Iron Curtain (countermeasure)
Iron Curtain is an active protection system designed by Artis, an American technology development and manufacturing firm. The system is designed to protect military vehicles and other assets by intercepting threats such as rocket-propelled grenades and other shoulder-launched missiles and rendering them inert; the system was part of an accelerated acquisition effort by the U. S. Army to characterize and field active protection systems as as possible, it was evaluated on the Stryker Infantry Carrier Vehicle, with two systems undergoing tests by the U. S. Army: one at Aberdeen Proving Ground in Maryland and the other at Redstone Arsenal in Alabama. Iron Curtain uses a radar to cue the system, it switches from armed-ready state to an armed state. As the round comes into close range, the optical sensor profiles the threat and tracks it within 1 cm of accuracy to select an aimpoint and determine which ballistic countermeasure to fire; the countermeasure deflagrates the RPG warhead without detonating it, leaving the dudded round to bounce off the vehicles side.
Because of its shelf-like design, the system can be modified to protect any surface, from the sides of the vehicle to all around protection, including a turret. Artis claims that the Iron Curtain can be enhanced to protect against “more challenging threats” like the RPG-29 and RPG-32 ‘Hashim’ multipurpose anti-tank grenade launchers, which utilize tandem warheads for penetrating tanks with explosive reactive armor. Iron Curtain should be able to defend against ATGMs; the system has 360° coverage, is multi-shot, low-cost, low power and rugged and reliable. The system, which began in 2005 as a DARPA program, is able to defeat threats if fired from an close range, it has undergone significant safety testing, including temperature and shock testing, its software architecture has been approved by the U. S. military's Joint Services Weapons Safety Review Process. The countermeasure fires straight down or up, neutralizing the incoming threat within inches of the vehicle and thereby separating the system from many others which intercept threats several meters out, resulting in minimal risk of collateral damage to dismounted troops or civilians.
Iron Curtain is designed to be modular, the system's radar does not need to track the threat. To date, two radars have been integrated onto Iron Curtain: the Mustang radar developed by Mustang Technology Group in Plano and the RPS-10 radar, built by RADA Electronic Industries. In 2016, the U. S. Army began an expedited effort to install and characterize several APSs, including Iron Curtain on the Stryker fighting vehicle, in preparation for fielding decisions by the Army. In April 2013, the company announced. “We proved not only that Iron Curtain defeats threats and saves lives, but the risk from collateral damage is minimal when compared with the alternative," according to the company's CEO, Keith Brendley. He said. To date, the system has been integrated onto four ground vehicles, including tracked and wheeled vehicles. In 2016, Iron Curtain was selected for integration onto the U. S. Army's Stryker, while the U. S. Army develops its Modular Active Protection System. However, in August 2018 the Army decided not to continue qualifying Iron Curtain onto the Stryker, saying that while the system "generally worked in concept" and was "generally able to hit its targets," it was still not mature enough and would have required greater time and investment than was within the scope of the program.
The system could not function reliably under field conditions such as in rain or snow, while moving over rough terrain. Iron Curtain was integrated onto the Army's Ground Combat Vehicle built by BAE Systems. In addition, General Dynamics Land Systems designed the system for integration onto its LAV III. Active protection system Artis Iron Curtain website DARPA video of Iron Curtain demonstration, shooting down missile National Geographic TV report on Iron Curtain
Armoured fighting vehicle
An armoured fighting vehicle is an armed combat vehicle protected by armour combining operational mobility with offensive and defensive capabilities. AFVs can be tracked. Main battle tanks, armoured cars, armoured self-propelled guns, armoured personnel carriers are all examples of AFVs. Armoured fighting vehicles are classified according to their intended role on the battlefield and characteristics; the classifications are not absolute. For example lightly armed armoured personnel carriers were superseded by infantry fighting vehicles with much heavier armament in a similar role. Successful designs are adapted to a wide variety of applications. For example, the MOWAG Piranha designed as an APC, has been adapted to fill numerous roles such as a mortar carrier, infantry fighting vehicle, assault gun; the concept of a mobile and protected fighting unit has been around for centuries. Armoured fighting vehicles were not possible until internal combustion engines of sufficient power became available at the start of the 20th century.
