Title: High Mobility Tactical Armored Car
Macabees - March 24, 2008 03:56 PM (GMT)
High Mobility Tactical Armored Car
The High Mobility Armored Car (HIM-TAC) is MecániCas’ second military vehicle developed and manufactured by the company’s Defense Industry Division (MecániCas DID). In Spanish, the vehicle is called the ‘Vehículo de Alta Mobilidad’ (VAM) and about nine hundred will be acquired by the Castillian Ejército de Tierra, although information on which versions is unknown. The HIM-TAC is a next-generation high mobility armored vehicle, designed primarily for reconnaissance, exploration and the transport of fireteam sized units. However, the modular design of the vehicle makes it completely multi-purpose, and therefore the HIM-TAC is able to operate over a wide range of mission profiles over a myriad of different terrains and against different enemies. One day the vehicle can be prepared for high intensity urban fighting, with complete protection against small caliber autocannon ammunition (20mm), and the next day the vehicle can be ready for humane peace-keeping operations with ballistically protected glass windows. Its usefulness has been underscored by the recent decision by the Macabee Army (Ejermacht) to procure around one hundred and twenty thousand HIM-TAC vehicles for foreseen peacekeeping operations in areas such as Theohuanacu, Zarbia or now occupied Guffingford. The vehicle also foresees high export success to other countries, now that these have expressed certain interests in such a vehicle. Furthermore, the HIM-TAC enjoys the fact that it has been preceded by the Tiznao-60 advanced armored truck, which has provided MecániCas with a debut of the quality of its engineering and production. The HIM-TAC, or the Tiznao-10, is no short in quality and perhaps is even one step ahead of the Tiznao-60, given that the HIM-TAC has truly been designed to cater to the necessity of every possible international client interested.
In the face of modern asymmetrical warfare, and even conventional warfare, the threat of large land mines and cheap improvised explosive devices (IED) has risen exponentially over the last four decades. The first great use of land mines and improvised mines using old artillery shells was first witnessed by Castillian forces during the Civil War (1967-1973), and although the Castillian Army has not been in any major war since that terrible conflict, it’s evident that such styles of resistance have seen more and more use throughout the world as the years progress. For this reason, vehicles designed during 1970s, 1980s or even the 1990s do not boast of a high level of protection against land-mines, and during conventional warfare such vehicles are not entirely expected to run into daily ambushes. Therefore, new vehicles must go by new standards of protection in order to insure survivability on a battlefield where one day nothing will happen, and the next the convoy will be ambushed by dozens of insurgents. On the other hand, the fluctuation between conventional warfare and asymmetrical third-world conflict means that one vehicle will find it difficult to excel in both types of battle. For this reason, new vehicles must be designed to be as modular as possible, without handicapping protection or mobility. This is a theory embraced by MecániCas and is what has led to the design and development of the HIM-TAC. The HIM-TAC can made to be conventional, with low-protection and lightweight for conventional operations, or even civilian law-enforcement necessities, or it can be completely protected against large caliber small-arms armor piercing ammunition and against improvised explosive devices. Furthermore, modularity allows the client organization to change roles within a matter of hours, or even minutes.
In a sense, protection can be found in mobility. New wheeled armored fighting vehicles, whatever the size, must find solutions for problems including flat tires, bad terrain or damaged suspensions. MecániCas has attempted to introduce a series of ‘new’ technologies to make the HIM-TAC superior to all other vehicles in its sector. Several of these have already been introduced by the Tiznao-60 truck, but their application into the HIM-TAC will ensure increased survivability by guaranteeing the vehicle’s mobility even when it has been damaged. This will allow the vehicle to run away if it has been severely damaged during an ambush, and to save the lives of the soldiers inside of it. It also means that the vehicle makes a great ambulance, given that it will be able to run even when certain components have been destroyed. Furthermore, the vehicle’s motorization is one of the best areas to lose important kilograms worth of weight, including a modern multi-fuel diesel engine, a modern mechanical transmission with a high power transfer efficiency level and an ultra-modern suspension offering a lightweight and a high ride tolerance for the vehicle’s crew. Saving weight in some sectors will allow weight increments in others – this includes more armor protection and extraneous systems which will increase survivability in other ways, such as a central inflation unit for the vehicle’s tires. Although such technology has been used before, namely in 6x6 and 8x8 armored fighting vehicles, volume efficiency of the mechanics in the HIM-TAC allow for the installation of a smaller system into said vehicle. This will make damaging the vehicle’s tires increasingly more difficult and time consuming and expensive.
This introduction alludes to the fact that MecániCas’ principle goal is to increase the survivability of the crew. This is not only achieved through a modular ‘crew central cell’ with high armor protection, but by improving the vehicle’s mobility and introducing new mechanics that will be far more difficult to damage enough to score a mobility kill on the HIM-TAC. Ultimately, MecániCas hopes that its dedication to the soldiers which will be fighting in its new vehicle is what provides the argument to export the vehicle abroad. With over one hundred thousand sales to date, it’s hoped that these will be opening customers who open the doors to the international market. Furthermore, it remains true that the HIM-TAC is possibly the first vehicle of its kind to be devised with this level of dedication. Of course, dozens of tactical vehicles have entered the market, but few of these show the quality that the HIM-TAC does. This quality, admittedly, is something that has been shown to be true for all weapon systems currently sold in Sistemas Terrestres Segovia Land System’s catalogue.
