Dostanuot Loj
30-05-2007, 12:42
OOC: Long time comming from me. So I'm posting this partially for reference, partially for export of the C to anyone interested. The export model is the MCA-7C, which will be the second post if no one else posts between the time I post and the time I copy, paste, and post again.
MCA-7B "Ubara Tirak" Medium Battle Tank
http://img.photobucket.com/albums/v322/Dostanuot/MCA-7B.png
Prmary Design Stages:
- MCA-7A: Initial Prototype Variant. Retired.
- MCA-7B: Primary production variant. In Production.
- MCA-7C: Export Variant. In Production.
- MCA-7D: Rebadged MCA-8. Under Development.
Basic Design:
The primary design of the MCA-7 series of vehicles is to provide the Sumerian Republican Guard with a highly protected, highly mobile, and highly efficient armoured killing platform for use both at home and abroad. As the latest incarnation of the MCA program, it is designed to engage enemy tanks in combat, with limited self protection from infantry as an adverse side effect. The nature of the terrain in and around Sumer forced designers to approach a slightly heavier design with thicker armour on the sides of the hull and turret to facilitate maneuvering in the open savanna that this vehicle would most often be encountering. While the resulting vehicle is able to operate in a limited fashion within mountainous and jungle terrain, the home terrain, as it would be, of this vehicle was deemed more to be the open fields and deserts. Thus care was taken to design a vehicle that would not compromise it's ability to operate effectively in the terrain of choice just to provide a more multi role oriented vehicle, a failure that befell the MCA-5 and MCA-6 earlier.
The hull layout of the MCA-7 series follows the standard Sumerian tank design since the MCA-4 program, that of a base structural armour with added on modular armour components to provide highly replaceable strength. Construction is done mostly of titanium alloys which are more widely available within Sumer then steel materials. Composite materials and synthetic fibers, as well as ceramics are also used heavily.
Power is provided by the new Guarita DO86-2S99 engine and accompanying transmission system, designed in a modular power pack that can be completely removed and replaced quickly in the field with minimal time, and if needed with no lifting crane. The vehicle is equipped with hydraulically adjustable suspension over a large number of small road wheels to lower the ground pressure as much as possible. Wide seventy two centimeter tracks are provided as standard to ensure the vehicle the ability to move through all terrain.
With a large 115mm smooth bore anti tank cannon and supporting machine guns and grenade launchers, as well as an effective armoured protection system the MCA-7 series was designed to be a force to be reckoned with for many years to come on the battlefield. The digital fire control system allows accurate fire from the main gun while moving out to as far as five kilometers. Additionally, advanced optical systems allow the commander and driver greater views of the battlefield around them, providing increased tactical mobility for the vehicle.
The MCA-7B has, overall, exceeded the design requirements for the Sumerian Republican Guard for their next generation medium tank, and has found a welcome home within the Temple Guard as well. As an effective fighting platform and tool, the MCA-7B has earned welcome respect within the Sumerian Armed Forces.
History:
Work on the MCA-7B program began shortly after the MCA-7A finished production. The A model was quickly found wanting in several areas when put into direct low intensity combat usage on the North-Western border. Engagements with numerous opposing armoured vehicles showed that while the A was satisfactory in its design features, it would soon be lacking when brought to bare against modern systems coming out in the near future. Thus a five year improvement development plan was put in effect by the Republican Guard to improve upon the A model in the near future. With detailed evaluations and reports on the performance of the A model and its features coming in almost daily the number and extent of improvements to the basic A design was showing. Within a year the Republican Guard Armour Standards Committee (RGASC) had compiled a list of required performance characteristics which the new model, designated the MCA-7B, would have to meet. The design requirements were shown to the Office of the Dictator, which approved the project for development, and then to the Civil Senate, which after a vote approved the funding needed. Design elements were quickly sent out to various production facilities to be designed in conjunction with the main vehicle components at the Nineveh Armour Works.
Among many design improvements, the pressing need for a more powerful main gun was foremost in the design features. Various approaches were tested to improve the 105-85mm tapered smooth bore of the A model with no success. Eventually more traditional 120mm, 125mm, 130mm and even 135mm smooth bore guns were tested, but again these projects were considered unsuccessful. Armour protection was also a major complaint from field reports, with the protection quality coming under serious question. The final nail in the coffin of the A series was the power plant, which was deemed too heavy and bulky to be effective within the vehicle. Different combinations of various alternative systems were tried, and the resulting nine first-run prototype test vehicles were put through combat trials outside of Nas-Arabeh on the 14th of Simanu, exactly three years after the project had begun. After three weeks of combat testing against each other, the MCA-7A, and several foreign vehicles of expected similar capabilities, all but three of the prototype combinations had been found to be unusable. The three remaining prototypes, BP2, BP5 and BP9, had all unfortunately broken down during the trials as well due to track failure. As all the prototypes used the suspension, road wheels and tracks of the MCA-7A, the order was added to the design requirements for a new track and suspension system.
With lessons learned from the Nas-Arabeh trials, and with neither of the three acceptable prototype designs completely fulfilling the design requirements, the project team returned to Nineveh and began work on the second series design prototypes which were to incorporate features of all three prototypes. Within a year a further three prototypes were under construction, designated BP10, BP11, and BP12. The three second series prototypes were identical to each other, with specific design features now settled on a prototype systems coming in from the affiliated production facilities. Two of the prototypes, B10 and B12, were put through combat rigorous trials outside of Nas-Arabeh again, and then quickly sent to the North-Western border for combat trials. The third prototype, B11, was demonstrated to the Office of the Dictator, representatives from the Civil Senate, and members of the RGASC outside of Nineveh. Following combat reports and the successful demonstration outside of Nineveh, the Office of the Dictator approved a slightly amended design to the second series prototypes for production as the MCA-7B. Production started in Tebetu of the year 10,118, with the first units delivered in secret to the Inanna Temple Guard Regiment by mid-10,119. Increased demand for the MCA-7B has led to increased need for production, and sixteen new manufacturing plants have since had to be constructed to facilitate the demand. Additional production is now avalible, as current goals are being met and exceeded.
