Heidar-7 / Heydar-7 - BTR-60PB + ERA (original) (raw)

The Iranians are looking for updates to their most obsolete armored vehicles. In accordance with its intended role, the BTR-60 was designed as a lightly-armored vehicle. According to the specifications for the basic tactical-technical characteristics of the BTR-60, its requirements for protection did not change from its predecessors - its frontal armor had to resist 12.7mm armor-piercing bullets and it had to offer complete protection from 7.62mm armor-piercing bullets from all angles of fire. Generally speaking, the BTR-60 only viable as a "battle taxi".

BTR-80s have been seen with slat armor sets in various conflict zones as a response to the presence of RPG threats. The BTR-70 and BTR-80 are nothing more than ungraded versions of the BTR-60 series vehicles, which were developed back in the late 1950s. Production of the BTR-80 has also been discontinued. It had endured a less than stellar existence.

On 24 September 2017 Iran unveiled a prototype Haydar 7 [or Heidar-7 or Heydar-7], a new Iranian version of the Soviet BTR-60. Heydar 7 comprises an eight-wheel drive vehicle, equipped with a new turret and an Automatic sniper 23-millimeter gun. The ERA bricks have been placed everywhere, and seem to be placed without any aesthetic criteria. The Iranian defense industry's new 8x8 armored vehicle personnel carrier is based on a Soviet-made BTR-60PB. The BTR-60PB is Soviet-made 8x8 armored vehicle personnel carrier (APC) which was developed in the late 1950s to replace the BTR-152 6x6 APC and was first seen in public in 1961.

The Soviets themselves who came to that conclusion after experimenting with BMPs equipped with ERA. Not that they were bad or ineffective in their role, but it was counterproductive mounting on IFV, since when the infantry landed, they were more a threat than a protection. The bricks ERA are a danger for the own infantry when the impact of an enemy ammunition is received.

Light-weight vehicles are subjected to a growing and significant problem, Explosively Formed Projectiles (EFPs). Originally reactive armor was designed to defeat anti-tank rounds. These rounds use a conical shape charge capable of producing a high temperature jet delivering a tremendous amount of energy on a single point. EFPs are highly dense solid matter traveling at 7,000 to 8,000 fps with very high kinetic energy making it much harder to stop using a flying plate method.

Explosive Reactive Armor, or ERA, consists of a layered explosive sandwiched between two steel plates and packages as a cassette. Armored vehicles, such as tanks, are appropriately covered, on the outside, with contiguously mounted explosive reactive armor cassettes as a measure of protection from the enemy. When a projectile impinges, preferably obliquely on the explosive reactive armor, an explosion is initiated, and a reaction occurs. The term projectile defines any kind of armor penetrating weapon, such as a kinetic energy projectile, or a hollow charge, or a shaped charge, or a high velocity slug.

The cross-section of an explosive reactive armor cassette consistsi of a front plate, a back plate, and an intermediate plate, or plate of explosive or fast exothermic reaction composition. The front plate faces the front directed towards the incoming projectile and the back indicates the opposite direction adjacent the structure protected by the explosive reactive armor.

As a result of the explosive reaction, both the front plate and the back plate are accelerated in separation, in opposite directions, normal to their surface. The translation of both plates actively interacts with the motion of the projectile, by crossing the trajectory thereof and hitting the projectile. Thereby, the projectile is broken and the severe perturbations that are caused, lead to a drastic reduction of the subsequent penetration capability of that projectile.

Although the two steel plates of an explosive reactive armor begin their protective effect as single-piece solid plates stacked in surface abutment as a cassette mounted outside the protected structure, they shatter into fragments a few microseconds after the initiation of the explosive reaction. From this moment on, the fragments of the plates of the reactive armor develop into a life-threatening danger, scattering as shrapnel on the outside of the protected structure. Fragments from the front plate FP endanger personnel, equipment, and vehicles dwelling on the outside of the protected structure, while fragments from the back plate BP, badly damage the protected structure itself. Even though the main objective of the explosive reactive armor is achieved and the personnel inside the protected structure escapes unharmed, by-standing troops may be killed or seriously wounded, and equipment may be destroyed by fragments from the front plate FP. In addition, the back plate BP, usually abutting and contiguous to, for example, the armor of an armored vehicle, may inflict so much damage as to render it unfit for service.

Furthermore, the contiguously mounted steel plates of the explosive reactive armor cassettes support sympathetic initiation, whereby the explosive reaction of one explosive reactive armor cassette triggers the reaction of neighboring cassettes, causing an unnecessary reaction, and thus waste, of a number of such protection cassettes.

The ERA bricks are a danger to friendly infantry when the impact of enemy ammunition is received. Equipping ERA with vehicles that interact with infantry around is usually discouraged, since they may produce more casualties than they try to avoid. The Soviets themselves came to that conclusion after experimenting with BMPs equipped with ERA. Not that they were bad or ineffective in their role, but it was counterproductive mounting on IFV, since when the infantry landed, they were more a threat than a protection.

The ERA on the BTR-60 Iranian modification is suspicious. As a rule, ERA is difficult to use on light armored vehicles (it is rarely seen today). The vehicle's main armor is too thin to survive the explosive reaction of the tiles themselves. There were a few examples over the years of attempts to put tank ERA tiles on smaller vehicles (including BMP-1s in Syria) but these failed. ERA tiles taken from tanks are especially dangerous to use on lighter vehicles, as these designed to work with the tank's thicker armor. These BTR-60 tiles are definitely smaller and thinner than those seen on MBTs, which may allow them to use them without being damaged themselves. However, with reduced thickness, the effectiveness of the ERA will be degraded. Also, the placement of the some of the tiles (especially around and BETWEEN the two windows up front) is a rather suspect. The slat or cage armor would be the simpler and smarter option.