A vehicle like the HIM-TAC can complete a wide array of jobs, including reconnaissance missions, ambulance duties and also has logistical capability. Therefore, ideally the armor of the vehicle should be designed in a way in which it can be changed according to the needs of the client and the operation. Consequently, MecániCas has decided to offer the armor as a modular ‘option’, while the structure only provides basic protection levels – such as against anti-personnel assault rifle (4mm – 7mm) projectiles. The panels can be bolted on within hours (which is an overstatement, depending on the mechanics crew) and there are three major armor kits for the HIM-TAC; ‘standard panels’, ‘medium weight’ and ‘heavy weight’. Standard panels only offer protection against small-caliber anti-personnel ammunition, while medium weight panels will offer protection against up to 8mm tungsten cored armor-piercing projectiles and heavy weight panels offer protection versus up to 15.5mm (15-16mm) heavy machine gun tungsten cored armor-piercing rounds. Although the panels are lightweight, normally a logistics vehicle will be fitted with either standard panels or medium weight panels (depending on the threat; in a conventional war, the logistics vehicles probably don’t need armor protection, since they will be behind friendly lines). However, two different types of doors are offered at structural levels – a peacekeeping and standard door, with larger windows, or what are called ‘battle rattle’ doors which include firing ports. In the latter’s case, embedded cameras can be included in the vehicle to increase the crew’s visibility. Nevertheless, the latter’s door offer increased armor protection by reducing window sizes, which are not armored to the same level as the rest of the vehicle. The ballistic windows come in two standards, as well – non-armored (polycarbonate to protect against artillery and grenade fragments and anti-personnel rounds) and armor (protected against up to 8mm tungsten cored or up to 15mm steel cored projectiles). The vehicle also includes two floor panels – a flat panel and a v-shaped hull multi-layer panel. In general, therefore, the vehicle can be changed according to varying needs. The modularity of the vehicle also allows for easy future armor upgrades and new armor kits of varying weights, if another more specific armor kit is needed.
The structure is designed for ballistic ‘efficiency’ – versus the minimum expected threat – and is actually designed in two parts. The vehicle has a modular ‘crew cell’, which is fitted onto the ‘propulsion unit’, which is formed by the engine bay in the front and the equipment compartment in the rear, united by the transmission and the supporting floor structure. Therefore, new crew cells can be designed with superior structural protection as the threat changes. Thanks to the decreasing costs of titanium and new welding techniques (see: Montgomery, Jonathan S., and Wells, Martin G.H., Titanium Armor Applications in Combat Vehicles, Journal of Metallurgy, April 2001 and Henriques, Vinicius A.R., et. al., Production of Ti-6%Al-7%Nb alloy by powder metallurgy, Journal of Material Processing Technology, 118, 2001) much of the steel structure can be replaced, and this means about a 50% decrease in the overall weight of the structure! Certain parts of the structure are still built of steel, however, especially those related to the suspension to withstand higher fatigue (due to the vibrations of the suspension). Although the crew cell is entirely constructed out of titanium and steel, to keep ballistic efficiency, parts of the engine bay and the rear module is also constructed out of high-strength aluminum alloy to save weight and cost. It should be noted that the structure outside of the crew cell is thinner than that of the crew cell, as survivability priority has been put on the vehicle’s occupants. ‘Special armors’ have been avoided to reduce cost and because given the modular protection kits which are available for the vehicle, high ballistic protection of the structure is deemed unnecessary – therefore, materials like engineered aluminum are avoided.
The most difficult parts of the vehicle to be armored, as found by the design team of the HIM-TAC, are the ballistic window panels. The windows are fabricated in modular ‘boxes’, surrounded by a titanium frame which is bolted-on to the vehicle. These window cells are fabricated to fit the standard door pieces for the HIM-TAC and for the windshield of the vehicle. The problem found in glass protection is that the thicker the glass the more it will hamper visibility, and different materials have different coefficients for the transfer of light. Consequently, until new materials are found, giving a window panel protection against the same threat as a standard armor module for a vehicle is very difficult. According to a research effort funded by Sistemas Terrestres Segovia Land Systems (STSLS), the most common armor piercing ammunition found is the medium caliber tungsten-core (WC) projectile, with a much smaller distribution of heavier projectiles. Some depleted uranium core (dUC) projectiles were found to be distributed, but for the most part these were issued to conventional units – such projectiles have not made a substantial appearance (at least, not to be noticed) in guerilla and terrorists organizations. Given these statistics, a prioritization of ballistic protection can be made and the ballistic window panels can be made to protect the crew from the majority of known threats. Furthermore, the armor can be designed to substantially lower a projectile’s ability to harm someone inside the crew cell by decelerating it – this can be achieved through new materials or by increasing panel thickness (an optimum has to be found between protection and visibility). The key is to study the probability of an impact by a 15mm armor piercing projectile, and this is completely dependent on the type of situation the vehicle will be put in. For example, it’s more unlikely that the vehicle will be impacted by this size of a round if in an asymmetrical conflict due to the low probability that advance ammunition for high caliber machine guns will be distributed. In a conventional war, it’s not likely that a vehicle such as the HIM-TAC will be used to directly engage major enemy forces (unless it’s used in an ambush or hit-and-run tactics) and therefore the probability of being engaged (in general) is much lower than the former example. Nevertheless, although absolute protection would be optimal, engineers have currently concluded that this is impossible with today’s materials.