Protection:
The armour layout of the MCA-7B is a radical change from the previous MCA-7A and MCA-6 series tanks in that it uses two to three layers of supporting armour types to provide maximum protection, a system inadvertently built into consecutive upgrades to the venerable MCA-3 series of tanks. The armour is, at it's base, an alternating series of solid titanium alloy plate and titanium alloy “box” plates which are made up of a honeycomb like mesh of titanium alloy encased in a titanium “box” like shell. The internal structure, at it's thickest, contains two “box” sections sandwiched within three thick titanium alloy plates to provide a strong and rigid base that is still light weight.
The secondary layer of the armour consists of modular blocks of ceramic-metallic material encased within a titanium alloy shell. Within the ceramic-metallic material are rigid depleted uranium sheets, each a hemispherical shape with the outer curve pointing outwards from the vehicle, set to provide as much overlapping cover of high density material as possible. The ceramic-metallic material is further reinforced through the impregnation of randomly positioned carbon nanotubes throughout the material, in a similar way to the way glass or carbon fiber is used to reinforce plastic. Such carbon nanotubes are produced through simple flame method, and are highly irregular in both size and quality, but add greater strength to the ceramic-metallic integrity then conventional glass, carbon, or synthetic fibers. The ceramic-metallic material is further encased in several layers of resign impregnated sheets of woven high performance polyethylene layered in interlocking and alternating patterns to provide excellent integral strength to the ceramic-metalic material, and together with the loose fiber reenforcement, keep the ceramic-metalic material from shattering, thus allowing it to absorb multiple rounds before failing. These second layer modules are layered in two alternating layers ontop of the structural componant of the armour to provide as few areas for penetration as possible. Each module is custom shaped and constructed for the vehicle, and varries in thickness and area covered, as well as shape, to allow maximum coverage. Modules not designed for the primary fighting arc of the vehicle, the forward and forward-side arcs, are not provided with the depleted uranium insert. Areas such as the hull and turret rear, as well as the rear-top of the hull and turret have only one layer of these modules, with the additional part occupied by integral water storage tanks formed of resin hardened high performance polyethylene, for storage of much needed distilled water.
The third and final layer of the armour is a made up of larger plates of the titanium alloy honeycomb “box” filled with a synthetic rubber material that is impregnated with loose high performance polyethylene fibers to increase strength. The entire assembly is encased in thin titanium plates and coated by several thick layers of resign hardened woven high performance polyethylene fiber sheets. This third layer is designed primarily to offer lower level ballistic protection to the vehicle within a highly modular package that can be changed and replaced as needed.
Finally the armoured protection suit of the vehicle is enhanced by the integral Enlil armoured protection system (APS), which uses milimeter wave radar and various IR sensors to detect incomming rounds and calculate their trajectory. The Enlil APS fire control system, when armeded, then automatically fires the coresponding launcher, or launchers, for the integrated 50mm defensive grenade system. The 50mm grenade system used by the Enlil APS is seperate from the defensive grenade launcher suit, and can only be fired from an active Enlil APS. The grenades themselves lob at a short but high arc, allowing them to cover essentially a sphere around the vehicle. The grenades themselves deatonate to throw a mass of high density tungsten rod fragments in the path of an incomming projectile to distroy, disable, or otherwise distort it's flight path and remove it's effective armour penetrating ability. The Enlil APS uses twenty such grenade launchers built into the turret, each firing from a nine grenade magazine, allowing the use of the system against multiple targets from the same area.
Armament:
The primary armament to the MCA-7B is the new Type-3650 115L60 smooth bore anti tank gun. The Type-3650 gun is a high velocity long smooth bore gun that uses a two stage loading round to achieve maximum power in a compact design. The Type-3650 uses the new An-1000 series of tank munitions which comprise of the projectile and the propellant as separate parts. The propellant stage is made from a compression formed and resin bonded solid propellant outer shell derived from the primary gelatin propellant contained inside. Within the outer case is a high efficiency gelatin propellant which provides greater power and a cleaner more efficient burn during ignition then conventional solid propellants. The propellant is ignited through the insertion of an ignition probe through the propellant casing to contact the gelatin primary propellant. The ignition of the propellant is done through the release of a short but high intensity ultraviolet radiation pulse into the propellant which forces the entire cartridge to detonate through chain reaction of the detonating primary propellant. This type of ignition allows for a design of the propellant which will be less likely to detonate when struck by an enemy anti tank round, as well as propellant that will burn more efficiently within the barrel reducing the amount of cleaning that must be done. Projectiles available to the new Type-3650 gun include the entire spectrum of An-1000 series 115mm rounds. Among the most promising rounds of the new series include the An-1000A Ballistic Shell Rocket Assisted Discarding Sabot Kinetic Energy (BSRADSKE) round, affectionately known as “The Thing” by crews. The An-1000A uses a new long rod penetrator design made of high density depleted uranium alloyed with titanium and molybdenum designed to provider greater penetration capability over previous long rod designs. Because of the inefficient aerodynamic qualities of the new penetrator design the round is encased in a copper ballistic shell which is designed to easily sheer off during penetration, but to increase aerodynamic efficiency of the round and allow it to hold a greater amount of kinetic energy over longer distances. The copper ballistic shell is designed to keep the overall diameter of the penetrator to no more then 34mm diameter, while providing a more streamlined flow of air over the round in flight. Stabilization of the round in flight is provided by four narrow titanium fins forward and four at the rear of the projectile, offset to provide the greatest stability over the length of the penetrator and allow greater accuracy over long range. Finally the An-1000A is equipped with a light weight solid fuel rocket motor which is designed to keep the round at a high velocity, close to that of the muzzle velocity, out to a greater distance, allowing longer ranges to be achieved. The rocket system, conversely, reduces the accuracy of the round slightly over range, however an unrocketed version, the An-1000B, is available with a more conventional kill range but slightly more accuracy out to those ranges. Other rounds available within the An-1000 series include conventional APBC, HEAT, HE, HE-Frag, Smoke, Illuminating, and APFSDS rounds, as well as the An-1000M gun fired guided missile currently under development.
