Damn the Torpedoes: Smaller, Cost Efficient, Less-than-Lethal Systems
Part 2 of a Series on Naval Mining Operations
Bottom Line Up Front:
Propulsion disablers can offer nations a less-than-lethal mine solution and flexible, cost-effective response options supporting sea denial and control.
Advanced mining systems offer increased minefield performance, area coverage, and manageable mine delivery requirements at a lower cost.
Naval mining technology is advancing. Today, navies have a broad spectrum of choices in mining technology, especially compared to previous eras when minelaying warships dropped spherical contact mines off the stern. Contemporary visions for the future of mine warfare promise persistent, reliable, and surgically accurate systems like the propulsion disabler (PD). The PD is a hypothetical system in a small form factor with a less-than-lethal torpedo-like warhead payload. PDs could disable a vessel’s propulsion system without catastrophically damaging the hull, thereby creating a variety of unique strategic opportunities for navies in possession of this capability. In this article, I compare PDs to other contemporary mining technologies using a simulated Baltic Sea scenario first introduced in a previous article (Part 1: The Return of Naval Mining) to better understand how novel mining capabilities can be employed in the Gulf of Finland to control sea lanes and deny adversary maneuver.
Setting the Stage: Naval Mining in the Baltic Sea
In a 2024 article from Proceedings, Commander Laanemets of the Estonian Navy asserts that the Baltic’s “new setting” requires the Northern Atlantic Treaty Organization (NATO) to possess an organic mining capability to enable anti-access/area denial (A2/AD). History and geography support the benefits of mining in this region. The Baltic Sea’s relatively shallow depth and abundance of maritime chokepoints create an ideal environment for mining operations. Indeed, the Crimean War and both World Wars demonstrated the effectiveness of mining operations in the region. Today, Russian capabilities at Kaliningrad include more than 50 vessels, alongside stores of land-based anti-ship missiles and numerous combat aircraft. Yet all of these capabilities possess limited utility if they cannot break out of the Baltic Sea at the outset of conflict. This fact makes the value of mining operations in the Baltic Sea self-evident. Moreover, illegal shipping practices and submarine cable sabotage linked to Russia present emerging reasons for Western militaries to establish sea denial and control in the Gulf of Finland. While the need for a deterrent mining capability is clear, what specific mine systems NATO should invest in is less obvious.
Options With Modern Mining Technology
The scenarios below assess the Quickstrike (QS), Hammerhead (HH), and Propulsion Disabler (PD) mining systems in a Baltic Sea use case. As the only widely fielded system, the legacy QS bottom mine serves as a reference point to the others. The HH, as described by Strikepod, is a moored mine with an encapsulated MK54 lightweight torpedo, sophisticated sensors, a communications suite, and high-capacity energy modules, primarily designed to target submarines. While conceptually similar, PDs do not yet exist. For the purposes of the scenario below, the system is loosely envisioned as an encapsulated, less-than-lethal version of the US Navy’s Compact Rapid Attack Weapon (CRAW). The CRAW system is considered a “Common Very Light Weight Torpedo (CVLWT),” capable of serving in both anti-submarine missions and as an anti-torpedo countermeasure. In this hypothetical scenario, the same housing is reprogrammed and fitted with a smaller warhead to disable ship propulsion systems. The assumed system characteristics for each mining capabilitity are summarized in the table below.
For modeling purposes, the advanced HH and PD mine systems are assumed to possess a higher probability of detection and actuation against enemy ships over the legacy QS system. The PD is also depicted with a slightly higher likelihood of actuation due to its less-than-lethal nature. The underlying assumption here is that nations might be more willing to target vessels with lower track qualities using less-than-lethal munitions. Finally, the PD cost, hypothesized at approximately $200k per unit, assumes that each system will cost less than the highly capable but expensive HH, and more than the legacy QS mine.
Gulf of Finland Simulations
To model these capabilities in the Baltic Sea, the baseline simulation from Part 1: The Return of Naval Mining returns with new enhancements. The simulation’s visualizations have been improved to depict simulated minefields on a world map and display General Bathymetric Chart of the Ocean (GEBCO) data. The two maps below show the model’s geographic visualizations for the Gulf of Finland minefield.
The top plot gives planners an appreciation for the minefield’s surrounding coastlines and territorial boundaries, while the bottom simulation plot depicts the Baltic Sea’s bathymetry, simulated routes, and mines. Each minefield configuration is simulated 1000 times, and each simulation generates 100 sequential vessels to transit the Gulf of Finland. In the simulation, once a vessel is successfully engaged, no other mines are expended. The baseline model assumptions are also tailored for the systems and environment simulated.