The windows are composed of a multi-layer transparent laminate, made-up of several different materials. The principle make-up of the panels is laminated float glass, united through thin layers of polyurethane. These layers are 9mm thick, each, and a total of five layers complete a thickness of 45mm worth of float glass. The problem with increased thickness of the glass is the green tint that is created by the iron oxide content of the glass (see: Hazell, Paul J., The Development of Armour Materials, Military Technology, April 2006, pp. 60-61), which also ultimately means that other materials are needed to provide the majority of the strength. On the other hand, there are considerable problems with increased weight of the panels which include the destabilization of the vehicle due to the movement of the center of gravity. Lately, new ceramic materials have begun to be introduced to provide the front plate of a laminate transparent armor – these have been used on several vehicles of the same type. These ceramics include sapphire (single crystal aluminum oxide) and magnesium aluminate spinel (referred to as spinel) – only the former provides sufficient enough protection to be considered a dramatic improvement and sapphire is rare in armored vehicles due to the fact that new processes for material manufacturing which are affordable have only been introduced recently. Perhaps one of the most used ‘new ceramics’ is quartz glass, and this is much more widely used than sapphire. None of these ceramics, however, provided MecániCas with the necessary protection to maximize survivability. Instead, the front plate of the multi-layer window panel is composed of aluminum oxynitride (AlON), a dense, but tough, transparent ceramic material – the front plate is 10mm thick (therefore, between the front plate and the glass the armor is 54mm thick). Finally, traditionally the backing layer is composed of polycarbonate, but polycarbonate only forms about 2mm worth of the back layer, with the rest composed of E-glass which has superior ballistics – total thickness of the window panels are 63mm (for information on all of these materials see: Patel, Patrimal J., et. al., Transparent Armor, The AMPTIAC Newsletter, Fall 2000, pp. 1-6; Klement, R., et. al., Transparent Armor Materials, Journal of the European Ceramic Society, Number 28, 2008; Wright, S.G., et. al., Ballistic Impact of Polycarbonate – An Experimental Investigation, International Journal of Impact Engineering, Volume 13, Number 1, 1993; Hazell, Paul J., The Development of Armour Materials, Military Technology, April 2006; and Sternberg, J. and Orphal, D.L., A Note on the High Velocity Penetration of Aluminum Nitride, International Journal of Impact Engineering, Volume 19, Number 7, 1997). The glass offers enough protection to offer multi-hit impact (as long as the part of the panel remains intact – this doesn’t include cratered panel) against up to 10mm tungsten-core (WC) armor-piercing projectiles, and therefore is proof against all small-caliber and medium-caliber automatic weapons. Hopefully, one day in the future new materials will allow the augmentation of protection to cover fire from heavy machine guns.
However, this protection can be offered for the rest of the vehicle for a relatively light weight. As mentioned before, there are three principle packages for the HIM-TAC. The most basic are ‘standard panels’ which only offer a very small increment in protection, next there is the ‘medium weight’ armor package which is a thinner version of the ‘heavy weight’ armor package (and the use of more metal – improved rolled homogenous armor and titanium - versus ceramic and plastic). The armor is very similar to ArmorMaxx, used on the Tiznao-60 truck, although it exchanges some of the materials for what is considered more proper for a vehicle such as the HIM-TAC; nevertheless, much of it is the same. Apart from designing armor that can withstand multi-hit impacts upon a single panel, multi-hit capability can also be established by introducing modular cells. Each cell has a predefined optimal surface area to distribute the energy of the attacking projectile, and this depends largely on the projectile. Larger long-rod penetrators, commonly used by tanks, are countered through much larger modular panels, but smaller caliber ammunition allows for the use of ‘mini-panels’; for example, a 7.62mm projectile can be defeated through a ceramic tile roughly 5x5cm in dimensions (probability of single cells receiving multiple impacts, based on cell size, is discussed in: Bless, S. J. and Jurick, D. L., Design for Multi-Hit Capability, International Journal of Impact Engineering, Volume 21, Number 10, 1998. See also: de Rosset, William S., Patterned Armor Performance Evaluation, International Journal of Impact Engineering, Volume 35, 2005). Against larger calibers, like a 15.5mm heavy machine gun, larger tiles are recommended. In the HIM-TAC’s case, the panels are of similar size to those used on the Tiznao-60. Furthermore, door panels are manufactured as single-piece modules to make application to the vehicle easier; depending on the threat, single-piece modules can also be considered multi-hit capable if the ammunition hits in different areas of the panel (where the ceramic isn’t cracked). Furthermore, the armor used can be considered multi-hit capable through the application of a rubber or aluminum foam back layer to the ceramic (in reality, a spacing layer).
