UC-42 Léon

UC-42 Léon
An Exersito Iverica UC-42 in 2017
Type	Main battle tank
Place of origin	Iverica
Service history
In service	2008-present
Used by	Gallambria Girkmand Greater Galicia Iverica Verde
Production history
Designer	Arx Arms Manufacturing
Designed	1999-2007
Manufacturer	Arx Arms Manufacturing
Unit cost	A1: $9.5 million (FY2022) A2: $11.5 million (FY2022) A3: $12.6 million (FY2022) E1: $7.5 million (FY2022) U1: $12 million (FY2022)
Produced	2008-present
No. built	2,286
Variants	UC-42-A1 UC-42-A2 UC-42-A3 UC-42-E1 UC-42-U1
Specifications
Weight	42-45 tonnes (Level I: baseline armour) 48 tonnes (Level II: composite applique) 51 tonnes (Level III: composite & ERA)
Length	9.48 m (31.1 ft) (gun forward) 8.25 m (27.1 ft) (hull only)
Width	3.4 m (11 ft) 3.7 m (12 ft) (Level-III applique)
Height	2.30 m (7.5 ft) (max) 2 m (6.6 ft) (min)
Crew	3 (commander, gunner, driver)
Armor	Level-I: Toledo Composite Pattern 3 (nano-metric steel with composites) Level-II: applique ceramic composite armour Additional applique explosive reactive armour
Main armament	A1, E1: 120 mm L/44 ARX 120-4 GCM smoothbore gun A2, A3, U1: 128 mm L/42 ARX 128-2 GCM smoothbore gun
Secondary armament	1 × 8.6 mm machine gun (coaxial) 1 × 12.7 mm machine gun (RWS)
Engine	A1, E1: THI 4D8CV 4-stroke 22.6-litre diesel V8 engine A2, U1: THI Gen-2 4D8CV-CD 4-stroke 22.6-litre diesel V8 engine A3: THI 2M6CO-CD 2-stroke, 22-litre multifuel, 6-cylinder opposed piston engine 1,200 hp (890 kW)/2300 rpm (4D8CV) 1,500 hp (1,100 kW)/2,600 rpm (2M6CO)
Power/weight	Baseline: 28.57-33.33 hp/tonne Level-II: 25-29.41 hp/tonne
Transmission	Continuously variable transmission
Suspension	hydropneumatic suspension
Operational range	A1 (Level-II): 500 km (310 mi) A2 (Level-II): 665 km (413 mi) A3 (Level-II): ~700 km (430 mi)
Speed	Road: 70 km/h (43 mph) Off road: 70 km/h (43 mph)
Steering system	Drive by wire

The UC-42 Léon is a fourth-generation main battle tank produced by Arx Arms Manufacturing. A result of the Universal Combat Vehicle (UCV) Programme, the tank entered service in 2008 with the Iverican Republican Armed Service. The UC-42 is notable for its ability to engage vehicles at stand-off ranges and its ability to support Network-centric warfare. The UC-42 also features advanced sensors such as radar and infrared systems that contribute to its survivability.

At a base mass of 42-tonnes, the UC-42 is lighter compared to most 3rd and 4th Generation MBTs. While this makes the tank efficient to field, it also enables high tactical mobility and contributes to its survivability in battle. Equipped with a 128 mm main gun, the UC-42-A2 is heavily armed compared to its peers in other armed forces. Compatible with different levels of armour protection, the vehicle can be outfitted for a variety of scenarios, allowing armoured units to prioritise armour protection if needed.

The UC-42 serves as a main battle tank in several national armies. Nations that have adopted the UC-42 as a main battle tank include: Verde, Gallambria, Girkmand, Galicia, and Iverica. In Iverican service, it saw extensive combat service during Operation Ultraviolet in Afropa and Operation Wolfhound in the Estaria. During both operations, the UC-42 was deployed in urban and open environments. During Operation Wolfhound, the UC-42s of the 3rd and 33rd Regiments of Tercios claimed a kill tally of up to 80 T-62s and 48 T-72s.

History

In 1996, the Iverican Office of Military Technology was tasked to conduct a study on the effectiveness of the Arx G-58 in-service as the primary main battle tank of the Iverican Army and the Republican Marine Regiments. The study found that poor fuel economy coupled with the system's high tonnage made its deployment in hilly, mountainous and coastal areas of Iverica difficult. Furthermore, the Iverican Navy had previously noted the transportation challenges the vehicle's dimensions and mass posed to amphibious operations in foreign training theatres.

By 1998, the Ministry of Defence requested tenders from Iverican military land system designers. Among the participating companies was Arx Arms Manufacturing, which had been developing the Universal Combat Vehicle programme modules and chassis designs since 1991. Design requirements were particularly strict on a 45-tonne baseline weight, a gun armament able to fire a kinetic penetrator capable of penetrating 800 mm of RHA in effective thickness while also being able to fire gun-launched ATGMs, a top speed of at least 65 kph, and internal accommodations for the newly developed Nousphera C4I system.

After a deliberation process wherein the Office of Military Technology and Ministry of Defence reviewed tenders submitted by contender entries from Cavallero Heavy Auto and Granada DynamiCo, Arx Arms and Cavallero were selected as finalists. After a lengthy post-bid review process, prototype development was allowed to begin in January of 1999.

For its tendered entry, Arx Arms' Universal Combat Vehicle Design Works collected first-hand accounts from crewmen who had seen combat during the 2nd Vasqqan Civil War. Particular attention was given to pitching ideas to maximise crew awareness, comfort, and survivability above any cost consideration. Later commentary given by members of the design team, suggested that their greatest point of confidence was the existing Universal Combat Vehicle hull's ability to make up for any shortcomings in those criteria with its excellent modularity and flexibility. Unlike other teams, the UCV design works had already tested 3 mobility testbeds and experimented with various module fittings before the tenders had been requested.

Many members of the Arx UCV Design Works were themselves former combat veteran crewmen and tenured technicians whom Arx Arms' Research & Development division had handpicked based on service history. Much of the design team's ideas drew from crew experiences with the G-58 for survivability, from the G-30 strike-reconaissance vehicle for awareness and detection, and from advancements in aerospace stealth technology. The design team based their ideas of survivability and protection on the "Survivability Onion" theory and model presented by Francoisbourger Brigadier General Jean Pierre Couteau. The theory, which emphasised that the first layers of protection were detection avoidance and difficulty to engage encouraged the team to index very high agility as a priority alongside forward-thinking firepower considerations.

Parallels between the G-58E's effectiveness as a fighting command vehicle during the Battle of River Valley during the Second Vasqqan Civil War was noted as the theoretical foundation for the team's design philosophy. In his book, Spall and Sabot, Tomas Vergara-Satorr, an early founder of the UCV programme and former Arx engineer speculated that the UX-42's intended capabilities as a low-profile sensor carrier and missile-launcher mixed with a main battle tank was likely a result of prior Arx pitches to the Office of Military Technology which had failed given the Ministry of Defence's aversion to the Missile-Carrier concept. Vergara theorises that the concept behind the UX-42 was informed by Arx's insider exposure to individuals within the Iverican Ministry of Defence, which at the time, had been in the midst of rethinking their combined arms doctrine to adapt to network technology and advanced materials. Arx's ensuing tender of a vehicle equipped to surpass the G-58E's pioneering capabilities was cited as a support to Vergara's assertion.

Both Arx and Cavallero had just over 14 months to produce a technology demonstrator. Whereas Arx Arms had already created and tested interoperable modules, Cavallero started from scratch. In March of 2001, both contenders presented their prototypes at the Corregidor Proving Grounds, picked deliberately for its exceptionally hilly and rocky topography. Cavallero's prototype, the MBT-X was pit against the Arx prototype, UX-42 in a series of inspections and performance tests. Both prototypes made use of 120 mm L/44 main guns but Cavallero's prototype made use of a heavier pattern of composite armour and used a 2-stroke 10-cylinder which showed reliability issues even during testing. The Cavallero MBT-X also went over the weight limitation, disqualifying it from the programme.

In contrast, the UX-42 performed comparatively better, its lighter weight and greater acceleration allowed it to traverse the mobility course in good time. During the trials, the UX-42 topped 70km/h on straight lanes and was measured to be well within the weight limit at 42 tonnes. In April 2002, Arx Arms was awarded the contract.

Initial Production

An early UX-42 technology demonstrator

Production started in 2008 with a gap period spent accommodating changes requested by the Office of Military Technology. A total of 90 UC-42 tanks were ordered for low-volume production during 2008-2010. The production series of vehicles first entered Iverican service in December of 2008 as the G-42 Léon. Production at the government-owned, Paseo Tank Plant in Nou Stille, was joined by vehicles built at the Llanuras Arsenal in Léon. Though the UC-42 featured a multifunction radar for surveillance and gun-laying assistance, this was dropped from most units. Units that were produced with the radar were designated command vehicles. Most UC-42 units were produced "fitted for but not with" the J-band radar.

The Office of Military Technology and its Land Warfare Design Bureau were heavily involved in designing ammunition for the 120 mm L/44. Telescoped Depleted Uranium Sabot and telescoped Tungsten penetrator ammunition entered service alongside the UC-42. Arx Arm's proprietary Multi-Purpose Charge (MPC) ammunition, a hybrid anti-tank and anti-personnel HEAT round was acquired by the Ministry of Defence Procurement Office and produced at the Toledo Ordnance facility in Toledo, Nou Stille. The MPC was later redesigned into the MP-T, a telescoped discarding sabot improvement with a programmable fuse and proximity switch.

After receiving letters of interest, the Ministry of Defence permitted Arx Arms to produce and sell an export variant, designated E1, to Iberic nations. In 2009, a contract was signed with the Greater Galician Armed Forces for 80 units of UC-42-E1. E1 units excluded the multifunction radar, autoloader, and C4I suite but were substantially more affordable at $11.8 million per unit in 2009. The price gap was large in comparison to the A1 units which cost $16.8 million per unit in the same year. In 2014, improving relations with Galicia and other Iberic states like the Duchy of Verde saw permits for the sale of A1 variants. In 2015, the Verdense Ducal Armed Forces procured 40 units of UC-42-A1. In 2016, the Galician Armed Forces purchased 32 A1 units.

Commentary by the Arx Arms Universal Combat Vehicle design teams suggest that the UC-42's design and initial construction was a feat that would have been out of the scope of possibility a decade prior. The volume and quality of rare-earths and petrochemical materials used to create UC-42 components had only become available from the United States of Prymont and the Confederate Union of Narva in the early 2000's. Advancement in precision tooling, materials engineering, and quality control methods had only advanced to requisite states at the turn of the millenium. The UC-42's manufacturing process utilised technologies like computer modeling, mass spectrometry, electroforming, laser micro machining, and laser cutting. The availability of these precision manufacturing technologies had only become feasible for large-scale practice and mass-production in the late 1990's.

