U.S. Army tests autonomous SLICE mine-breaching system to keep soldiers out of danger.

U.S. Army tested the new autonomous SLICE (Slurry Line Charge Explosives) mine-breaching system during a live-fire event at Fort Drum, demonstrating a new unmanned capability to clear explosive obstacles while keeping soldiers out of direct danger zones.

The system, operated by the 10th Mountain Division, used a modified Ford F-250-based autonomous ground vehicle to deploy and detonate a slurry explosive line charge against a simulated minefield, reducing human exposure during breach operations. Conducted on April 14, 2026, as part of the Summit Strike 2026 exercise, the test integrated the SLICE system into a combined-arms scenario involving artillery, mortars, and maneuver units.

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Slurry explosives are mixtures typically based on ammonium nitrate combined with fuels, sensitizers, and various chemical agents, which exist in liquid or gel-like forms, allowing them to be pumped or shaped into flexible containers or hoses. (Picture source: US Army)

On April 14, 2026, the U.S. Army’s 10th Mountain Division conducted a live-fire training event at Fort Drum, New York, within the Summit Strike 2026 exercise, integrating a new autonomous breaching capability into a combined-arms scenario. The demonstration involved an autonomous ground vehicle (AGV) based on a modified 5th Gen Ford F-250 Super Duty equipped with a Slurry Line Charge Explosives (SLICE) system, used to approach and clear a simulated obstacle belt. Statements from unit leadership indicate that development of autonomous breaching has been underway for approximately two years, with the stated objective of removing soldiers from direct exposure at the breach point.

During this military experimentation, the SLICE system was evaluated in conditions involving coordinated fires, maneuver planning, and timed execution with long-range fires and mortars. The SLICE is also a new attempt by the US Army to integrate robotic systems into engineer tasks that traditionally require dismounted teams operating within tens of meters of explosive hazards. The Summit Strike 2026 exercise was structured as a combined, joint, and multi-domain training event focused on division-level coordination of combat functions. The scenario included synchronized use of indirect fires, maneuver elements, and engineering assets, requiring units to execute tasks under simulated combat timelines.

The 10th Mountain Division, identified as one of the most frequently deployed U.S. Army formations, used the exercise to integrate new systems, such as the Sling Blade Counter Unmanned Aircraft System, at the unit level rather than in isolated testing environments. Training activities included live-fire demolitions and obstacle reduction sequences designed to replicate current combat breaching conditions, such as those in Ukraine. For instance, the breaching demonstration was embedded within a sequence requiring both route clearance and lane creation to enable follow-on movement. The presence of artillery and mortar fire imposed further constraints on the timing and positioning of engineer assets.

For the US Army, this exercise allows the observation of how the SLICE autonomous system interacted with command decisions, fire coordination, and maneuver tempo. The Slurry Line Charge Explosives (SLICE) system consists of a slurry-based explosive line charge carried and deployed by an unmanned ground vehicle capable of remote navigation along a designated path. The autonomous vehicle used during the test was described as a remotely driven Ford F-250 pickup truck, indicating the use of a non-armored commercial chassis adapted for military purposes, similar to the Leonidas AGV. Therefore, the SLICE system is designed to move along a road or approach route, stop at a designated point, and initiate an explosive sequence to clear obstacles.

The explosive payload is not pre-rigid like the US Army's traditional line charges, but is based on a slurry mixture that can be distributed along a flexible medium. The F-250’s role includes both transport and positioning of the charge, eliminating the need for soldiers to manually emplace explosives. The current configuration suggests modularity, with the possibility of changing payload types depending on mission requirements. The use of a wheeled platform implies reliance on existing road networks or relatively stable terrain for deployment. This differs from tracked armored breaching vehicles such as the M1150 Assault Breacher Vehicle (ABV), optimized for cross-country movement under fire. 

Line charge systems function by detonating a continuous explosive line laid across a minefield or obstacle, generating a pressure wave sufficient to initiate or disrupt mines. In conventional systems such as the M58 Mine Clearing Line Charge (MICLIC), a rocket deploys approximately 100 meters of explosive line containing C-4 charges, which detonate in sequence within milliseconds. The resulting blast creates a cleared lane typically between 6 and 14 meters wide, depending on soil composition and charge configuration. Effective breaching requires continuous contact between the explosive and the ground surface to ensure consistent energy transfer, as each interruption in the line or poor ground coupling can result in uncleared sections.

The SLICE concept replaces the MICLIC's rigid explosive segments with a slurry-filled line, which can conform more closely to terrain irregularities, and this may improve contact in uneven or debris-filled environments. However, it also introduces an increased dependence on the correct placement and distribution of the slurry charge before detonation. Slurry explosives used in systems like SLICE are typically composed of ammonium nitrate as the primary oxidizer, combined with fuels such as hydrocarbons or metallic powders, and stabilized with water and gelling agents. Their density generally ranges from 1.1 to 1.5 grams per cubic centimeter, higher than ANFO (Ammonium Nitrate/Fuel Oil) but lower than solid high explosives.

Detonation velocity varies depending on formulation, commonly between 2,000 and 5,500 meters per second, significantly lower than C-4, which detonates at approximately 8,000 meters per second. Slurry explosives are also not inherently sensitive to standard detonators and require a booster charge to initiate detonation. Their main advantage lies in water resistance and the ability to be pumped or shaped into flexible configurations, which allows a better adaptation to different terrain profiles and obstacle geometries. However, the slurry explosive's performance is sensitive to mixture consistency, confinement, and initiation quality. Variability in these factors can affect reliability in operational conditions. 