The ‘heavy weight’ kit is composed of a front-plate of titanium, offering enough protection (at a low weight) to stop 155mm artillery fragments and nearby grenade blasts, without damaging the composite armor underneath. The main defeat mechanism of the armor is the titanium-diboride (TiB2), encased in titanium – the ceramic is manufactured through ‘spark plasma sintering’, since it has been found that titanium-diboride is overall more efficient when manufactured through this processes (over hot isostatically pressed titanium-diboride, for example; see: Patterson, Annika, et. al., Titanium-titanium diboride composites as part of a gradient armour material, International Journal of Impact Engineering, Volume 32, 2005). To improve the material’s fracture toughness the titanium diboride has been ‘prestressed’, which means that is has been shrunk and compressed during manufacture to increase the ceramic’s ability to better withstand an impact without fracturing (see: Bao, Yiwang, et. al., Prestressed ceramics and improvement of impact resistance, Material Letters, Volume 57, 2002; Holmquist, Timothy J. and Johnson, Gordon R., Modeling prestressed ceramic and its effects on ballistic performance, International Journal of Impact Engineering, 2003). Thereafter, a thin back layer of aluminum foam is included for multi-hit capability. The aluminum foam also absorbs a large portion of the stress waves related to penetration and decelerates the rest, meaning penetration has less of an impact on the armor’s back plate, increasing resistance to penetration. Originally, this layer has been attributed to rubber or polyurethane, but it has been found that closed-cell aluminum foam performs better and hardly increases weight (see: Gama, Bazle A., et. al., Aluminum foam integral armor: a new dimension in armor design, Composite Structures, Volume 52, 2001). This is followed by a thicker backing-plate, which is normally composed of a hard material, although recently replaced by composites such as S-2 glass. On the HIM-TEC, the backing layer is composed of carbon-nanotube-doped poly-vinyl-ester-epoxy matrix reinforced by E-glass. Although this sounds like something of the future, and is indeed expensive to produce in small quantities, carbon-nanotubes will help increase protection levels while decreasing weight. High hardness carbon-nanotubes will help increase the material’s ability to deflect incoming projectiles, while their ductility will help absorb the projectile’s energy. In other words, they achieve what very little other materials can – both aspects of armor protection. Given these characteristics, such a composite backing layer is a superior substitute to metal (steel or titanium) and give the HIM-TEC high protection for low weight (see: Grujicic, M., et. al., Ballistic-protection performance of carbon-nanotube-doped poly-vinyl-ester-epoxy matrix composite armor reinforced with E-glass fiber mats, Material Science & Engineering A, 2007). Together, this laminate composite armor can achieve protection against heavy machine gun fire (even against depleted uranium core armor piercing projectiles) with a light weight penalty, meaning the vehicle’s size and mobility will not be hampered as a consequence (for more information on the materials used, see: Hogg, Paul J., Composites for Ballistic Application, Department of Materials, Queen Mary, University of London; Nemat-Nasser, S., et. al., Experimental investigation of energy-absorption characteristics of components of sandwich structures, International Journal of Impact Engineering, Volume 34, 2007; Kwok, Richard W.O. and Deisenroth, F. U., Lightweight Passive Armour for Infantry Carrier Vehicle, 19th International Symposium of Ballistics, 7-11 May 2001; Übeyli, Mustafa, et. al., On the comparison of the ballistic performance of steel and laminated composite armors, Materials and Design, Volume 28, 2007; Reaugh, J.E., et. al., Impact Studies of Five Ceramic Materials and Pyrex, International Journal of Impact Engineering, Volume 23, 1999; Gower, H.L., et. al., Ballistic impact response of laminated composite panels, International Journal of Impact Engineering, 2007).
Laminate composites armor should have a greater thickness efficiency (and mass efficiency) as compared to armored steel (RHA), and so the armor required should be less than it would be if the armor was composed of steel. If a tungsten-core 15mm armor piercing projectile can penetrate an estimated 40mm at 1km (it should be noted that engagement ranges expected are probably less than 100m), then necessary protection equivalent to armored steel should be 50-70mm. If we estimate a thickness efficiency of the multi-layer composite to be approximately 1.6 (a guess which might not be correct for this specific armor; but, it should be over 1.5 and probably at around 2.0) then we can say that the required armor thickness to defeat a 15.5mm WC API threat is between 30-50mm. For thickness of specific locations, the armor will be thinner where structural protection is higher (for example, the lower area of the door). Nevertheless, all-around protection against 16mm depleted uranium cored armor piercing projectiles is to be expected (therefore, a maximum of around 50mm of armor). Against less powerful rounds, this armor is also multi-hit capable and will stop multiple medium-weight small arms projectiles (around the 7.62mm caliber). The ‘medium weight’ armor package is similar in make-up, but – as mentioned before – will only offer protection against 8mm WC armor-piercing projectiles (therefore, around 15-30mm thick at most). In terms of mass gain, this armor is much more efficient than other existing armor modules and will cost less in weight – the ‘heavy kit’ will add about 1,000 kilograms (based on values provided by: Iveco LMV Para el Ejército de Tierra, World Military Forces, Number 65, 2008, pp. 21-29). The medium weight appliqué panels will add considerably less (less than half the weight), and therefore will increase the available transportation weight.
On the modern battlefield, however, ballistic protection against armor piercing bullets is no longer the only necessity. The use of land mines to defeat mounted warriors has existed even before the invention of the anti-tank shaped charge, as medieval infantry used sharp metal spikes littered throughout the battlefield to defeat charging horsemen and knights. However, it is true that only recently has the necessity to defend armored vehicles from anti-vehicle land mines become a priority, as only recently have these weapons been manufactured in homes and have been distributed enough to impact mounted warfare. Therefore, new vehicles are showcasing increased protection against land mines; the HIM-TEC is, as expected, in the vanguard of this movement. Several anti-mine features were included in the Tiznao-60, including laminate floor panels. For example, the wheels are placed as far away from the crew cell as possible, as when the explosive is triggered it will be less probable that it will harm the vehicle’s crew. Furthermore, all mechanical components are arrayed in such a way that if the vehicle undergoes the compressive shockwave of an explosion these components will be flung away from the crew cell, instead of at the crew cell. The spacing between the crew cell and the ‘chassis’ also decreases the rate and strength of the transfer of mechanical shockwaves to that specific part of the vehicle, meaning the crew will feel less of an impact. The HIM-TEC is also protected through a laminate, lightweight, v-shaped floor panels which basically look like a wedge projected towards the floor – although not as steep as is evident on larger and taller vehicles, these floor panels will both absorb the energy (through the composite materials used) and deflect (the v-shaped hull) the explosion – it will also increase the depth of penetration (DOP) necessary of a shaped charge or explosive formed penetrator (EFP) to perforate into the engine bay or crew cell. The HIM-TEC can survive a 10-17kg charge, depending on the location in which the charge is detonated (related to the position of the crew) – by survive, this means that the crew will stay alive, although the vehicle may be destroyed. Finally, all crew members have suspended seats – similar to those used in the Tiznao-60 and Lince main battle tank – to protect them and to reduce the snapping movements of their body parts, especially the neck. (For further reading, see: Kahl, Dieter, Conceptos de protección actuales y futuros para vehículos blindados ligeros y medios, Tecnología Militar, Number 2, 2007; Iveco LMV Para el Ejército de Tierra, World Military Forces, Number 65, 2008; and, Bianchi, Fulvio, Mine Protection for AFVs, Military Technology, February 2005.)
