>>519808804
They don't work because they aren't spiky like the Russian ones.
Western cage are just shurtzen on the top :why they don't work? Because it's a thin layer of nothing so once the projectile punched through to stop the projectile- it's the same reason why shurtzen in WW2 while a good idea barely worked.
Superior spike-hedgehog: spikes stick outward in all directions so when a projectile either solid OR shaped liquid charge etc hit spike the projectile is now thrown off course veering any and all directions besides straight, MOST IMPORTANTLY even if the projectile were to head straight still to the target the projectile now needs to run the course of this entire metal spike so the projectile is losing velocity and force the whole time it's interacting with a spike/multiple spike ultimately resulting in a non penetration and or a richotcet. And even if the charge/projectile lands on target after that it will most likely not have the force left over to cause a pen or any sort of real damage to the vehicle.