|This article or section is in the process of an expansion or major restructuring. You are welcome to assist in its construction by editing it as well. If this article or section has not been edited in several days, please remove this template.|
Theatre Entry Standard HT9A7 Block II
|Type||Main Battle Tank|
|Place of origin||Anemos Major|
|In service||2009 -|
|Used by|| Anemos Major|
The Empire of Common Territories
|Designed||2003 - 2008|
|Manufacturer||Fierei-Oblastinei IECpl, Fyrkondierikan Military-Industrial|
|Weight||77t (base combat)|
|Width||3.8m (hull), 4.2m (skirts)|
|Height||2.7m (turret roof)|
|Crew||3 (commander, gunner, driver)|
|Armor||Calumnis-3 (metal-composite matrix outer layer, (N)ERA, composite tiles, DU alloy mesh, IRHA plates/hull, fibreglass/rubber/Spectra spall liner)|
|128mm SC10.8 55 calibre solid propellant smoothbore cannon (42 rounds, 25 ready in continuous belt autoloader magazine)|
| Co-axial: 20mm Arsenal Karonin M.28 Autocannon (600 rounds, replaceable with modular block compatible weapons) |
PRWS: 12.7mm MG/H8A3 HMG (1000 rounds)
|Engine|| MA.252/mod H OP10 Hyperbar Diesel|
|Transmission||Automatic (8 forward, 3 reverse)|
|515km (internal fuel, road)|
|Speed|| 72km/h (road)|
52km/h (cross country)
The HT9A7 'Yvernyr' (Anemonian: Ȳvernyr, "wyvern") is an Anemonian main battle tank, formerly employed as the first line battle tank of the Imperial Army and developed as a successor to the failed HT7 'Yrdestyr' and the HT8 Leclerc subsequently pressed into service. The first vehicle developed under Project Fiensietyr, the 2000 effort to provide workable domestic alternatives to foreign and obsolescent vehicles in Anemonian service, the HT9A7 has since gone on to see remarkable success in both armed and export conflicts alike.
Designed as a heavy main battle tank capable of withstanding projected incoming fire along its frontal arc while utilising unconventional munitions to allow the tank to engage and destroy tanks ostensibly larger and more powerful than itself, the HT9A7 was designed as a 'statistics sheet breaker' capable of meeting and eliminating any projected armoured threat without necessarily resorting to the 90-100t weight levels then being favoured by overseas designers.
Entering serial production in 2008, the first HT9A7 (then Block I vehicles) entered frontline service in early 2010, with Block II vehicles entering production and subsequent service some six months later. The HT9A7 is currently in the process of being replaced in first-line service by the HT9A8 'Istrenyr' Block I Main Battle Tank, a process expected to last until 2015.
- 1 Development and Service
- 2 Armament
- 3 Protection
- 4 Electronics
- 5 Mobility
- 6 Crew Amenities and Survivability
- 7 Variants
- 8 Operators
Development and Service
The 128mm SC10.8 55 calibre solid propellant smoothbore cannon was developed as a replacement for the 140mm SC9.21 50 calibre Electro-Thermal Chemical smoothbore cannon utilised in the HT9A6 main battle tank. Opting to use a conventional propellant and smaller round for ammunition and weight efficiency purposes, the SC10.8 makes up for its decrease in comparative firepower through a number of ammunition based solutions designed to maximise its utility in head-on-head combat with enemy main battle tanks of any standard, giving it per-shot killing power that far exceeds the performance of its main armament on paper.
Though the 42 rounds standard ammunition carrying capacity of the HT9A7 is high, when considering the combat intensity and periods that the tank is likely to face, there are a number of reasons for it. Firstly, it gives the HT9A7 combat flexibility where other armoured vehicles simply opt for larger guns; though it is not intended that the HT9A7 will enter and remain in combat for periods of time that allow for the complete utilisation of the 42 rounds carried by the tank, it does mean that the HT9A7 does not have to rely upon high frequency maintenance and resupply, allowing it to respond flexibility to unforeseen circumstances on the field of battle. Secondly, however, a combination of ammunition mixture and the usage of high performance GLATGMs and guided ammunition actually decreases the combat carried anti-tank ammunition of the HT9A7 to about 25 to 30 rounds overall; as a number of high explosive rounds must be carried to ensure the responsiveness of the HT9A7 to a wider variety of potential threats, as well as, potentially, other specialist rounds, the higher ammunition capacity allowed by the 128mm gun is necessary to ensure that the HT9A7 is able to retain its battlefield endurance together with the flexibility of response that it requires.
The SC10.8 is a 128mm solid propellant smoothbore cannon with a length of 55 calibres (6.6m). The barrel itself is constructed of autofrettaged steel. Responding to problems concerning the decreasing barrel life of modern smoothbore guns due to the increased performance of propellants, it utilises a barrel construction that departs from the chromium-lined steel barrels of most modern guns. With a silicon nitride (Si3N4) barrel, the SC10.8 aims to use ceramic liners to decrease the effect of propellant erosion of the barrel when compared to chromium gun barrel linings, and gives the gun either a greater service life or the ability use increasingly powerful propellants. However, as a ceramic, silicon nitride is also very brittle, and due to the inability of the material to undergo the same autofrettaging process used by steel barrels to induce pre-compression in the gun barrel, it also utilises a 35% glass reinforced polymer composite overwrap to induce the pre-compression necessary to compensate for the brittleness of silicon nitride, utilising computer modelling to determine the deposit locations and angles necessary to achieve the desired levels of strength and stiffness within the gun barrel itself. The result of this is that the SC10.8’s gun barrel, through significantly decreased erosion in comparison to chromium-lined barrels, is able to withstand propellant-induced damage for longer periods of time. The weapon’s thermal jacked is also made of 35% glass reinforced polymers, and, opting not to utilise a standard pattern bore excavator, the SC10.8 chooses instead to utilise an automatic compressed air fume extraction system at the rear end of the gun barrel to prevent oxygen depletion and other potential effects on the crew.
Recoil mitigation is achieved through two primary methods; directive and absorptive. The porting-type muzzle brake employed at the forward end of the SC10.8 redirects propellant gases to counteract the recoil forces generated with the firing of the weapon. Furthermore, the weapon features the hydro-pneumatic recoil mechanism utilised on most modern tank armaments today, together with a pair of hydraulic retarders located to either side of the weapon (with four originally used with the SC9.21). Overall, these recoil control mechanisms permit the HT9A7 to limit recoil forces and regain stability quickly after firing, increasing the overall accuracy, aimed firing rate and mobile engagement capabilities of the tank. Stabilisation is achieved via two independent electro-hydraulic systems with independent horizontal and vertical stabilisation (full dual-axis electro-hydraulic stabilisation), as well gyro-stabilisation, further increasing the mobile engagement capabilities of the HT9A7.
Though the round used by the SC10.8, the 128mm, is smaller than the 140mm originally envisaged as that to be used in the HT9, its size, together with the potential need to replace the main armament of the HT9A7, resulted in the utilisation of an autoloader with the HT9A7. In general, 25 rounds are stored in the autoloader with 17 additional rounds in storage for later use. As a number of rounds (GLATGM, MRKE, APFSDS and HE in combat use, with other potential rounds for specialist purposes) are used in a largely interchangeable manner on the battlefield, the autoloader system used within the HT9A7 could not, by default, be a simple bustle system as used by many other main battle tanks, while the carousel system favoured by many Eastern Bloc armoured vehicles was also not a valid option due to its storage inefficiency. As such, the system utilised is a rotary belt type bustle system with a storage capacity of 25 128mm rounds (regardless of type) behind the crew. The control system uses a combination of virtual memory-stored location records of rounds and bar code designations to correctly select and prepare rounds; rather than automatically loading rounds upon firing and spent case extraction, the gunner is able to select a number of potential options; as well as being able to set the autoloader to ‘single type automatic’, which causes the autoloader to consistently select a single type of round and load it upon extracting the spent casing of a firing round without confirmation, he is also able to set up a ‘firing list’, selecting a number of rounds in firing order for the autoloader to automatically select and load, and can also utilise a manual confirmation system where he selects a desired round prior to loading, allowing the Anemonian gunner to make full use of the wide selection of rounds employed within the HT9A7. The average rate of fire of the autoloader-equipped cannon when on automatic loading is 12 rounds per minute, but this figure decreases when the gunner opts to utilise individual selection.