Unfortunately, all this armor has a tendency to spall, especially ceramics – normally, materials with more yield strength and the ability to compress more than others will fracture less and thus spall less. Nevertheless, spall protection is an important concept of survivability, as the armor can be a threat to the crew if pieces of armor are flung into the crew cell. Furthermore, the penetrating projectile can spall itself, as pieces of the projectile erode and are separated from the main body. Even if not fatal to the crew – which it can be – it can seriously wound crew members and even blind them, if pieces perforate the eyes. Therefore, modern armored fighting vehicles use certain materials to ‘catch’ spall or reduce the area of the spray. On the HIM-TEC, the spall liner is composed of aramid fabric due to its high elastic modulus, high specific strength (five times that of steel), low density (one fifth that of steel), low elongation, flame resistance, ease of fabrication and excellent fatigue characteristics. This fabric is included throughout the vehicle, even along the floor (to protect against fragments of mine and floor panel which may shoot upwards into the crew cell), although it’s specifically used to protect the crew (so it’s not used near the engine bay or the in rear of the vehicle). Furthermore, aramid is cheap and is used in many other ways, including as encasement material for bullet proof vests (for more information, see: Meffert, Bernd and Milewski, Gerhard, Aramid Liners as Armor Augmentation, Proceedings Annual Reliability and Maintainability Symposium, 1988).
Although advanced night vision devices (NVD) are still characteristic of well trained and supplied conventional ground forces, ‘low technology’ infra-red devices are widespread enough so that one can expect them to be used by an insurgent group. Furthermore, in case of an ambush during a conventional war, one can expect more advance night vision devices. This isn’t the only major threat, either, as some vehicles have thermal imaging systems (such as the TI devices on tanks) that can detect the recent presence of a vehicle (such as the M1 Abram’s: Green, Michael and Stewart, Greg, M1 Abrams at War, Zenith Press, 2005, p. 43)! New anti-vehicle missiles can be locked on through heat, or an insurgent can decide when to blow up an improvised explosive device by what he sees through his night vision device. Therefore, reducing the heat signature of a vehicle is paramount for survivability, and the HIM-TEC has incorporated many existing technologies to reduce the signature as much as possible. This may come in handy if the two-door version is used for reconnaissance or for screening, and you need to hide the presence of the vehicle – even after it has left the area. On the other hand, it’s also important when establishing ambush points, now that 3rd generation thermal imaging devices can detect heat even after the engine has been turned on (for a limited amount of time, of course). Establishing a low heat signature is not only a goal of a light armored vehicle, like the HIM-TEC, but it has also been a goal of even heavy main battle tanks.
Reduction of the vehicle’s radar signature is also paramount, especially with the newfound threat of tank borne high-efficiency radars with line of sight ranges of up to ten to eleven kilometers. Although many of the new radars offered on today’s tanks have overstated capabilities – such as the millimeter radar’s ability to detect threats up to eleven kilometers away –, they still provide an important threat to consider. This threat escalates in open areas, where foliage doesn’t exist to hide the presence of an ambushing vehicle. Although conventionally ground-based anti-vehicle radar has never been considered a real threat, the battlefield is changing with new technologies. New light vehicles are being designed to reduce radar signature, and even main battle tanks are looking to reduce their signature. The threat, of course, isn’t only detection by an enemy vehicle or soldier, but detection by top-attack submunitions. These top-attack submunitions are often armed with small explosively formed penetrators, which perforate the vehicle’s roof at a velocity of up to 1,800 meters per second, and can penetrate at least 100mm of steel armor (see: Weickert, C.A. and Gallagher, P.J., Penetration of Explosively Formed Penetrators, International Journal of Impact Engineering, Volume 14, 1993). These submunitions are mostly guided by independent radar seekers, which are fitted to each device, and others are guided by infra-red seekers (see: Boschma, James H., STAWs: New Threat from Above – Smart Top Attack Weapons, ARMOR Magazine, September 1996). These can be fired from mortars, tank guns, field artillery pieces and howitzers, and the round can carry up to a dozen submunitions! Reduction of the vehicle’s radar signature, even the roof’s flat panel, is paramount to ensure the survival of the vehicle against these threats (if its presence is found).