The Type-3650 main gun is made from high strength titanium alloys, allowing the use of greater pressure propellants, but at a slight cost in reduced life time of the barrel. The gun itself is fed through the Type 998-X16B two stage autoloader, which uses a mixed carousel and bustle storage system within the tank to store the rounds and propellant sections. The rounds are stored individually within armoured containers around the turret basket similar in operation to older Soviet T-80 auto loaders, storing the rounds upright and ready for loading. This design feature of only the actual projectiles being stored in the turret bustle allows for all forty two rounds carried by the tank to be fired in succession quickly. The projectiles are loaded into the gun by a lifting arm which when level with the breach also acts as a bridge for the propellant pushed in from the bustle. The propellant is however stored in individually armoured bins within the turret bustle and aligned on a chain type automatic selection system. Propellant storage is separated from the rest of the vehicle by an armoured bulkhead, with blow out panels provided encase the propellant is hit and detonated. The propellant sections are fed into the gun by an electric actuator which pushes the round onto the projectile lift arm, and then forces both the projectile and the propellant stages into the gun. Although more complicated then the typical autoloader system, the Type-998-X16B allows for fast and reliable rates of fire while maintaining a high number of rounds ready to fire and providing safe storage for those rounds.
Additional armament of the MCA-7B includes a dual feed 15mm heavy machine gun mounted coaxially to the main gun, as well as a 50mm smoke and fragmentation grenade system which fires four grenades from eight launchers provided around the rank. The heavy machine gun is slaved to the main gun and operated by the gunner, but allows the destruction of light vehicles and infantry without the use of the main gun, while maintaining enough power to penetrate light walls or to reach infantry at a greater range. The grenade dispersion system is designed to give overlapping fields of fire around the tank to lay either a full smoke screen, or to lay fragmentation grenades to discourage nearby enemy infantry from approaching, the system is controlled by the tank commander, who may fire the launchers individually or in groups ranging from two launchers to all of them. Provisions for lighter machine gun mounts are provided for both the commander and gunner hatches as well, but rarely used.
Mobility:
The MCA-7B is powered by the next generation in tank engine to come out of the Guarita Engine Production Facility, the DO86-2S99. This new engine was designed specially for the B series upgrade to replace the previous Flat-12 cylinder engine in the A series, a carry over from late model MCA-6 upgrades. The DO86-2S99 is an opposed piston engine that consists of two banks of four cylinders layered one atop the other, in similar fashion to the H configuration of some Boxer engines. The engine is multi fuel capable, allowing greater versatility in the field, and compatibility with foreign fuel stocks if needed. The major design difference of the DO86-2S99 as compared to previous opposed piston engines is the use of a water injecting six stroke cycle. In this system the engine operates as a typical four stroke engine for the first four strokes, except following the exhaust stroke fresh distilled water is injected into the cylinder where the residual heat of the combustion turns the water into steam, forcing another power cycle after the combustion cycle, as well as cooling the engine. This process allows a close to fifty percent gain in fuel efficiency for a given amount of power, with the added benefits of vastly cooler engine and exhaust temperatures, as well as lower maintenance issues related to normal wear and tear from the heat of combustion.
The cylinder design of the DO86-2S99 is not a pure opposed cylinder design. The two pistons are separated by an hour glass shaped cylinder pseudo-head which contains the necessary injection systems for the fuel and water injection as well as secondary ignition systems, while providing optimum compression and flow through required for linear operation. The layout of the engine is such that exhaust from the engine flows through a central exhaust conduit inside the engine between the cylinder banks, allowing the intake systems to be more isolated from heat on the outside edges of the engine.
The engine itself is made primarily out of milled titanium, and special poured ceramic insulation. The ceramic insulation is mainly used to surround the cylinders and exhaust conduit to isolate residual heat from the rest of the engine. Milled Titanium makes up the primary component of the majority of the engine, including the block, cylinders, pistons and crankshafts. Milled Titanium is used to increase engine life and durability and strength while reducing weight.
In it’s primary configuration the DO86-2S99 uses two mechanically powered twin-screw type supercharges which take in air from the engine filtration system and compress it. The compressed air from the superchargers is fed through an inter cooler before being split evenly between the two cylinder banks through a series of pipes. Each supercharger being individually driven from one of the two crankshafts. The engine itself having two crankshafts, one per side, each running eight pistons, similar in action to a V8 engine.
At half the mass and volume of the previous Flat-12 engines, while maintaining the same power output, the new DO86-2S99 engine enabled the integration of transmission and engine into a single modular removable component of the drive train, which has greatly reduced engine change and repair times in the field.
The Under Armour Auxiliary Power Unit UAAPU of the MCA-7B uses a small gas turbine powered generator system to provide power to the vehicle while the engine is not running, or damaged. An added feature of the UAAPU is that the exhaust from the gas turbine used to generate electrical power can be ducted into the intake system of the main engine performing what is known as a dry start. The dry start capability of this system allows the use of the gas turbine's hot exhaust gases to preheat the DO86-2S99 cylinders before use, allowing much quicker start up times and faster time to power of the engine.