Updates & Further Production

A pair of UC-42s demonstrating new 128 mm L/42 guns

In 2014, the Ministry of Defence tasked the Office of Military Technology to do a peer comparison of contemporary main battle tank designs. The results of the study showed that advances in signals intelligence, composite armour, and the widespread adoption of the 120 mm calibre were proliferating across the wurld battlespace. In response, Arx Arms was contracted to design an A2 variant with a more capable main armament, an updated applique armour package, and a greater emphasis on passive and active protection against observation and guided munitions. Arx Arms accepted the contract and released prototypes in 2016. Among the prototypes were ceramic-composite armour segments, a polymer outer coating, a 128 mm main gun 42 calibres in length, improvements to the powerpack and exhaust systems, and an array of infrared transceivers for warning and surveillance. The modules were successfully mounted and operated on a stripped-down A1 serving as a testbed. Approval to produce the A2 was given in March of 2017 after more practical tests were run on the testbed.

The A1 and A2 shared completely identical chassis, turret, transmission, suspension, track, and roadwheel designs. Thus, Paseo Tank Plant and Llanuras Arsenal needed only minimal retooling, reorganisation, or staff retraining. Both facilities did require new assembly and storage facilities for the new A2 modules to be added to the assembly process. Arx Arms produced the modules in-house in their Toledo City manufacturing facility. Though to accommodate the estimated volume of orders, Arx partnered with Fortis Defence Electronics' operating subsidiary, Fortis Technologies Manufacturing, to produce electronic modules like Sense-6 Semi-Active Infrared Warning Sensor under license. Arx likewise subcontracted the original manufacturer of the J-band VPS-5C multifunction radar to its original designer, Suisa Signals Systems. The Level-II Composite applique armour for the A2 was constructed using Toledo Metals materials, which Arx agreed to partner with for supply.

The UC-42-A2 variant entered production in 2018 with the first 270 Iverican units being produced from January to April 2018. Unfortunately, unforeseen delays in the final assembly process lengthened the target production volume of 2.5 tanks per day in both Paseo and Llanuras facilities. The increasingly diversified supply chain among several subcontractors and supply partners also contributed to production delays. Technicians also noted that the A2 variant was significantly more complex to assemble given that it had to be properly fitted for several sensitive computer and signals systems. By June of 2018, supply chain issues were largely solved and more staff had been trained and hired to assist with logistics and simple assembly. Fortunately for Arx Arms, this coincided with a 376 unit order from the Gallambrian Ministry of Defence, an order which brought the cost of materials down considerably. A 240-unit procurement order was made by the Iverican Navy for the Republican Marine Regiments and was signed in 2019. One of the units in this order marked the 1000th UC-42 completed. Successive smaller procurement orders to fill armoured battalions were made. The Exersito and the Tercios each procured a 60-vehicle regiment of the U1 urban assault variant.

Revealed in October 2021 at the 2021 Altaria Arms Expo, the A3 entered trials in early 2022 and pre-production by July 2022. Though the A2 had started production only 3 years prior to the A3's reveal, Arx announced that it had completed testing modules originally intended for the A2 and would be producing the intended modules as an "A3" conversion package. Planned for production in late 2022, the A3 modules included a new powerplant rated to output 1,500 horsepower, an multifunction Active electronically scanned array radar replacing the A2's 2 radar units, and a new composite armour pattern partially constructed with titanium. Arx also revealed that new ammunition for the 128 mm main gun would be utilising new propellant and disintegrating case coatings to improve thermal efficiency.

In February 2022, the Exersito procurement office announced that it had signed a contract for a large quantity of A2 vehicles in response to growing tensions between Great Anglia and the Federated Commonwealth of New Iberium. The exact number was not disclosed, though Arx Arms announced that Paseo Tank Plant and Llanuras Arsenal would be hiring additional staff and maximising their production volume. Arx Arms also announced that it would be temporarily converting its Lima Plant in Oehéa for A3 production. The Lima Plant is normally used for the production of test beds and demonstrators. On the 28th March of 2022, Arx announced that its combined production was exceeding 44 UC-42s per month with estimates of reaching 50 vehicles finished per month by May of the same year.

According to an Arx press release in January 2023, first production A3 modules have been accepted by the Republican Armed Service with approx. 50 A2 units converted to A3s. A total of 62 A3s have also been produced as new vehicles and not conversions.

Service

The UC-42 first saw combat service in the 2018 Operation Ultraviolet in Afropa. During the operation, the UC-42-A1s and U1s deployed by the Armada Tercios engaged Afropa Liberation Army insurgent forces on several occasions. Most notably in the city of M'pala, where the Tercio expeditionary unit took part in a joint operation to clear several high-value targets and caches surrounded and trapped within the city. During the operation a U1 vehicle was struck up to 18 times by RPG-7 warheads but remained combat effective throughout this encounter. No UC-42 was mission-killed or completely-killed during Operation Ultraviolet.

During the events of Bloody November, 2018, elements of the 2nd Brigade of Cuirassiers of the 2nd Division of Horse Grenadiers were deployed as a peacekeeping force in Vilvau, Vasqqa. Elements of the 2nd Brigade's 1st Regiment assisted in dispersing rioters and used their company of UC-42-U1s in nonlethal shows of force.

As part of Operation Wolfhound in March of 2021, the 33rd Tercio Regiment's UC-42 companies were deployed in a joint combined arms campaign to liberate the capital of the Republic of Estaria, then occupied by a Sentist force. During the campaign, 6 UC-42s suffered mission-kills. 4 of the kills were due to multiple saturation strikes using a mix of IFV-launched ATGMs and RPGs fired from buildings. Most of the kills took place during an urban assault operation on Estaria City. In most instances, the crewmen were able to survive or bail-out and escape successfully.

Design

Multiview drawing of prototype UX-42 "Bravo"

The UC-42 is a 42-tonne main battle tank built to be compatible with many Universal Combat Vehicle modules. The chassis allows for the reduction of weight or instalments of modular kits for greater armour protection, electronic warfare, and C4I roles. It is designed especially to handle mountainous, hilly, or uneven topography with its hydraulic-pneumatic suspension and its high power-to-weight ratio. Design objectives included emphases on strategic mobility, modularity, and ease of in-theatre maintenance. The UC-42's modular design, relatively low mass, and small baseline form factor allow for more efficient logistical handling in air-mobile and amphibious scenarios.

The main armament is a 12.8 cm ARX smoothbore gun capable of firing MP-T, APFSDS, HEAT, and ATGM ammunition. The coaxial machine gun is a 8.6 mm (.338) GPMG fed with an 800 round belt. The Léon may also carry additional 12.7 mm heavy machine gun on a remote weapon station. The tank is protected by lightweight composite armour using a mix of nano-metric steel, elastomers, and high-hardness steel. Additional protection includes a 2 additional levels of applique protection including ballistic-ceramic composite and explosive-reactive armour.

Safety measures include CBRN protection, an FM-200 fire-suppression system, and bulkhead separation and blow-off panels for ammunition storage. For protection against enemy fire, the UC-42 uses a hard-kill active protection system. UC-42 vehicles can also mount a counter-IED CREW jammer, the RI/VLQ-12.

Sensors include J-Band multifunction radar, an AESA pulse-doppler fire-control radar for an Active Protection System and infrared warning and proximity sensors.

Protection

Armour

diagram showing Pattern 3T, the base armour layer on A3 variants' frontal arcs and turrets

The UC-42's baseline armour is constructed from nano-metric steel panels laminated with 2 elastomer layers and a high-hardness steel strike-face with ductile properties. The outer strike-face and the central nano-metric plate are intended to shatter a striking penetrator. As the armour absorbs force, the elastomer layers distribute forces across the area of the plate. When the elastomer layers expand after initial compression, the material expansion contributes to weakening or shattering projectiles. A final layer of softer steel backs the armour plate. Separating the crew from this is a fibre-resin spall liner with a final kevlar layer. The composite armour is designated as "Toledo Composite Pattern 3" and is used in other Universal Combat land vehicles. Due to its physical properties, it has been nicknamed "Ferro-Fibrous" or "Star League" armour by vehicle crews and military enthusiasts, a reference to armour in the popular WarTech science-fiction franchise.

Applique armour is available in 2 forms: composite and explosive-reactive. The UC-42's Level-II armour consists of 6 tonnes of composite steel outer layers encasing spaced and angled nano-ceramic ballistic plates. Square-hollow steel reinforcement helps protect against deformation, displacement, or warping. The nano-crystalline ceramic materials are stated to increase the hardness compared to current ceramics by 70% and reduce weight by 30% compared to previously used plates. The Level-II segments added to the turret are also shaped to reduce the UC-42's radar cross-section. Applique armour around the turret includes an array of explosive-reactive cells between the outer strike-face and the inner panels. An upward-facing blowout panel is located just above the ERA array. The ERA array presents additional obstacles to kenetic penetrators by using metal deflector or flyer plates to destabilise impacting projectiles. Storage compartments are typically mounted on the applique, consisting of a Carbon fiber reinforced plastic shell backed by an aluminium frame. These storage compartments are shaped to reduce the vehicles radar cross-section and are coated in a polymer and paint coating that reduces observability by thermal and infrared sensors.

Level-III consists of Level-II armour with added explosive-reactive armour tiles to the sides of the hull and the lower front glacis plate. These ERA tiles are also furnished with flyer plates. Level-III's ERA additions can be limited to only 1 layer of ERA, adding only 1.5 tonnes of weight. A second layer is added to further increase survivability against heavy tandem shaped-charge munitions. At its full configuration, a combat-loaded UC-42 with Level-III would have a mass of 51 tonnes.

On A3 variants, Toledo Composite Pattern 3T panels mounted on the turret and frontal arc use titanium alloys instead of steel for the final inner layer of plating. The alloy used in the new panels is stronger and lighter. Tests with kinetic penetrators and shaped-charge munitions revlealed a greater resistance to deformation and buckling while being 30% lighter than the previous Pattern 3's inner layer. The lightened inner layer displaces the increase in weight added by the pattern's thicker panels of nano-metric and high hardness steel and its replacment of an outer elastomer layer with a layer of fire retardant coated aluminium foam similar to Aluminium 8009. The 3T weighs only 8% more than the Pattern 3. The heavier armouring on towards the front of the vehicle balances the mass displaced by the heavier 2M6CO-CD powerplant.

