Source: Ministry of Defense of Ukraine
A previous posting discussed the ubiquitous RPG-7 to include how it works and one of the numerous rockets that it can use, the 70mm PUI-7 practice rocket. To view that post, point your browser here:
The rocket shown here, in the hands of a soldier of the 43rd. Mechanized Brigade, is the most lethal to any tank on the battlefields of the Russo-Ukrainian War. The Bulgarian produced 93mm PG-7VT is a very long rocket as clearly evidenced here, having a total length of 3.7 feet long with a weight of 7 pounds. The cause of the rocket's length it what gives it its lethality: a tandem-charge warhead.
At the very front of the rocket is a smaller, 40mm HEAT (High-Explosive Anti-Tank) warhead. Within this small warhead is a OKFOL explosive shaped charge with a piezoelectric crystal equipped VP-22 fuze. This type of fuze is often used with HEAT munitions due to its robustness and simplicity. When the warhead strikes the target, the crystal undergoes mechanical stress which in turn causes crystal deformity which then releases an electric charge. This discharge then triggers the detonator on the explosive charge.
In the case of the PG-7VT, the small warhead will strike explosive reactive armor (ERA) which is commonly found on Soviet-era and Russian tanks. Examples include Kontakt-1, Kontakt-5, and Relikt. All three types of ERA can be seen on Russian and Ukrainian tanks and in the case of Western tanks being utilized by the Ukrainian Army, many have been fitted with Kontakt-1 (the most common) and Kontakt-5 blocks. Upon hitting a ERA block, the warhead's impact will cause the explosive within the block to detonate, creating a blast traveling outwards, away from the tank. With HEAT munitions, the outward pressure wave of the block's detonation deforms the plasma jet formed by the shaped charge to the point that the tank's armor itself will not be penetrated by the warhead.
Except, in the case of the PG-7VT, there is a 93mm HEAT warhead coming right behind the small one. With the ERA cleared away by the first charge, the larger OKFOL filled warhead can detonate against the tank's actual armor. The second charge also uses the same fuze type as the first but adds IIF (Impact, Inertia, Fired). IIF combines impact and inertial resistance to trigger the warhead and this feature is a safety measure from accidental detonation. Capable of penetrating a minimum of 500mm of rolled homogeneous armor (RHA), the PG-7VT can defeat just about every tank it would meet on the Russo-Ukrainian War's combat zones. About the only tanks that could survive, from a frontal hit, is the M1A1 Abrams and FV4034 Challenger II which the Ukrainian Army fields. The Russian Army's latest tank, the T-14 Armata, is also capable of shrugging off the PG-7VT but to date, not a single T-14 has ever been deployed to Ukraine. If the PG-7VT is fired at a tank without ERA or hits a location not protected by ERA, the penetration is no less than 500mm of RHA.
It should be noted that this tank killing capability comes at a cost. The maximum effective range of the PG-7VT is a minuscule 300 meters with the optimal range being no more than 220 meters. In open terrain (which a good bit of Ukraine's battlefields are), effecting a hit against enemy armor means getting suicidally close. If firing from a trench in the defense, it means letting enemy armor get uncomfortably close. However, if the combat is in built up urban areas (such as in villages, towns, or small cities), the opportunity to get close enough to enemy tanks without being spotted are far higher and effecting escape after firing (as the backblast will betray the firer's location) is also higher. This is one reason tank troops do not like entering urban areas without infantry support.
The PG-7VT can also be used against targets other than tanks. If firing at a building composed of bricks or construction masonry, the rocket can drill through around 65 inches of block. If used against reinforced concrete, penetration drops to 49 inches. If used against improvised trench works consisting of logs, sandbags, and dirt fortifications, the PG-7VT can make short work of such defenses with a penetration of 10 feet.
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