Can a Single BM-21 Destroy a Tank 20 km Away with a Thermobaric Warhead?

Modern thermobaric warheads for the 122mm rocket family like the BM-21 Grad (BM-21) are not available. However, the Grad battery, consisting of six vehicles, fires 240 122mm Katyusha rockets into a target area in a matter of seconds. Any tank or thin-skinned vehicle within this zone faces severe damage, often leading to disarray within the formation.

BM-21 Grad Rocket Battery

The BM-21 Grad is a multi-rocket launcher system capable of firing 40 122mm Katyusha rockets in a rapid volley, with a propulsion system capable of hitting targets accurately over short to medium ranges. This high volume of fire creates a concentrated explosion, thereby maximizing the damaging effect on the target area.

The system's inaccuracy is not a significant issue, as its primary purpose is to blanket a large area with a high volume of ordnance, creating both destruction and a cover for subsequent engagements. The Soviet doctrine calls for the use of massive indirect fire to create openings for maneuver forces to exploit, requiring multiple hits from various weapon systems to achieve the desired effect.

Munitions for the BM-21 Grad

The BM-21 Grad can deploy a wide variety of ammunition, from conventional high-explosive point-detonating rounds to anti-tank submunitions, smoke scatterable mines, and chemical agents. Longer-range rockets, while capable of reaching up to 40 kilometers, often sacrifice payload in favor of greater range.

Currently, there is no precision-guided munition available for the BM-21, limiting its effectiveness against well-protected targets. For a thermobaric warhead, which relies on igniting an aerosolized fuel/air mixture to create an explosive overpressure, achieving the necessary conditions in a 22mm diameter projectile poses significant challenges.

The extended range rockets, while useful for broader area attacks, may also reduce the effectiveness of the warheads due to the pre-ignition of explosive clouds by successive rockets. This issue may render a single thermobaric warhead launched from a BM-21 ineffective against a tank from a distance of 20 kilometers or more.

Challenges to Single-Kill with Thermobaric Warhead

Even if a suitable thermobaric warhead were available, two major challenges would still exist:

The first challenge lies in hitting the tank with a weapon designed for area fire, typically employed by a battery of six or a battalion of 18 launchers. The probability of a single volley hitting a specific target in such a vast area is exceedingly low.

The second challenge is the defensive systems of the tank. Modern tanks have robust protection systems that can withstand significant overpressures when the tank is properly sealed and properly shielded from the initial blast and secondary effects of a thermobaric explosion.

In conclusion, while the BM-21 Grad can be a formidable weapon system for area destruction and creating openings for maneuver, the challenges in hitting a specific target, particularly a well-protected tank, make it unlikely for a single BM-21 Grad-launched thermobaric warhead to destroy a tank from 20 kilometers away.