In terms of ammunition used, there are four primary types of ammunition used with the SC10.8 128mm gun; M07/S Kinetic Energy, M07/E High Explosive Dual Purpose, M07/mod M Gun Launched Anti-Tank Guided Missile and M07/mod I Medium Range Kinetic Energy. As the gun is a smoothbore, ever round uses some form of individual stabilisation to maintain its firing trajectory. The first two are conventional propellant, conventional trajectory rounds, while the third is a rocket-propelled, top-kill HEAT missile and the latter is a range extended, LOS/BLOS forward/top kill guided KE round. The propellant utilised in the standard rounds is a combination propellant (60% nitrocellulose, 20% nitroglycerine, 4% RDX, 15% diethylene glycol dinitrate with 1% of other content and 55 grams of igniter); the utilisation of a low level of RDX in place of the nitroglycerine used in other propellants provides the 128mm round with a higher level of more stable propellant performance while nonetheless restricting the increase so as to retain a practically sustainable barrel service life. The M07/S Kinetic Energy round is an armour-piercing discarding sabot round, with a kinetic energy penetrator constructed out of a depleted uranium alloy (composed of uranium, vanadium and niobium for machining purposes), creating a high density KEP which, combined with the high muzzle velocities generated by the powerful propellant mixture utilised by the round, forms a highly lethal round against most conceivable battlefield targets. The M07/E is a High Explosive Dual Purpose round; fin stabilised like the M07/S, it utilises a tandem charge warhead together with a fragmenting casing, giving the HT9A7 the ability to engage both armoured and unarmoured targets with what is essentially a shaped charge and anti-personnel round in the same munitions system. However, though these two conventional pattern rounds are highly effective, utilising a number of design features to give them performance and flexibility that surpasses its competition, the core of the 128mm SC10.8’s effectiveness as a modern tank armament lies in the other two munitions it utilises for the sole purpose of hunting other tanks. The M07/S is, as a 128mm solid propellant KE round, incapable of penetrating the frontal armour profile of most top-tier main battle tanks in service today, and as an anti-tank round, the M07/E is at a natural disadvantage due to the frequent use of NERA, composites and slanted armour on modern tanks. Rather, the heart of the SC10/8’s anti-tank capabilities lies with its other rounds.
The M07/mod M is a GLATGM (gun-launched anti-tank guided missile) utilising a HEAT warhead and a three stage seeker system to defeat the vast majority of existing tanks at extended ranges by accomplishing highly countermeasure-proof top-kill attacks. The seeker head uses a combination of millimetre-wavelength radar, passive IR CCD sensors and a semi-active laser seeker to acquire and track the target while in flight, decreasing the effectiveness of single-purpose countermeasure units against the missile. Utilising a soft-launch system, the M07/mod M clears the barrel of the gun before engaging its flight motor, thus greatly increasing the service life of the barrel itself when used in conjunction with the GLATGM. With folding stabilisation fins used to fit as large a missile as possible into the HT9A7’s 128mm gun barrel, the missile’s internal seeker system tracks the acquired enemy target and rises to the appropriate trajectory before entering its terminal descent, placing itself into a high speed, top-kill position to virtually guarantee a kill; potential targets range from a wide variety of land vehicles to, potentially, landing ships and helicopters. The warhead of the missile is a tandem charge; upon striking the enemy target, the impact detonation mechanism first detonates a smaller ‘initial’ charge to activate and eliminate the ERA lining of the tank; furthermore, the ‘initial’ charge utilised by the M07/mod M takes advantage of the increased capacity of the missile by being somewhat larger than that of the standard M07/E round, giving it enough explosive force to either destroy or damage NERA/NxRA blocks on enemy tanks and thus leave them vulnerable to the larger shaped charge warhead located behind the initial charge (separated from it by a titanium diboride blast shield). The main charge is then detonated. As such, the M07/mod M not only provides the HT9A7 with the ability to defeat the lighter roof armour of an enemy main battle tank from nearly 15km away utilising an independent seeker mechanism that permits BLOS engagement, it also possesses the capacity to engage and eliminate ERA, NERA and NxRA protected vehicles if necessary. There is a three stage control mechanism on the M07/mod M that prevents premature detonation; the two safety mechanisms are deactivated upon firing the missile (acceleration-based detection) and entering the terminal trajectory (computer controlled), while a tertiary protective mechanism ensures that the delay between initial and main charge detonation is maintained to permit effective use of the tandem charge layout.
The M07/mod I Medium Range Kinetic Energy round is a rocket assisted and propelled, LOS/BLOS forward/top kill capable guided KE round, with a uranium alloy KEP at its heart but utilising rocket/fin stabilised active guidance and terminal stage propulsion to give it both range and power far surpassing that of the M07/S. The apparent inherent incompatibility of the high speed requirements of the kinetic energy penetrator and the difficulty of precisely guiding high speed, rocket propelled projectiles is solved through the utilisation of an effective terminal stage guidance mechanism that ensures that precision is mostly maintained while bringing the overall impact velocity of the kinetic energy penetrator to about 1.5-2.0 times that of a standard M07/S round. Utilising a conventional propellant to achieve initial velocity, the MRKE utilises a millimetre-wavelength radar and semi-active laser seeker to track enemies; it can be used as a Within Line of Sight round, where the gunner designates the desired target prior to opening fire, or a Beyond Line of Sight round, where the round is launched into the air and acquires a target from there. Utilising fin stabilisation and impulse thrusters to guide and occasionally boost the round in its flight path, the M07/mod I enters either a level or a ballistic trajectory and guides itself as necessary towards the enemy target. Upon reaching a given distance from the target, the ‘no-escape’ zone, the round then engages its main rocket propulsion system while shedding its seeker head to expose the kinetic energy penetrator, radically increasing the terminal velocity and velocity retention (through superior aerodynamics) of the KEP in the terminal stage of its target engagement. With a maximum potential range of nearly 12km and high levels of accuracy through an effectively utilised guidance/propulsion system, the M07/mod I retains high levels of accuracy by engaging its propulsion only after target impact is virtually assured upon entering its terminal stage. This allows the M07/mod I to bring the kinetic energy penetrator’s vast advantage against modern main battle tanks’ composite armour layout to bear at almost three times the maximum distance of a standard 120mm gun with even more effectiveness than a round fired utilising solid propellants, making it a highly effective anti-tank weapon that gives the HT9A7 the ability to engage enemy targets accurately and effectively from a significantly large ‘safe zone’.
By disassembling part of the base turret structure, not only can the L/55 barrel be replaced, the 128mm SC10.8 gun system in its entirety can be replaced. At the moment, however, the range of replacements offered by FOAM is relatively restricted; the SC9.21 140mm L/50 ETC smoothbore cannon is retained as an option by the Imperial Armed Force in the event that the 128mm main armament currently used must be replaced, while the SC8.60 120mm L/55 solid propellant smoothbore cannon, a development of the original main armament of the HT8 MBT, is also provided for use by the Asakuran Armed Forces.
The HT9A7, aside from its highly effective main armament, also features a number of other weapons.
As its co-axial armament, the HT9A7 features one of two weapons. The 20mm Arsenal Karonin M.28 Autocannon is a 20mm L/22 automatic cannon utilising a 1hp motor located within the receiver to cycle the weapon’s action, allowing for greater control over the feeding and cycling process of the weapon to ensure greater reliability and control over its firing qualities. Though many modern cannons utilise 25mm rounds and, more recently, larger developments such as the 50mm round to counter improvements in IFV/APC armour and protection, the choice made to utilise the 20mm round was one based upon a very practical consideration; the ammunition capacity of the co-axial weapon. The utilisation of a large, 50mm cannon restricted ammunition capacity to levels around 200-300 rounds overall, an unacceptably low figure for an automatic weapon. By adopting a 20mm co-axial weapon instead, the ammunition capacity was raised to nearly 600 rounds (usually a 200 APFSDS/400 HEDP mix), giving the HT9A7 a significant ammunition capacity advantage over the HT9A6. The 1hp motor powers a rotating sprocket system that feeds and removes the ammunition from the autocannon’s chamber, and a second sprocket layer feeding the ammunition belts into the weapon mean together with disintegrating links mean that the gunner can easily switch between the two types of ammunition he will be using on the battlefield. The barrel of the autocannon is constructed of cold hammer-forged steel with a chromium lining to increase barrel life, and porting along the barrel permits for gas release and redirection (though the rigid co-axial mounting makes recoil less of a problem). Another advantage of the electric control is the ability to set highly controlled firing rates for the weapon; by default, there are four firing modes used with the M.28 – Single (Semi-Automatic), Low (120rpm), High (240rpm) and Very High (400rpm) – but other rates can be programmed into the weapon if desired.