List of Model Assumptions
Minefield is preemptively established.
Advanced mine systems deconflict with each other through undersea communication networks and target vessels individually.
Mine systems are effective at simulated depths.
Mine systems detect target vessels according to system detection probability.
Mine systems will attempt to actuate when a target vessel passes within system employment ranges.
Vessels become casualties when successfully engaged by a single mine system.
Performance and Cost of Simulated Minefields
Minefield performance is assessed according to expected casualties, initial threat on sea route, and casualty density distribution measures of effectiveness (MOEs). These MOEs are outlined in Part 1: The Return of Naval Mining. The descriptions of the simulated blocking scenario and associated performance are summarized below. As discussed in the previous article, a blocking minefield should “present a high initial threat on sea route, have a sizable left skew in its casualty density distribution, and have high expected casualties.”
Scenario Descriptions:
QS Scenario: a densely seeded minefield using legacy QS mines. This scenario requires the most systems at the highest cost.
HH Scenario: a minefield employing advanced HH systems at emplaced at a distance of 60% the system’s maximum effective range. This scenario has the least number of mines.
PD Scenario: an advanced minefield employing less-than-lethal PDs, emplaced at a distance of 60% at 66% of the system’s maximum range.
PD Reinforced Scenario: reinforces the PD scenario with nearly twice the mine systems and covers more area.
The simulation results support the thesis that advanced mining systems offer better-targeting performance, wider minefield coverage, and manageable delivery considerations at a lower cost. The QS configuration, serving as a baseline for cost and effectiveness, achieves fewer expected casualties and covers a significantly smaller area at the highest price point. Setting the minefield cost aside, delivering 1542 mines places a significant, perhaps infeasible, burden on delivery aircraft, subsurface, and surface vessels.
The next three advanced minefield configurations offer comparable performance with similar costs and area coverage. All minefields create 14 expected casualties and are substantially cheaper than the QS minefield. Notably, the PD and PD Reinforced configurations produce the same number of disabled vessel casualties. The simulated vessels incrementally degrade the minefield integrity until a shipping lane is cleared, allowing successive vessels to transit safely. In reality, the vessels’ willingness to transit the minefield would likely decrease with each subsequent casualty. Reseeding operations would be used to maintain the minefield, replenish expended mines and mitigate vessel penetrations. Additionally, the feasible delivery requirements for the HH and PD minefields are more appealing to planners and cover 100x the minefield area.
The minefield casualty density distribution is assessed as a measure of minefield capacity and effectiveness. The three advanced mine configurations, shown in red, green, and blue, reliably produce higher casualty numbers across simulations. These minefields experience 14+ casualties in the majority of simulation runs. Conversely, the QS mines, shown in purple, perform slightly worse and produce fewer casualties more often.
The Case for Smaller, Cheaper Mines, and Larger Mine Magazines
Smaller, cheaper, and more capable mines are needed to provide minefield effectiveness and response flexibility. PDs seemingly meet all the requirements for flexible mining capabilities and could minimize civilian minefield casualties. If developed and proliferated, PDs would conceivably be outfitted with AI targeting algorithms for enhanced target discrimination, high-capacity batteries for persistence and propulsion, extended employment range, and remote control capability. The possibilty of leveraging these sophisticated capabilities at a scalable cost in large minefield use cases is the main value proposition of the PD.
By comparison, the HH mine possesses a similar suite of high-tech capabilities, but while the existing HH mine’s form factor and capabilities provide evidence that the PD is technologically feasible, the HH does not support the same operational goals. For example, the HH is tailored for anti-submarine warfare rather than surface targets. Presumably, the system could be reprogrammed for anti-surface applications, but the ~$1.1M price tag makes it relatively unscalable and cost-inefficient for distributed use. Furthermore, the MK54 lightweight torpedo employed by each HH eliminates the flexible response options that a PD provides. The victim of a PD attack can be sunk by supporting land or air-based fires, seized, or assisted and repaired. As Captain Dismukes, USN (ret.) explains, “disabling an enemy’s naval ship rather than sinking it will almost always be the superior choice, certainly for the U.S. Navy” and, presumably, NATO members.
Successfully employed and supported Baltic PD minefields could provide flexible options for Western militaries to disrupt illegal shipping from St. Petersburg and Kaliningrad and constrain the Russian Baltic Fleet’s maneuver options in the event of a conflict, potentially at lower cost and risk than other like capabilities. Targeted vessels with propulsion systems rendered inoperable could present opportunities for follow-on seizure and exploitation or subsequent targeting by lethal means.
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.