The transmission used is the Type-190 Hydrostatic transmission from the Guarita Production Facility as well. Using the two crankshafts from the DO86-2S99 to power two dual hydraulic pumps, each one both pushing and pulling the fluid through the system, the transmission works using high pressure hydraulic fluid inside specially designed piping to provide both electrical generation power and movement. Through a series of thick double-layer titanium pipes, hydraulic fluid flows through two input transfer pumps which transfer the energy of the hydraulic fluid to the two drive train final gearboxes. The final gearboxes are both automatically variable planetary gear systems, allowing automatic shifting as needed through six forward and four reverse gears. The use of variable volume pumps for both the input transfer pump and the push-pull power pumps allows the speed of the final drive shaft to be altered without altering the speed of the engine or the gear ratios, which allows the engine to run at optimum RPM and power output regardless of the speed of the tank. Forward and reverse gears are used to increase or decrease speed frames in both directions for the whole vehicle, while directional input from the driver changes the speed of either track to change direction. This RPM-independent power system allows the vehicle to utilize it’s full power range at all speeds, giving it superior mobility on all terrains then previous MCA generations, and indeed many contemporary vehicles.
The vehicle is suspended on eighteen road wheels through a long-arm hydro-torsion bar system. The system is based around the standard tube-over half-length torsion bar system of the A series, mounted in a semi-twisting housing that allows the whole apparatus to twist fifty degrees before being stopped by a block in either direction from a set plane. A hydraulic ram system is used to change the angle of the torsion bar assembly allowing the system to change ride height to the road wheels individually while maintaining the suspension qualities of the torsion bar system. In the event of a failure to the hydraulic system the hydraulic ram is locked in whatever position it was in at the time and left to operate as a pure torsion bar system. A pressure relief valve in each ram cylinder allows pressure to be bled from the cylinder if the weight of the vehicle is unequally shared by up to three road wheels on either side, allowing the vehicle to distribute the vehicle weight over all the road wheels available on one side evenly even if the system locks up with the suspension set to different angle planes.
Crew Systems:
The MCA-7B comes with a wide variety of advanced systems to provide both efficient execution of the crew's tasks and provide optimal comfort to the crew within the vehicle. The vehicle is equipped with, among other things, an integrated air conditioning system which controls the general climate within the vehicle as well as controlling the internal atmosphere and protecting the crew from external nuclear, biological and chemical threats. The air conditioning system is further taken to provide each of the three crew members with an adjustable climate at their station, allowing the crew maximum comfort in all temperature ranges. Additionally the use of adjustable gelatin filled seats integrated with the climate control system through the use of air tubes within the seats to carry warm or cold air from the air conditioning system and either heat or cool th seat as needed, for extra comfort and to allow the crew to operate for extended periods of time. Each crew station has additionally, enough room to provide enough limb movement to allow the crew to stretch without having to vacate the vehicle.
Additionally, a water storage system is integrated into the vehicle, as well as a water reclamation system from the engine exhaust and a filtration and distillation system to clean the water. Each crew member is provided with a variable temperature outlet for drinkable water from this system, which is also shared by the engine for it's six-stroke design. This feature allows the crews to drink plenty of water, an essential aspect of operations within the harsh tropical and desert climates of Sumer.
Fire control is provided through a digital fire control computer, and can be operated by both the gunner and the commander if needed. The MCA-7B fire control system allows maximum accuracy for the main gun, and is separate from the rest of the vehicle's systems. The commander has around his station a series of flat screen monitors providing him a day or night image of the outside through a number of carefully placed high definition and wide angle digital cameras on the turret, allowing quick observation of the surrounding terrain. The commander also retains an electrically operated rotating hatch with integrated optical periscopes for use regardless of the state of the digital optics suit. The commander's hatch also contains the combined optical and digital primary commanders sight which provides the commander with both day and night viewing through normal and IR views, as well as the ability to designate targets for the gunner quickly.
All crew controls are provided as digital, with the commanders primary control systems being through touch screen monitors. The driver and gunner however are also provided with limited touch screen capabilities for their stations, including ammunition selection for the gunner and vehicle profile and engine management controls for the driver.
Designation: MCA-7B
- Name: "Urbara Tirak" - "Timber Wolf"
Dimensions:
- Length: 7.7m (Hull)/11.75m (Gun Forward)
- Height: 2.48m (Turret Roof)
- Width: 3.8m (4.2m with Skirts)
- Mass: 78,800 kg
- Track Width: 720mm
Internal Systems:
- Crew: 3
- Autoloader: Type 998-X16B 2-Stage Autoloader
- Ammunition: 42 (Main), 1000 (Coaxial), 180 (Enlil), 32 (Grenade)
- Transmission: Guarita Type 31A Automatic 8-forward 3-reverse
- Fuel Capacity: 1100L (Internal Tank), 400L (External Drum)
- Water Capacity: 600L (Internal Tank), 400L (External Tank)
Powerplant: Guarita DO86-2S99
- Power: 2600 bhp
- Displacement: 21.7 Liters
- Layout: 8 Cylinder Hotozontally Opposed
- Induction: Twin-Supercharger, Dual Fan-assisted Intercoolers
- Fuel Consumption: 1.8L per 1km Average
Performance:
- Maximum Speed (Road): 85km/h
- Range: 610km (830km with extra fuel)
- Power-Weight Ratio: 32hp/ton (Approx.)
- Ground Pressure: 0.9kg/cm2
Armament:
- Primary: Type-3650 115L60 Smoothbore (Single)
- Coaxial: 15mm Heavy Machine Gun (Single Coaxial)
- Dischargers: Grenade, Enlil APS
Armor: Listed maximum approximate armor values.
- Armor Place: RHAe KE/CE thickness
- Hull Glacias: 2800mm/3500mm
- Hull Front: 1500mm/1900mm
- Hull Sides: 1500mm/1900mm *Skirt Included*
- Hull Rear: 600mm/750mm
- Hull Top: 240mm/360mm
- Turret Front: 2800mm/3500mm
- Turret Top: 260mm/400mm
- Turret Sides: 1500mm/1900mm
- Turret Rear: 600mm/750mm
- Turret Mantlet: 3000mm/3700mm
MCA-7B "Ubara Tirak" Medium Battle Tank
http://img.photobucket.com/albums/v322/Dostanuot/MCA-7B.png
Prmary Design Stages:
- MCA-7A: Initial Prototype Variant. Retired.