Modern armoured fighting vehicles represent the realization of an ancient concept - that of providing troops with mobile protection and firepower. Armies have deployed war cavalries with rudimentary armour in battle for millennia. Use of these animals and engineering designs sought to achieve a balance between the conflicting paradoxical needs of mobility and protection. Siege engines, such as battering rams and siege towers, would be armoured in order to protect their crews from enemy action. Polyidus of Thessaly developed a large movable siege tower, the helepolis, as early as 340 BC, Greek forces used such structures in the Siege of Rhodes; the idea of a protected fighting vehicle has been known since antiquity. Cited is Leonardo da Vinci's 15th-century sketch of a mobile, protected gun-platform; the machine was to be mounted on four wheels which would be turned by the crew through a system of hand cranks and cage gears. Leonardo claimed: "I will build armored wagons which will be invulnerable to enemy attacks.
There will be no obstacle which it cannot overcome." Modern replicas have demonstrated that the human crew would have been able to move it over only short distances. Hussite forces in Bohemia developed war wagons - medieval weapon-platforms - around 1420 during the Hussite Wars; these heavy wagons were given protective sides with firing slits. Heavy arquebuses mounted on wagons were called arquebus à croc; these carried a ball of about 3.5 ounces. The first modern AFVs were armed cars, dating back to the invention of the motor car; the British inventor F. R. Simms designed and built the Motor Scout in 1898, it was the first armed, petrol-engine powered vehicle built. It consisted of a De Dion-Bouton quadricycle with a Maxim machine gun mounted on the front bar. An iron shield offered some protection for the driver from the front, but it lacked all-around protective armour; the armoured car was the first modern armoured fighting vehicle. The first of these was the Simms' Motor War Car, designed by Simms and built by Vickers, Sons & Maxim in 1899.
The vehicle had Vickers armour 6 mm thick and was powered by a four-cylinder 3.3-litre 16 hp Cannstatt Daimler engine giving it a maximum speed of around 9 miles per hour. The armament, consisting of two Maxim guns, was carried in two turrets with 360° traverse. Another early armoured car of the period was the French Charron, Girardot et Voigt 1902, presented at the Salon de l'Automobile et du cycle in Brussels, on 8 March 1902; the vehicle was equipped with a Hotchkiss machine gun, with 7 mm armour for the gunner. Armoured cars were first used in large numbers on both sides during World War I as scouting vehicles. In 1903, H. G. Wells published the short story "The Land Ironclads," positing indomitable war machines that would bring a new age of land warfare, the way steam-powered ironclad warships had ended the age of sail. Wells' literary vision was realized in 1916, amidst the pyrrhic standstill of the Great War, the British Landships Committee, deployed revolutionary armoured vehicles to break the stalemate.
The tank was envisioned as an armoured machine that could cross ground under fire from machine guns and reply with its own mounted machine guns and cannons. These first British heavy tanks of World War I moved on caterpillar tracks that had lower ground pressure than wheeled vehicles, enabling them to pass the muddy, pocked terrain and slit trenches of the Battle of the Somme; the tank proved successful and, as technology improved. It became a weapon that could cross large distances at much higher speeds than supporting infantry and artillery; the need to provide the units that would fight alongside the tank led to the development of a wide range of specialised AFVs during the Second World War. The Armoured personnel carrier, designed to transport infantry troops to the frontline, emerged towards the end of World War I. During the first actions with tanks, it had become clear that close contact with infantry was essential in order to secure ground won by the tanks. Troops on foot were vulnerable to enemy fire, but they could not be transported
A tandem-charge or dual-charge weapon is an explosive device or projectile that has two or more stages of detonation. Tandem charges are effective against reactive armour, designed to protect an armoured vehicle against anti-tank munitions; the first stage of the weapon is a weak charge that either pierces the reactive armour of the target without detonating it leaving a channel through the reactive armour so that the second warhead may pass unimpeded, or detonating the armourplate causing the timing of the counter-explosion to fail. The second detonation from the same projectile attacks the same location as the first detonation where the reactive armour has been compromised. Since the regular armour plating is the only defence remaining, the main charge has an increased likelihood of penetrating the armour. However, tandem-charges are useful only against ERA types of reactive armour, much less so against the non-explosive reactive armour types, since their inner liner is not explosive itself and thus not expended by the small forward warhead of tandem-charge attack.