The other weapon that is available as a co-axial weapon for the HT9A7 is the 12.7mm MG/H8A3 Heavy Machine Gun. The MG/H8A3 is a short-recoil operated rotating bolt machine-gun utilising forced air cooling and forward porting to evacuate heat and propellant gases. With a barrel constructed of cold hammer forged steel, the external receiver of the weapon itself is, as a relatively new weapon, constructed of 30% glass reinforced polymer (making it relatively lightweight while remaining resistant to temperature buildups and sudden shocks), and the need for a replaceable barrel is largely removed through the installation of the highly efficient air cooling system. The ammunition is fed via a disintegrating link (a scaled up version of that utilised in the MG3/MG3R1 series’ 7.7mm ammunition), and the cyclic rate of fire of the weapon is mechanically alterable via the trigger block like the MG3 series, alternating between 450 and 750 rounds per minute as desired. The weapon itself is normally operated via a trigger located on the weapon’s single-handle (as opposed to the spade trigger used by some), but one of the differences between the infantry deployed and most vehicle deployed versions of the MG/H8A3 is the fact that they are, in fact, initial electrically ignited weapons (i.e. the initial trigger pull is replaced by electric ignition) to make them compatible with the HT9A7’s co-axial block system and greatly mechanically simplify the Remote Weapon Systems in service with the Anemonian Armed Forces. In general, two types of rounds are used with the MG/H8A3 as a component of the HT9A7 MBT; ball ammunition, for use against ‘soft’ targets, while HEIAP is employed for use against harder targets.
The co-axial station of the HT9A7 is highly flexible through its use of a quick-change/replacement layout known as the Modular Block System. The weapons systems themselves are placed in modular ‘blocks’ which are installed into a co-axial weapon ‘socket’ in their entirety (hence the electrical ignition for the MG/H8A3), while the ammunition and ammunition feed can be adapted without difficulty to fit into a small storage area located near the co-axial weapon itself (while most mechanical feed components, such as the sprockets used in the M.28, are placed within the modular block itself). Theoretically speaking, this means that almost any co-axial weapon can be installed in the HT9A7 as long as it is modular-block compatible and modified to fit the appropriate specifications; foreign heavy machine-guns and other support weapons aside, larger weapons such as 50mm cannons can potentially be retrofitted to become modular block compatible, the limited ammunition capacity of such an arrangement notwithstanding.
The roof mounted weapons station is equipped at production with the Ortel Powered Remote Weapons System. Capable of accepting anything up to a 40mm automatic grenade launcher, the station is usually equipped with the MG/H8A3 12.7mm machine gun in service. Capable of 360 degrees rotation, as well as +75, -25 elevation, the Ortel is a fully armoured RWS, utilising IRHA plating on sensitive areas like connections and optical equipment, equipped with optical, target acquisition and ballistic correction capabilities. Interfacing is achieved through a joystick for traversing and a 15-inch touch screen, which is linked in turn to a pair of cameras, one 3CCD daytime camera system and one forward-looking infra-red thermal imaging system. Both equipped with a laser rangefinding system, the gyrostabilised platform is able to offer a high degree of accuracy, even when on the move. Via the touch screen, the user is able to utilise both available optics to designate and ‘lock-on’ to targets, from where the laser rangefinder will feed distance information back to the ballistic computer which, utilising environmental data such as vehicle movement and round performance, will automatically adjust the firing arc to compensate for these. As such, the Ortel is capable of offering a high degree of accuracy, day and night, mobile or not, due to a high degree of environmental awareness and inbuilt ballistic correction capabilities that give it the ability to strike distant targets within seconds. As weapons fired from the Ortel tend to utilise electrical ignition, fire control (firing mode, safe) are all monitored and changed from within the vehicle itself.
In addition to these armaments, the HT9A7 responds to recent developments in tank development by incorporating support for a variety of additional equipment. The gun-launched M07/mod M can also be accommodated in a number of side slung box launchers like many other similar vehicles, though this approach is only used in high intensity open field combat due to the obvious disadvantage posed by the additional bulk of the missile launchers. Furthermore, in response to recent developments in missile technology, the Arteyr Anti-Tank Missile (a 240mm (fins folded) development of the M07/mod M built with a far longer range and larger warhead) can also be fitted into larger box launchers for engagements with enemy tanks.
Protection on the HT9A7 was envisaged from the beginning as a primary consideration, and as such, extensive material research and testing was conducted over a range of areas to create the armour layout currently used. One particularly crucial aspect of the design doctrine behind the armour layout in the HT9A7 is the utilisation of an armour-first, crew space-second approach to the creation of the vehicle. The significance of this approach lies in a departure from the long-period crew endurance focus seen in the design of armoured vehicles like the T-80 series of main battle tanks. Due to the increasing ammunition size of modern main battle tanks, and the increasing ability of other vehicles, based on multipurpose wheeled bases, to fill infantry support roles once covered by main battle tanks, it can be suggested that modern combat situations have reached the point where the ability of the main battle tank’s crew to operate effectively for extended periods of time stretching beyond six to seven hours of combat is worth trading off for increased armoured protection. Ammunition expenditure means that it is unlikely high intensity combat will see main battle tanks operating for such extended periods, and the high support-relief nature of Anemonian armoured doctrine means that most armoured vehicles can be replaced on the frontline when necessary. As such, the design doctrine followed with the HT9A7’s armour layout, drawing from past experience with large calibre guns and compact crew compartments from the Leclerc 140, is one that relies upon the maximisation of vehicular protection in exchange for making the crew compartment as compact as practically possible, resulting in far higher protective capabilities than a vehicle of its size would suggest.
Outer layer protection is achieved through the use of a Titanium Diboride (TiB2) based metal composite matrix with a fibreglass spall backing. This metal composite matrix, by being significantly harder than materials used in most ammunition-based applications, is capable of breaking up rounds, including penetrators, and, through the toughness of the metal composite matrix, results in the controlled distribution of kinetic energy absorbed from the round. As the controlled distribution results in the creation of a damage area only marginally larger than the size of the round from which energy has been transferred, with any spall effects absorbed by the fibreglass backing, the external protection is capable of sustaining multiple hits from anything up to the 12.7-14.5mm round range commonly utilised in modern heavy machine-guns. The resultant outer layer of armour protection is significantly lighter than the equivalent volume of RHA, and nonetheless capable of entirely stopping armour piercing small arms fire while significantly wearing down the effectiveness of high performance kinetic penetrators before they reach the armour blocks themselves.
Another component of the HT9A7’s passive protection suite is non-energetic reactive armour (NERA). In modern times, the continued utilisation of explosive reactive armour (ERA), widely used as most armoured vehicles’ first-line protection against shaped charge warheads, has been proven to be impractical and ineffective due to a number of reasons. Firstly, the explosive composition of the filler utilised in ERA results in a situation where hits against the vehicle can potentially result in collateral damage, especially in confined spaces. Due to the necessity of utilising infantry support for armoured vehicles in such environments, this means that the practicality of ERA equipped tanks is greatly decreased due to their subsequent inability to operate effectively in certain combat situations. Secondly, however, the modern development of tandem shaped charge warheads and their frequent employment in anti-tank guided missiles, where a smaller charge detonates ERA prior to the detonation of the main charge, has created a situation where the combat threats faced by the Anemonian Armed Forces are more than capable of easily defeating ERA based solutions with minimal effort through the use of a simple design aspect in their anti-tank warheads. As such, the utilisation of NERA was looked into by FOAM during the design process for the HT9A7, and eventually replaced all planned employment of ERA in the tank due to its clear advantages over its predecessor. The NERA utilised within the HT9A7 is formed out of panels consisting of a 10mm thick layer of rubber lining sandwiched between two 6mm thick plates of steel (Domex Protect 500). When a projectile hits the NERA panel, resultant outward motion by the two Domex plates increases the effective thickness of the armour in that area, providing increased protection against projectiles. Furthermore, however, the lack of an explosive element means that the NERA utilised within the HT9A7 is both capable of taking multiple hits (to some extent) and causes no resultant collateral damage, as well as being far more resistant to the effects of a tandem charge warhead; both in terms of protection and resultant damage, it is a more desirable form of protection. Cross-wise orientation of NERA panel is employed in the armour layout to ensure that the jet bulge in the first panel generated upon impact does not result in material erosion in the second, increasing the overall protectiveness of the NERA layers against shaped charge warheads in exchange for a minimal increase in volume. Overall, the result of this is that the NERA protection of the HT9A7 is both superior to that of standard ERA and parallel arrangements of NERA, giving it first-line protection against almost any shaped charge warheads thrown at it.
