Naval mines, perhaps more than any other maritime weapon, hold the potential to so substantially tip the cost of warfare as to make employment of forces practically unpalatable to a naval commander. Indeed, since the advent of modern warfare in the mid-1800s, mines have played a role in most major conflicts between nations. During the Civil War, naval mines cost Union forces more losses than Confederate guns. The mine barrage in the North Sea during World War I precluded German submarines from fully exploiting the battlefield. A quarter century later, the United States, Japan, Germany, and Italy employed naval mines against each other in World War II. Naval mines saw extensive use in Korea, Vietnam, and the Iran-Iraq War.
The Korean War, in particular, showed the potential cost borne by a technologically superior navy arrayed against a nation seeking to deny access or without a navy capable of achieving parity on the high seas. In technology also lies the solution. Rapid advances in autonomous underwater systems and a cultural shift toward capabilities and disposability, decoupled from the platform, provide the ability for a single platform to possess modest and scalable defensive and limited offensive mine warfare capabilities.
Fielded en masse, simple naval mines present a serious antiaccess threat. Commercial technology exists to provide a modicum of low-cost mine defense capabilities to any ship.
History as Prelude
In October 1950, the conflict in Korea seemingly was going well. General Douglas MacArthur was racing to the northern border, and the end appeared to be near—but trouble lurked. The North Koreans began a sizable mining campaign that sent the USS Mansfield (DD-728) to Japan for repairs and sank the minesweeper USS Magpie (AMS-25). Two weeks later, the U.S. X Corps was ordered to deploy in support of MacArthur’s forces in a combat amphibious landing on the eastern coast of North Korea at Wonsan. The North Koreans, with Soviet advisers, deployed more than 3,000 naval mines in the approaches to Wonsan to stall or thwart the operation. The 250-ship armada lolled about the waves as the small minesweeper squadron worked feverishly to clear a channel to the beach.
Two of the minesweepers, the USS Pirate (AM-275) and USS Pledge (AM-277), struck mines and sank within an hour of each other on 12 October. Magnetic mines were detected during the subsequent salvage and mine-clearance operations when a South Korean minesweeper sank after being struck, further delaying and complicating mine clearance and the planned landing of X Corps.
On 25 October, X Corps finally landed, a week after South Korean forces cleared the area. Rear Admiral Allan Smith, the commander at Wonsan, sent a message back to Washington: “We have lost control of the seas to a nation without a Navy, using pre-World War I weapons, laid by vessels that were utilized at the time of the birth of Christ.”1 Less than two months later, the Peoples’ Republic of China entered the war, decimating U.S. forces and affecting a general retreat to the south. Allied forces were ordered amphibiously evacuated in December 1950 in another operation complicated by naval mining.
All five warships sunk during the Korean War were minesweepers. Several other warships received major damage and casualties from mines.
The Modern Threat
Today, our potential adversaries combined can field more than 400,000 naval mines, many of them far more lethal and advanced than the contact and simple magnetic influence mines the North Koreans laid at Wonsan.1
Lyle Goldstein, a leading China watcher, reports that the People’s Liberation Army-Navy (PLAN) believes it can seed more than 14,000 mines in as little as two weeks, with more than 2,000 per day easily achievable.2 Though many doubt the Chinese government could carry out such an operation, stopping or slowing it would be far from trivial. Even if the political leadership in the United States directed prompt military action, time and distance prohibit it. Coupling mines with an overwhelming number of antiship cruise missiles, the Chinese effectively could prevent the United States, or any allied coalition, from massing combat power at the critical point should they so choose.
Retired Navy Captain Wayne Hughes reveals the root of the problem for allied planners:
At sea the essence of tactical success has been the first application of effective offensive force. If the tactician’s weighty weapons substantially outrange the enemy’s, then his aim is to stand outside the effective enemy range and bring down his attack with sufficient concentration of force to destroy the enemy. . . . The second great constant of offensive force applies here: Other things being equal, a small advantage in net combat power will be decisive and the effect will be cumulative. The necessary margin of superiority, however, widens when the enemy for any reason can be expected to deliver a first, but indecisive, attack.3
The simple naval mine, employed en masse, threatens to deny the sea to allied forces such that the effective range of allied weapons prevents them from being brought to bear effectively, if at all, on PLAN ships, thus achieving the indecisive first attack of which Hughes speaks.
