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Disclaimer: This paper partially fulfills a writing requirement for first year (freshman) engineering students at the University of Pittsburgh Swanson School of Engineering. This paper is a student paper, not a professional paper. This paper is based on publicly available information and may not provide complete analyses of all relevant data. If this paper is used for any purpose other than this author’s partial fulfillment of a writing requirement for first year (freshman) engineering students at the University of Pittsburgh Swanson School of Engineering, users are doing so at their own risk.

TROPHY SYSTEM AS A SAFEGUARD AGAINST ATGMS

Nicolas Obeso ([email protected])

A SERIOUS THREAT TO ARMORED increasing the chances of armor failure. This behavior FIGHTING VEHICLES of the explosive is known as the “Munroe Effect”. Due to the requirement of an empty space, shaped charges are able to deal more damage to armor with the bonus As the United States armed forces have found of requiring less explosives. Shaped charges are both themselves embroiled in more asymmetrical conflicts, more efficient and more effective than conventional the proliferation of small anti-tank weapons has explosives when taking out armor [2]. become a pressing issue. Even the latest main battle tanks such as the American M1A2 TUSK (Tank Urban YESTERDAY’S SOLUTIONS Survival Kit) are still vulnerable to attack from anti- tank guided missiles (ATGM) like the 9M133 Kornet Today’s munitions use tandem HEAT charges. and unguided rockets like the RPG 29 [1]. Kornets These tandem charges are designed to take out a tank’s require a team to operate but have a range of several secondary defenses while still having the killing power kilometers and can be guided to their targets. Man- to take out the main armor. These secondary defenses portable systems like the RPG 29 sacrifice range, include explosive reactive armor (ERA) and spaced penetrating power, and guidance, but their ability to be armor. Explosive reactive armor consists of panels of used by one man means that a tank may find explosive sandwiched between metal plates. When a overwhelmed by enemy fire from varying angles. This HEAT round impacts an ERA tile, the tile detonates becomes even more of a problem in an urban and sends one of the metal plates in the opposite environment where unseen combatants. Compared to direction of the rocket. The energy of the metal plate main battle tanks, anti-tank rockets and missiles are neutralizes some of the energy of the rocket’s incredibly inexpensive. This means that they pose a explosion giving the tank’s crew a better chance of serious risk monetarily as well as to life. survival [3]. Tandem charges are able to defeat this type of supplementary armor. The first, smaller, charge FUNCTION OF SHAPED CHARGES of the rocket defeats the tile while the second, larger, charge penetrates the main armor, killing the crew. Given the destructive nature of these weapons, it is Spaced armor can be integrated into the hull or it can critical to know where their killing power comes from. take the form of side skirts or “Schürzen”. Spaced All anti-tank rockets and missiles fall into the High armor uses air gaps to defeat the molten metal of a Explosive Anti-Tank (HEAT) category of munitions. shaped charge. The airgaps require the metal stream to HEAT warheads are a type of shaped charge. Shaped travel further which gives it time to cool off and lose charges focus their explosions into a smaller point. energy [4]. Like with ERA, tandem charges can defeat This improves their ability to penetrate armor. A this type of armor, easily. typical modern shaped charge, with a metal liner on the charge cavity, can penetrate armor steel to a depth of This poses a serious problem to designers. The seven or more times the diameter of the charge. The threat of these weapons is massive in an urban explosive power of the charge is focused by using a environment. And while spaced armor and ERA hollow space in the explosive. The charge generally offered adequate protection against the single charge has a conical hole cut out. The vertex of the cone is HEAT rounds used in World War Two and the facing away from the target. When the charge goes off, majority of the Cold War, they are hopeless against the the explosion comes out the same shape but in the tandem rounds introduced in the tail end of the Cold opposite direction. The vertex of the explosive cone War. The composite main armor of tanks also became naturally contacts the target first. The explosive force is largely ineffective. This is because of the uneven focused into an incredibly small point. This increases armoring of tanks. All modern main battle tanks were the pressure applied to the target by the explosive, thus designed during the Cold War for use in conventional University of Pittsburgh, Swanson School of Engineering 1 10.31.2017