- MCA-7B: Primary production variant. In Production.
- MCA-7C: Export Variant. In Production.
- MCA-7D: Rebadged MCA-8. Under Development.
Basic Design:
The primary design of the MCA-7 series of vehicles is to provide the Sumerian Republican Guard with a highly protected, highly mobile, and highly efficient armoured killing platform for use both at home and abroad. As the latest incarnation of the MCA program, it is designed to engage enemy tanks in combat, with limited self protection from infantry as an adverse side effect. The nature of the terrain in and around Sumer forced designers to approach a slightly heavier design with thicker armour on the sides of the hull and turret to facilitate maneuvering in the open savanna that this vehicle would most often be encountering. While the resulting vehicle is able to operate in a limited fashion within mountainous and jungle terrain, the home terrain, as it would be, of this vehicle was deemed more to be the open fields and deserts. Thus care was taken to design a vehicle that would not compromise it's ability to operate effectively in the terrain of choice just to provide a more multi role oriented vehicle, a failure that befell the MCA-5 and MCA-6 earlier.
The hull layout of the MCA-7 series follows the standard Sumerian tank design since the MCA-4 program, that of a base structural armour with added on modular armour components to provide highly replaceable strength. Construction is done mostly of titanium alloys which are more widely available within Sumer then steel materials. Composite materials and synthetic fibers, as well as ceramics are also used heavily.
Power is provided by the new Guarita DO86-2S99 engine and accompanying transmission system, designed in a modular power pack that can be completely removed and replaced quickly in the field with minimal time, and if needed with no lifting crane. The vehicle is equipped with hydraulically adjustable suspension over a large number of small road wheels to lower the ground pressure as much as possible. Wide seventy two centimeter tracks are provided as standard to ensure the vehicle the ability to move through all terrain.
With a large 115mm smooth bore anti tank cannon and supporting machine guns and grenade launchers, as well as an effective armoured protection system the MCA-7 series was designed to be a force to be reckoned with for many years to come on the battlefield. The digital fire control system allows accurate fire from the main gun while moving out to as far as five kilometers. Additionally, advanced optical systems allow the commander and driver greater views of the battlefield around them, providing increased tactical mobility for the vehicle.
The MCA-7B has, overall, exceeded the design requirements for the Sumerian Republican Guard for their next generation medium tank, and has found a welcome home within the Temple Guard as well. As an effective fighting platform and tool, the MCA-7B has earned welcome respect within the Sumerian Armed Forces.
History:
Work on the MCA-7B program began shortly after the MCA-7A finished production. The A model was quickly found wanting in several areas when put into direct low intensity combat usage on the North-Western border. Engagements with numerous opposing armoured vehicles showed that while the A was satisfactory in its design features, it would soon be lacking when brought to bare against modern systems coming out in the near future. Thus a five year improvement development plan was put in effect by the Republican Guard to improve upon the A model in the near future. With detailed evaluations and reports on the performance of the A model and its features coming in almost daily the number and extent of improvements to the basic A design was showing. Within a year the Republican Guard Armour Standards Committee (RGASC) had compiled a list of required performance characteristics which the new model, designated the MCA-7B, would have to meet. The design requirements were shown to the Office of the Dictator, which approved the project for development, and then to the Civil Senate, which after a vote approved the funding needed. Design elements were quickly sent out to various production facilities to be designed in conjunction with the main vehicle components at the Nineveh Armour Works.
Among many design improvements, the pressing need for a more powerful main gun was foremost in the design features. Various approaches were tested to improve the 105-85mm tapered smooth bore of the A model with no success. Eventually more traditional 120mm, 125mm, 130mm and even 135mm smooth bore guns were tested, but again these projects were considered unsuccessful. Armour protection was also a major complaint from field reports, with the protection quality coming under serious question. The final nail in the coffin of the A series was the power plant, which was deemed too heavy and bulky to be effective within the vehicle. Different combinations of various alternative systems were tried, and the resulting nine first-run prototype test vehicles were put through combat trials outside of Nas-Arabeh on the 14th of Simanu, exactly three years after the project had begun. After three weeks of combat testing against each other, the MCA-7A, and several foreign vehicles of expected similar capabilities, all but three of the prototype combinations had been found to be unusable. The three remaining prototypes, BP2, BP5 and BP9, had all unfortunately broken down during the trials as well due to track failure. As all the prototypes used the suspension, road wheels and tracks of the MCA-7A, the order was added to the design requirements for a new track and suspension system.
With lessons learned from the Nas-Arabeh trials, and with neither of the three acceptable prototype designs completely fulfilling the design requirements, the project team returned to Nineveh and began work on the second series design prototypes which were to incorporate features of all three prototypes. Within a year a further three prototypes were under construction, designated BP10, BP11, and BP12. The three second series prototypes were identical to each other, with specific design features now settled on a prototype systems coming in from the affiliated production facilities. Two of the prototypes, B10 and B12, were put through combat rigorous trials outside of Nas-Arabeh again, and then quickly sent to the North-Western border for combat trials. The third prototype, B11, was demonstrated to the Office of the Dictator, representatives from the Civil Senate, and members of the RGASC outside of Nineveh. Following combat reports and the successful demonstration outside of Nineveh, the Office of the Dictator approved a slightly amended design to the second series prototypes for production as the MCA-7B. Production started in Tebetu of the year 10,118, with the first units delivered in secret to the Inanna Temple Guard Regiment by mid-10,119. Increased demand for the MCA-7B has led to increased need for production, and sixteen new manufacturing plants have since had to be constructed to facilitate the demand. Additional production is now avalible, as current goals are being met and exceeded.
