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	Duchy of Verde Gallambria Girkmand Greater Galicia Iverica
Production history
Designer	Arx Arms Manufacturing
Designed	2004-2007 (A1)
Manufacturer	Arx Arms Manufacturing
Unit cost	A1: $10.5 million (FY2021) A2: $13.5 million (FY2021) E1: $9.5 million (FY2021) U1: $14 million (FY2021)
Produced	A1: 2008-present
No. built	1,018
Variants	UC-42-A1 UC-42-A2 UC-42-E1 UC-42-U1
Specifications
Weight	42 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 armor Additional applique explosive reactive armour
Main armament	A1, E1: 120mm L/44 ARX 120-4 LSG smoothbore gun A2, U1: 128 mm L/41 ARX 128-1 LSG smoothbore gun
Secondary armament	1 × 8.6 mm machine gun (coaxial) 1 × 12.7 mm (RWS)
Engine	A1, E1: Toledo Heavy Industries 4D8CV 4-stroke 22.6-litre diesel V8 engine A2, U1: Toledo Heavy Industries Gen-2 4D8CV-CD 4-stroke 22.6-litre diesel V8 engine 1,200 hp (890 kW)/2300 rpm
Power/weight	Baseline: 28.57 hp/tonne Level-II: 25 hp/tonne
Transmission	Continuously variable transmission
Suspension	hydropneumatic suspension
Operational range	A1 (Level-II): 480 km (300 mi) A2 (Level-II): 520 km (320 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 Co. 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 equipped to support Network-centric warfare in addition to its ability to engage vehicles at stand-off ranges. The UC-42 also features advanced sensors such as radar and infrared systems that contribute to its survivability.

History

In 1999, 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 2001, 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 40-tonne baseline weight, a gun armament capable of penetrating 1200mm of RHA in effective thickness while also being capable of firing 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 2004.

Both companies had just over 14 months to produce a functional prototype. Whereas Arx Arms had already created and tested interoperable modules, Cavallero started from scratch. In March of 2005, 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 120mm 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 April, the following month, Arx Arms was awarded the contract.

Initial Production

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 produced during 2008-2010 and 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 120mm 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 C41 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.

Updates & Further Production

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 120mm 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 128mm main gun 41 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 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 200 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 200-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.

Design

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 maintence. 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 gas-operated 8.6mm (.338) GPMG fed with an 800 round belt. The Léon may also carry additional 12.7mm heavy machinegun remote weapons system. The tank is protected by lightweight composite armour using a mix of nano-metric steel, elastomers, and high-harndess steel. Additional protection includes a 2 additional levels of applique protection including ballistic-ceramic composite and explosive-reactive armour.

Safety measures include CBRN protection, a 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.

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

Multiview drawing of prototype UX-42 "Bravo"

Protection

Armour
The UC-42's baseline armour is constructed from nano-metric steel panels laminated with 2 layers of steel composites. Elastomer layers are pressed between two high-hardness steel strike faces to help distribute forces across the area of the plate. The outer surface is coated in slip-resistant fibreglass and a thin polymer that adds some thermal-reflective and radar-absorbing properties. A fibre-resin spall liner is added to sections of armour exposed to the fighting compartment and driver's compartment.

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 ballistic-ceramic plates. Square-hollow steel reinforcement helps protect against deformation, displacement, or warping. The Level-II segments added to the turret are also shaped to reduce the UC-42's radar cross-section. 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. 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.

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.

An Interfector EFP launcher

Infrared Sensors
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 Infrared Proximity Warning Sensor is composed of 6 transceivers and a computer. Each sensor passively scans a 70 x 70-degree area in front of it to detect thermal signatures and dense, opaque obstructions. When a thermal profile matching a missile or rocket is detected, Sense-6's computer system can trigger the Interfector APS launchers. Sense-6 is also effective at detecting enemy laser marking and can act as an electro-optical disruptor against range-finders, designators, and ATGMs reliant on laser guidance. Sense-6 can also function as a close-quarters infantry sensor for the crew, to detect if infantry are moving around the vehicle; this can reduce the risk of driving accidents or warn the crew of potentially hostile infantry. Though initially selected for use on the UC-42, reliability concerns and false-trigger accidents resulted in the disabling of Sense-6's fire-control function.

Other Countermeasures
To block line of sight, a visual lock, or a laser-guided lock, the UC-42 crew can trigger a pair of 66mm Smoke launchers containing 6 grenades each. Though a variety of grenades including teargas grenades can be loaded, the most common type of grenade loaded is the G-53 smoke & chaff grenade which is a Hexachloroethane grenade that also releases alumina particles to obscure laser or radar targeting.

Detection Avoidance
The UC-42-A1, E1, and U1 have no stock detection avoidance features. Thus far, the A2 variant is the only variant to feature these measures by default. Current detection avoidance measures for the A2 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 absorbing 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 heatsink 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.

Safety Measures
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 last 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 risk. Instead, interior mounting was usually fixed using a slotting system.

Bulkhead & blow-off, FM-2000, CBRN, ventilation & filtration, anti-incindiary measures, periscope/optical cleaning systems.

Mobility

Engine

A 4D8CV engine

All variants of the UC-42 are equipped with a 4-stroke V8 diesel engine. It is a high-displacement, high-compression, liquid-cooled, naturally-aspirated engine rated to output 1200 horsepower at 2300 RPM and a maximum torque of 3880 Nm. The engine is classified as the Type 4D8CV, part of a family of engines used in Universal Combat Vehicles in the weight range of 30-50 tonnes. 4D8CV engines use a 60-degree V-block arrangement and Intelligent Variable Timing and Lift Electronic Control, or I-VTEC. Units produced for UCVs utilise a high percentage of niobium in the engine block, cylinder head, 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. However, natural aspiration was chosen for most variants to conserve fuel economy.

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 three of the 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 offset, to the left-hand side of the central axis. It is adjacent to the rear left side of the fighting compartment. This is done to accommodate an auxiliary power unit (APU) 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.

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 UC-42 demonstrating its braking and suspension

Suspension
All variants are equipped with Hydropneumatic Active Suspension. The chassis rests on 5 torsion bars connected to 5 pairs of roadwheels by a 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 degrees glacis-downward or glacis-upward.

Auxiliary Power Unit
The UC-42's APU is mounted adjacent to the fighting compartment, on the front right-hand side of the engine compartment. The APU is a liquid-cooled, multifuel, diesel generator capable of a maximum output of 22kW. The APU is capable of powering the suspension, optics, active protection system, ventilation, autoloader, driving controls, communications, and C4I systems. However, neither the multifunction radar nor the Sense-6 IR transceivers can function while all the aforementioned 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.

Armament

File:German Rheinmetall 130mm.jpg

an L/51 variant of the 128-1 LSG