The problem gets acute as the Chinese mining campaign shifts to the offensive. Goldstein reports that modifications to PLAN submarines may facilitate an increased loadout of naval mines, with the ability to mine U.S. bases in the Pacific or even threaten U.S. ports on the West Coast.4 The mere threat of mining would shut down a U.S. port until cleared. The direct economic effects may seem insignificant, but an extended port closure, at Long Beach and Los Angeles, for example, could destabilize the global economy. Together, these ports process nearly half a trillion dollars in trade annually, with an indeterminate amount of additional sales, services, and taxes in the local region.5 In addition, the backlog of cargo ships that would develop from a port closure would send shock waves through a global economy that depends on just-in-time deliveries as cargo sat idle, produce rotted, and goods missed delivery deadlines.
Critics may doubt the PLAN could pull that off, but does it actually have to mine the ports to achieve the desired effects, or merely convince U.S. leaders that it might have occurred? Could the Russians, with a penchant for working through darker connections laced with plausible deniability, do the same?
The Navy’s current mine countermeasures (MCM) construct relies on platforms with complete detection and neutralization capabilities. Minesweeping forces and the MCM package for the littoral combat ship (LCS)—now truncated—use a single platform to complete a thorough search of the environment for floating, moored, and buried mines. The original MCM program for the LCS consisted of a suite of systems, including the remote multimission vehicle (RMMV) towing a sonar array, the common unmanned surface vehicle, a helicopter-mounted airborne laser mine detection system and airborne mine neutralization system, an unmanned helicopter system for coastal mine hunting, and a Knifefish unmanned underwater vehicle for buried mines.6
The RMMV was canceled in March 2016 for reliability concerns.7 That leaves the LCS mission package with five major components. The complicated concept of operations for these systems flies against the simple logic of General George Patton, still relevant today: “A good plan violently executed now is better than a perfect plan executed next week.”8 The LCS MCM package is the engineers’ attempt at a perfect plan. It likely would deliver a very low rate of missed detections, but at the expense of both time and stealth.
Current Navy MCM does not provide scalable capabilities to achieve the desired effect. As the stories of the Magpie, Pirate, and Pledge demonstrate (see sidebar), minesweepers do not fare well in combat environments. But commanders do not want to risk warships or supply ships in an area laced with mines. So how do we reduce the risk to manned platforms while still achieving the objective?
Advances in commercially available sensors, autonomous control systems, and retrofitting installations can permit each ship to be fitted, when necessary, with a simple, rapid solution that does not require integration with the proprietary underpinnings of the Aegis combat system or the full suite of MCM systems. Each ship requiring it can be provided with a modicum of MCM capability for self-defense to ensure that the anti-access role that naval mines play becomes vastly reduced. This does not imply that all warships should be fitted with them, since the risks toward damage or, worse, loss of capital ships far outweigh the benefit of installation. The technological suite of systems would permit scouting forces, to continue with Hughes' logic, to be employed in scouting for and neutralizing naval mines.
• Navigation and mapping sonar. Easily retrofitted onto hulls, with simple user interfaces and providing high resolution of the water column, commercially available sonar systems can detect mine-like objects at tactically significant ranges. Current systems can provide detection ranges to 600-1,500 meters ahead of the ship, 350 meters off the beam, 50 meters or more in depth; stabilization in seas with up to 20-degree rolls; and angular accuracy of a degree or less at speeds up to 25 knots.9 Lateral detection would be permitted at ranges greater than the necessary standoff from most moored and contact mines, and ahead detection ranges would permit maneuvering to open range beyond acceptable limits. Ships would be able to navigate through moderately dense minefields at operationally significant speeds. As an added benefit, ships so equipped would become part of the search process. It may not be a perfect search with perfect equipment and perfect detection and localization, but imperfect information is better than no information in the hands of a decision maker.
• Neutralization and offensive mining. Should the need arise to neutralize mines, each ship can be fitted with small autonomous underwater vehicles (AUVs) equipped with low-cost sensors and a warhead sufficient to disable a mine. Several companies have AUVs that can be launched from a standard sonobuoy launcher—meaning they are man portable—or can be launched with the standard naval 5-inch gun. These AUVs have depth ratings to 200 meters, well in excess of the obstacle avoidance sonars described above, and can carry sufficient payloads to make them useful for self-defense.10
Moving to the operational level of war, these same systems can be launched from helicopter or aircraft sonobuoy launchers, preprogrammed to neutralize a specific mine in a previously mapped field. This permits decoupling the minefield search and mapping functions from the neutralization function, something the current force construct does not support. Alternatively, it supports the rapid emplacement of an offensive minefield. These systems provide the ability to install a temporal minefield to deny access to a particular area, and their commutations abilities permit modest control of the field to enable transient access by allied forces.