Protection:
The armour layout of the MCA-7B is a radical change from the previous MCA-7A and MCA-6 series tanks in that it uses two to three layers of supporting armour types to provide maximum protection, a system inadvertently built into consecutive upgrades to the venerable MCA-3 series of tanks. The armour is, at it's base, an alternating series of solid titanium alloy plate and titanium alloy “box” plates which are made up of a honeycomb like mesh of titanium alloy encased in a titanium “box” like shell. The internal structure, at it's thickest, contains two “box” sections sandwiched within three thick titanium alloy plates to provide a strong and rigid base that is still light weight.
The secondary layer of the armour consists of modular blocks of ceramic-metallic material encased within a titanium alloy shell. Within the ceramic-metallic material are rigid depleted uranium sheets, each a hemispherical shape with the outer curve pointing outwards from the vehicle, set to provide as much overlapping cover of high density material as possible. The ceramic-metallic material is further reinforced through the impregnation of randomly positioned carbon nanotubes throughout the material, in a similar way to the way glass or carbon fiber is used to reinforce plastic. Such carbon nanotubes are produced through simple flame method, and are highly irregular in both size and quality, but add greater strength to the ceramic-metallic integrity then conventional glass, carbon, or synthetic fibers. The ceramic-metallic material is further encased in several layers of resign impregnated sheets of woven high performance polyethylene layered in interlocking and alternating patterns to provide excellent integral strength to the ceramic-metalic material, and together with the loose fiber reenforcement, keep the ceramic-metalic material from shattering, thus allowing it to absorb multiple rounds before failing. These second layer modules are layered in two alternating layers ontop of the structural componant of the armour to provide as few areas for penetration as possible. Each module is custom shaped and constructed for the vehicle, and varries in thickness and area covered, as well as shape, to allow maximum coverage. Modules not designed for the primary fighting arc of the vehicle, the forward and forward-side arcs, are not provided with the depleted uranium insert. Areas such as the hull and turret rear, as well as the rear-top of the hull and turret have only one layer of these modules, with the additional part occupied by integral water storage tanks formed of resin hardened high performance polyethylene, for storage of much needed distilled water.
The third and final layer of the armour is a made up of larger plates of the titanium alloy honeycomb “box” filled with a synthetic rubber material that is impregnated with loose high performance polyethylene fibers to increase strength. The entire assembly is encased in thin titanium plates and coated by several thick layers of resign hardened woven high performance polyethylene fiber sheets. This third layer is designed primarily to offer lower level ballistic protection to the vehicle within a highly modular package that can be changed and replaced as needed.
Finally the armoured protection suit of the vehicle is enhanced by the integral Enlil armoured protection system (APS), which uses milimeter wave radar and various IR sensors to detect incomming rounds and calculate their trajectory. The Enlil APS fire control system, when armeded, then automatically fires the coresponding launcher, or launchers, for the integrated 50mm defensive grenade system. The 50mm grenade system used by the Enlil APS is seperate from the defensive grenade launcher suit, and can only be fired from an active Enlil APS. The grenades themselves lob at a short but high arc, allowing them to cover essentially a sphere around the vehicle. The grenades themselves deatonate to throw a mass of high density tungsten rod fragments in the path of an incomming projectile to distroy, disable, or otherwise distort it's flight path and remove it's effective armour penetrating ability. The Enlil APS uses twenty such grenade launchers built into the turret, each firing from a nine grenade magazine, allowing the use of the system against multiple targets from the same area.
Armament:
The primary armament to the MCA-7B is the new Type-3650 115L60 smooth bore anti tank gun. The Type-3650 gun is a high velocity long smooth bore gun that uses a two stage loading round to achieve maximum power in a compact design. The Type-3650 uses the new An-1000 series of tank munitions which comprise of the projectile and the propellant as separate parts. The propellant stage is made from a compression formed and resin bonded solid propellant outer shell derived from the primary gelatin propellant contained inside. Within the outer case is a high efficiency gelatin propellant which provides greater power and a cleaner more efficient burn during ignition then conventional solid propellants. The propellant is ignited through the insertion of an ignition probe through the propellant casing to contact the gelatin primary propellant. The ignition of the propellant is done through the release of a short but high intensity ultraviolet radiation pulse into the propellant which forces the entire cartridge to detonate through chain reaction of the detonating primary propellant. This type of ignition allows for a design of the propellant which will be less likely to detonate when struck by an enemy anti tank round, as well as propellant that will burn more efficiently within the barrel reducing the amount of cleaning that must be done. Projectiles available to the new Type-3650 gun include the entire spectrum of An-1000 series 115mm rounds. Among the most promising rounds of the new series include the An-1000A Ballistic Shell Rocket Assisted Discarding Sabot Kinetic Energy (BSRADSKE) round, affectionately known as “The Thing” by crews. The An-1000A uses a new long rod penetrator design made of high density depleted uranium alloyed with titanium and molybdenum designed to provider greater penetration capability over previous long rod designs. Because of the inefficient aerodynamic qualities of the new penetrator design the round is encased in a copper ballistic shell which is designed to easily sheer off during penetration, but to increase aerodynamic efficiency of the round and allow it to hold a greater amount of kinetic energy over longer distances. The copper ballistic shell is designed to keep the overall diameter of the penetrator to no more then 34mm diameter, while providing a more streamlined flow of air over the round in flight. Stabilization of the round in flight is provided by four narrow titanium fins forward and four at the rear of the projectile, offset to provide the greatest stability over the length of the penetrator and allow greater accuracy over long range. Finally the An-1000A is equipped with a light weight solid fuel rocket motor which is designed to keep the round at a high velocity, close to that of the muzzle velocity, out to a greater distance, allowing longer ranges to be achieved. The rocket system, conversely, reduces the accuracy of the round slightly over range, however an unrocketed version, the An-1000B, is available with a more conventional kill range but slightly more accuracy out to those ranges. Other rounds available within the An-1000 series include conventional APBC, HEAT, HE, HE-Frag, Smoke, Illuminating, and APFSDS rounds, as well as the An-1000M gun fired guided missile currently under development.