Detection Avoidance

Illustration of a UC-42's heat sink

An Interfector EFP launcher

The UC-42-A1, E1, and U1 have no stock detection avoidance features. Thus far, the A2 and A3 variants are the only variants to feature these measures by default. On A2 and A3 variants, the outer surface of the armour is coated in slip-resistant fibreglass and a thin polymer that adds some thermal-reflective and radar-absorbing properties. On Iverican UC-42's a course gravel made of common hematite is stuck onto the surface. This acts as an added anti-slip measure, extra radar-absorbing layer, and can help break-up the visual colour profile of the vehicle. Current detection avoidance measures for the A2 and A3 units can be applied to other variants during depot-level maintenance. Variants have the option of mounting a multi-spectral camouflage net if available.

In addition to the thermal reflective and radar-absorbent coating applied to its armour, the UC-42-A2 variants are equipped with an extra liquid cooling system for the engine and a 2-vent exhaust system that reduces the vehicle's thermal signature by cooling the exhaust. Heat is diffused in the pipes by a fan heat sink and a short convection heat exchanger segment. Gases exit on both flanks of the tank's rear. The 4D8CV-CD engine's cylinder deactivation feature also lowers the A2 variant's noise when idling and at low RPM levels to a range of 50-60 decibels.

Equipped with their full suite of detection avoidance measures, the UC-42-A2 and A3 emit comparatively low thermal signatures and radar-cross sections. During tests against FGM-148 Javelin, static mock-up UC-42-A1 hulls with A2 coatings occasionally required multiple attempts to lock-on with the Javelin's command launch unit (CLU). 100 lock-on tests were conducted with the CLU with 12 attempts resulting in a failure to lock in the first attempt.

The radar-absorbent material and surface shaping of the UC-42-A2 makes the vehicle more difficult to detect by radar. At ranges further than 4,000 metres the UC-42-A2 scanned from its smallest cross-section face may be filtered out as background clutter; having appeared to be the size of a deer or individual on a motorcycle.

Active Protection System

The UC-42 is equipped with the Dahlbein Defence Interfector active protection system. Interfector is a hard-kill system that utilises explosively formed penetrators (EFP) guided by an F/G-Band fire-control radar. The RI/VPG-040 guiding the system's 2 launchers is a four-faced distributed active electronically scanned array Pulse-Doppler radar designed to detect and automatically track Anti-Tank Rockets, Anti-Tank Guided Missiles and Tank Rounds. A cone of EFPs are fired at an incoming threat, intended to detonate the warhead at safe proximity. The EFP launcher is reloadable and can orient to intercept threats approaching at a high angle of attack.

Interfector's VPG-040 radar is capable of detecting, analysing, and reporting potential threats to the vehicle's onboard computer, creating a shot detection capability. This information can be shared at low-latency with other units connected to the same datalink channel as the Interfector unit. VPG-040 can operate in a Low-probability-of-intercept mode to reduce its Electronic Warfare footprint. Apart from tracking shots fired, the system's computer instantly provides the estimated shooter location on the existing platform display. If Interfector identifies that the threat is going to miss the platform, it will not activate the countermeasure but will provide the shooter's location, enabling instantaneous counter-fire.

If the operational needs do not permit the use of active radar emissions, the Interfector can be integrated with and triggered by the vehicle's infrared sensors. In this instance, the VPG-040 radar can either be switched off or operated on a passive mode.

On A3 variants, the APS fire-control radar is the Aerano Huntsman ACRDS-L, a combined surveillance and fire-control unit.

A Sense-6 transceiver unit

A Mago-6 launcher

Infrared Warning & Countermeasures

The UC-42-A2 is equipped with an array of infrared transceivers. Initially designed as an alternative to the APS's fire-control radar, the Sense-6 Semi-Active Infrared Warning Sensor is composed of 6 transceivers and a computer functioning as both Laser warning receivers and Infrared search and track sensors. Each sensor passively scans a 70° x 70° area in front of it to detect thermal signatures and dense, opaque obstructions. When a thermal profile matching a missile or rocket is detected, the array's computer system can trigger the Interfector APS launchers. It is also effective at detecting enemy laser emissions and is able to approximate the bearing of a laser emission passing within its scan area.

Sense-6 can also function as a close-quarters infantry sensor for the crew. It is capable of detecting infantry moving around the vehicle; this can reduce the risk of driving accidents or warn the crew of potentially hostile infantry. The system is also capable of acting as an auxiliary fire-control system for the Interfector APS. However, reliance on Sense-6 alone reduces Interfector's probability of kill. Compared to the VPG-040 radar, the system is less capable of classifying a target and anticipating its ballistic performance. The transceivers can be run on passive and low-emission modes to decrease observability.

On the UC-42-A2, Sense-6 is directly linked to a gimbal-mounted Directional Infrared Counter Measure (DIRCM) dazzler unit that acts as an electro-optical disruptor against range-finders, designators, and ATGMs reliant on laser guidance or infrared homing. Using the transceivers for guidance, the DIRCM module can be used to reduce the accuracy of incoming laser-guided or infrared-homing munitions. The gimbal mount articulates 360° and the dazzler head can pitch at 180°. The whole DIRCM unit is encased in a ballistic glass dome on the left-hand side of the turret, opposite the commander's hatch. The DIRCM module is not present on the UC-42-A3 or any UC-42 module equipped with Sense-6 Block II. The Block-II units are an upgraded version reportedly capable of performing electro-optical soft-kill by directing their infrared beams toward incoming projectiles.

Other Countermeasures

To block line of sight, a visual lock, or laser guidance, the UC-42 crew can trigger any of 18 of 66 mm grenades mounted on 3 Mago-6 launchers (6 per launcher). Mago-6 is a remote grenade launcher system composed of 6 discharger tubes fixed to a remote mount capable of independent rotation and pitch. Though a variety of grenades can be loaded, most launchers are loaded with the G-53 smoke and chaff grenade which is an aerosolised Hexachloroethane grenade that uses a higher concentration of zinc and alumina particles to obscure laser or radar targeting. Different grenades can be used in a mixed loadout;Fragmentation, infrared decoy, or tear gas grenades are often used as alternative countermeasures, being loaded into 4 or 6 of the launcher tubes. The launchers can be triggered automatically if a threat is imminent or can be triggered using any of the 3-4 crew stations.

As of 2022, Arx Arms reported that a UC-42 is being used to test the Spiker interceptor munition for the Mago-6. Spiker is intended to be a high velocity 66 mm projectile carrying a directional blast warhead capable of destroying or deflecting an incoming projectile by detonating its warhead. In a recent test conducted at the Altaria Arms Expo in March of 2022, Spiker demonstrated its ability to destabilise a kinetic energy penetrator, a top-attack tandem-charge HEAT missile, and explosively formed penetrators deployed from another top-attack missile. The demonstration proved a level of effectiveness against kinetic projectiles, direct-fire explosive munitions, and top-attack munitions. The Mago-6 used to demonstrate Spiker was linked to an Interfector RI/VPG-040 fire-control radar and the Sense-6 infrared array.

Demonstrations of the UC-42-A3 variants by the Exersito variants claim that some units previously carrying the VLQ-12 CREW jammers have been upgraded with the VLQ-12 Block II, which adds super high frequency and ultra high frequency electronic warfare. Block II jammers are reportedly able to jam receivers operating between 3 MHz and 30 GHz, allowing jammer equipped units to interfere with low-flying drones and munitions relying solely on radio-frequency command guidance.

Crew Safety

A UC-42-E1 interior. Note the absence of the autoloader

All variants feature several safety measures as contingencies to enemy action, fire incidents, and CBRN hazards. To protect against enemy fire, the fighting compartment is lined with a fibre-resin layer and a final mesh of kevlar. This layer acts as a spall liner. Additional preventative measures were taken in designing of the fighting compartment. Bolts, screws, and loose fixtures were avoided in equipment mounts facing the hull or turret armour as these presented significant spalling risks. Instead, interior mounting was usually fixed using a slotting system. Interior fixtures are mostly designed with rounded or padded edges and corners to limit crew injuries from jarring impacts. Crew seating is equipped with air dampers to reduce joint fatigue and to provide some safety from collisions or sudden impacts. Vehicle hatches are secured with 2 independently powered bolts that can also be manually disengaged. All crew stations have lock/unlock toggles that can be used to control individual hatches or all crew hatches.

Ammunition is stored in the turret bustle behind an armoured bulkhead. Secondary storage is located in an armoured container behind the commander, protruding into the hull's rear compartment. The hull ammunition storage is compartmentalised into 3 columnar bins holding 5 rounds each and can be used to reload the conveyor in the bustle or loaded into the gun directly. Both ammunition storage areas are accessed through blast doors and are equipped with blow-out panels. In compliance with TRIDENT AOP-39, ammunition storage is rated to contain hazardous initiation of Energetic Materials (EM). The bustle storage is rated to contain Type II (partial detonation) and III (explosion) hazards. The hull storage is rated to contain Type III and IV (deflagration) hazards.

A thick steel bulkhead separates the fighting compartment from the turret bustle ammunition storage. An armoured blast door allows the autoloader system to access rounds from the rotating cassette-style conveyor belt in the bustle storage compartment. If an explosion is triggered, a welded and bolted set of blow-off/blow-out panels will be ejected from the top and bottom of the ammunition storage compartment. The welds on the blow-off panels are structurally weaker than the welds on the rest of the turret structure. The bolts that hold the panels in place are also not crimped and soldered, being loose enough to eject in the event of an explosion or fire.

A cyclonic filter, part of the UC-42's CBRN protection system

The UC-42 also comes with a number of CBRN protection measures. A sensor mounted on the top surface of the turret incorporates a dosimeter, geiger counter, and biochemical detector. A secondary sensor is located inside the fighting compartment. Upon detecting a hazard, the sensor will alert the crew with an audio and light cue. The CBRN protection system activates automatically 0.3 seconds from the time a hazard is first registered. Normally, the interior UC-42 is a positive-pressure space using a CBRN filtered ventilation system. However, the entire vehicle can be hermetically sealed, with hatches and access ports to the hull lined with neoprene and treated EPDM rubber. For radiation shielding, the spall liner includes a polypropylene layer beneath the kevlar layer and the internal-facing armour plates have a thin coating of boron carbide. The vehicle's main ventilation intake is located on the rear deck, above the engine compartment and adjacent to the engine air intake. The air passing through this intake can be cooled by the engine compartment's liquid cooling system. Likewise, convection coils in the ducts can provide heated air. A secondary intake is located atop the turret. Ventilation uses a cyclonic system equipped with HEPA filters and a classified biochemical scrubber and filter. The filtration system is accessible from inside the fighting compartment and can be maintained or changed from inside the vehicle. In the event that harmful gases spread inside the fighting compartment, the ventilation system can also be used as an evacuator, working in reverse to flush gases from the interior. Intakes and exhausts can be sealed if the system is compromised. Individual gas masks and extra filters are normally stowed inside the vehicle. Iverican crew gas mask systems have adaptors that allow connection with the personal ventilation port available at each crew station allowing the crew to breathe filtered air at their stations for as long as the CBRN filter is functioning. An adjacent port can be used to connect a crewman's cooling vest, a tubed array worn over the torso that circulates cooled air from the CBRN ventilation system. Due to the appearance of these safety articles, the crewman's full battledress is sometimes referred to as "mech suits" or "space suits" by Iverican personnel.