The PG-7VR warhead for the RPG-7 rocket launcher and the PG-29V warhead for the more modern RPG-29 rocket launcher are examples of tandem charges, but the technology is employed worldwide because they were designed in the Cold War era to counter the reactive armour, a common feature on Soviet tanks. Examples of missiles that use tandem charges include the BGM-71 TOW, FGM-148 Javelin and the MBT LAW. Dual charges are effective at increasing the effectiveness of warheads when used against structures; because the explosion of a unitary high explosive charge will follow the path of least resistance, much of the explosive power of a warhead will be lost to the air surrounding the target if detonated outside the structure. This effect can be countered by using constructed gravity bombs with delay fuzes which penetrate the earth, etc. of the target before exploding—thus containing the explosion inside the structure and increasing its effect. Gravity bombs require aircraft to fly rather close to what may be a heavily-defended target which poses a significant risk to the launch aircraft.
Cruise missiles equipped with large tandem-charge warheads can use the first charge to create a hole into which the missile flies before exploding the second charge, creating a similar effect of the delayed gravity bomb. An example of an anti-structure tandem-charge warhead is the BROACH warhead. Shaped charge HEAT
Shtora-1 is an electro-optical active protection system or suite for tanks, designed to disrupt the laser designator and laser rangefinders of incoming anti-tank guided missiles. The system is mounted on the Russian T-80 and T-90 series tanks and the Ukrainian T-84; the existence of Shtora was revealed in 1980 by Adolf Tolkachev. Shtora-1 is an electro-optical jammer that disrupts semiautomatic command to line of sight antitank guided missiles, laser rangefinders and target designators. Shtora-1 is a passive-countermeasure system; the system was shown fitted to a Russian main battle tank during the International Defense Exposition, held in Abu Dhabi in 1995. The first known application of the system is the Russian T-90 main battle tank, which entered service in the Russian Army in 1993, it is available on the BMP-3M infantry fighting vehicle. The Shtora-1 has four key components: Two electro-optical/infrared "dazzlers" interface station one each mounted to the left and right of the main gun, which includes an infrared jammer and control panel.
A bank of forward firing grenade launchers or dischargers mounted on either side of the turret, which can fire grenades dispensing an aerosol smoke screen opaque to infrared light. A laser warning system with precision and coarse heads. A control system comprising control panel and manual screen-laying panel; this activates the aerosol screen-laying system. Two infrared lights, one on each side of the main gun, continuously emit coded pulsed-infrared jamming when an incoming ATGM has been detected. Shtora-1 has a field of -- 5 to +25 degrees in elevation, it weighs 400 kg. The screening aerosol lasts about twenty seconds; the screen-laying range is from 50 to 70 meters. According to Defense Update, the Shtora system can locate the area within 3.5–5 degrees where the laser originated from and automatically slew the main gun to it, so that the tank crew can return fire and so that the stronger frontal turret armour is facing it. Shtora-1 can operate in automatic or semi-automatic modes, continuously for six hours against anti-tank guided missile attack.
According to Steven Zaloga and Tankomaster: Laser illumination sensors: 2x TShU-1-11 precision sensors and 2x TShU-1 rough sensors Field of view: −5°.. +25° elevation and 90° azimuth Field of view: 360° azimuth EO interference emitters: 2x OTShU-1-7 Operating band: 0.7.. 2.7 mkm Protected sector: 4° elevation and 20° azimuth Energy consumption: 1 kW Light intensity: 20 mcad Anti-FLIR smoke grenades: 12x 81mm 3D17 Obscured band: 0.4.. 14 mkm Bloom time: 3 sec Cloud persistence: 20 sec
A capacitor is a passive two-terminal electronic component that stores electrical energy in an electric field. The effect of a capacitor is known as capacitance. While some capacitance exists between any two electrical conductors in proximity in a circuit, a capacitor is a component designed to add capacitance to a circuit; the capacitor was known as a condenser or condensator. The original name is still used in many languages, but not in English; the physical form and construction of practical capacitors vary and many capacitor types are in common use. Most capacitors contain at least two electrical conductors in the form of metallic plates or surfaces separated by a dielectric medium. A conductor may be sintered bead of metal, or an electrolyte; the nonconducting dielectric acts to increase the capacitor's charge capacity. Materials used as dielectrics include glass, plastic film, mica and oxide layers. Capacitors are used as parts of electrical circuits in many common electrical devices. Unlike a resistor, an ideal capacitor does not dissipate energy.