The Type-3650 main gun is made from high strength titanium alloys, allowing the use of greater pressure propellants, but at a slight cost in reduced life time of the barrel. The gun itself is fed through the Type 998-X16B two stage autoloader, which uses a mixed carousel and bustle storage system within the tank to store the rounds and propellant sections. The rounds are stored individually within armoured containers around the turret basket similar in operation to older Soviet T-80 auto loaders, storing the rounds upright and ready for loading. This design feature of only the actual projectiles being stored in the turret bustle allows for all forty two rounds carried by the tank to be fired in succession quickly. The projectiles are loaded into the gun by a lifting arm which when level with the breach also acts as a bridge for the propellant pushed in from the bustle. The propellant is however stored in individually armoured bins within the turret bustle and aligned on a chain type automatic selection system. Propellant storage is separated from the rest of the vehicle by an armoured bulkhead, with blow out panels provided encase the propellant is hit and detonated. The propellant sections are fed into the gun by an electric actuator which pushes the round onto the projectile lift arm, and then forces both the projectile and the propellant stages into the gun. Although more complicated then the typical autoloader system, the Type-998-X16B allows for fast and reliable rates of fire while maintaining a high number of rounds ready to fire and providing safe storage for those rounds.
Additional armament of the MCA-7B includes a dual feed 15mm heavy machine gun mounted coaxially to the main gun, as well as a 50mm smoke and fragmentation grenade system which fires four grenades from eight launchers provided around the rank. The heavy machine gun is slaved to the main gun and operated by the gunner, but allows the destruction of light vehicles and infantry without the use of the main gun, while maintaining enough power to penetrate light walls or to reach infantry at a greater range. The grenade dispersion system is designed to give overlapping fields of fire around the tank to lay either a full smoke screen, or to lay fragmentation grenades to discourage nearby enemy infantry from approaching, the system is controlled by the tank commander, who may fire the launchers individually or in groups ranging from two launchers to all of them. Provisions for lighter machine gun mounts are provided for both the commander and gunner hatches as well, but rarely used.
Mobility:
The MCA-7B is powered by the next generation in tank engine to come out of the Guarita Engine Production Facility, the DO86-2S99. This new engine was designed specially for the B series upgrade to replace the previous Flat-12 cylinder engine in the A series, a carry over from late model MCA-6 upgrades. The DO86-2S99 is an opposed piston engine that consists of two banks of four cylinders layered one atop the other, in similar fashion to the H configuration of some Boxer engines. The engine is multi fuel capable, allowing greater versatility in the field, and compatibility with foreign fuel stocks if needed. The major design difference of the DO86-2S99 as compared to previous opposed piston engines is the use of a water injecting six stroke cycle. In this system the engine operates as a typical four stroke engine for the first four strokes, except following the exhaust stroke fresh distilled water is injected into the cylinder where the residual heat of the combustion turns the water into steam, forcing another power cycle after the combustion cycle, as well as cooling the engine. This process allows a close to fifty percent gain in fuel efficiency for a given amount of power, with the added benefits of vastly cooler engine and exhaust temperatures, as well as lower maintenance issues related to normal wear and tear from the heat of combustion.
The cylinder design of the DO86-2S99 is not a pure opposed cylinder design. The two pistons are separated by an hour glass shaped cylinder pseudo-head which contains the necessary injection systems for the fuel and water injection as well as secondary ignition systems, while providing optimum compression and flow through required for linear operation. The layout of the engine is such that exhaust from the engine flows through a central exhaust conduit inside the engine between the cylinder banks, allowing the intake systems to be more isolated from heat on the outside edges of the engine.
The engine itself is made primarily out of milled titanium, and special poured ceramic insulation. The ceramic insulation is mainly used to surround the cylinders and exhaust conduit to isolate residual heat from the rest of the engine. Milled Titanium makes up the primary component of the majority of the engine, including the block, cylinders, pistons and crankshafts. Milled Titanium is used to increase engine life and durability and strength while reducing weight.
In it’s primary configuration the DO86-2S99 uses two mechanically powered twin-screw type supercharges which take in air from the engine filtration system and compress it. The compressed air from the superchargers is fed through an inter cooler before being split evenly between the two cylinder banks through a series of pipes. Each supercharger being individually driven from one of the two crankshafts. The engine itself having two crankshafts, one per side, each running eight pistons, similar in action to a V8 engine.
At half the mass and volume of the previous Flat-12 engines, while maintaining the same power output, the new DO86-2S99 engine enabled the integration of transmission and engine into a single modular removable component of the drive train, which has greatly reduced engine change and repair times in the field.
The Under Armour Auxiliary Power Unit UAAPU of the MCA-7B uses a small gas turbine powered generator system to provide power to the vehicle while the engine is not running, or damaged. An added feature of the UAAPU is that the exhaust from the gas turbine used to generate electrical power can be ducted into the intake system of the main engine performing what is known as a dry start. The dry start capability of this system allows the use of the gas turbine's hot exhaust gases to preheat the DO86-2S99 cylinders before use, allowing much quicker start up times and faster time to power of the engine.