The oldest threat is, by far, visual profile. The profile of a vehicle has been an issue since the introduction of the armored car in the late 18th century, and is even more a problem today. In most cases, the lower the roof, the better its survivability, given that the harder the vehicle will be to see by either insurgents or even conventional armed forces. This isn’t only important for tanks, as even light armored vehicles like the HIM-TEC avoid visual detection during reconnaissance missions. Furthermore, the smaller the vehicle, the easier it is to hide in the foliage during an ambush mission. Therefore, the HIM-TEC has been designed to be as low as possible without sacrificing protection and mobility. Due to the steeper v-shaped plates on the hull floor, the HIM-TEC is a couple of centimeters taller than some other small high mobility trucks, which might present a disadvantage – the roof is shaped, on the other hand, to minimize the visual effect of this height, which decreases internal volume but increases survivability. Nevertheless, the vehicle’s carrying capacity is not jeopardized now that the vehicle can carry up to six passengers in its stretch version. The HIM-TEC also has small mounting points along the vehicle to hold tight a camouflage netting, such as Castillian ‘Jungla’ – such netting also reduces the heat signature of the tank and can absorb the radar waves of top-attack ammunition. This might be more important during a conventional conflict, but can also be considered important in uneven terrain, where the vehicle’s movement can be hidden by low rise hills and where height might have an impact when the vehicle is smaller than the hill it’s moving behind.
To defeat the previous two threats – radar and infra-red signature – the HIM-TEC incorporates new materials to absorb its emissions and deflect foreign detection waves. None of these materials are innovative or unique to the HIM-TEC, but the HIM-TEC does a very good job of using them in opportune locations to increase its survivability. For example, absorbent materials are used around ‘inevitable hot spots’ of the vehicle – exhaust pipes, engine bay, transmission parts and the wheels. Ideally, the temperature difference between the vehicle and the surrounding area should be less than 5º C! Metal parts have to be covered with special paints to absorb heat, and special fiber reinforced materials used along the vehicle’s surface (especially around the engine bay). To hide the heat produced by the transmission and even by the exhaust pipes, other than special materials these are hidden between two ‘rails’ of the chassis which work to absorb the heat produced. On the outside of the vehicle, radar absorbent materials are used in conjunction with infra-red absorbent materials (depending on the surface of the vehicle) – this is especially true for the roof, to avoid detection from top-attack submunitions. The fact that the vehicle is light and small is also important, now that this means that the engine can be made to be less powerful and thus produce less heat. Furthermore, absorbent materials around the engine and exhaust pipe don’t only absorb heat, but also absorb noise to hide the vehicle’s movements from nearby detection. Overall, the HIM-TEC is one of the stealthiest vehicles on the market, or at least on par with several other advanced high mobility vehicles (generally, information is based on: Kahl, Dieter, Conceptos de protección actuales y futuros para vehículos blindados ligeros y medios, Tecnología Militar, Number 2, 2007; and Iveco LMV Para el Ejército de Tierra, World Military Forces, Number 65, 2008).
The HIM-TEC uses a 190 horsepower diesel engine, coupled to a hybrid electric drive train (for similar information, see: http://www.globalsecurity.org/military/sys...d/hmmwv-he.htm), which doubles fuel economy, increases the vehicle’s range, accelerate fasters, decreases emissions by almost 75% and is substantially lighter. The HIM-TEC is not the first vehicle in the Castillian arsenal to have an electric drive train, given that the Lince main battle tank also uses one. Nevertheless, it’s the first vehicle in the country to be designed with an electric drive train and a diesel engine. Most hybrid automobiles in Castilla y Belmonte, now entering the market with a greater vigor (hydrogen fuel cell vehicles are also beginning to enter production for civilian usage), use two gas turbines between 5kW and 16kW in power (depending on vehicle weight) and a 100kg battery – these are the direct competition of the new fuel cell vehicles (see: Capata, Roberto and Sciubba, Enrico, The concept of the gas turbine-based hybrid vehicle: System, design and configuration issues, International Journal of Energy Research, Volume 30, 2006). Unfortunately, the lack of a gas turbine for a combat vehicle of the weight class of the HIM-TEC is currently unavailable, and it’s thought that for the time being a diesel engine would be more desirable. Furthermore, for the sake of export potential, the diesel was chosen due to the greater affinity towards diesel engines on the international market. Although there have been worries about greater mechanical necessity (see: Sharoni, Asher H. and Bacon, Lawrence D., The Future Combat System (FCS): A Satellite-fueled, solar-powered tank?, ARMOR Magazine, January 1998), actual testing on the HIM-TEC has proved otherwise. Perhaps just as important as fuel economy, logistics and velocity is the fact that noise and thermal emissions are reduced considerably, enhancing the vehicle’s survivability.