Nicolas Obeso pitched battles against the Soviets. In a pitched battle, the missile/rocket [6]. In addition, the designers had the the majority of fire will come from the front, so the foresight to keep collateral damage to a minimum. armoring is focused on the front. The sides are less Tanks always operate with infantry nearby, so the armored, and the rear engine compartment has little not system’s kill zone is large enough to render the threat’s no armoring at all. The nature of urban combat means explosion ineffective but small enough to not maim that this armoring scheme is useless. When fighting friendly infantry. through city blocks, enemy fire can come from the sides and the top. It may seem obvious to just add OPERATIONAL HISTORY IN THE IDF supplementary or “appliqué” armor to the rest of the tank. This does help with less powerful threats, but the It is obviously not enough for a product to work protection of additional armor can never match the in experimental testing. For one to truly consider protection of frontal armor without sacrificing something a success, it must be tested in the field mobility. Given that maneuvering has been the central where there are a greater number of variables affecting part of warfare since the 19th century, giving up speed performance. In the Israeli’s case, the environment they is unacceptable. fight in is incredibly hilly and dusty. Both of these characteristics could possibly hamper the system’s ACTIVE PROTECTION AND THE ability to detect incoming threats by blocking some TROPHY SYSTEM radar waves. The system finally got a chance to prove itself in 2014 during Operation Protective Edge. The The solution to the problem needs to provide 360- operation consisted of Israeli forces interdicting into degree protection from threats while remaining light Hamas territory in the Gaza Strip. At the beginning, the enough as to maintain the tank’s mobility. This is a Trophy System was installed on at least four Merkava seemingly impossible task given the destructive power IV main battle tanks (MBT). These few MBTs had the of HEAT rounds. However, engineers have come up system installed because they served as the command with a solution which required creativity and a change vehicles of senior commanders. These four tanks of mindset. Instead of developing something to stop the intercepted five missiles during the operation. On July penetration of the armor after contact, designers 14, 2014, the Trophy system successfully intercepted a attempted to prevent the rocket/missile from impacting Kornet missile. On July 22, 2014, according to a video the vehicle all together. To do this, the “Active by a Palestinian group, the Trophy system installed on Protection System” was developed. There are two a Merkava IV tank intercepted an RPG-29 rocket [7]. forms of active protection. There are “soft kill” and In addition to protecting the tank, the approach “hard kill” systems. Soft kill systems like the Russian information given by the fire control radar allowed the Shtora use jammers to prevent guided missiles from tank to engage the anti-tank team. The success of the being steered to their target. This essay will specifically Trophy System during Operation Protective Edge discuss the Israeli “Trophy System” by Rafael. convinced the military to move towards a widespread adoption of the system for tanks and lighter armored The Trophy System is a form of hard kill active personnel vehicles (APC). Trophy is currently protection. Hard kill systems destroy the incoming operational on all Merkava Mark-IV tanks of the IDF's projectile before it can make contact with the vehicle. 401st Armored Brigade, as well as with the 7th The Trophy System is result of a collaboration between Armored Brigade 75th Battalion new Merkava IV the Israeli defense contractors Rafael and Elta. Elta tanks. In November 2016 it was announced that the manufactures aircraft radar and developed a specialty IDF will purchase additional Trophy systems to be pulse doppler radar to detect incoming threats [5]. installed on almost all of its Merkava IV MBTs and Rafael developed the device that takes out the threat. NAMER APCs [8]. The complete system consists of the following: one Elta EL/M-2133 F/G band fire control radar and two rotating shotgun-like launchers. The system works as POTENTIAL OF THE TROPHY follows. The radar constantly scans a 360-degree SYSTEM perimeter around the tank. When an incoming threat is detected, the system’s computer is able to detect the The Trophy System’s capabilities make it threat’s approach vector and speed. Based on this data, incredibly important to Israeli society. Israel is a the system determines the proper orientation that the country with a small population and mandatory launcher should fire at and at what time they will fire. military service. Under these circumstances, Once the time comes, the launchers shooters fire a commanders must take even more precautions to shotgun like blast of metal pellets. This wide spread of preserve life than those of other countries would. For many pellets results in an almost certain destruction of the IDF, it takes less casualties for a tactical victory to

2 Nicolas Obeso be a strategic defeat. This means that for the IDF to continue waging war, it cannot lose a great amount of [9] Anna. Ahronheim. “US Army Close to Giving Go- men and machines in every battle. Compared to the Ahead to Install Israeli Tank Defense Technology.” cost of life and the cost of losing a vehicle, the 350k it 08.29.2017. Accessed 10.30.2017. costs to create a Trophy System is meaningless [9]. The benefits of the Trophy System are also felt in the ACKNOWLEDGEMENTS civilian world. The widespread implementation of this system effectively neutralized the biggest threat in the [1] I would like to thank my friends in Forbes Hall for modern battlefield which means that less families have giving me advise on this project. to hear the news of their children’s passing. It is important for engineers to continue refining and [2] I would like to thank my senior year literature producing this product. Working to protect one’s teacher, Carlos Maza, for helping further refine my soldiers is a noble vocation and falls in line with what writing skills. engineers are meant to do. Engineers work to help people live better lives. Keeping families together and preventing gruesome injuries is undoubtedly helpful for the common man. As far as I am concerned, it would be a tremendous privilege to work on a project like this one. I have always had a great interest in military technology and I would be proud in knowing that my machine is saving lives.

SOURCES

[1] R. Bunker. “Non-state Threats and Future Wars.” The Chechens and Urban Operations. 11.12.2012. Accessed 10.28.2017.

[2] W. Walters. “A Brief History of Shaped Charges.” 09.22.2008. Accessed 10.28.2017.

[3] H. Manfred. “Propellants, Explosives, Pyrotechnics.” Pg. 29. 01.20.2004. Accessed 10.28.2017.

[4] A. Hurlich. “Spaced Armor.” 11.20.1950. Accessed 10.28.2017. http://www.dtic.mil/dtic/tr/fulltext/u2/a954865.pdf

[5] Elta-IAI. “WindGuard.” Senior Year. 12.04.2016. Accessed 10.29.2017. http://www.iai.co.il/sip_storage/files/8/38048.pdf

[6] D. Donald. “Trophy-LV is Ready to Protect.” 06.18.2014 Accessed 10.29.2017. http://www.janes.com/article/39533/trophy-lv-is-ready- to-protect-es14e3

[7] Y. Azulai. “Anti-Tank Missile Defense System Makes Debut.” 06.20.2014. Accessed 10.29.2017. http://www.globes.co.il/en/article-debut-for-anti-tank- missile-defense-system-1000956678

[8] Y. Lappin. “Defense Ministry Unveils First NAMER APC With Trophy Anti-Missile System.” Senior Year. 01.28.2016. Accessed 10.29.2017.

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