For fire suppression, all UC-42s are equipped with 4 FM-2000 canisters. FM-2000 system use HFC-227ea, a clean agent fire suppressant deployed as a gas. The agent is notably safer to use than Halon gas. Canisters are located beside the driver's station, in the fighting compartment, in the ammunition storage, and in the engine compartment. Though the crew can continue to work for a short time after the gas deploys, the low oxygen environment created by the gas makes prolonged work unsafe. The crew must either dismount or flush the interior using the ventilation system in evacuator mode. Spring-loaded hatches are automatically unlocked if a fighting compartment fire is detected. Crew hatches are designed to be opened with very little impulse. Iverican safety drills emphasise that bumping the interior face of the hatch with the head will be enough to swing hatches open, assisting a quick exit. Redundant hand-held chemical fire extinguishers are mounted inside the fighting compartment and on the vehicle's exterior.

In addition to fire suppression, the UC-42 features anti-incendiary design measures that prevent harm or compromised effectiveness from flammable material, fumes, and other discharge. Ventilation and engine air intakes feature a top plate for initial protection. Vertical intakes are also designed to prevent direct dripping or seeping into delicate internals. Ducts and piping are curved at right angles and have run-off sumps at junctions. To reduce fire risk inside the fighting compartment, the turret drive uses an electric traverse system. The electrical system was chosen to both reduce weight and reduce the fire hazard presented by semi-flammable hydraulic fluids. Periscopes, optics, and other vision devices feature spray washers to prevent dirt, dust, and fluids from obscuring the crew's vision. Larger vision devices have small wipers to help clear dirt.

Fluid storage on the UC-42's were designed with 2 additional purposes in mind; better weight distribution and a marginal increase in protection and fire safety. While the primary fuel tank is a 1,200-litre tank located between the engine and the bulkhead to the fighting compartment, an array of fuel tanks are spread out across the chassis. The driver's station is flanked by a pair of 100-litre fuel tanks partitioned from the crew compartments by steel plates. What would be otherwise empty gap spaces between the turret and the hull flanks have been used to mount a series of 8 20-litre fuel tanks. These tanks are mounted in a hollow portion of the chassis and can act as hollow sections to reduce the effectiveness of shaped-charge weapons. An independent fuel tank for the auxiliary power unit is kept seprate from the main fuel system. All fuel tanks on the UC-42, are self-sealing and firewall partitioned. A 60-litre water tank is located between the engine and the fighting compartment bulkhead. It acts as an additional water supply for the crew and is adjacent to the heat exchanger, helping diffuse engine heat more effectively.

Mobility

A 4D8CV engine

A UC-42 demonstrating its braking and suspension

A UX-42 "leans" to the right

Power Pack

All variants of the UC-42 are equipped with a Toledo Heavy Industries 4-stroke V8 diesel engine. It is a high-displacement, high-compression, liquid-cooled, twin-turbocharged engine rated to output 1,200 horsepower at 2,300 RPM and a maximum torque of 3,880 N m. The engine is classified as the Type 4D8CV, part of a family of engines used in industrial, and military land vehicles in the weight range of 30-50 tonnes. Given their widespread use, 4D8CV engines can easily be serviced given many TRIDENT mechanics' familiarity with the design and the ubiquity of replacement parts.

The engine on the UC-42 uses a 60° V-block arrangement and Intelligent Variable Timing and Lift Electronic Control, or I-VTEC. Units produced for UCVs utilise a niobium strengthened alloy for the engine block, cylinder heads, and piston assembly. The entire engine alone has a dry mass of 1500 kilograms. The engine can be turbocharged or supercharged—as in the UC-42-U1 Urban Assault Vehicle.

A2 units are equipped with a cylinder deactivation feature to increase fuel efficiency when out of combat. When activated, the system will stop injecting fuel into 2 or 3 of the valves. The computer uses a timing program to deactivate valves in an ordered series to avoid placing too much wear on a single set of valves. During this operation, the valves are fully closed to compress air inside the cylinder during the exhaust stroke. The compressed air expands during the succeeding downward stroke to recover some of the energy thus decreasing the load an inactive cylinder would add to the operation. A further measure that contributes to fuel efficiency comes in the form of an extra heatsink fan in the exhaust. The fan's pressure allows it to double as an evacuator, helping outward gas flow.

The engine placement is mounted transversely, to rear most section of the hull. The rear compartment of the hull also accommodates a set of secondary ammunition bins and parts of the exhaust cooling system and liquid cooling system. Further to the rear are 2 partitioned self-sealing fuel tanks. The engine compartment contains part of the vehicle's FM-200 fire suppression system which can be triggered automatically or manually using a switch in the driver's station or the commander's station.

A3 units are equipped with the Toledo Heavy Industries 2M6CO-CD. it is a 2-stroke, 22-litre 6-cylinder, opposed-piston engine rated to output 1,500 horsepower. In collaboration with Cavellero Heavy Auto, ARX designed the engine to be a scalable and multifuel—with a higher compression ratio than the 4D8CV family. The engine shares the same liquid-cooling system, cylinder deactivation feature, and twin-turbochargers as the 4D8CV-CD though its I-VTEC system had to be re-engineered for the new piston layout and action. The new opposed piston design is projected to be a compact alternative to comparable 1,500 h.p. V-layout engines. The design's lower mass and lower overall footprint offsets the upscaled size of parts needed to meet a higher compression ratio. The 2M6CO-CD is compact enough to fit into A1 and A2 engine housings and only requires a minor modification of the drivetrain. However, its slight increase in width necessitated a reduction in the main fuel tank's volume; a difference which was compensated for by enlarging the auxiliary tanks beside the driver's station. Despite its more space and mass efficient design the 2M6CO-CD is approximately 360 kg heavier, with a dry mass of 1860 kg.

All UC-42 variants are equipped with a continuously variable hydraulic mechanical transmission. This transmission allows the vehicle to reach its top speed in forward and reverse modes and allows for a smooth transition in all speeds using a single lever. A double-differential is used to enable neutral steering.

Suspension & Running Gear

All variants are equipped with Hydropneumatic Active Suspension. The chassis is powered by a pair of rear-mounted drive sprockets and rests on 5 pairs of steel roadwheels connected to a hydropneumatic suspension arm. A bolt, slotted into the suspension arm, is then moved by a belt-driven pump from either the engine or APU to pressurise a special hydraulic fluid, which powers both the brakes and suspension. The extension and retraction of the bolt cause a rising or falling action. On the UC-42, this can be used to help lay the gun if the vehicle is resting on uneven surfaces. The UC-42's suspension allows for a maximum pitch of 10° glacis-downward or glacis-upward. This system also works with the fire-control system to stabilise the gun when firing on the move. It also dampens intertia and jarring impulses when stopping, reversing, throttling, or turning suddenly.

The roadwheels rest on a pair of Composite Rubber Tracks (CRT). The tracks are comprised of a complex matrix of metals, rubbers, plastics and fabrics. It is reinforced by a range of composite materials including carbon fibre and carbon nanotubes, as well as longitudinal and lateral steel cords, or ‘belting’. This core belting consists of a single 1,500 m-long steel cord, wrapped about 100 times around the profile of the track. Above and below this belting are multiple layers of steel mesh configured to resist track twisting and maximise the longitudinal torsional stiffness of the track matrix. The UC-42's CRT is designed for AFVs of up to 52,000 kg. It uses more than 12 separate rubber compounds with an overall composition of approximately 49% rubber, 29% steel and 22% composites. A range of rubber compounds are used throughout the track matrix, with stiffer compounds in the lug cores and softer, more pliable, and UV-resistant compounds on the surface. Those elements, interfacing with moving parts such as the surface of the drive lugs that engage with the drive sprocket, use compounds that have high resistance to abrasion, a low friction coefficient, and are self-lubricating. The typical life of CRT on the UC-30 Pantera IFV vehicles of up to 55,000 kg is approximately 6,000 km up to a max of 8,000 km.

Composition of a CRT

Trials by the Iverican Army's Land System Testing Unit showed that a UC-42 driving with CRT yielded a 16% fuel reduction on roads and 24% off road over a 5,000 km repetitive battlefield mission cycle, increasing range by 19% and 31% respectively. Combining these figures into a mixed mission profile (25% road, 75% off road) would see around a 28% range increase from 520 km to 665 km. The CRT also reduces noise significantly. It yields a 60% and 70% reduction to noise and vibrations depending on where the measurements are being made. Outdoor tests in open terrain show a reduction of 10-15 decibels. The dampening of vibrations is also estimated to decrease wear on relatively delicate internal systems.

The elasticity of the track allows it to be more resistant to torsion and tension from offroad use. The track is coated with a resin and fibre-based stiffener on the surface, allowing it to meet a required tolerance of more than 160°C of applied heat. These qualities make it surprisingly resistant towards blast, heat, and offroad wear. When subjected to ballistic attack CRT will be penetrated in essentially any instance, however the very high pressure of the rubber structure means that holes are essentially self-sealing as the rubber elements expand to fill the void, where impacts with metallic tracks can credibly cause pin fracture failures or damage bushings. In most cases CRT is relatively unaffected by blast damage unless directly under the track or directly atop mine blasts that cause destruction of the suspension. Though the tracks are vulnerable to laceration, kevlar reinforcement allows it to resist this type of damage. Despite its resistance qualities, UC-42's in long-term storage are not usually equipped with CRT. Instead, they are either stored without tracks or with surplus steel tracks.

The UC-42 uses an automatic track tensioning system. A pair of hydraulic-electric pistons can move the idlers to increase or decrease tension. The system uses a pressure sensor to ensure that track tension is always exact and remains constant throughout the track wear cycle. It also makes replacing an entire track system easier as the driver is able to remove tension entirely.

