Ukraine 120mm Mortar Systems 2026: Infantry Fire Support in Trench Warfare

1. The Mortar's Role in This War

In modern high-intensity warfare, the mortar occupies a unique tactical niche: it provides high-angle indirect fire that can engage targets in defilades — trenches, reverse slopes, and buildings — that flat-trajectory artillery cannot reach. A 120mm mortar's plunging trajectory means rounds fall near-vertically into a trench system, whereas 152mm artillery rounds arrive at a lower angle and are more likely to be deflected by parapet walls or cause near-miss craters rather than direct trench hits.

The Ukraine-Russia conflict has featured some of the most intensive mortar use in any conflict since World War II. Opposing forces occupying static trench lines separated by 200–2,000m use mortars almost constantly for harassing fire, immediate fire support for assault teams, and counter-battery engagement of enemy mortar positions. Mortar attrition rates — both of the systems themselves and their crews — are significant. Mortar tubes are destroyed in counter-battery fire; crews are killed at higher rates than most infantry positions due to their exposed firing positions and tell-tale visual/thermal signatures during sustained fire.

2. 2B11 Sani: Ukraine's Primary 120mm Mortar

The Soviet-designed 2B11 "Sani" (Sled) is the primary 120mm mortar of both Ukraine and Russia — a smoothbore muzzle-loading mortar produced in enormous quantities during the Soviet era. It remains the workhorse of both sides' infantry fire support:

• Weight: 210 kg (complete with base plate, bipod, barrel)
• Range: 7,200m maximum; minimum 480m
• Rate of fire: 15 rounds/min burst; 5–8 rounds/min sustained
• Crew: 5 (though often operated with 3–4 in combat)
• Ammunition compatibility: All Soviet/Russian 120mm mortar rounds including OF-843 HE, OF-843Zh illumination, D-843Dsh smoke

Ukraine inherited large quantities of 2B11 systems from Soviet stockpiles and has continued operating and producing (or refurbishing) them throughout the war. The 2B11 also forms the towed mortar component of the 2S12 Sani system (the same mortar on a transport vehicle). Losses have been significant — mortar positions are high-priority counter-battery targets, and the 2B11's long preparation time and static firing position make it tactically vulnerable to radar-directed counter-battery fire.

3. Western 120mm Mortar Donations

Multiple Western nations have contributed 120mm mortars from their own inventories. Unlike artillery caliber, 120mm mortar ammunition is broadly standardized — most Western militaries use 120mm smoothbore mortars with NATO-standard ammunition, which is compatible with Soviet-pattern 120mm smoothbore mortars (a fortunate interoperability coincidence). Western systems donated include:

• US M120 mortar systems: The US M120 is a direct copy of the French Brandt MO-120-RT-61, itself a NATO-standard 120mm smoothbore. US donations include M120 systems from Army and Marine Corps inventories.
• UK L16 81mm + heavier: UK donated primarily 81mm mortars initially, later transitioning to 120mm commitments
• German Tampella/Rheinmetall 120mm systems: Germany provided mortars from Bundeswehr and reserve stocks
• Finnish and Swedish 120mm: Nordic nations contributing from their own 120mm-equipped infantry

The key interoperability advantage: NATO 120mm HE rounds (M934, M934A1, M929 smoke, etc.) are generally compatible with the same smoothbore 120mm barrels that fire Soviet OF-843 rounds. Ukraine can use either NATO or Soviet 120mm ammunition stocks in most of its mortar fleet, providing supply flexibility that does not exist for artillery (where NATO 155mm and Soviet 152mm are entirely incompatible).

4. Polish M120 Rak Self-Propelled Mortar

Poland has supplied Ukraine with M120K Rak self-propelled 120mm mortar systems, representing a capability upgrade over towed 2B11 systems. The Rak (Cancer) system delivers:

• Armored IFV hull (Rosomak 8×8 chassis — the same platform as Rosomak IFV) providing crew protection
• 120mm smoothbore mortar in a rotating turret — fully enclosed protection
• Automatic loading system: rate of fire up to 8 rounds/min with automatic loading assistance
• Fire control: digital fire control system with GPS positioning, automatic computation
• Shoot-and-scoot: the Rak can fire a salvo and immediately move within seconds, dramatically reducing vulnerability to counter-battery fire
• Crew: 3, fully protected during firing

Poland delivered Rak systems to Ukraine in 2023–2025, with numbers assessed at 24–48 systems. The Rak represents a generational leap over towed heavy mortars — crew survivability improves dramatically with armored protection and rapid displacement capability. Polish delivery of Rak alongside Rosomak IFV creates a logistically coherent combined arms package using the same 8×8 platform for multiple roles.

5. Vehicle-Mounted Improvised Mortar Platforms

Ukrainian ingenuity has produced numerous improvised vehicle-mounted mortar solutions beyond formal programs like the Rak. A common improvised configuration involves mounting a 2B11 or similar 120mm mortar on the bed of a pickup truck, HMMWV, or light utility vehicle. These improvised mortar carriers provide:

• Mobility — rapid displacement after firing (critical for surviving counter-mortar fire)
• Ammunition carriage — vehicle carries additional rounds unavailable to foot-mobile mortar crews
• Tactical flexibility — can follow assault forces or rapidly reposition

Limitations of improvised mounts: the mortar base plate typically must still be grounded (not fixed to vehicle) for accurate fire, partially negating the mobility benefit for precision; recoil is transmitted to vehicle rather than ground, creating structural stress on lighter vehicles after sustained fire; no crew protection against counter-battery fire or drones.