Today, the ammonium nitrate fuel oil (ANFO) remains one of the most widely used blasting agents due to its low cost and ease of production, with detonation velocities typically between 2,300 and 4,600 meters per second. However, ANFO is highly sensitive to water and loses effectiveness in wet conditions, limiting its use in many military environments. Slurry explosives were developed to address these limitations by incorporating water into the mixture and using gelling agents to maintain stability. This allows consistent performance in saturated soils, riverbanks, and post-rain conditions where ANFO would fail. Slurry systems also provide higher density, increasing energy per unit volume.

In military applications, these properties are relevant for breaching operations where environmental conditions are unpredictable. The trade-off is increased complexity in handling and preparation compared to dry blasting agents. For now, the M58 MICLIC system remains the standard U.S. Army line charge capability, using a rocket to deploy a chain of C-4 demolition charges across a minefield. Each system carries a line approximately 350 feet (about 107 meters) long, containing hundreds of pounds of high explosive. The detonation produces a rapid pressure wave capable of initiating anti-tank and anti-personnel mines within the lane. By using a M147 firing kit, the system could be mounted on vehicles such as the M1150 Assault Breacher Vehicle and the M113, or be used on trailers towed by armored vehicles.

Deployment time from launch to detonation is typically under one minute, allowing rapid breaching under fire. Compared to the SLICE, the use of pre-packaged explosives ensures consistent energy output and predictable performance. However, the MICLIC system requires the launch vehicle to approach within several hundred meters of the obstacle, and its fixed geometry limits adaptability to terrain features such as bends, elevation changes, or confined urban spaces. The primary difference between SLICE and MICLIC lies in deployment speed and placement control. MICLIC provides rapid lane creation, with the entire charge deployed and detonated within seconds, making it suitable for assault breaching under direct fire.

The SLICE requires the unmanned vehicle to traverse the approach route and position the charge, which increases exposure time but allows more precise placement. The slurry-based charge can follow terrain contours, potentially improving effectiveness in non-linear or obstructed environments. However, the lower detonation velocity of slurry explosives reduces peak overpressure compared to C-4, which may affect reliability against certain mine types. SLICE introduces additional dependencies, including vehicle mobility, communication links, and proper charge preparation. MICLIC, by contrast, relies on a simpler sequence of launch and detonation with fewer intermediate steps. The two systems, therefore, might address different operational conditions rather than serving as direct replacements.

In a representative employment scenario, the unmanned SLICE vehicle would move ahead of the main force along a designated route, carrying the explosive payload toward a suspected minefield. Upon reaching the obstacle, the system would deploy or position the slurry line across the target area and initiate detonation remotely. This sequence removes the need for engineers to physically enter the minefield during initial breach creation. The cleared lane would then be verified and expanded by follow-on forces if necessary. The system could potentially be reused if it remains functional after detonation.

Timing would need to be coordinated with suppressive fires and maneuver elements to reduce vulnerability during emplacement, which may reflect a future shift toward more staged, risk-managed breaching operations for the US Army. For now, the SLICE system introduces several operational constraints that affect its applicability in high-intensity combat. The unmanned vehicle must physically approach the obstacle, increasing exposure time compared to rocket-based systems. The Ford F-250 Super Duty, being a lightly protected or unarmored pickup, is vulnerable to small arms fire, artillery fragments, and loitering munitions.

The reliance on remote control or autonomous navigation introduces potential failure points in contested electromagnetic environments. Slurry explosives require proper mixing, containment, and initiation, adding complexity relative to the MICLIC's pre-packaged charges. Lower detonation velocity may also reduce effectiveness against deeply buried or hardened mines. The system also depends on terrain accessibility, as wheeled vehicles are limited in mobility compared to tracked breaching platforms. These factors constrain its use to scenarios where time and control are available.

Traditional breaching operations require combat engineers to approach within close proximity of minefields to emplace charges or operate breaching equipment. This exposes them to mines, direct fire, and indirect fire during the most vulnerable phase of the operation. The SLICE system shifts this initial exposure from personnel to an unmanned platform, reducing immediate casualty risk. Engineers remain responsible for planning, control, and follow-on verification, but are not required to physically enter the hazard area at the outset. This redistribution of risk aligns with broader efforts in all military forces across the globe to reduce personnel exposure in high-threat environments.

However, the SLICE does not eliminate risk entirely, as follow-on clearance and lane expansion may still require human involvement. Therefore, the effectiveness of this approach depends on the reliability of the unmanned system. Development of the SLICE concept has been underway for approximately two years before the April 2026 demonstration, indicating a relatively early stage in capability maturation. Testing within a division-level exercise suggests an intent to evaluate integration with operational units rather than limiting trials to specialized testing centers. Future development, based on the exercise feedback, is likely to focus on improving deployment speed, vehicle survivability, and reliability of the explosive system.

Integration with other unmanned systems, such as aerial reconnaissance platforms, could enhance targeting and route planning. Like many programs, the SLICE's adoption will depend on demonstrated effectiveness relative to existing breaching systems and the ability to operate under contested conditions. Being part of a broader trend toward incorporating autonomous systems into military roles, the SLICE's progression will likely determine whether it becomes a niche capability or part of the US Army's standard breaching doctrine.

Written by Jérôme Brahy

Jérôme Brahy is a defense analyst and documentalist at Army Recognition. He specializes in naval modernization, aviation, drones, armored vehicles, and artillery, with a focus on strategic developments in the United States, China, Ukraine, Russia, Türkiye, and Belgium. His analyses go beyond the facts, providing context, identifying key actors, and explaining why defense news matters on a global scale.