Handling System & Control Surface

Early configuration of the driver's handling bar on the UX-42 demonstrator

Driving the UC-42 is accomplished by a drive by wire system connected to the driver's station. Manipulation of the drive systems is handled through a wired remote control handling bar and a display panel with a button interface. The handling bar resembles a bicycle or motorcycle handlebar set. The right grip is twisted to control throttle while the left grip has a pair of levers. The longer lever resembled a bicycle brake that shifts the gear up when squeezed. The shorter lever, resembling a mountain bike gear lever, shifts the gear down when pushed. To turn, the driver rotates the handling bar. The electric system reads very small incremental changes and translates the movement to how much power should go into one track. This system allows the UC-42 to make precise banks and turns, allowing it to handle sensitive movements. To brake, the driver can squeeze a lever attached to the right grip. To turn on an axis, or "neutral steer" the driver depresses and holds-down a pedal above the left foot. The vehicle will then counter-rotate its tracks to a corresponding direction when the bar is rotated. Another pedal located above the right foot doubles as a mechanical emergency brake and a parking brake; it is directly connected to a purely mechanical system that locks the CVT's pulley pair in place half-depressed and locks a set of idler and roadwheel disk brakes in place when fully-depressed. The isolation of most driver movements to the handling bar was intended to decrease the driver's overall fatigue by eliminating lower-limb strain from manipulating clutch, brake, and gas. The handling bar's position can also be pulled closer to the driver allowing the arms and shoulders to rest. The backrest is at a 45° reclining position and can be raised or reclined by an additional 10°.

The hydropneumatic suspension is controlled by a yoke on the left-hand side of the driver's seat. When pulled, it pitches the vehicle glacis-up. When depressed, it pitches glacis-down. The twistable grip controls the roll of the vehicle. When twisted left or right, the corresponding side of the suspension will elevate or depress allowing the vehicle to effectively lean left or right. The system can only be engaged if the safey button on the tip of the lever is depressed first.

The driver's control display shows fuel levels, RPM, speed, heat, oil pressure, suspension pressure, battery statistics, fuel consumption, and mileage. The buttons on the display can be used to control a lighting array composed of visible white light, infrared light, and signal lights. The display can split its picture to show an obstruction map created by the Sense-6 infrared system. Sense-6 can act as a proximity sensor, warning the driver of obstacles or movements around the vehicle. Sense-6 uses IR light to create a low-resolution map of the vehicle's surroundings accurate to 15 metres around the vehicle. When IR beams are obstructed, Sense-6 displays a dead-zone or shadow cast by the obstacles. Sense-6 can detect and track moving objects around the vehicle. The display can also show the UC-42's rear-view camera feed.

A G5P12 genset

The driving controls are directly wired to the engine and drive train. In the event of a power failure, the drive system can still be operated for a limited time using a rechargeable battery located in the driver's compartment. This auxiliary battery has an estimated life of 2 hours when used conservatively and can also be used to power the engine's electric starter if the main battery is discharged or damaged.

For visibility, the driver has an independently rotating low-profile camera array that uses a wide-angle RGB camera and a wide-angle night vision camera. The night vision camera uses ambient light intensification that can be enhanced by using the infrared spotlights in the forward lighting array. The driver uses a flip-down panel of three panoramic LCD displays. The array is capable of 180° panning using a TrackIR system to follow the driver's head movement. In case of damage, the driver can manually pan the cameras using a D-pad near the right-hand grip of the handling bar. If the array is compromised, the driver can peer through 3 ballistic glass episcopes arranged to give a 120° view of the UC-42's front arc. At distance, the driver can see up and down at a total angle of 35°.

Auxiliary Power Unit

The Toledo Heavy Industries G5P12 auxiliary power unit (APU) is mounted in the turret's external bustle rack, taking up the central rear section of the rack. The APU is a liquid-cooled, multifuel, diesel generator rated to output 12kW. The APU is capable of powering the suspension, optics, active protection system, ventilation, autoloader, driving controls, communications, and C4I systems. However, high power draw systems like the RI/VPS-5C multifunction radar and the DIRCM module are typically run on lower power while all other systems are active. All systems can be run simultaneously if the vehicle's main battery is switched on or if the engine is active on idle. A breaker switchboard to the lower right-hand side of the commander's station can be used to selectively power modules and subsystems.

UX-42 climbs a slope

A UC-42 column driving down a small road

Tactical Mobility

The suspension can be also adjusted on the left or right and front or rear. The UC-42 MBT can run at a maximum speed of 70 km/h and thanks to the CVT gearbox, its reverse speed matches its forward speed, allowing rapid changes of position. It has a maximum range of 600 km at combat weight (Level-III armour with fuel and ammunition at full capacity). During peacetime or when travelling inside built-up areas, the engine is often run on an economy mode using cylinder deactivation. The estimated range of the UC-42 is 665 km when 80% of the work is travelled using cylinder deactivation at approximately 1500 RPM.

When unencumbered by extra armour, the UC-42 can climb an 80° slope of stable concrete. At combat weight, the vehicle can climb up a 60° slope, move on a 30° side slope, cross a trench 2.7 m wide, and cross a vertical obstacle of 1m. Equipped with a supercharged 4D8CV engine, UC-42-U1 urban assault vehicles can climb a short 80° slope at combat weight if the slope surface is not granular or slippery.

All UC-42 variants may ford water obstacles up to 5 m in depth. A 1.5 m fording snorkel and exhaust can be set up in under 10 minutes. Intakes on the side and rear of the vehicle are sealed using rubber plugs. Though vehicles in factory condition have perfect hermetic seals, damage and wear can result in water leaking or seeping into the fighting compartment. To counter moisture build-up inside the vehicle, the CBRN ventilation system can work as a dehumidifier, expelling air and intaking heated air.

Strategic Mobility & Logistics

The UC-42 was designed to be more efficient to store, transport, and maintain. It can be deployed to the theatre of operations via train, truck, ship, or aircraft. Thanks to its modularity, relatively light baseline weight, and small dimensions compared to other MBTs, the UC-42 can easily be prepared and packed for transport. Its modules can be packed more efficiently on cargo containers for separate trips or on the same transport platform.

An A-992M ASV can rearm the UC-42 using a mechanical arm

The Sant Anton-class Amphibious Assault Ship can transport up to 40 UC-42s and their modules. The low baseline weight allows trucks and rail cars carrying stripped UC-42s to traverse most bridges, small roads, and railways in less-developed regions of the wurld. UC-42s deployed by a quick-reaction amphibious ready group can receive extra modules by airdrop. Modules are designed to be fitted during O-level stations located wherever company-level Logistics Packages (LOG PAC) are set up. During exigent circumstances, crews can equip armour modules, APS reloads, infrared transceivers, CBRN filters, and fire-fighting equipment without the assistance of technical personnel. Reload and Resupply can be completed by the crew without other assistance. However, quick ammunition resupply can be facilitated by the A-992M Ammunition Support Vehicle. External storage racks and compartments around the turret and lashed to the sides of the hull can be used to carry extra fuel and crew supplies.

The UC-42 is also relatively easy to store compared to other vehicles. Stripped of its exterior modules, the fibreglass outer coating and neoprene-EPDM sealed access ports make the baseline chassis remarkably resilient to degradation from weathering. Drained of fluids and with minimal shade, UC-42 weather resistance is rated to last at least 3 years in storage before D-level maintenance checks and reapplication of coatings and sealing material are needed. Maintenance manuals suggest that depot stored vehicles should be inspected, lubricated, and cleaned semi-annually or annually at the very least.

Armament

UC-42s are armed with 1 main gun and at least 2 machine guns. Ammunition is stored in the turret bustle behind an armoured bulkhead. Secondary storage is located in an armoured container behind the commander, protruding into the engine compartment. Both ammunition storage areas are accessed through blast doors and are equipped with blow-out panels. They are rated to contain Type II (partial detonation), Type III (explosion), and Type IV (deflagration) hazards. The UC-42-A1 can carry a total of 47 128 mm rounds; 32 in the bustle and 15 in the hull storage. The E1 or variants with no autoloader, like the U1 can carry 32 rounds in the bustle and 15 rounds in the hull. The UC-42-A2 carries 22 rounds in the bustle's autoloader storage and 15 rounds in the hull storage. The A2 has an additional ready-rack for 3 rounds located in the hull, in front of the commander. The additional ready-rack is not always stocked.

Using an autoloader, both the 120-4 and 128-2 guns have a firing cycle duration of approximately 4-5 seconds depending on the crew. Without considering time spent on calculating and acquiring a firing solution, the autoloader can cycle the gun in 2-3 seconsd. The autoloader for the 128-2 gun consists of a continuous link carrier magazine made of 22-cells and a rammer assembly. The autoloader for the 120-4 is similar, but has a 26-cell magazine.

ARX 120-4 GCM

Arx's 120 mm L/44 tank gun has a length of 44 calibres (5.28 metres (17.3 ft)). The gun's barrel weighs 1,190 kilograms (2,620 lb), and on the UC-42 the gun mount weighs 3,317 kilograms (7,313 lb). The bore evacuator and the gun's thermal sleeve, are made of glass-reinforced plastic, while the barrel has a chrome lining to increase barrel life. Originally the gun had an EFC barrel life of ~1,500 rounds, but with recent advances in propellant technology, the average life has increased even further. The gun's recoil mechanism uses two hydraulic retarders and a hydropneumatic assembly to stabilise the gun on 2 planes.

The 120-4 GCM is mounted on early-production, A1 variants, and the export E1 variants. Gallambrian A2 variants were produced with the 120-4 GCM until they were refitted with 128-2 guns in 2022

ARX 128-2 GCM

File:German Rheinmetall 130mm.jpg

An L/51 variant of the 128-2 GCM

Responding to requirements set by the Iverican Ministry of Defence, Arx Arms introduced a larger 128 mm L/51 tank gun. The gun was initially designed to be 51 calibres long but was shortened to 42 calibres to fit technical requirements for the UC-42-A2 contract. The gun was purpose-designed and built for the A2 variant. Its design was based on the Arx 128 mm L/64 mounted on surface ships and used extensively since 1991.

The gun's L/51 barrel was cut to a total length of 5.12 metres. It features a chrome-lined smoothbore barrel with a vertical sliding breech mechanism, increased chamber volume, a muzzle brake adapted for discarding sabots, a thermal sleeve, a bore evacuator, and a muzzle reference system (MRS) enabling it to be bore-sighted on a more regular basis without the crew needing to leave the platform. Compared to the 2,700 kg 120 mm gun, the 128 mm has a 1,153 kg (2,480 lb) barrel and an all-up weight of 2,853 kg (6,290 lb) including the recoil system. As the 128-2 L/42 was designed to fire shorter telescoped ammunition, the breech was shortened by 128mm, allowing the overall gun-forward length of the vehicle to remain equal to the length of UC-42's equipped with the 120 mm L/44.

