) for the DDG-1000, a single-mission gun capable of striking land targets at up to 63 nautical miles. This program has also suffered from technical challenges and cost increases, resulting in the truncation of the program from 64 barrels to 6.4 Other gun systems the Navy is developing offer less range than the Mk 45. The 25-mm, 30-mm, 57-mm, and 76-mm guns all have ranges from between one to ten nautical miles and are for self-defense only.
The Right Gun for the Job
The lack of a multimission naval gun with a range capable of servicing lower-end targets before they enter a ship’s threat envelope forces the Navy to rely on its expensive and limited numbers of high-end cruise missiles for all missions. During the opening salvos of Operation Odyssey Dawn, war planners were required to use Tomahawks to take out all land targets because that was the only weapon available with the required range, lethality, and accuracy, and that did not put any aircraft at risk. In the early stages the Navy launched 124 Tomahawks against land targets. Given Libya’s known military capabilities and geography, it is not difficult to assume that the majority of those targets were lightly defended and located within a railgun’s projected range. The total cost of these initial strike missions was reportedly $174 million—$1.4 million per missile.5
The Navy has recognized the gap in its ability to service lower-end targets at low cost and has pursued the development of short-range multimission missiles. But these have either experienced significant development problems or been canceled because of cost. The most recent example is the cancellation of the non-line-of-sight precision attack munition, a joint Army-Navy program to develop a low-cost/high-capacity missile system for use on both land and in ships. The Navy is investigating alternative options, but given that missiles by their very nature are expensive and low-capacity, it is unlikely an economical missile system will be developed for use against such targets.
Railgun technology can deliver large numbers of rounds over distances comparable to those of most current missiles and with the same lethality and accuracy but at higher quantities and lower costs. Railguns work by passing an electrical current along a set of parallel rails. The resulting magnetic field generates a vector that forces the round through the barrel at hypervelocity. The entire process is driven electrically; no explosive propellant is required. The Office of Naval Research has established a goal of launching a projectile more than 200 nautical miles and recently fired a world-record 32 megajoule shot that equates to roughly half that distance. The round itself relies solely on kinetic energy to provide its destructive power—no explosive warhead is required—and will be equipped with a GPS unit to allow for accuracy over long distances. The lack of an explosive propellant frees space in the magazine for more rounds.
An Mk 45 has a magazine capable of holding 600 rounds and an equivalent number of propellants. The AGS has a magazine of 750 rounds, including propellants, which are integrated into the loading and handling system. A railgun-equipped ship would triple that capacity, and likely more, given that railgun rounds will be smaller than either Mk 45- or AGS-fired rounds.
By combining a railgun’s range with a variety of multimission rounds, including air defense, ballistic-missile defense, precision strike, antisurface warfare, and naval surface fire support, a railgun-equipped ship would be capable of conducting long-range missions less expensively and with fewer risks.
For antisurface warfare, a ship could put dozens of shotgun-like dispersing rounds down range that would release their submunitions at the same time, enveloping the target in a massive cloud of shrapnel that would shred its sensors and communications equipment, effectively taking it out of the fight. This tactic would be useful against large-area land targets as well. If the mission called for the destruction of a target in an area where collateral damage was a concern, the shotgun round would be exchanged for a single, larger, and more accurate round designed for precision strike. This would limit collateral damage to below that of a comparable missile as there would be no explosive component. The total cost for conducting these missions would be an order of magnitude cheaper than using current or projected antiship or land-attack missiles. The same theory applies to other missions currently serviced by missiles, including cruise-missile and ballistic-missile defense.
The Navy’s Game-Changer?
It is not difficult to envision a scenario where a railgun would prove itself as the “force multiplier” it is often touted to be. During Operation Odyssey Dawn, the ships involved in the initial Tomahawk strikes were forced to return to port after only a few days on station because they had exhausted their supply of missiles. To ensure that Tomahawks were always available to the theater commander, multiple ships were required to rotate in and out of port. While the exact details remain classified, given that an Arleigh Burke destroyer can carry a maximum of 96 missiles and a Ticonderoga cruiser a maximum of 126, it would not take long before a single ship had expended its allotment of missiles and have to return to port, especially when one considers that the cells must be allocated between SM-2s, SM-3s, SM-6s, Evolved SeaSparrow Missiles, Tomahawks, and vertical-launched antisubmarine rockets.6
By replacing the Mk 45 with a railgun and using that to service the lower-end missions such as airfields, radar stations, and truck depots, and using Tomahawks only against high-end objectives such as command centers or hardened targets, a single ship would be able to accomplish what today requires multiple ships while simultaneously providing greater capability and flexibility to mission commanders.