In terms of ceramics, the HT9A7 primarily employs nano-ceramic Titanium Diboride (TiB2). Titanium Diboride is, in terms of properties, highly similar to the titanium carbide currently frequently used in many armoured vehicles armour and armament suites; however, in many respects, it can be said to be superior. At room temperature, its hardness is almost three times that of the equivalent volume of fully hardened structural steel. Its melting point is also incredibly high, at 3225˚C, and the result is that armour blocks incorporating normal Titanium Diboride tend to be both incredibly impact resistant and capable of withstanding the high heat generation of chemical energy warheads. Chemically, it is also a relatively field-friendly material, insofar as it is more stable than tungsten carbide when in contact with iron, and less prone to oxidation at anything short of extremely high temperatures. As such, Titanium Diboride is a highly effective material when used in impact-resistant armour applications, capable of withstanding the effects of both HEAT rounds when used in conjunction with other forms of armour but, more importantly, very effective through high levels of hardness against kinetic energy rounds and penetrators. In addition, not content with stopping there, designers decided to take the high-performance characteristics of Titanium Diboride one step further through the use of modern technological developments in nanotechnology. By starting with high purity powders and running them through plasma melting and hot isostatic pressing to inhibit grain growth, the time-temperature window of densification was extended. With nanograin sizes maintained throughout, the result was the significant decline of porosity in ceramics passed through the treatment procedure, and the subsequent production of full density ceramics at the nanometer scale. Higher strength and hardness was achieved, as such, due to the resultant low-angle, high-strength grain boundaries and less dislocation within the overall structure due to the finger grain size. The resultant nano-ceramic Titanium Diboride improves upon an already superior material to create a uniquely effective and efficient ceramic for use within the HT9A7’s composites.
The three metal alloys utilised in the HT9A7 are Type 7720 Titanium-Aluminium alloy, depleted uranium based Stakalloy, and IRHA (HRc 40, HRc 48). Type 7720 Titanium-Aluminium alloy draws from the natural advantages of a titanium-based alloy (high stress resistance and toughness for its weight range, as well as corrosion and temperature resistance). In this particular case, however, the primary advantage of Type 7720 stems from its weight advantage; compared to RHA, Type 7720 is capable of providing properties close to those of ceramic materials at 38% the weight of the equivalent volume of RHA. Of course, the difficulty of machining Type 7720 makes it an impractical choice for usage across the entirety of a main line battle tank, and the result has been that the titanium alloy has not been used as the hull material for the HT9A7 out of purely practical concerns about the workability of the material.
Stakalloy is a depleted uranium based alloy used only as a mesh-based layer of armour rather than a block in itself. The high density of depleted uranium based materials means that the weight gain, despite its highly effective protective capabilities resulting from its sheer density, is prohibitive when overused, and the radiation emission, however limited, of depleted uranium makes it a material that must be approached with trepidation when utilised as a protective material. As brittle as it is dense, depleted uranium is incapable of being used effectively as a standalone material within armour; as such, it must be used within an alloy for maximisation of effectiveness. Departing from the usual uranium-titanium alloys (Staballoy) favoured in most developments of the material, the alloy used here instead is one formed of niobium and vanadium with the depleted uranium to create a more machinable material for use within the HT9A7 while retaining the high density qualities of depleted uranium (~95% of the alloy’s composition being of DU).
IRHA, or Improved Rolled Homogeneous Armour, is a metal alloy that modifies the basic chemical composition of standard RHA to create a far harder material, altering one of the base components of many modern tanks to create a more effective alternative suited to the battlefields of the 21st century. The basic chemical composition of IRHA (by weight percentage) is 93.68% iron, 0.26% carbon, 3.25% nickel, 1.45% chromium, 0.55% molybdenum, 0.4% manganese, 0.4% silicon and some impurities (<0.01% phosphorous, <0.005% sulphur). With a 1% increase in the nickel composition of the alloy and a smaller increase in a number of other elements (chromium, molybdenum and manganese), the resultant material is much harder than standard RHA whilst retaining similar levels of ductility and toughness. Weldability and machinability, of particular importance for IRHA’s hull applications, is similarly preserved at RHA levels by maintaining carbon content at ~0.26% or below. IRHA’s physical properties are further determined by the heat level at which it is tempered; HRc 40 grade IRHA, which is used for hull applications, is tempered at 529˚C, which HRc 48 grade IRHA, for applique armour, is tempered at 218˚C. The differentiation in role stems from the fact that HRc 48 grade IRHA is more effective against kinetic energy penetrators at the cost of far less resistance to fragmented munitions that HRc 40, making it more usable in applique armour (where its shortcomings are compensated for by other materials). IRHA, as such, provides the HT9A7 with all the advantages of rolled homogeneous armour but, again, goes one step further by modifying the basic chemical composition of this erstwhile material to give the HT9A7 another advantage over many contemporary armoured vehicles.
In terms of layout, the armour is separated into two parts; the armour itself, and the hull construction and interior. The armour consists of an outer layer of TiB2 based metal composite matrix over a cross-wise oriented NERA layer, another layer of the metal composite matrix, then panels of Type 7720 TiAl alloy sandwiching square tiles of HRc 48 IRHA and nano-ceramic TiB2. Beneath this is another layer of NERA, nano-ceramic TiB2 tiles structurally maintained by Type 7720 TiAl alloy, a Stakalloy mesh and a plate backing of HRc 48 IRHA. NERA layers and some armoured protection can also be found on the roof of the tank for protection against HEAT-based ATGMs. The hull itself is constructed of HRc 40 IRHA. The tank’s interior is equipped with a spall liner made of 20% glass composition fibreglass backed by Spectra and rubber; the energy is expended against the fibreglass, with any further spalling being absorbed by the backing to provide the crew with highly effective protection against internal damage.
Slat armour constructed of aluminium alloy for weight reduction is also widely used to protect the rear of the vehicle (the engine block) from damage by shaped charge warheads, but this is an additional unit sold by FOAM and not considered to be a component of Calumnis-3.
Active Protection System
In order to augment and complement the already formidable Calumnis-3 armour layout of the HT9A7, the Yvernyr also features an extensive array of active protection under the umbrella of the Solothel Networked Vehicle Protection system. A development of the Calumnis-2 units tested on late Leclerc 140 models prior to the introduction of the HT9A7, Solothel utilises a wide variety of soft and hard kill measures to disrupt, deflect and destroy hostile fire before they engage with the vehicle’s passive protection. Solothel is a system that incorporates the very latest concepts and advances in active protection and networks them in a manner that creates a system that is unrivalled in its ability not only to act independently but as a component of a larger formation efficiently and effectively. Furthermore, it aims to go beyond the traditional restrictions of active protection systems; with an effective hard-kill suite and microsecond-level reaction through effective coordination of active protection resources, Solothel aims to provide the HT9A7 with protection not only against HEAT-based anti-tank missiles, but high speed kinetic energy missiles and gun launched projectiles.