The gun is rated for a maximum chamber pressure of 10,000 bar. To compensate for the shortened barrel's decreased velocity, ammunition for the 128-2 typically uses a higher propellant density and volume. Sabot projectiles for the L/42 are also slightly scaled-down compared to ammunition fired from longer barreled variants. To keep the turret within acceptable weight and size parameters, the gun was designed to fire more compact 128 mm telescoped ammunition, slightly reducing the length of the round and by extension, the length of the bustle ammunition storage and gun chamber.

For most A1 and A2 variants, the loading of the main gun is facilitated by an autoloader system. The system consists of a segmented hydropneumatic rammer, an erecting feed rail, an armoured blast door, and an 22-round continuous link carrier magazine. When the gunner or commander indexes a type of ammunition to be loaded, the belt rotates, bringing the requested round in line with the gun breech. A Radio Frequency Identification scanner identifies the round before it is loaded. Then, the blast door swings upward, perpendicular to the bulkhead. This is followed by the erecting feed rail which serves to guide the cylindrical round canister to ride forwards on an attached parallel rail. The rammer arm then pushes the canister with the round contained forward until the canister is stopped at the edge of the breech. The rammer follows through, pushing the round until it is fully out of the canister and seated securely in the gun's chamber. The breech then shuts itself and seals, chambering the round. In the event of a failure to fire the round or if the crew decides that the round should be unloaded or switched, the system can work in reverse. For retrieval of the round, either the gunner or commander must first reach into the chamber and partially pull the round out of the breech. Then, 3 extracting claws attached to the terminal segment of the rammer arm are triggered, swinging forward to catch the rim of the round casing. The system then pulls the round back into the canister, which slides back along the feed rail and returns to the ammunition storage. The commander has access to a reloading port at the rear bulkhead of the commander's station. The commander can feed ammunition into the autoloader cells while in combat by slotting ammunition from the hull storage or ready rack into the reloading port. The autoloader cannot be operated while its belt is being reloaded.

When mounted on the UC-42, the gun's depression and elevation are relatively restricted, allowing -6°/+9° of vertical depression due to the enlarged breech and low-profile turret. This is offset by the UC-42's hydropneumatic suspension, which allows the hull to shift its stance to accommodate greater firing depression and elevation angles. The suspension can add a maximum +10°/-10° to the gun's turret-mounted pitch range.

The 128-2 gun also mounts other features to assist with performance in battlefield conditions. The end tip, midpoint, and mantlet base of the gun barrels have alignment sensors to track deviations like vibration and flexing. The fire-control computer uses this dynamic muzzle reference data to adjust its firing solution, improving accuracy by accounting for both external and internal forces. Another feature of the gun is a low-profile muzzle brake. The muzzle brake is designed not to interfere with petals ejected in the process of firing discarding sabot ammunition. Its internal diameter is uniform with the rest of the barrel, eliminating spaces for the petals to tumble prematurely and disrupt the flight of the sabot projectile while also providing a significant reduction in recoil forces. The gun also features a bore evacuator around the midpoint of the barrel.

Machine Guns

A remote weapon station equipped with a 12.7 mm machine gun

All UC-42 variants are armed with at least 2 Machine Guns. The coaxial weapon mount may be fitted with a 7.62×51 mm machine gun or an 8.6×70 mm machine gun. The commander's hatch may be equipped with a pintle-mounted machine gun. Most variants aside from the E1 use a Remote Weapon Station (RWS) armed with a 12.7×99 mm machine gun. Both pintle-mounted and RWS stations may be equipped with a 40 mm Automatic grenade launcher or 14.5×114 mm machine gun.

The control system of the UC-42's RWS consists of a console at the commander's station with a display screen for the cameras on the mount and a simple stick controller. If needed, the gunner can take control of the system through the station's control surfaces. The turret is gyro-stabilised and electrically driven. An optical observation and sighting system is mounted on the turret alongside the weapon with a variety of daylight and thermal imaging cameras and laser rangefinder. The standard option includes a 3 field-of-view daylight rgb camera and a thermal night sight. An optional fit consists of an infrared night sight with togglable visible red light illuminator, a 2 field-of-view daylight camera, and a laser rangerfinder. Its camera systems can accurately identify and profile targets out to 2,500 m away, and the mount's absorption of about 85% of weapon recoil delivers an estimated 95% accuracy rate, as well as the ability to auto-track targets moving 25 mph (40 km/h). Large ammunition boxes enable sustained firing periods, carrying 96 rounds for a 40 mm GMG, 340 rounds for a 14.5mm, 400 rounds for a 12.7 mm, 800 rounds for a 8.6 mm, and 1,000 rounds for the 7.62 mm. An optional armoured shroud can be mounted to protect the barrel and feed system with steel plating.

The RWS can be partially guided by radar systems mounted on the vehicle if an aerial threat is detected. Depending on the radar used, the RWS machine gun can be layed on to targets like drones or helicopters.

The urban-assault U1 variant uses a human loader instead of an autoloader. The loader can operate a secondary RWS armed with an 8.6×70 mm machine gun. This system is a low-profile RWS located adjacent to the loader's hatch.

Ammunition

A MBT-110 gun-launchable ATGM

The 120-4 L/44 GCM can fire a variety of ammunition including the depleted uranium G829 APFSDS, MP-T, Canister, the MBT-101 ATGMs, and others.

The 128-2 L/42 was designed to fire telescoped ammunition, shorter conventional ammunition, and ATGMs. The gun's capability to fire projectiles at higher velocities made firing long-rod tungsten penetrators viable, replacing the more expensive and scarcer depleted uranium penetrators.

Most ammunition types for the 128-2 also feature improvements to casing design and material. The insulation of the disintegrating nitrocellulose-nitroglycerin material was increased significantly, improving the efficiency of the propellant's burn by decreasing the amount of energy lost to the casing and barrel.

Some common ammunition loaded on UC-42-A2s include:

• G900-WU APFSDS: The G900-WU, sometimes referred to as the "Wu-Tang" supersabot, has a penetrator composed of 85% Tungsten with a narrow Depleted Uranium core for added mass and penetration capability as the projectile slows on impacting armour plate. It designed for use against 3rd and 4th generation main battle tanks. The round has a measured muzzle velocity of 1,770 m/s (5,807 ft/s) when fired from the 128-2 L/42. The round is estimated to be capable of penetrating 900-1000 mm of RHAe at a range between 1,000 and 3,000 metres.
• MBT-110 ATGM: The MBT-110 Balistario is a 128 mm tandem-charge HEAT missile capable of either beam riding guidance or Semi-Active Laser Homing. Targets can be marked by the launch vehicle or by a 3rd party with a laser designator. The missile can be fired in a direct-attack or a top-attack mode (using semi-active laser homing). The missile is also capable of lock-on after launch, effectively allowing the launch vehicle to destroy targets out of its line of sight. The time of flight to a target at 4,000 m (2.5 mi) is 14 seconds and the missile hits the target at an accuracy of 0.7 m (2.3 ft) CEP and an angle of over 30°, providing effective penetration of up to 800-900 mm (31-35 in) of RHAe with its tandem warhead to deal with add-on reactive armour. It has a maximum range of 8,000 m when fired from the Arx 128-2 GCM.
• G830-T MP-T: The G830-T is a fin-stabilized round with a discarding sabot and tactical service round with a tracer. The conical nose of the projectile consists of the Frontal Impact Switch Assembly (FISA) coupled to the warhead body and the M74 Proximity Switch coupled to the FISA. The FISA is a secondary switch which closes upon impact against a ground target. The primary switch contains two parallel “switches,” either of which, when closed, will complete the firing circuit. One switch closes upon direct impact with a target. The other is an electronic switch (a transistor) which “closes” when the proximity switch senses the presence of an air target. For all modes, a flexible electrical cable provides a path between the switches and the base element. In any of the functioning modes of the G830T fuzing system, the connector of the fuse is returned to "ground potential" which completes the fuse firing circuit. It is capable of engaging helicopters thanks to its dual-purpose fuse that offers impact or proximity modes.
• G1028-F APERS: The G1028-F is a shortened 128 mm anti-personal flechette round. It features a timed fuse set by the gunner's computer which triggers the payload of 8000 flechettes at a designated distance. The fuse can be set to detonate upon leaving the muzzle or at the maximum range of 4000 metres. In interviews following Operating Wolfhound, Iverican crews have referred to the round as a "nail yeeter, infantry deleter".
• G1101-TB: The G1101-TB is a 128 mm thermobaric High-explosive squash head round developed for the UC-42-U1 urban assault vehicle. The round is a multipurpose round designed for the U1's 128-2 L/34 main gun but can be fired from the L/42 as well. It provides bunker-busting capability and can be used effectively against lightly armoured vehicles.

Fire-Control System

C4I Panel in the commander's station

The standard fire-control system on the UC-42 is the Arx Fusiliero-IV fire-control system. The system integrates a primary sight array, a Commander's Independent Thermal Viewer (CITV), a fire-control program on the vehicle's Mariscal II computer, and several other environmental sensors. The gunner can interact with the system through a user-interface overlayed on the primary sight picture. A separate display for ballistic data and sighting data is present to the right side of the primary sight.

Visual contact is facilitated by an array of day/night sights mounted around the turret, providing a full 360° coverage as well as providing input to the C4I system. For target acquisition, the UC-42 uses a primary gun sight with a variable magnification and autostabilisation. The sight uses an integrated neodymium yttrium aluminium garnet (Nd:YAG) laser rangefinder and a 120 element Mercury cadmium telluride, HgCdTe (also known as CMT) thermographic camera. Thermal imagers on crew stations are 3rd Generation FLIR, dual band (MWIR and LWIR) thermal imagers. The gunner's sight can also track vertically from −29° to +29°, as well as track horizontally through 180°. The CITV is a stabilised panoramic and periscope sight designed for day/night observation and target identification. The CITV provides an all-around view with a traverse of 360°. A display inside the tank projects the thermal image from the CITV and can also be sued to view the primary sight picture. Both the gunner's sight and the CITV have digital marking and data overlays displayed in-picture. Either overlay will show the elevation and bearing that the other is oriented towards. Either optic can be auto-oriented to acquire its counterpart's target and both the commander's and gunner's LCD displays can show their counterpart's sight picture. Both optics are capable of optical magnification up to 25x with digital zooming and post-processing providing a smooth transition between lenses. A backup 8x auxiliary telescope with a stadiametric rangefinder is mounted coaxially for the gunner. The telescopic sight is bore-sighted to the main gun known and has two interchangeable reticles; one for MP-T rounds and one for APFSDS.