Ukraine has also produced more formally engineered vehicle-mounted solutions through defense enterprises, including bolt-down mount kits for specific vehicle platforms with more robust recoil management systems.

6. 120mm Ammunition Types and Availability

Standard 120mm mortar ammunition types in Ukrainian service:

• Soviet OF-843B HE-Frag: Primary standard high explosive round; 120mm caliber with 3 kg TNT equivalent charge; standard issue across all units
• NATO M934 HE: US standard 120mm HE compatible with smoothbore systems; supplied via Western assistance packages
• Illumination rounds: Both Soviet S-843 and NATO M930 mates depending on inventory; essential for night operations
• Smoke rounds: D-843Dsh (Soviet) and M929 (NATO format) for obscuration and signaling
• Precision-guided (discussed separately): Kvitnik (Soviet), M395 (US), STRIX (Swedish) guided variants

120mm mortar ammunition has been in higher supply than comparable 122mm or 152mm artillery rounds throughout the conflict, reflecting both: (1) the compatibility between NATO and Soviet rounds enabling dual-source supply, and (2) a broader base of production among both NATO and former Soviet-bloc nations.

7. Domestic Ukrainian 120mm Round Production

Ukraine has established domestic production of 120mm mortar rounds through state defense enterprises and private sector producers entering the defense market under the wartime industrial mobilization framework:

• Artem State Enterprise produces fuze components and final assembly of mortar rounds
• Several private Ukrainian defense firms established 120mm production with government contracts from 2023
• Production rate: estimated thousands of complete 120mm rounds per month by 2025, scaling toward tens of thousands per month as facilities expand
• Advantage of 120mm over 152mm production: mortar rounds have simpler propellant requirements (incrementing propellant charges vs. fixed cartridge) and smaller diameter making case production less demanding

Domestic production providing meaningful supply to frontline brigades, supplementing Czech, Slovak, and Western donations. The 120mm mortar round is one area where Ukraine's domestic production is making a meaningful contribution to consumption requirements, unlike the more demanding 152mm and 155mm categories where imports remain dominant.

8. Precision-Guided 120mm Rounds

Precision-guided mortar rounds extend the mortar's utility considerably for specific engagement tasks requiring accuracy unachievable with unguided rounds:

• Kvitnik (Soviet): Laser-designated semi-active guided 120mm mortar round; a forward observer or another platform must "paint" the target with a laser designator throughout the flight. Effective against point targets like armored vehicles or bunker entrances.
• M395 (US PPGM): Precision Pulse GPS-guided mortar round; GPS guidance with INS, CEP approximately 3m; compatible with standard 120mm mortars and does not require a laser designator — fire-and-forget with grid coordinate input. US has transferred M395 rounds to Ukraine.
• STRIX (Sweden): Infrared homing autonomous 120mm mortar round developed by Sweden; homes autonomously on warm targets (vehicles, personnel); supplied to Ukraine and used with reported effectiveness against vehicle concentrations.

Precision mortar rounds are expensive (M395 costs approximately $10,000–15,000 per round versus $50–100 per unguided round) and are therefore used selectively for high-value targets where unguided fire would require disproportionate expenditure for uncertain effect.

9. Counter-Mortar Warfare: Radar Systems

Both Ukraine and Russia conduct intensive counter-mortar operations — detecting enemy mortar fire, computing back-bearing to the firing position, and engaging before the mortar can displace. Ukraine operates several radar systems capable of counter-mortar/counter-battery missions:

• AN/TPQ-36 (US): Primary counter-mortar radar; detects incoming mortar rounds in flight and computes the firing position; range ~24 km; supports counter-battery fire; multiple systems donated by US
• AN/TPQ-37 (US): Longer-range system for counter-battery role against artillery; complementary to the -36 for mortar missions
• Zoopark-1M (Soviet): Ukraine inherited Soviet counter-battery radars and continues operating them where serviceable
• COBRA/ARTHUR (Germany/Sweden): NATO counter-battery radars contributed by European allies; ARTHUR from Sweden is highly regarded for accuracy

The counter-mortar radar network creates the "shoot and scoot" imperative that defines modern mortar tactics: a mortar crew detectable by radar that does not displace within 90–120 seconds of final round fire will be struck by counter-battery fire before the crew can take cover. This tactical reality has fundamentally changed mortar employment doctrine — each mortar mission is now typically limited to 2–5 rounds before mandatory displacement.

10. Tactical Employment: Mortar Teams in 2026

Current Ukrainian mortar team employment doctrine, evolved through four years of intensive war:

• Extreme dispersion: Mortar positions are located 300–1,000m behind the front line, not co-located with infantry platoons, to prevent a single drone strike from destroying both mortar support and the maneuver element it supports
• Active counter-drone measures: Mortar crews now travel with portable EW jammers and camouflage nets designed to reduce thermal signature during the high-heat post-firing period when the barrel glows in IR
• Radio silence protocols: Digital fire mission coordination is preferred over voice radio to reduce electronic signature; use of encrypted apps (Signal, Wire, protected military equivalents) for fire mission coordination
• Drone forward observation: Forward observer role is increasingly performed by FPV or reconnaissance drone rather than exposed solo observer; the drone watches the mortar impact, corrects via digital link to the mortar crew
• Night operations: Mortar operations heavy at night to leverage illumination rounds for friendly operation while limiting own exposure to Russian reconnaissance UAVs

11. Mortar vs. Artillery Role Comparison

FAQ: Ukraine Mortar Systems