When two conductors experience a potential difference, for example, when a capacitor is attached across a battery, an electric field develops across the dielectric, causing a net positive charge to collect on one plate and net negative charge to collect on the other plate. No current flows through the dielectric. However, there is a flow of charge through the source circuit. If the condition is maintained sufficiently long, the current through the source circuit ceases. If a time-varying voltage is applied across the leads of the capacitor, the source experiences an ongoing current due to the charging and discharging cycles of the capacitor. Capacitance is defined as the ratio of the electric charge on each conductor to the potential difference between them; the unit of capacitance in the International System of Units is the farad, defined as one coulomb per volt. Capacitance values of typical capacitors for use in general electronics range from about 1 picofarad to about 1 millifarad; the capacitance of a capacitor is proportional to the surface area of the plates and inversely related to the gap between them.
In practice, the dielectric between the plates passes a small amount of leakage current. It has an electric field strength limit, known as the breakdown voltage; the conductors and leads introduce an undesired resistance. Capacitors are used in electronic circuits for blocking direct current while allowing alternating current to pass. In analog filter networks, they smooth the output of power supplies. In resonant circuits they tune radios to particular frequencies. In electric power transmission systems, they stabilize power flow; the property of energy storage in capacitors was exploited as dynamic memory in early digital computers. In October 1745, Ewald Georg von Kleist of Pomerania, found that charge could be stored by connecting a high-voltage electrostatic generator by a wire to a volume of water in a hand-held glass jar. Von Kleist's hand and the water acted as conductors, the jar as a dielectric. Von Kleist found that touching the wire resulted in a powerful spark, much more painful than that obtained from an electrostatic machine.
The following year, the Dutch physicist Pieter van Musschenbroek invented a similar capacitor, named the Leyden jar, after the University of Leiden where he worked. He was impressed by the power of the shock he received, writing, "I would not take a second shock for the kingdom of France."Daniel Gralath was the first to combine several jars in parallel to increase the charge storage capacity. Benjamin Franklin investigated the Leyden jar and came to the conclusion that the charge was stored on the glass, not in the water as others had assumed, he adopted the term "battery", subsequently applied to clusters of electrochemical cells. Leyden jars were made by coating the inside and outside of jars with metal foil, leaving a space at the mouth to prevent arcing between the foils; the earliest unit of capacitance was the jar, equivalent to about 1.11 nanofarads. Leyden jars or more powerful devices employing flat glass plates alternating with foil conductors were used up until about 1900, when the invention of wireless created a demand for standard capacitors, the steady move to higher frequencies required capacitors with lower inductance.
More compact construction methods began to be used, such as a flexible dielectric sheet sandwiched between sheets of metal foil, rolled or folded into a small package. Early capacitors were known as condensers, a term, still used today in high power applications, such as automotive systems; the term was first used for this purpose by Alessandro Volta in 1782, with reference to the device's ability to store a higher density of electric charge than was possible with an isolated conductor. The term became deprecated because of the ambiguous meaning of steam condenser, with capacitor becoming the recommended term from 1926. Since the beginning of the study of electricity non conductive materials like glass, porcelain and mica have been used as insulators; these materials some decades were well-suited for further use as the dielectric for the first capacitors. Paper capacitors made by sandwiching a strip of impregnated paper between strips of metal, rolling the result into a cylinder were used in the late 19th century.
The T-90 is a third-generation Russian battle tank that entered service in 1993. The tank is a modern variation of the T-72B and incorporates many features found on the T-80U. Called the T-72BU, but renamed to T-90, it is an advanced tank in service with Russian Ground Forces and the Naval Infantry; the T-90 uses a 125 mm 2A46 smoothbore main gun, the 1A45T fire-control system, an upgraded engine, gunner's thermal sight. Standard protective measures include a blend of steel and composite armour, smoke grenade dischargers, Kontakt-5 explosive-reactive armour and the Shtora infrared ATGM jamming system, it was built by Uralvagonzavod, in Nizhny Tagil, Russia. Since 2011, the Russian armed forces have ceased any further orders for the T-90, are instead increasing their numbers of the T-14 Armata that began production in 2016; the T-90 has its origins in a Soviet-era program aimed at developing a singular replacement for the T-64, T-72 and T-80 series of main battle tanks. The T-72 platform was selected as the basis for the new generation of tank owing to its cost-effectiveness and automotive qualities.
