Adding armor can help save the lives of armored vehicle crews, but extra weight and the hazards associated with explosive protection create challenges of their own. Israeli defense company Plasan has developed two different systems designed to address the threat of rocket-propelled grenades without relying on the same protective approach.
By Hezy Laing
Rocket-propelled grenades (RPGs) remain a serious threat to tanks and other armored vehicles, particularly in close combat, where attackers can exploit gaps in a vehicle’s defenses. Many RPG warheads use a shaped charge, which focuses explosive energy into a narrow jet capable of penetrating armor.
One traditional response is explosive reactive armor (ERA), which uses explosive tiles to disrupt the penetrating jet when a warhead strikes. Although effective against certain threats, these systems add weight and can create blast and fragmentation hazards for nearby personnel.
Plasan has pursued alternatives that approach the problem differently. Its ATHENA system uses a non-explosive reactive mechanism, while its Hybrid Slat Fence (HSF) is an external structure designed to interfere with certain RPG warheads before they can function as intended.
ATHENA: protection without explosive tiles
ATHENA combines conventional composite armor with an expanding interlayer. When a shaped-charge warhead strikes the module, the interlayer reacts mechanically, disrupting the penetrating jet and helping prevent it from reaching the vehicle’s main armor.
The key distinction is that ATHENA does not depend on detonating an explosive tile to produce its protective effect. This avoids the particular blast hazard associated with explosive reactive armor, an important consideration when armored vehicles operate alongside dismounted infantry.
HSF: a different defense against RPGs
Plasan’s Hybrid Slat Fence takes a more visible approach. It uses an external structure of hybrid metal-composite bars designed to disrupt the functioning of certain RPG warheads before they can strike the vehicle’s primary armor.
Slat armor can interfere with some impact-fuzed warheads, but the result depends on the weapon’s design and the circumstances of impact. It cannot guarantee that every incoming RPG will fail to detonate or that the vehicle will remain undamaged.
The system is designed to be modular, allowing damaged components to be replaced rather than requiring the entire structure to be rebuilt. That can simplify repairs and help operators return vehicles to service, although actual maintenance benefits depend on the damage sustained and the availability of replacement parts.
In February 2022, Plasan announced a contract with Spanish defense consortium TESS Defence to supply HSF and additional protection for the VCR Dragon 8×8 armored vehicle program. The initial phase covered 348 vehicles, providing a concrete example of the system’s intended application beyond a laboratory demonstration.
The challenge is protecting without adding unnecessary burdens
For armored vehicle designers, protection is only part of the equation. Added weight can affect mobility, while complex systems can increase maintenance demands and certain protective mechanisms can create risks for troops operating nearby.
ATHENA and HSF address different parts of that challenge: one uses a non-explosive reactive mechanism, while the other relies on an external structure intended to disrupt certain RPG warheads. Neither eliminates the danger posed by anti-tank weapons, but both illustrate the engineering effort required to improve protection without overlooking the realities of military operations.