The detection system utilised by Solothel is three-tiered, and aims to achieve the highest possible detection speed with a minimal number of false detects by utilising a range of data from different sources to create an accurate picture of the tank’s combat environment, and thus maximise the effectiveness of its threat detection and thus prevention and interception. The first tier of the vehicle’s sensor system is a set of laser warning sensors installed around the vehicle. Within each sensor unit, both coarse and fine resolution detection systems are employed to provide a wide degree of coverage to the HT9A7. With overlapping sensor coverage, the system detects lasing and is able to provide the crew not only with warnings, but informs them of the specific sector in which lasing has been detected, providing the crew with directional threat awareness that then allows for accurate reaction by both the crew and the automated threat response systems. The second tier of the detection system is an infrared sensor installed with the commander’s 3CCD multi-directional periscope for more immediate threat direction. The infrared sensor allows the HT9A7 to detect munitions, either when launched or in mid-flight, and the high placement, 360˚ coverage of the system means that it is able to provide Solothel with yet more directional awareness, further increasing its ability to react at speed to incoming threats. Finally, the HT9A7 utilises millimetre-wavelength radar based on flat panel additions around the vehicle and a single fixed unit to provide the HT9A7 with 360˚ degrees radar protection, allowing the HT9A7 to not only acquire incoming targets, but their speed, relative distance and profile to create an accurate picture of the projectile. The effectiveness of the system is, again, greatly increased by overlapping search sectors; together with the high performance processors utilised by Solothel, this allows the overall target acquisition array to utilise its wide selection of sensors to achieve extremely high reaction speeds, greatly increasing the speed and thus effectiveness and success rate of its target interception. The three tiers of the system guarantee the accurate and effective threat detection of a number of different threats at a number of different ranges, and it is this effectiveness that gives Solothel the ability to surpass and exceed most current active protection systems.
However, in order to make the most of Solothel’s comprehensive threat detection suite, the HT9A7 required a target interdiction and interception system that would make full use of the electronics suite at its disposal. As such, Solothel utilises a number of varying target harassment techniques across a wide spectrum, both soft and hard kill, to provide Solothel with a nigh-unrivalled array of tools with which to assure that projectiles are challenged by the very real prospect of interception before even managing to reach the tank’s passive protection. As its soft-kill suite, Solothel utilises a combination of smoke generation and electro-optical jamming to hinder and prevent both target tracking and locking by airborne missiles as well as weapons stations themselves.
Smoke generation is usually achieved by a number of 80mm grenade units, generally varying from between twelve to twenty-four launchers with a total of anything between twenty-four to forty-eight canisters installed on the vehicle itself, and can be set to be launched via manual ignition or automatic ignition upon sensor reception. The exact parameters can be set in detail; as the different sensor equipment used by Solothel, and to some extent profile comparison, allow it to identify reception information and categorise it, automatic smoke ignition can be set to occur within limited parameters, such as lasing.
The 80mm grenade launchers themselves are not restricted to a single type of ammunition. In some cases, they can be equipped with 80mm anti-personnel grenades; these utilise hexogen tolite as an explosive base for the directional shattering of a steel casing, resulting in a high-explosive/metal fragmentation based anti-infantry defence mechanism with the directional deployment of the device optimised by direct control by Solothel itself, which is capable of utilising returns from its IR sensors if necessary to identify and eliminate hostile infantry forces (though this option can be turned off when operating in conjunction with allied infantry).
In terms of smoke, the HT9A7 is provided with two separate types of smoke for operation in close proximity to unarmoured elements, and operation in open areas against hostile forces. This differentiation is necessary due to the nature of the smoke composition used in each grenade. The ‘A’ model, designed with operation in close proximity to non-protected elements in mind, utilises the explosive dispersal of chlorosulfuric acid to spread out an aerosol smoke cloud and reduce the acid concentration of the hydrochloric and sulphuric acid produced as a result of the reaction. To compensate for the resultant reduced effectiveness of the smoke cloud, the smoke composition also contains fine metal coated carbon fibres to act as obscurants in the millimetre wave region, thus allowing Composition A to provide the HT9A7 with adequate protection in a variety of ranges. Composition B differs slightly from Composition A in that, while retaining the explosive dispersal mechanism and the carbon fibre content to act as a radar obscurant, the actual chemical composition of the smoke grenade has been changed to a white phosphorous-based composition. This is due to the pyrophoric qualities of WP; because it burns when put into contact with the air, it creates a short period of IR inhibition through a highly volatile exothermal reaction. Furthermore, the chemical content of Composition B grenades is increased in comparison to A, with the explosive dispersal lessened, due to the fact that it is designed solely for effectiveness and disregards general welfare due to its envisaged area of use; as such, Composition B grenades offer a much higher performance alternative to the HT9A7 when engaging hostile forces in the open field, a quick acting smoke grenade that, through the use of white phosphorous and metal coated carbon fibres and their explosive dispersal, create a quick blanket of thick smoke effective as an obscurant in the visible, infra-red and millimetre-wave spectrums to provide the HT9A7 with full spectrum defence. Of course, both Composition A and B are potentially harmful to those caught within the device’s area of effect upon ignition (without protective equipment in the case of A, and in either case with B), and as such, automatic deployment by Solothel is an easily alterable option; Solothel’s control mechanism, displaying flexibility as always, allows the crew to select the parameters within which the smoke canisters are to be deployed, ranging from full automation upon threat detection to complete manual control. As such, the 80mm grenade-based defensive suit utilised by the HT9A7 provides the tank’s crew with a highly effective set of soft-kill defence mechanisms capable of block the target locks of weapons operators and in-flight munitions, but also allows them to minimise collateral damage via a selection of ammunition and the flexibility of the control system.
The second soft-kill mechanism employed by Solothel is an electro-optical defensive suite, mounted in two box units to either side of the HT9A7’s turret. The electro-optical defensive suite relies upon the emission of interference directed towards older generation missiles relying upon detection and engagement in the infra-red range (TOW, MILAN, AT-3, etc.) and takes advantage of the nature of the guidance system used universally in such missiles to create a jamming mechanism that virtually guarantees successful munitions interdiction. The targeting equipment of wire-guided missiles utilising infra-red targeting rely upon ‘flares’ located at the back of the missile to create a reference point concerning the location of the missile in relation to the target, and the electro-optical defensive suite employs ‘jamming’ that replaces this flare by emitting a larger hotspot that takes the place of the missile’s ‘flare’. The result of this is that the course correction of the targeting computer becomes faulty, as the location of the flare no longer corresponds to that of the missile. In practice, as the engagement range of the system is relatively extended, this results in most targeted wire-guided systems losing control as a result of false course correction and failing to hit their intended target.
Though the soft-kill component of Solothel is capable of interdicting and breaking target locks across the full spectrum of targeting equipment, and disabling wire-guided missiles altogether, the threat posed by alternately guided, modern anti-tank missiles and high speed tank projectiles is still extant. In order to combat this, Solothel is equipped with a very different set of projectile interception equipment. The hard-kill suite employed by Solothel utilises a combination of area effect and kinetic energy projectiles to engage and destroy a wide range of potential threats posed to the HT9A7; fully controlled by the Solothel control system, they are directionally deployed in the most efficient and effective manner possible based on sensor returns to engage incoming targets at high speed. The first component of the system is a canister-based system employing the vertical launch of ‘grenade’ units; though six are mounted at the front of the HT9A7, additional units can be added around the vehicle as necessary. Similar to a grenade in appearance, this unit is similar to the anti-personnel 80mm grenades employed by the HT9A7 in principle; utilising a composition of hexogen tolite and RDX as its explosive base, these canisters directionally deploy titanium carbide ball bearings to intercept and destroy incoming projectiles. A soft launch mechanism propels the canister at high speed from its launcher, and impulse thrusters allow it to make rapid course corrections in mid-air before engaging and eliminating the target, either destroying it outright or destabilising it to the extent that it is incapable of effectively hitting the tank. Though the system is highly effective against anti-tank guided missiles, the reaction speed and style of the system (involving launch, rotating and explosive detonation) is nonetheless insufficient against ‘fast’ projectiles, due to the relatively time consuming launch procedure and the insufficiency of explosive propelled titanium carbide bearings as interceptors against such munitions. As such, the HT9A7 is equipped with another hard-kill system that abandons engagement at range and opts to utilise kinetic energy kills to eliminate high speed threats to the vehicle. Using titanium carbide rods, the system initially launches the interceptor with a ‘hard’ soft-launch, giving it a higher initial velocity than most comparable soft launch systems. It then utilises impulse thrusters to adjust its trajectory in the very limited period prior to target impact; depending on the location and position of the target, Solothel will either guide the interceptor into or into the path of the incoming projectile. The result may not be absolute destruction, but as this component of Solothel is a terminal stage interceptor, it is highly likely that the destabilisation caused by its impact will deflect the target object to either knock it off target or force it to hit the HT9A7 at a less damaging angle, restricting damage to the tank itself. Again, additional units can be mounted around the vehicle as necessary. This two-component system allows Solothel to intercept almost any conceivable target capable of breaking through its soft-kill systems, not only last generation anti-tank missiles but the whole range of threats faced by it.