Once visual contacts are registered, the fire-control system's laser rangefidner can be used to provide up to three range values in 2.5 seconds. The laser rangefinder can operate using a low-observable pulse mode to decrease the chances of detection from a laser warning receiver. The maximum range of the laser rangefinder is up to 10,000 metres with a measuring accuracy within 10 metres at this range. A laser desginator is mounted alongside the laser rangefinder. Alternatively, software on the fire-control computer can estimate range using the optical array's coincidence rangefinder to remain completely undetected when obtaining a range value. The range data is transmitted to the fire-control software on the vehicle's central Mariscal computer. The computer's fire-control software uses the range data, meteorological data, dynamic muzzle reference data, suspension data, and the chambered round's pre-input ballistic characteristics to calculate a firing solution. The gunner can read all firing solution data in a single digital overlay on any one of the gunner displays. At long range, a semi-autonomous firing mode can be used wherein the fire-control computer autonomously fires the gun once the reticle is over a designated target and all sensors indicate that the vehicle and gun are perfectly aligned. This system minimises the risk of firing when factors like barrel flexion or vehicle intertia might reduce accuracy. In the semi-autonomous mode, the gunner simply places the reticle over a designated target and holds down the firing switch or trigger on the dual-stick controller. During testing at maximum effective firing range, firing was triggered between 0.5-2.2 seconds of target acquisition.

When acquiring a target outside of the gun's depression/elevation arcs, the hydropneumatic suspension will automatically compensate, raising or lowering the pitch response to the gunner or commander's movement of the control stick. The suspension can be controlled by the any of the crew through their respective control surfaces. Turret traverse, main gun elevation, and firing can be accomplished through the gunner's or commander's control stick. If powered fire-control, turret rotation, or gun elevation systems are compromised, manual handles and cranks can be used as a manual backup.

Using an Identification Friend or Foe/Selective Identification Feature (IFF/SIF) system, the UC-42 can positively identify targets before engaging. Located on the main gun mantlet, just above the gun, the system fires a 38 GHz beam in the direction of the gun for a response from the targeted vehicle. If a proper response signal is shown by the target, the fire-control system automatically identifies it as friendly. If the target fails to respond to the identification signal, it is then declared hostile. Usage of the system is only effective if a compatible IFF system is mounted on friendly vehicles in the same area of operations. The laser system itself is small and can be easily mounted or jury-rigged on most vehicles. UC-42s equipped with the VPS-5C or the Huntsman ACRDS-L multifunction radar can also send & receive Radar or Radio Frequency IFF responses to assets within its range.

Both the RI/VPS-5C and Huntsman ACRDS-L radar can provide data to lay the gun directly on a detected target without the use of the gunner's control stick. Using the automatic snapshot gun-laying function, the fire-control software translates the radar data to a bearing and elevation. The computer automatically orients the turret and lays the gun at the approximate bearing and elevation of the contact. In this mode, the gunner can take manual control at any time and make adjustments as needed. The radar is also used to track low-altitude aerial contacts like ATGMs, rotorcraft, and slow, low-flying fixed-wing contacts. The system can accurately engage low-speed aircraft using MP-T, or G1028-F flechette ammunition. The FCS also has an automated tracking system and is capable of engaging moving or stationary targets while moving in day or night. The automatic target tracking system uses a thermal image display which can be controlled by either the tank gunner or commander. It is capable of tracking soldiers, vehicles and helicopters. The targeting computer can also calculate lead on moving targets.

The combined system allows the UC-42 to track and engage moving targets at ranges of up to 5,000 meters with kinetic munitions while on the move over rough terrain. Clear target identification is possible between 2,000-3,000 metres. Stabilisation when firing on the move is provided by the gun's gyro stabiliser which integrates with the tank's hydropneumatic suspension.

Electronics, Signals, & Support Measures

RI/VPS-5C J-Band Multifunction radar

• Aerano Huntsman Advanced Compact Radar Defence System-Land: The Huntsman ACRDS-L is a system of 4 AESA panels capable of simultaneously searching, tracking, and providing fire-control for the Interfector Active Protection System and the Fusiliero-IV fire-control computer. The Huntsman radar was designed as an advancement of the Interfector's VPG-40 radar, adding adaptive beamforming, frequency modulation, multi-mode send & recieve, Electronic Counter-Countermeasures, and adding an organic processor to assist interface with an onboard combat management computer. The entire system weighs 138 kilogrammes, consumes an average of 1 kW/h and can be equipped on the VPG-40's panel mounts without alteration. The system can operate in a low-probability-of-intercept mode, and is jam-resistant. It can detect targets beyond line-of-sight using beamforming and modulation features to diffract its emissions. It can detect small UAVs at 3 km, person-sized contacts at a maximum of 7 km, surface vehicles at 15 km, and larger aerial vehicles at 15-22 km depending on altitude. An accurate firing solution quality track on an MBT-sized contact can be resolved at approx. ~5 km depending on terrain and the height of the contact. The Huntsman has an active air and liquid cooling system for operation in temperatures exceeding 55°C.
• Beagle Mine Detection System: Some UC-42s in a formation can be equipped with a ground penetrating radar array used to detect buried threats. The collapsible system is mounted on the front lower glacis plate and has an auxiliary magnetometer.
• Combat Network Radio Suite: Consists of a tactical radio providing secure Low-probability-of-intercept and electronic-attack resistant voice communications in the frequency hopping (FH) mode. The communition suite also features a secure communications tactical satellite (TACSAT) link and a HF/UHF transceiver unit to facilitate multimedia send & receive. TACSAT links are typically found on command vehicles and not the majority of UC-42s currently in service.
• Dahlbein Microtronics Opera-L IV ESM: Opera-L IV is a compact Electronic Support Measure equipment consisting of a collapsible intercept mast linked to the vehicle commander's computer. The system enables electronic listening, direction finding for D-K band signals, and passive recording of radio frequency communication intercepts. The direction finding estimate is accurate up to 6°. Like the VPS-5C, the Opera-L is commonly equipped on platoon commander vehicles. The mast is detachable and can be operated via an extension wire up to 30 metres away from the vehicle.
• Fortis Defence Electronics Nousphera Mariscal II: Sold to TRIDENT nations as the "Noosphere Marshal-2", the Mariscal II is a C4I computer system designed for use on ground combat vehicles. The system set consists of a water-resistant, electromagnetic, shock, and impact shielded-case computer and an adjustable LCD set with an integrated button interface. The computer is linked to the UC-42s optics, sensors, and communications equipment. The computer hosts control software for the vehicle's electronic modules, forces tracking, and a unit-synchronised map tool application projecting a 3D topographic display. Other applications include interfacing for Nousphera II multimedia datalink communications, remote-control capability for drone interface, and combat management software. Command vehicles receive the Mariscal II-C, a unit with a more powerful processor and with operations-scale management software.
• Fortis Defence Electronics RI/VPS-5C multifunction radar: The VPS-5C is a J-band multifunction radar system mounted on an adjustable 1.5-metre mast. It can use active, passive, and LPIR modes. Radar contact information can be used to direct an automatic snapshot gun-laying function, which automatically aims the gun at the approximate bearing and elevation of the contact. The radar integrates with the C4I computer's HF/UHF data sharing capability with nearby units, allowing for Cooperative Engagement Capability within an area of operations. Units not equipped with the VPS-5C can still use the automatic snapshot function by receiving targeting data from the radar vehicle. The complete radar weighs 30 kilograms (66 lb) It can detect targets out to 30 kilometres (19 mi), with a maximum range of 42 kilometres (26 mi). The VPS-5C is commonly equipped on A2 platoon commander vehicles.
• RI/VLQ-12 Jammer: A modular jamming unit allowing equipped vehicles to disrupt radio-frequency receivers from 3 MHz to 30 GHz ranges. Block II units are capable of directional jamming and have multiple channels for barrage jamming different frequency ranges at the same time. Originally designed to block radio remote detonators, VLQ-12 units in the Block II series are not capable of jamming low-flying drones and munitions relying solely on radio-frequency command guidance.

The vehicle's electronics are managed through a multiple-redundancy wired network. The network uses electromagnetically shielded Category 5E cables to connect modules with the primary computer. The cables are run through easy to access but out of the way mounting points along the turret ring circumference and terminate in access ports or in module ports. Cables that run outside of the vehicle are separated through small air and water-tight junctions slotted through the armour plate. Individual cables are colour coded and are easy to replace. A single crew member can replace essential cables in under 30 minutes.

If the primary computer or wired connections are compromised, modules can still operate independently on their native computers. To control the individual modules in the event of primary computer failure, a touchscreen handset compatible with the Nousphera OS can be plugged into any network port on the vehicle.

Variants

2 Exersito Iverica UC-42s on an exercise in Argon

A1

Entering service with the Exersito Iverica in 2008, the A1 variant was armed with the 120 mm L/44 gun and powered by the conventional 4D8CV 8-cylinder engine. This first variant of the UC-42 already featured modules and systems that would later be improved or enhanced by the addition of subsequent systems. The A1 lacked the detection avoidance features that would later come stock on the A2 variant. During the time of its release, the Sense-6 Infrared system was still being tested and A1 units entered service with only the passive laser-warning receivers installed. The A1 featured an optional autoloader that would later come standard on the A2. It also mounted the first generation of the Interfector hard-kill Active Protection System, the Mago-6 countermeasure launcher, and the Mariscal II computer. A1 and A2 Units designated for command vehicles also entered service with the VPS-5C radar installed, though all vehicles could easily mount the radar unit if needed. The first generation of 4D8CV engines did not yet feature cylinder deactivation, nor the advanced cooling system.

A2

The A2 variants entered service in 2018 and at the time, were widely considered by TRIDENT militaries as the most advanced main battle tank to enter service in the wurld. The UC-42-A2 firepower was greatly improved with the installation of the Arx 128 mm L/42 gun, an armament designed to take advantage of the MBT-110 Balistario gun-launchable ATGM and the G900-WU tungsten supersabot. The vehicle featured a full electronics suite adding the complete Sense-6 system, detection avoidance coatings and upgrades, an advanced engine and exhaust cooling system, and the second generation 4D8CV-CD engine which increased fuel efficiency.

Gallambrian A2 variants entered service as the M4A1 Malya. M4A1s were procured with the 120 mm L/44 gun mounted. As of 2022, Malyas have been refitted with 128 mm L/42 guns.

A3

a Huntsman radar panel

Comprised of updated powerpack, titanium armour plates for the front arc, and a multifunction AESA radar, the A3 was a modular update to the same A1 and A2 chassis. The A3 modules were initially planned to be produced stock for the A2 but issues in earlier trial stages delayed their acceptance by the Iverican Ministry of Defence Procurement Office.