The Kartsev-Venediktov Design Bureau from Nizhny Tagil was responsible for the design work and prepared two parallel proposals—the Object 188, a simple upgrade of the existing T-72B tank, the far more advanced Object 187—only vaguely related to the T-72 series and incorporating major improvements to the hull and turret design, armor and armament. Development work was approved in 1986 and the first prototypes were completed by 1988; the vehicles resulting from the Object 187 program have not been declassified to this date, but it was the lower risk Object 188 upgrade that would be approved for series production as the T-72BU. The T-72BU was accepted into service on 5 October 1992 by the Russian Ministry of Defence and renamed as the T-90 for marketing and propaganda purposes aimed at distancing the new type from existing T-72 variants; the principal upgrade in the T-90 is the incorporation of a modified form of the T-80U's more sophisticated 1A45T Irtysh fire control system and an upgraded V-84MS multi-fuel engine developing 830 hp.
The T-90 was manufactured at the Uralvagonzavod factory in Nizhny Tagil, with low-level production being carried out since 1993 and ceasing towards the end of the 1990s for the native market. Less than 200 T-90 tanks were delivered to the Russian Ground Forces before production was resumed in 2005 of an upgraded version. By September 1995, some 107 T-90 tanks had been located in the Siberian Military District. Facing tapering domestic orders and with the permanent closure of the last turret casting line in the former USSR, owned by Azovstal in Mariupol, the designers at Uralvagonzavod together with experts from NII Stali using trials data obtained from the Soviet-era, created a new, welded turret to offer further improvement and attract foreign buyers for the T-90. India signaled interest in the T-90 in response to Pakistan's acquisition of 320 Ukrainian T-84 tanks, an intuitive decision considering India held rights to manufacture the T-72M1 in Avadi, with production being adapted to assemble the T-90.
The first 42 complete Indian tanks were delivered in 2001 and were designated T-90S, still equipped with the older cast turrets of the early series and powered by the V-84 engine making 840 hp. This was followed up next year with delivery of 82 vehicles, now equipped with the new welded turrets and the V-92S2 engine, generating 1,000 hp; the initial contract stipulated the following batch of 186 tanks—now called the Bhishma—to be completed in India from Russian-supplied kits, gradually replaced with domestically manufactured parts, but the low rate of domestic Indian production compelled the Indian authorities to place an additional order for 124 complete vehicles in 2007 from Uralvagonzavod. In 2005 the Russian army resumed delivery of the T-90, requesting the "original" specification for the vehicle with a cast turret, but with the new order numbering a paltry 14 tanks, the large capital investment required to set up production of new cast turrets, the Russian Ministry of Defence agreed on a new configuration close to the Indian T-90S, expeditiously accepted into service without any trials as the Object 188A1 or T-90A.
That same year saw delivery of an additional 18 new tanks - enough to equip five tank platoons. These new Russian tanks were powered by the V-92S2 engine, carried a T01-K05 Buran-M gunner's sight and were protected by the most recent Kontakt-5 reactive armor with 4S22 explosive tiles; the years 2006-2007 saw the delivery of 31 T-90A tanks each, now fitted with passive ESSA main gunner's sights supplied by Peleng in Belarus and using the 2nd-generation thermal camera Catherine-FC from Thales, as well as improved 4S23 ERA tiles. The joint venture established on the basis of JSC Volzhsky Optical and Mechanical Plant" and Thales Optronics, produced Catherine-FC thermal imaging devices, which were further used to develop "ESSA", "PLISA" and "SOSNA-U" sighting systems produced for the Russian armoured vehicles, including T-72B3 tanks and export versions of T-90S, and since 2012, Russia was able to produce 3rd-generation of Catherine-XP cameras based on QWIP matrix technology. In 2012, the Russian-made commander of the combined sample of supervisory-sighting system "T01-K04DT/Agat-MDT" was presented