Equipped with a wide variety of highly advanced automotive components and armaments, the HT9A7 is designed to achieve full spectrum dominance on the field of battle. Accordingly, the component control of the HT9A7 is naturally complicated; as such, in order to maximise the effectiveness of both the hardware and the crew itself, the electronics suite of the HT9A7 aims to be both comprehensive enough to ensure that the advanced capabilities of the tank are fully exploited by those utilising it, as well as being accessible. The latter point may seem irrelevant in terms of defining the HT9A7’s combat capabilities, but the over-complication of a vehicle’s control systems can result in the inhibition of the tank crew’s ability to operate effectively on the battlefield, over long periods of time if not at all. As such, the HT9A7 aims to marry a complex set of electronics with ease of control and system streamlining to ensure that the tank in combat is not only high performance on paper, but in practice.
Fire Control System
The FCS (Fire Control System) of the HT9A7, known as ‘Io’, was built to accommodate the highly technically complicated SC10.8 gun system utilised by the tank, and as such, it is a high performance fire control module capable of managing the variety of ammunition and circumstantial variables necessary to accurately operate the weapon while remaining operator-friendly. Firstly, in order to acquire targets, Io utilises a tetrad of semi-automated sensors to gather accurate data not only of the enemy, but of the terrain on which the enemy stands. The first component of the target acquisition system is the gunner’s standard telescopic sight, a 3CCD camera which utilises three step (3x, 10x, 20x) magnification to provide the gunner with day sights effective at extended ranges. A FLIR thermal imaging system with five step (3x, 6x, 10x, 15x, 20x) magnification is utilised to extend the viewing range of the gunnery system to night operations, and the ability of the system to detect heat signatures in the day allows it to root out concealed targets regardless of the time of day, greatly increasing its utility in the gunner, and Io’s, hands. A single phased array radar unit is also used by the HT9A7 to perform extended range target searches, decreasing the effectiveness of traditional IR-based defensive measures against Io; capable of providing the fire control system with target data at extreme ranges, the phased array radar gives Io the ability to reach out beyond traditional IR-based obscurants, and the flexibility of such a radar system allows it to transfer at high speed from wide search scans to a tracking mode, providing the gunner with another source of fire control data if necessary. Finally, Io is also equipped with a LADAR array. LADAR is a particularly unique choice in that, by most standards, it is an extraordinarily ineffective targeting device; as frequent, high speed scans, necessary for any fire control system to continuously provide accurate firing data to the ballistic computer, consume too much energy and processing power, it is both impossible and ill-advised to attempt to use LADAR as a constant-input firing solution source. Rather, Io takes full advantage of LADAR’s high resolution searches and employs it to augment the firing solution obtained by other systems, rather than utilising it independently as one. Upon activation, or automatically if so desired, the HT9A7’s LADAR system (which is restricted to a relatively narrow search band in front of the vehicle) can be utilised to initiate a scan, providing Io with a high resolution image of the terrain composition of its target tracking area, providing the fire control system with additional environmental data to aid in improving the accuracy of the final firing solution. As such, Io is able to utilise LADAR in an effective, power-friendly manner that makes the most of its advantages.
The gunner utilises an eye-safe pulsed CO2 laser rangefinder with optical heterodyne detection for target acquisition purposes. Carbon Dioxide lasers, originally conceived in the 1980s as a replacement for traditionally used rangefinding equipment, mark a step up from current-use Nd:YAG rangefinder systems through its decreased system size and weight, and the ability to penetrate most extant smoke dispersal systems, giving Io the ability to pierce certain soft-kill mechanisms to ensure a higher hit probability. High speed system response and fast processing thus allow the gunner to acquire, target, track and obtain a firing solution on a target in just over a second if so desired, with a modern, multi-tiered system that gives Io exceptional resilience to traditional targeting countermeasures. The optical suite itself is gyrostabilised, retaining its accuracy during movement over broken terrain. On the sight picture itself, as well as the reticule (which alters depending on the weapon used by the gunner), the range is shown on the top of the reticule, while the bottom left displays the turret position relative to the hull and system status, the bottom shows the ammunition type selected, and the bottom right displays display mode, targeting system status (automated or otherwise), APS status (automated, manual, off), as well as a target list and highlighted targets selected by Io and the tank commander if so desired. Additional status icons can be added or removed from the gunner’s reticule at will via the gunner’s touch screens. System redundancy is achieved via a secondary, emergency sighting module located in the gunner’s station which is non-digital, though its accuracy is greatly limited in comparison to the electronically controlled FCS aided firing solutions produced by the HT9A7 and it only exists for emergency control.
Io itself is a control system with high processing power and memory, and most certainly one of the contributing factors through power consumption to the disproportionately large engine employed in the Yvernyr. The sheer processing power of Io is necessary to ensure that it is able to achieve competitive response speeds whilst remaining able to collate the comparatively large amount of data input into the system, and this is something it is able to do almost effortlessly; firing solutions, for example, take fractions of seconds to be calculated, and overall, the system’s performance is far beyond both expectations and competition (though this is only achieved in exchange for higher procurement costs). However, though systems capability are a vital part of a tank’s effective operation in a 21st century battlefield, a case study exists in the Leclerc tank (used prior to the introduction of the HT9A7) as to why capabilities can, in fact, be restrictive; the advanced nature of the Leclerc’s systems were only achieved through the introduction of additional complexity to the tank’s operation, and the result was that concentrated crew operation could only be achieved for a maximum of about six hours, following extensive training and familiarisation with the tank. Noting this disadvantage of the Leclerc, one of the primary objectives of Io’s development, and the HT9A7’s electronics suite as a whole, was superior interfacing and automation to ensure that the tank’s advanced electronics suite operated solely as a beneficial factor rather than hindering the vehicle.
Operation of the gunnery system is achieved through the utilisation of a pair of 30cm touch screens (mounted in front of and to the right of the gunner, who is located to the right of the turret itself), which also come with multifunction buttons for system redundancy purposes. As the visuals from the sensor and optical equipment are digitally transmitted into the vehicle, the targeting scope through which the gunner looks can be stored above, allowing him to access the touch screens without obstruction if necessary; when utilising the scope, it is pulled down from above, locked in position with a lever-pattern lock, and operated like so; a control panel located to one side of the rifle scope allows the gunner to adjust brightness, reticule contrast and other factors. A stowable keyboard is located under the forward 30cm screen for computer interfacing, both for redundancy purposes and the management of areas not covered by the touch screen/MFB interfacing. For gunnery control, a yoke placed underneath the turret is used to control most aspects of the interface, from target acquisition to ammunition selection. By placing a large quantity of the interface on the yoke, Io allows the gunner to run through the firing process without moving from a fixed position, greatly increasing the speed of said process over other interfaces requiring movement around the gunnery station. Ammunition selection is managed by a series of 5 ridged buttons located on the side of the yoke, pre-programmed to select a certain type of round, while a pair of control sticks are used to cycle through lists, including target selection, weapon selection (main gun/co-axial). A firing button, safety catch and sight control unit (sight type, magnification etc) are all components that are also found on this yoke.
In terms of the firing process itself, the HT9A7 is a highly ‘intelligent’ tank if so desired; the systems of the vehicle can, of course, be set to manual control in the interests of redundancy and flexibility, but the fully active Io Fire Control System is one of the most automated systems of its kind today. Drawing from design concepts utilised in the Asakuran Type 90, a tank equipped with an Anemonian-developed electronics suite, Io’s fire control system is equipped with an extensive target profiling database that allows the fire control computer not only to recognise potential targets, but to compare them to known target profiles stored within the FCS’s database (in some cases making loose affiliations such at identifying the target as a tank, while making more accurate judgments in other cases) and thus create priority lists that greatly ease the target identification and selection process for the gunner. These priority lists allow the gunner, as well as the commander, to easily cycle through potential targets, especially invaluable in a high intensity combat situation involving engagement with a large number of hostile combat assets. The ability to shift different targets around on the priority list prior to entering an engagement and to thus greatly shorten the target acquisition period gives Io a notable advantage in combat situations by streamlining the target selection process to the point where all the gunner must do is select a target from a list. At this point, Io generates a firing solution based on a number of sensory inputs; as well as the gunner’s sensors (laser rangefinder, LADAR and potentially the phased array radar system), a crosswind sensor, a dynamic vertical angle sensor, a barometric sensor, data concerning the boresight alignment (obtained via laser bore sighting), an automatic muzzle reference system that also allows Io to compensate for instability while mobile, a tachometer to determine the target’s speed and thus necessary lead distance, and information concerning the ballistic properties and temperature of the ammunition. This self-updating fire control system is able to achieve unparalleled accuracy together with one of the fastest fire control information cycling and update speeds today via a combination of multiple sensory inputs and high performance data processing and storage, updating the fire control information multiple times a second while tracking targets. The firing process itself can actually be automated down to the point where the gunner’s involvement is limited to selecting a target from a list; from there, the turret can automatically traverse, acquire the target, the firing solution and fire when ready. This allows the gunner to simply select a list of targets together with ammunition and allow the FCS to autonomously work its way down it; however, it is found, especially when operating in conjunction with other tanks, that manual control is required for effective coordination, as well as the obvious rate of fire limitations of a fully automated system, and the result is that complete automation is not utilised as much as it would otherwise be (though in practice, manual control can simply involve trigger depression).