Railguns also could increase overall ship safety. New missiles are required to travel faster and farther than their predecessors, forcing the development of new types of propellants. As Rear Admiral Nevin P. Carr Jr., former head of the Office of Naval Research, noted regarding ballistic-missile defense, “We’re fast approaching the limits of our ability to hit maneuvering pieces of metal in the sky with other maneuvering pieces of metal.”7 (From a cost perspective, this may be a good thing, as the SM-3 Blk IB interceptor has a per-unit cost of $13 million.)
Most recently, liquid-fueled boosters and hypergolic-based warheads are being explored to provide the required range, speed, and accuracy. These developments present a problem for the Navy as liquid fuel and hypergolics pose significant shipboard safety concerns. By comparison, railgun munitions have no explosive component and require no combustible propellant. Given the Navy’s emphasis on insensitive munitions and its goal of maximizing shipboard safety while maintaining sufficient lethality, railgun technology seems a natural fit.
As with any new technology, the railgun comes with significant technical risk and potential for increased expense. The Senate Armed Services Committee, which canceled all railgun research and development funding in the National Defense Authorization Act for FY12, said power generation and bore life, both of which have made significant progress and are no longer considered “show stoppers,” remain problems that must be resolved. However, once initial development is complete (the cost of which likely will be equivalent to any new single-mission missile system), procurement costs will be far less than those of comparable missile systems.
Lowering the costs of missiles is difficult not only because they are expensive to develop, but because it is not the launcher that drives up the cost, it is the missile itself. Because of their complex nature and relatively small quantities, missiles do not take significant advantage of economies of scale. The costs do not significantly decrease the more you buy, at least not at the rates the Navy can afford to buy them. The economics of guns are the opposite. With guns the cost is the launcher, not the rounds. Once the launcher is developed, the rounds will be able to be produced in large quantities and at low cost, allowing the Navy to purchase far more railgun rounds than it could comparable missiles.
The Navy has already invested significant resources into the development of a railgun launcher and proved the feasibility of the technology. Combined with the advances that have been made in bore life, power generation, and ship integration, many believe the Navy could equip a ship with a railgun before 2020.8 By contrast, next-generation missiles for both antiship and land attack are not expected to be fielded until the mid to late 2020s.
The time is right for naval gunnery to come back into vogue. Railguns can fill the gap created by overdependence on missiles and provide future ships with a low-cost, high-capacity, multimission capability that can be employed as an adjunct to high-cost, low-capacity, single-mission missiles. As then-Chief of Naval Operations Admiral Gary Roughhead noted, “You’re beginning, maybe, to see the end of the dominance of the missile. . . . There may still be some applications that come into play that you might want to use them in.”9
Just as naval strategists once recognized the inevitability of the gun over the ramming bow, the moveable turret and exploding shell over the broadside, and the guided cruise missile over the conventional gun, so must modern naval strategists recognize the unsustainable nature of the missile race and begin developing an appropriate adjunct capability by investing in railgun technology.
1. Roger W. Barnett, Navy Strategic Culture: Why the Navy Thinks Differently (Annapolis, MD: Naval Institute Press, 2009) pp. 74-85.
2. R. J. Grant, Battle at Sea: 3000 Years of Naval Warfare, (New York: DK Publishing, 2008), pp. 8-13, 30-31, 130-131.
3. MAJ Stephen Sim, “The Anti-Ship Missile—A Revolution in Naval Warfare,” Journal of the Singapore Armed Forces, Vol. 2, No. 4, 1998.
4. Ronald O’Rourke, “Navy DDG-51 and DDG-1000 Destroyer Programs: Background and Issues for Congress,” Congressional Research Service, 14 March 2011.
5. Tony Capaccio, “Raytheon Missiles Used in Libya Won’t Need Replacement Purchases,” Bloomberg News, 23 March 2011.
6. Norman Polmar, Naval Institute Guide to the Ships and Aircraft of the U.S. Fleet, 18th edition (Annapolis, MD: Naval Institute Press, 2005).
7. Spencer Ackerman and Noah Shactman, “Navy Vows to Fight for its SuperLaser, Hypersonic Gun,” 24 June 2011, www.wired.com/dangerroom/2011/06/navy-vows-to-fight-for-its-superlaser-hypersonic-gun/.
8. CDR Michael Ziv and John M. Johnson, “Electromagnetic Rail Gun: Providing Greater Flexibility for the 21st Century,” Office of Naval Research.
9. Spencer Ackerman, “Navy Chief Dreams of Laser Warships, Ocean-Spanning Robots,” 25 May 2011, www.wired.com/dangerroom/2011/05/laser-warships-ocean-robots/.