The transmission used is the Type-190 Hydrostatic transmission from the Guarita Production Facility as well. Using the two crankshafts from the DO86-2S99 to power two dual hydraulic pumps, each one both pushing and pulling the fluid through the system, the transmission works using high pressure hydraulic fluid inside specially designed piping to provide both electrical generation power and movement. Through a series of thick double-layer titanium pipes, hydraulic fluid flows through two input transfer pumps which transfer the energy of the hydraulic fluid to the two drive train final gearboxes. The final gearboxes are both automatically variable planetary gear systems, allowing automatic shifting as needed through six forward and four reverse gears. The use of variable volume pumps for both the input transfer pump and the push-pull power pumps allows the speed of the final drive shaft to be altered without altering the speed of the engine or the gear ratios, which allows the engine to run at optimum RPM and power output regardless of the speed of the tank. Forward and reverse gears are used to increase or decrease speed frames in both directions for the whole vehicle, while directional input from the driver changes the speed of either track to change direction. This RPM-independent power system allows the vehicle to utilize it’s full power range at all speeds, giving it superior mobility on all terrains then previous MCA generations, and indeed many contemporary vehicles.
The vehicle is suspended on eighteen road wheels through a long-arm hydro-torsion bar system. The system is based around the standard tube-over half-length torsion bar system of the A series, mounted in a semi-twisting housing that allows the whole apparatus to twist fifty degrees before being stopped by a block in either direction from a set plane. A hydraulic ram system is used to change the angle of the torsion bar assembly allowing the system to change ride height to the road wheels individually while maintaining the suspension qualities of the torsion bar system. In the event of a failure to the hydraulic system the hydraulic ram is locked in whatever position it was in at the time and left to operate as a pure torsion bar system. A pressure relief valve in each ram cylinder allows pressure to be bled from the cylinder if the weight of the vehicle is unequally shared by up to three road wheels on either side, allowing the vehicle to distribute the vehicle weight over all the road wheels available on one side evenly even if the system locks up with the suspension set to different angle planes.
Crew Systems:
The MCA-7B comes with a wide variety of advanced systems to provide both efficient execution of the crew's tasks and provide optimal comfort to the crew within the vehicle. The vehicle is equipped with, among other things, an integrated air conditioning system which controls the general climate within the vehicle as well as controlling the internal atmosphere and protecting the crew from external nuclear, biological and chemical threats. The air conditioning system is further taken to provide each of the three crew members with an adjustable climate at their station, allowing the crew maximum comfort in all temperature ranges. Additionally the use of adjustable gelatin filled seats integrated with the climate control system through the use of air tubes within the seats to carry warm or cold air from the air conditioning system and either heat or cool th seat as needed, for extra comfort and to allow the crew to operate for extended periods of time. Each crew station has additionally, enough room to provide enough limb movement to allow the crew to stretch without having to vacate the vehicle.
Additionally, a water storage system is integrated into the vehicle, as well as a water reclamation system from the engine exhaust and a filtration and distillation system to clean the water. Each crew member is provided with a variable temperature outlet for drinkable water from this system, which is also shared by the engine for it's six-stroke design. This feature allows the crews to drink plenty of water, an essential aspect of operations within the harsh tropical and desert climates of Sumer.
Fire control is provided through a digital fire control computer, and can be operated by both the gunner and the commander if needed. The MCA-7B fire control system allows maximum accuracy for the main gun, and is separate from the rest of the vehicle's systems. The commander has around his station a series of flat screen monitors providing him a day or night image of the outside through a number of carefully placed high definition and wide angle digital cameras on the turret, allowing quick observation of the surrounding terrain. The commander also retains an electrically operated rotating hatch with integrated optical periscopes for use regardless of the state of the digital optics suit. The commander's hatch also contains the combined optical and digital primary commanders sight which provides the commander with both day and night viewing through normal and IR views, as well as the ability to designate targets for the gunner quickly.
All crew controls are provided as digital, with the commanders primary control systems being through touch screen monitors. The driver and gunner however are also provided with limited touch screen capabilities for their stations, including ammunition selection for the gunner and vehicle profile and engine management controls for the driver.
Designation: MCA-7B
- Name: "Urbara Tirak" - "Timber Wolf"
Dimensions:
- Length: 7.7m (Hull)/11.75m (Gun Forward)
- Height: 2.48m (Turret Roof)
- Width: 3.8m (4.2m with Skirts)
- Mass: 78,800 kg
- Track Width: 720mm
Internal Systems:
- Crew: 3
- Autoloader: Type 998-X16B 2-Stage Autoloader
- Ammunition: 42 (Main), 1000 (Coaxial), 180 (Enlil), 32 (Grenade)
- Transmission: Guarita Type 31A Automatic 8-forward 3-reverse
- Fuel Capacity: 1100L (Internal Tank), 400L (External Drum)
- Water Capacity: 600L (Internal Tank), 400L (External Tank)
Powerplant: Guarita DO86-2S99
- Power: 2600 bhp
- Displacement: 21.7 Liters
- Layout: 8 Cylinder Hotozontally Opposed
- Induction: Twin-Supercharger, Dual Fan-assisted Intercoolers
- Fuel Consumption: 1.8L per 1km Average
Performance:
- Maximum Speed (Road): 85km/h
- Range: 610km (830km with extra fuel)
- Power-Weight Ratio: 32hp/ton (Approx.)
- Ground Pressure: 0.9kg/cm2
Armament:
- Primary: Type-3650 115L60 Smoothbore (Single)
- Coaxial: 15mm Heavy Machine Gun (Single Coaxial)
- Dischargers: Grenade, Enlil APS
Armor: Listed maximum approximate armor values.
- Armor Place: RHAe KE/CE thickness
- Hull Glacias: 2800mm/3500mm
- Hull Front: 1500mm/1900mm
- Hull Sides: 1500mm/1900mm *Skirt Included*
- Hull Rear: 600mm/750mm
- Hull Top: 240mm/360mm
- Turret Front: 2800mm/3500mm
- Turret Top: 260mm/400mm
- Turret Sides: 1500mm/1900mm
- Turret Rear: 600mm/750mm
- Turret Mantlet: 3000mm/3700mm