The commander’s sight is similar to that of the gunner. Five sights can be selected from by the commander; his main sight, the sighting block located prominently slightly to the left of the turret, is primarily used for long range target identification and acquisition, and employs a three step magnification 3CCD camera and five step magnification FLIR imaging system like that of the gunner. His secondary sight is that utilised on the tank’s Remote Weapon System (3CCD/FLIR/laser rangefinder), and he is also provided with a 3CCD 360˚ periscope, the 3CCD forward panoramic sensors located under the commander’s sight and a 3CCD/FLIR periscope mounted on the back of the HT9A7. The result is that the commander is capable of maintaining overwatch around the entirety of the vehicle, compared to the restricted vision of most modern tank commanders, and though the commander is under no obligation to fully employ all of these sighting methods, it nonetheless allows him to quickly identify targets in what would normally be a tank’s blind spot. Control of the system is managed via a stick pattern interface located to the right side of the commander’s seat, a stowable keyboard and three 30cm touch screens with MFBs located in front of the commander’s station to create a panoramic viewing arrangement that can quickly be changed into a highly streamlined and effective systems control suite. As well as utilising the RWS (which can either be controlled manually, set to ‘fix’ itself on a single position or ‘track’ an identified target), the commander is also capable of utilising his main sight to ‘set’ targets for Io or the gunner (depending on the level of automation) and, in the event of an emergency, employ his station to control the entire gunnery system via the 30 cm touch screens and his stick, with full turret automation greatly decreasing the workload on the commander. In theory, this allows the commander to utilise the entire turret alone, but it is difficult to maintain concentration in a work intensive situation of this kind for over an hour or so, making it a highly impractical option for all but the direst of situations.
The driver employs a 3CCD panoramic camera arrangement and FLIR on a three-screen arrangement of 30cm touch screens with MFBs located in a panoramic viewing arrangement for sighting purposes. The system is able to identify and colour code obstacles in the HT9A7’s path of advance on the driver’s display, greatly enhancing the response speed of the driver to such things and putting less pressure on the driver to identify such obstacles in high concentration combat situations.
The HT9A7’s networking system, due to the high quantity of information sharing between the HT9A7 and various organisational structures at both a vertical and horizontal level, is designed to be both high performance on paper and usable in a variety of different manners to ensure that the high specifications of the HT9A7 are not only used independently, but to their full extent when coordinated with other tanks and, vertically, in conjunction with other assets. The HT9A7’s combat networking suite, labelled SAIC, connects the individual tank to the Anemonian Crown Army’s CombatNet (supporting units up to the battalion level). CombatNet, due to the introduction of the ICS21 program, is a battalion networking system utilises by everything from Mechanised infantrymen to artillery batteries, and is universally employed to facilitate integration into control networks at a higher level (BattleNet, WarNet etc). Rather, instead of utilising completely different software for each combat asset networked into the Crown Army’s C4I structure, CombatNet utilises a combination of base software together with asset-specific modules (for tanks units, mechanised infantry, artillery and other assets) to simplify networking logistics while catering to the specific needs of individual combat assets to create a system that is both efficient and effective. At its most basic level, CombatNet is a cartographic display. With rapid updating enabled at the platoon, company and battalion level, this cartographic display is able to show blue force and enemy troop locations and movements as detected by allied assets, operational plans fed down from various levels, as well as status reports and information from various levels to greatly increase the level and quality of group coordination, amalgamating the myriad of information entering the system via a highly capable Geographical Information System. Beyond this, however, the HT9A7 is also capable of utilising SAIC to share targeting data with other tanks at the platoon level if desired; the rapid sharing of data allow tank platoons operating in conjunction to further hone their capabilities in this area by increasing the effectiveness and efficiency of their combat employment and countermeasure deployment via the sharing of targeting data.
SAIC is also utilised to manage the HT9A7’s communications suite. The high capacity combat network radio employed by SAIC for limited range communications is a high capacity data radio operating as a frequency-hopping system in the UHF range (225-450 MHz), and supports high data transfer speeds to permit the utilisation of the HCDF connection for rapid and secure voice and data transfer and communications between vehicles for limited distance level coordination. At this level, the HT9A7 is also capable of employing IEEE 802.11 standard encrypted wireless local area networks for inter-vehicle connection. E-WLAN connectivity permits vehicles to achieve high speed, ad-hoc networking supporting secure data, video and voice transfers between individual tanks. A chipset incorporated into the computer utilises an encryption algorithm to secure access to Crown Army level WLAN networks, employing COMSEC/NETSEC encryption, meaning that enemy access or viewing of such networks is impossible, especially in the combat environments where the use of such systems is envisaged. For communications and networking at higher speed and longer range, SAIC is also equipped with digital broadband connectivity with satellite and stationary fibre-optic links; though such tactical internet connections allow for theatre-wide secure high speed connection, data transfers and features such as extended inter-formation communication and messaging, not to mention commercial internet interfacing if necessary, and though most Anemonian theatre-wide networking hubs of this kind employ automatic network formation and autonomous organisation, together with interconnection by utilising individual users not only as recipients but as intermediary nodes, to maximise speed (over six time the speed of HCDF connections when transmitting messages, for example), ease of use and efficiency by removing the need for a significant dedicated communications infrastructure, the reliability of such networks on the battlefield is nonetheless susceptible to enemy attack. As such, the HT9A7’s broadband internet connection is more of a ‘bonus’ feature permitted further effectiveness if usable; SAIC, and CombatNet, are designed to operate at maximum efficiency via the HCDF connection alone if necessary.
SAIC is also equipped with a highly effective computer malware detection and elimination system; this dynamic malware protection employs frequent database updates together with a connection to a central control system which both possesses a larger database and analyses the coding of unidentifiable threats to maximise its effectiveness against any threat, known or unknown, which manages to get past the HT9A7’s firewall.
The utilisation of SRAM, depleted boron coating of key computer chip arrays, partially redundant computer systems and error correcting memory arrays allows for system resistance, recovery and redundance against electromagnetic pulses and waves (as well as the metal hull of the vehicle itself), hardening the HT9A7 against such attacks and giving it the capacity to operate effectively in nuclear environments if so required.
In terms of automotive requirements, the overall capabilities and limitations of the HT9A7 meant that it established itself as a uniquely demanding vehicle. Sheer weight and high power requirements meant that it required a very powerful engine, but the degree of accuracy to which the tank was able to reach out and strike its opponents meant that the ride quality had to be high, offering unparalleled stability and smoothness to make the most of the tank’s already significant accuracy, both when stationary and when on the move. Uniquely as a nation, Anemos was a nation well placed to answer these needs to the letter, but not because of domestic innovation per se; ultimately, it would be the technology employed within the Leclerc tank previously employed by the Crown Army that would influence and direct the development of the HT9A7’s automotive qualities more than anything else.