The diesel engine itself, designed by MecániCas, occupied roughly 2,700cc and is variable geometry turbocharged engine, providing 136kW of power at 3,500rpm and 450Nm of torque at 1,700rpm. The engine works without problem within a temperature range of -32º and +49ºC, even in areas with high humidity. This engine provides the vehicle with a power to weight ratio greater than twenty (to one), although the engine is heavier than MecániCas originally envisioned (it’s standard when taking into consideration diesel engines, but MecániCas was looking for something similar to the TA series 600 gas turbine used on the Lince and Lynx, which does not work for power outputs of less than 900hp). The HIM-TAC has an automatic transmission providing for five forward gears and one gear in reverse, with a final drive within a differential in the rear area of the chassis (the engine is based on information provided in: Iveco LMV Para el Ejército de Tierra, World Military Forces, Number 65, 2008; and http://www.army-technology.com). In the engine bay, along with the motor generators which form part of the hybrid electric drive train, there is a battery which not only transfers power to the transmission and differential, but gives the possibility of silent over watch (normally provided by an auxiliary power unit [APU]). Furthermore, using an electric transmission decreases the chances of a large metal piece entering the crew cell and hurting one of the vehicle’s occupants. Apart from considerations detailed above, hybrid engines also make it easier to convert the two-door version of the HIM-TEC into a command vehicle, radar vehicle, or other systems, and reduce the necessary logistics for these conversions (see: Axe, David, Engine Tests: U.S. Army diesel-electric hybrid motors get a reality check, Defense Technology International, September 2007). For example, the vehicle could be used to recharge electric unmanned aerial vehicles (UAV) for tactical reconnaissance by mounted infantry. It should be noted that the demand in the commercial sector for hybrid vehicles has increased the cost-effectiveness of introducing this technology into military vehicles, and therefore it’s a cost effective solution that can now be realistically considered (in a world [real-world, for example] where only the military has a demand for lithium-ion batteries, a lithium-ion battery can cost up to $3,500 per kilowatt of power).
Convention dictates that an armored vehicle should only be wheeled when their expected terrain of travel is composed of at least 41% road or weigh less than ten metric tons; this fits the characteristics of the HIM-TEC and vehicles like it, especially when taking into consideration the ideal road-speed of the vehicle (see: Hornback, Paul, The Wheel versus Track Dilemma, ARMOR Magazine, March 1998). However, the HIM-TEC still tries to maximize off-road travel by incorporating new technologies to improve mobility. The large wheels have an angle of attack of 60º and an angle of departure of 52º, and the vehicle has four-wheel drive (4x4 or 4WD) for off-road travel. Each wheel has an independent hydropneumatic suspension, taking advance of the vehicle’s weight class, allowing for a faster off-road velocity, greater stability and the ability to reduce the vehicle’s height by up to four-tenths of a meter. The tires are of the run-flat type, allowing the vehicle to escape from the area even if the tires have been punctured – run-flat tires have been proven to be able to travel up to 20km whilst flat – and a central inflation unit (CIU) keeps the tires at their ideal pressure, which is important for off-road travel. The hydropneumatic disc anti-lock brakes (ABS) are designed close to the differential and away from the crew cell, while still providing a superior reaction time for the driver; the brakes are also fixed elastically to the chassis. While each part of the suspension and brake system is designed to be efficient, they are also designed to enhance survivability, explaining the locations where these are installed.
The high ballistic protection offered by the windshield panels is important when considering the field of view of the driver. Ensuring that the driver has a large field of view means that the driver will be able to see more of the terrain in front of him, improving his reaction to non-ideal terrains or even against improvised explosive devices. Apart from enhancing survivability, it also enhances mobility. Just as important, the hydropneumatic suspension increases the ride tolerance of the crew – as proven by the suspension’s integration into tracked vehicles, such as the Lince – meaning that the driver has less of a chance of being fatally fatigued by the vibrations of the vehicle. All of this will enhance the driver’s reaction time, also affected by the high efficiency hybrid diesel drive train (these last two paragraphs are based largely on: Bianchi, Fulvio, Off-Road Mobility: Problems & Solutions, Military Technology, March 2007). As is witnessed, most of the components on the vehicle are designed to improve the vehicle’s survivability, which is the single most important priority in the HIM-TEC. In essence, the vehicle might come out of the battle almost completely destroyed, but its occupants will come out alive and ready for the next fight. This not only decreases costs by making sure one’s soldiers survive a battle, but it also means that soldier’s confidence will increase as they see that their equipment guarantees the wellbeing of their lives. In that sense, the high protection for low weight, new mobility features and stealth features are probably worth the cost. It should further be noted that the vehicle has the capability to wade through up to 90 centimeters of water without preparation and can be driven with night vision devices or thermal cameras.
The product includes no remote weapon station, although the roof panel includes a mounting area for a remote weapon station. For example, combat versions of Castillian and Macabee HIM-TECs will be armed with the HammerFist remote weapon station, mounted on a wide variety of other vehicles sold by Sistemas Terrestres Segovia Land Systems (STSLS). The mounting area allows for a wide variety of these remote weapon stations to be added – effort is dependant on the design of the remote weapon station. For example, thanks to the design of the HammerFist intrusion into the vehicle is minimal, so the impact on protection is almost none. On the other hand, other remote weapon stations may need more modifications inside the vehicle, making application more difficult and perhaps putting in danger the ballistics of that particular part of the panel. Nevertheless, due to the wide proliferation of remote weapon systems this option is available. Of course, STSLS and MecániCas prefer the HammerFist remote weapon station of national fabrication due to its high quality and the ability to mount it on any given vehicle without requiring heavy modifications inside of it (except for a fiber optic cable). HammerFist is also lightweight and can mount a wide variety of weapons. By far, it’s far simpler to mount a machine gun used by your armed forces, then an all-new remote weapon station. HammerFist is also very affordable for the amount of technology offered with the system. The Tiznao-60 can also mount a HammerFist remote weapon station, and this is done on Tiznao-60s manufactured for the Castillian Armed Forces (CAF).