The A3's powerplant was announced in 2021 as the Toledo Heavy Industries 2M6CO-CD and was designed in collaboration with Cavellero Heavy Auto. The 2M6CO-CD is a 2-stroke, 6-cylinder, opposed-piston engine with a displacement of 22 litres and an output of 1,500 horsepower. The engine was designed to be a multifuel engine with a higher compression ratio than the 4D8CV family. Though it retains an identical liquid-cooling system, cylinder deactivation feature, and is equipped with the same twin-turbochargers as the 4D8CV though its I-VTEC system had to be re-engineered for the new piston layout and action. The design is projected to deliver a large increase in power and acceleration while minimising the increase in consumption that comparable 1,500 h.p. V-layout engines would normally entail. The engine is also compact enough to fit into A1 and A2 engine housings and only requires a minor modification of the drivetrain. However, its increased width necessitated a reduction in the main fuel tank's volume; a difference which was compensated for by enlarging the auxiliary tanks beside the driver's station.

The new composite armour panels for the A3 package are similar to the Toledo Composite Pattern 3 used by the A1 and A2 variants. However, the new Toledo Composite Pattern 3T panels use titanium alloys instead of steel for the inner layer of soft steel. The alloy used in the new panels is stronger and lighter. Tests with kinetic penetrators and shaped-charge munitions revlealed a greater resistance to deformation and buckling while being 30% lighter than the previous Pattern 3's inner layer. The lightened inner layer allows for the Pattern 3T to mount a thicker core of nano-metric steel and a thicker high-hardness steel strike-face while weighing only 8% more than the Pattern 3. The heavier armouring on towards the front of the vehicle balances the mass displaced by the heavier 2M6CO-CD powerplant.

A3 units feature a consolidated surveillance and APS fire-control radar, replacing the 2 radar systems mounted on previous variants. RI/VPS-5C and VPG-40 units will be replaced with the Aerano Huntsman Advanced Compact Radar Defence System-Land (ACRDS-L), a set of 4 AESA panels capable of simultaneously searching, tracking, and providing fire-control for the Interfector Active Protection System and the Fusiliero-IV fire-control computer. The Huntsman radar was designed as an advancement of the Interfector's VPG-40 radar, adding adaptive beamforming, frequency modulation, multi-mode send & recieve, Electronic Counter-Countermeasures, and adding an organic processor to assist interface with an onboard combat management computer. The entire system weighs 138 kilogrammes, consumes an average of 1 kW/h and can be equipped on the VPG-40's panel mounts without alteration. The system can operate in a low-probability-of-intercept mode, and is jam-resistant. It can detect targets beyond line-of-sight using beamforming and modulation features to diffract its emissions. It can detect small UAVs at 3 km, person-sized contacts at a maximum of 7 km, surface vehicles at 15 km, and larger aerial vehicles at 15-22 km depending on altitude. An accurate firing solution quality track on an MBT-sized contact can be resolved at approx. ~5 km depending on terrain and the height of the contact. The Huntsman has an active air and liquid cooling system for operation in temperatures exceeding 55°C.

Subvariants

UC-42-B

The "B" variant of the UC-42 is a breaching vehicle in use by mechanised engineer units. It has a a similar hull and running gear configuration as the U1 urban assault variant. The breaching vehicle has no main gun and is instead equipped with 2 Mine-clearing line charge launchers mounted atop the turret. These breaching vehicles are often equipped with mine plows, a Beagle Mine Detection System, and a RI/VLQ-12 CREW Jammer.

UC-42-E1

In 2009, the Export variant of the UC-42 first entered service with the Galician Army. Like the A1, it utilised the 120 mm L/44 and the first generation 4D8CV engine. It did not come equipped with the advanced cooling system, the Sense-6 infrared system, detection avoidance features, nor the multifunction radar. Features like the the Mariscall II computer and composite rubber tracks were also absent. Instead, the E1s were equipped with a basic combat management and ballistic processing computer that did not utilise many of the C4I enhancements present on Nousphera systems. The CRT tracks were also replaced with conventional steel tracks.

UC-42-U1

The U1 urban assault vehicle was a special limited variant intended to outfit the UC-42 for operations in built-up areas and densely vegetated areas. Initially requested by the Armada Tercios who often deployed in foreign urban areas, the U1 has since been included in Exersito inventories.

Developed on an A2 testbed, the UCV design team intended for the U1 to used some A2 features while also excluding many modules thought to be irrelevant to the urban assault mission set. Most notably, the U1 featured a shortened 128 mm L/34 main gun, additional applique armour, and a supercharged 4D8CV engine. The shortened gun sported a reinforced barrel short enough to bring to bear in the tight confines of an urban battlefield. The additional velocity provided by the L/42's length was disregarded as the U1 primarily fired high-explosive, shaped charge, anti-personnel, or missile ammunition which did not benefit very much from added velocity at urban engagement ranges. Given its extra armour, the U1 is the most heavily armoured and well-protected variant of the UC-42 family. Apart from Level-III armour, it sports additional ERA blocks on top and rear areas of the hull and features modular anti-rocket slat barding to help defeat shaped charge attacks. The supercharger was added on the engine to drastically increase torque and power almost instantaneously while also being easier to maintain than an advanced twin-turbo. The UC-42-U1 was envisioned as a vehicle capable of easily traversing large concrete debris mounds, steel fencing, and other vehicle chassis with ease. Its tracks were also strengthened to supplement urban mobility, being made partially out of tungsten.

The vehicle was designed to carry an additional crewman, a loader as the design requirements called for an increased ammunition capacity. The inclusion of a loader also improved the vehicle's overall close-quarters situational awareness and enabled the mounting of a low-profile 8.6 mm (.338 calibre) remote weapons station on the left-hand side of the turret. To assist the loader with hefting 128 mm ammunition, the fighting compartment features an adjustable hydraulic feed tray and rammer to reduce the physical strain.

Unlike other variants, the U1 was thought to have no need for a multifunction radar given its urban mission. Instead, U1s are typically equipped with a pair of mine and blast resistant dozer-blades, have their under-hulls reinforced with double-v applique plating, and have a slightly increased ride height to help defeat mine or IED blasts. The U1s can also mount RI/VLQ-12 IED jammers and the Beagle Mine Detection System. The Mago-6 launchers on the U1 variants are commonly loaded with tear gas grenades alongside the combined smoke and chaff grenades.

Specifications

	UC-42-A1	UC-42-A2	UC-42-A3
Designer	Arx Arms Manufacturing, Universal Combat Vehicle Design Works
Manufacturer	Paseo Tank Plant, Llanuras Arsenal
Produced	2008-2017	2018-present	2022-present (in limited production)
Operator	Ducal Army of Verde, Girkmandian Army, Galician Army, Iverican Army	Gallambrian Army, Iverican Army, Republican Marine Regiments (Armada Tercios)	Gallambrian Army, Iverican Army, Republican Marine Regiments (Armada Tercios)
	Technical Details
Length	9.48 m (31.1 ft) (with gun forward)
Width	3.4 m (11 ft)
Height	3.1 m (10 ft) (turret roof) 3.7 m (12 ft) (with gun mount)
Weight	42 t (41 long tons; 46 short tons) (Baseline/Level-I Armour)	42.6 t (41.9 long tons; 47.0 short tons) (Baseline/Level-I Armour)	45 t (44 long tons; 50 short tons) (Baseline/Level-I Armour)
Engine	4D8CV 4-stroke 22.6-litre diesel V8 engine 1,200 hp (890 kW)/2,300 rpm	Gen-2 4D8CV-CD 4-stroke 22.6-litre diesel V8 engine 1,200 hp (890 kW)/2,300 rpm	2M6CO-CD 2-stroke, 22-litre multifuel, 6-cylinder opposed piston engine 1,500 hp (1118 kW)/2,600 rpm
Power/weight	28.57 hp/ton	28.16 hp/ton	33.33 hp/ton
Range	500 km (310 mi)	665 km (413 mi)	approx. ~700 km (430 mi)
Max. Speed	70 km (43 mi) /h
Suspension	Hydropneumatic suspension
Crew	3 (commander, gunner, driver)
	Armament
Primary	Arx 120-4 GCM, 120 mm L/44 smoothbore gun	Arx 128-2 GCM, 128 mm L/42 smoothbore gun
Ammunition	APFSDS (hybrid tungsten-depleted uranium sabot), Anti-personnel flechette, ATGM, Thermobaric HESH, MP-T, others
Secondary	1×12.7 mm Remote Weapon Station 1×8.6 mm Coaxial Machine Gun
	Protection
Armour	Toledo Composite Pattern 3 (baseline armour) with applique composite armour and ERA		Toledo Composite Pattern 3 & Pattern 3T (turret & front arc) with applique composite armour and ERA
Passive	Applique Multi-spectral Camouflage Net, Laser-Warning Receiver	Multi-spectral coating (anti-infrared/anti-thermal, radar-absorbing polymer)
Active	Interfector APS	Interfector APS, Sense-6 Semi-Active Infrared Warning Sensor with Directional Infrared Counter Measure dazzler.
Launchable	18 × grenades
	Electronics, Signals, & Support Measures
Communications	HF Tactical Radio (LPIR Capable), Compact TACSAT, Access to Nousphera Digital Data Link
Computers & Software	Mariscal-II C4I Computer running: Fusiliero-IV Ballistic Calculator DorTAK BMS (network sync mapping, plotting, & forces tracking) vehicle management controller drone controller Auxiliary fire-control computer
Electronic Support	Opera-L IV ESM (command vehicles only)
Signals Surveillance	Optional mounting for RI/VPS-5C Multifunction Radar and Beagle Mine Detection System		Aerano Huntsman ACRDS-L Optional mounting for Beagle Mine Detection System

Operators

• Duchy of Verde
  • Ducal Army of Verde
    • 62, UC-42-A1
• Gallambria
  • Gallambrian Army
    • 376, UC-42-A2 (M4A1 Malya)
    • Unknown quantity, UC-42-A3
• Girkmand
  • Girkmandian Army
    • 60, UC-42-A1
• Greater Galicia
  • Galician Army
    • 80, UC-42-E1
    • 50, UC-42-A1
• Iverica
  • Exersito Iverica
    • 186, UC-42-A1
    • 784, UC-42-A2
    • 112, UC-42-A3
    • 120, UC-42-B
    • 126, UC-42-U1
  • Armada Tercios
    • 225, UC-42-A2
    • 15, UC-42-A3
    • 30, UC-42-B
    • 60, UC-42-U1