Requiring higher output than normal engines, the idea of utilising a standard diesel for the HT9A7 was rejected outright. Rather, it was decided that the engine layout of the Yvernyr (following minor experimentation with multi-fuel gas turbines) would follow that of the Leclerc to maximise the power output of the engine in exchange for an increase in mechanical complexity and fuel consumption, both negative qualities that could be compensated for by the fully professional and educated personnel handling these engines, and the focus on the Crown Army’s logistical efficiency (reflected in its 1:3 combat to logistics personnel ratio). The hyperbar engine thus employed by the HT9A7, generating 2200hp of power, is a design which utilises the additional exhaust flow from a gas turbine together with that of the diesel to boost the effectiveness of the engine’s hybrid turbocharger. The higher boost pressure resulting from this gives the engine power and torque that far exceeds that which would be obtained from the diesel engine alone, making it suitable for use on the power-hungry HT9A7. The result of this is a high power engine that manages to be remarkably responsive; going from 0 to 32km/h in 4.8 seconds, the top speed of 72kph achieved by the HT9A7 is, in fact, governed so as to lengthen the service life of the tank’s tracks. In addition, the noise production of the engine is far below that of a standard diesel engine, closer to that of a gas turbine while remaining more fuel efficient. Furthermore, the gas turbine employed by the engine is capable of acting as an independent power supply; in practice, this means that the HT9A7 is able to save more space by utilising the gas turbine as an auxiliary power supply, but in static positions, the tank is also able to decrease its signature and fuel consumption significantly by powering itself via its APU. However, in exchange for the significant rise in power and torque offered by a hyperbar engine, this is accompanied by a corresponding rise in pressure, a change that requires further changes to be made to such an engine beyond the traditional design of a diesel engine. On the powerplant employed by the Leclerc, this problem is solved by retaining a V-layout engine and utilising large head bolts to contain the pressure. Though this solution worked to some degree on the Leclerc when employed by the Crown Army, it was nonetheless an imperfect aspect of the design that was a cause of concern to maintenance crews, and an alternate solution was pursued in the HT9A7. Ultimately, the layout utilised was the opposed piston rather than the ‘V’ layout used in the Leclerc; by creating a cylinder with pistons at either end, and no head, the pressure problem was largely solved. Another issue with the hyperbar engine is the high heat generation and air consumption of the system, which required extensive temperature control and cooling in the engine block; however, this was achieved by utilising an effective electric air cooling and recycling system in the rear tank block itself in addition to the natural air cooling employed by most engines, with the added advantage of decreasing the thermal footprint left by the HT9A7’s powerplant and increasing its environmental flexibility. In order to manage the complicated climate control, as well as other aspects of the engine’s control (fuel injection, etc), an electronic control system is utilised to obtain information from the sensors located within the engine block and respond accordingly, as well as to provide the driver with information concerning the engine’s status while in use. The result was a powerful and effective powerplant for the HT9A7, with a host of advantages over traditional diesels and a number of disadvantages that could simply be absorbed by existing military infrastructure.
The transmission utilised in the HT9A7, unlike many of the other parts, is a conceptual placeholder while development on newer technologies advanced. The immaturity of many newer technological concepts used in next generation tanks, such as the Continuously Variable Transmission employed in the Type 10 Main Battle Tank, compared to the relatively advanced development of planetary gear automatic transmissions meant that the chances of using the former resulting in a protracted development process were high. As such, an automatic transmission was used in the HT9A7 in place of an envisioned later update, mostly likely employing a hydromechanical transmission. The system employs 8 forward and 3 reverse gears; this planetary gear automatic transmission is computerised to allow for both higher efficiency and effectiveness, as well as simpler interfacing by the driver. The system is partly manual; by setting an upper gear limit, the driver is able to set a boundary within which the transmission operates. However, within these boundaries, the automatic transmission is able to shift between available gears at will. The braking system is a dual circuit hydrodynamic/mechanical system, with an additional hydrostatic retarder in place to act as an ‘emergency brake’ system.
The Yvernyr employs a hydractive suspension that marks a step up from the hydraulic suspensions widely utilised by main battle tanks in the combat environments the HT9A7 is built for. The suspension operates around the same mechanical principles as a hydropneumatic suspension; the utilisation of an incompressible hydraulic fluid’s transfer within a ‘sphere’ to alter the pressure of nitrogen at the top of the sphere, in theory creating a suspension with an infinite number of potential positions. Already, this gives the suspension a significant advantage; this allows is to adopt a theoretically infinite number of positions, and allows the HT9A7 to adopt a variety of positions, ranging from standard ride, to ‘kneeling’, depending on the circumstantial necessities, giving it a high degree of flexibility in this respect. Furthermore, in terms of ride characteristics, an uncompressed hydropneumatic suspension is softer than a steel spring, while a compressed one is capable of being harder than a fully contracted spring. This gives the hydraulic suspension the ability to display comfortable and stable ride characteristics in almost any situation, making it the ideal candidate for use within the HT9A7. The introduction of a hydractive system was one that simply increased the already significant inherent advantages of the hydraulic suspension. Sensors within various areas of the tank’s automotive parts feed data concerning speed and conditions to a computer control system. By gauging the nature of the ride conditions, the computer control system is able to modify the allocation and compression of spheres at millisecond speeds so as to alter the suspension to provide the optimal ride conditions under any circumstances, creating a constantly variable suspension of sorts capable of responding on the move to changes in terrain to maximise its effectiveness. Of course, fully automated suspensions are not necessarily the optimal solution considering the individual requirements of individual crews, and as such, a high degree of crew input into the system automation is also employed. It can be returned to ‘manual’ to turn it into a normal hydropneumatic suspension, of course (with a control interface that allows the driver to shift the position of the tank minutely and manually), but when in automatic, the ride characteristics can be set to a ‘constant’ preset (balances between handling against comfort), and the hydroactive suspension control systems will respond accordingly to keep the vehicle handling as close to the preset levels as possible across all terrain environments, greatly increasing the flexibility of the HT9A7’s suspension in the hands of the driver.
Turret traverse is controlled by electrically powered servo amplifiers; as with the rest of the tank’s electronics, these draw power from the engines, as well as lithium ion batteries used for energy storage.
Crew Amenities and Survivability
The centre of any manned vehicle is, by default, the crew itself, and as such, great efforts have been made to ensure both comfort and survivability. Of course, this is within the bounds of feasibility; it must be understood that whatever the measures implemented to maximise comfort, as well as the superior ride characteristics of the hydractive suspension, the HT9A7 is fundamentally a cramped and relatively uncomfortable vehicle designed as such to maximise protection and volume efficiency.
NBC protection is achieved via fully filtered dry air and climate control managed via an air outlet into the crew compartment. This NBC protection suite can be powered via the engine or the turbine APU, allowing for functionality even when idle, and also serves to maximise crew comfort by allowing for a fully adjustable operating environment (ranging from humidity to temperature). In the event of system failure, the vehicle is also equipped with a smaller secondary NBC protection suite; this system supplies filtered air to individual crew stations, and is also equipped with personal ventilation masks to maximise the distribution of a limited supply of air.
Against fire, the crew is protected by two mechanisms. Firstly, sensors within the crew compartment itself are able to detect the outbreak of fires, and are connected directly to a pentafluoroethane fire extinguishing system within the crew compartment, designed to minimise both crew and component damage while providing rapid fire control to ensure safety. A Halon-1301 based fire extinguishing system is employed within the HT9A7’s fuel tank; again, sensors are able to detect breaches in the fuel tank, and Halon-1301 is employed to neutralise explosive vapours. The tank itself is self-sealing, employing an open-cell polyether safety foam to ensure that fuel tank punctures are quickly dealt with to limit damage to the HT9A7.
In terms of seating, as well as limited reclining and an adjustable head-rest, footpads, lower hull plating and a design that allows for minor seat displacement, the tank’s seating is also fully mine protected (with shock isolation and redirection) to ensure that under-hull threats are protected against, both in terms of the vehicle but also from the shock to the crew compartment itself.
As far as comfort is concerned, the HT9A7 is equipped with the bare minimum. A water tap employing filtered water to one corner of the crew compartment, capable of providing hot and cold water, is used alongside an electric hot-plate as rudimentary tools for food and water supply provision to the crew when on the move. The electronics system of the HT9A7 is equipped to interface with a wide variety of commercial MP3 players (transmitted over the crew intercoms or over internal and even external loudspeakers, if so inclined) as well as connection to commercial internet via military broadband. In practice, however, the employment of such electronic interfaces during combat operations is greatly frowned upon by Anemonian officers (insofar as they result in concentration losses), resulting in the restriction of their use to peacetime operations, and their use during combat generally involves tank crewmen playing death metal and Wagner’s Walkürenritt while charging terrified and confused insurgents in Asakuran combat environments.