All these components can be readily fitted to nearly any ship in the force or distributed among different platforms to achieve singular goals. This includes the novel use of joint high-speed vessels and afloat forward staging bases to employ greater numbers of AUVs to produce more refined maps of an area or to neutralize a minefield once air and sea control have been achieved.
Perhaps more important, the low cost of procurement, especially for AUVs, will usher in the missing element in our naval culture: disposability. The systems in the LCS MCM package, the tools on our current minehunters, and the slow approach to systems development introduce risk aversion into strategic thinking. Loss of assets represents a loss in recouping the time and money spent in development. However, the ability to achieve a good, but not perfect, solution at a significantly reduced cost likely would make naval commanders more willing use their systems to their fullest extent, with fewer consequences for loss.
A Potential Scenario
The vision coalesces in a plausible scenario: As tensions build near the Senkaku Islands, the Seventh Fleet commander orders an additional submarine and LCS into the South China Sea for presence operations. Another destroyer is readied for sea, with the ship’s divers installing the forward-looking sonar system on the bow and the gunner’s mates loading additional AUVs into the ship’s magazines. The LCS already had the systems installed, and the submarine loaded a complement of AUVs prior to deploying. All begin conducting freedom of navigation and mine-search operations in the East and South China seas.
It is not long before all three units begin detecting mines. Information flows back to Seventh Fleet headquarters, which orders the minefield quietly neutralized. The submarine comes to periscope depth, receives the compiled map, and slips back beneath the waves. The AUVs make quick work of the mines as the submarine clears a route for follow-on forces. In an attempt to diffuse tensions, a carrier battle group sets sail from Yokosuka and begins transiting the East China Sea. The Central Military Commission in Beijing is baffled as to why the U.S. ships are not being struck by their mines, so carefully laid a few weeks before. The calculus shifts . . .
Nearly all U.S. losses of surface ships suffered since the end of World War II have come from naval mines. In future conflicts, the Navy is likely to face adversaries at a disadvantage to its forces who see naval mines as a cheap and effective weapon. To ensure success, each ship in the U.S. fleet must be able to provide for its own defense when needed. Commercial technology exists today to provide a modicum of low-cost MCM capabilities to any ship. We have the means—only the cultural barriers remain.
1. Sydney Freedberg, “Sowing the Sea with Fire: The Threat of Sea Mines,” Breaking Defense, 30 March 2015.
2. Lyle Goldstein, “Old School Killers: Fear China’s Sea Mines,” The National Interest, 14 October 2015.
3. Wayne Hughes, Fleet Tactics and Coastal Combat (Annapolis, MD: Naval Institute Press, 2000), 206.
4. Goldstein, “Old School Killers: Fear China’s Sea Mines.”
6. “Littoral Combat Ships - Mine Countermeasures Mission Package,” U.S. Navy, 6 December 2016.
7. Megan Eckstein, “Navy’s Remote Minehunting System Officially Canceled, Sonar May Live On,” USNI News, 24 March 2016.
8. “General George S. Patton Jr. Quotations,” The Official Website of General George S. Patton Jr.
9. “Forward Looking Navigation Sonar,” FarSounder. “NOAS - Navigation and Obstacle Avoidance Sonar System,” Sonardyne.
10. “Bluefin SandShark,” Bluefin Robotics, 2015. “SeaScout,” Qinetic North America, 2016.
Lieutenant Commander Hilger is a requirements officer in the Undersea Warfare Division (N97), Office of the Chief of Naval Operations. Previously, he served as engineering officer in the USS Springfield (SSN-761), completing a one-month surge and a six-month deployment to the European theater of operations, including operations in support of Operations Active Endevour and Inherent Resolve. He graduated from the Naval Postgraduate School in December 2014, having completed a thesis in autonomous underwater vehicle navigation and graduate certificates in antisubmarine warfare and regional security studies.