Apart from a remote weapon station, the roof hatch ring allows for the mounting of a machine gun or an automatic grenade launcher of similar proportions. Depending on the design of the machine gun, mounting and dismounting operations is simple and the machine gun can be dismounted in order to provide fire support for infantry units on the ground. Automatic weapons of up to 20mm can be mounted (in other words, infantry heavy machine guns) and automatic grenade launchers of up to 40mm. Macabee HIM-TACs will mount the S30 13.3mm heavy machine gun (manufactured by HTC and designed by Mekugi), while Castillian VAMs will mount the indigenous G4 heavy machine gun of the same caliber (different cartridge length). More so than the HammerFist, the ring mount can accommodate any national weapon and can double the vehicle’s firepower, or reduce the necessity for a remote weapon station (reducing costs; a remote weapon station will cost over $100,000) – the versatility of both the ring mount and the remote weapon station allow client nations to customize the vehicle with their own automatic weapons. The modular design of the hatch and roof panels allow redesigns to allow for heavier weapons, if the client nation decides that this is a necessity. The roof hatch is large enough to allow for the use of light ceramic composite armor and to allow a fully armored infantryman to escape without problem. Soldiers can also post guard through the hatch when the vehicle is not moving, or use it to increase the field of visibility.
Apart from the grenades mounted on a remote weapon station, MecániCas’ HIM-TEC includes two mounting points – one on either side – for two heavy grenade launching packs. Castillian vehicle mounted electric grenade launchers are normally built to accommodate 76mm grenades, but the grenade launchers can be manufactured indigenous to fit the indigenous grenade caliber as long as the pack fits on the mountings. Nevertheless, the mounting allow for grenades between 40mm and 100mm to be mounted without the reduction in the number of tubes (unless the tube firing mechanisms are bulky). For example, the grenade packs issued on Castillian and Macabee HIM-TECs include six grenades per group, for a total of twelve grenade launchers (each grenade launcher carries at least two grenades). The type of grenades launched is up to the client. The HIM-TEC is perfect for modification into surrogate vehicles – UAV launchers, et cetera. Put it can be modified into other types of armament carriers; for example, an anti-tank vehicle fitted with a number of anti-tank missiles, or even a light mortar carrier. Normally, these modifications are done to the two-door variant.
As mentioned before, the vehicle itself comes in two main variations – a four-door stretch version and a two-door version. Both can be armored to three different levels (for now); standard ballistic panels for minimum protection, medium weight ballistic panels and heavy weight ballistic panels. Furthermore, MecániCas offers two different types of doors – one with large windows for peacekeeping operations and one with firing slots for the vehicle’s passengers. Two different types of floor panels are also available – a v-shaped laminate composite armored floor and a standard panel floor. Therefore, a total of twenty-four different variants exist for the vehicle, while the modular nature allows for indigenous companies to play a part in the manufacturing by building their own armor modules for the different parts of the vehicle. Furthermore, armor modules manufactured by MecániCas can be intermixed – for example, a highly protected roof can be issued to a vehicle with standard ballistic panels for the side. These modifications can be done easily and quickly by the crew or by mechanics crew. The only integral part of the vehicle is the structure, and even that comes in modules – the lower chassis (including the engine bay and rear area of the vehicle) and the crew cell. This also makes it cheaper and easier to convert the vehicle into surrogates, such as discussed in the lethality section. It makes the HIM-TAC a very versatile vehicle.
In terms of cost, the first initial batch of vehicles will likely be expensive. Nevertheless, the guaranteed procurement of over one hundred thousand vehicles by the Macabee Fuermak has lowered the cost of production considerably. Therefore, the price of the HIM-TAC is comparable to other existing vehicles, despite the technological advantage. Furthermore, new technologies – such as a hybrid power pack – decrease the cost of logistics, while the easy bolt-on armor panels make superficial repairs quick and cheap. For the most part, unless the vehicle is completely destroyed, repairs can be done in shops behind the lines or in allied camps. Some new technologies enjoy considerable production for the civilian sector, meaning that they are more economical to apply to military vehicles (such as an electric transmission of this size). Production will be the key to lower costs, but as has been mentioned, the HIM-TAC is already as cheap as any other vehicle of its class. On the other hand, whatever the price, the vehicle is worth it due to the amount of engineering MecániCas has put into the Tiznao-10 HIM-TAC to make it the best vehicle of its type.
Although no special attention has been paid to fightability, this also enjoys priority in the HIM-TAC. The vehicle includes an air conditioning system for the crew, and the control panel in the front of the vehicle is accessible to the driver without strain. The automatic transmission makes driving easy for the driver, allowing him to focus on the road ahead. The fact that the HIM-TEC is one of the safest vehicles of its class means that the driver and the passengers will feel reassured for their safety. In tests conducted, even when the vehicle has been completely mangled, the crew has left unscathed. This type of ballistic quality is what differentiates the HIM-TAC from other high mobility tactical trucks. High protection against all known threats possible and lightweight design make any price affordable for an army truly interested in the best tactical truck on the market.
Distance Between Axels: 3.2m
Angles of Attack/Departure: 60º/52º
Gross Weight (Basic Two-Door/Medium/Heavy): 3.1t/3.7t/4.1t
Gross Weight (Basic Four-Door/Medium/Heavy): 3.8t/4.25t/4.9t
Maximum Weight: 7.5t
Towing Capacity: 4t
Maximum On-Road Velocity: 140km/h
Engine: 136kW hybrid diesel
Transmission: Automatic; 5+1
Brakes: Hydropneumatic disk brakes
Passenger Capability (four door stretch): 6+1 (driver)
Basic Panels: $25,000
Medium Weight Panels: $50,000
Heavy Weight Panels: $100,000
Notes: A little imagination is needed to guess the cost for more complicated variations of the vehicle with armor.
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