Rocket-propelled anti-tank grenades.
Rocket-propelled anti-tank grenades
WORK on the creation of rocket-propelled anti-tank grenades in the USSR began at the turn of the 1970s. Their main developers were the Bazalt Design Bureau and the TsKIB SOO Tula. In the 1970s and 1980s, these design bureaus developed several highly effective systems that successfully passed tests and were accepted into service.
The concept behind their design and tactics of use implied simplicity of design, speed of use, high maneuverability in combat, single-use and high armor penetration. The first of the systems adopted for service (1972) was the RPG-18 “Fly” anti-tank rocket grenade. I would like to dwell on its design (the most complex in its design).
By design, all RPGs are actually a grenade and a launcher.
The “Fly” launcher consists of two tubes – an internal aluminum one and an external one made of impregnated fiberglass. The external tube contains the sighting devices, the firing mechanism, the locking mechanism, the firing tube, the carrying strap and a reminder on safety precautions and firing procedure. The launcher is closed with covers on both ends, while the rear cover is secured with a metal pin. To prepare the grenade for firing, it is necessary to open the rear cover and move the tubes apart to their full length. In this case, the front cover will fold back by itself, and the sighting devices, under the action of their springs, will take a vertical position. The grenade is aimed by combining the diopter hole of the rear sight and the corresponding mark on the front sight glass. Four aiming marks have divisions corresponding to 50, 100, 150 and 200 m to the target. In early batches of RPG18, the front sight was made as a stamped metal frame. In addition, there is a protrusion in the upper part of the front sight, and a slot in the upper part of the rear sight, designed for aiming at night.
One of the rear sight diopter holes is designed for shooting in temperature conditions from 0 to +50° C, the other from 0 to -50° C. For shooting in these conditions, each of the holes is covered with a rotary curtain. The rear sight safety post is the cocking lever of the firing mechanism. To cock the trigger mechanism, it is necessary to lower the safety bar down and release it. A shot is fired by simply pressing the sear trigger key. At the same time, the sear releases the spoke, which, under the action of the mainspring, moves forward and strikes the primer-igniter with the striker tip, the flame nozzle moves along the fire tube and ignites the grenade's jet engine charge.
The grenade itself consists of a warhead, a solid-fuel rocket engine with a feather stabilizer. The warhead of the grenade contains an Okfol explosive charge. The fuse is piezoelectric, head-on, instantaneous impact fuse with a long-range arming and a pyrotechnic self-destructor. When it encounters an obstacle, the warhead generates an electrical impulse, which is transmitted via a current lead to the bottom of the fuse and initiates the detonator, which in turn initiates the main charge. As a result, a cumulative jet is formed, which, due to its high temperature and high pressure, destroys armor, affects manpower, ignites fuel and ammunition.
The solid propellant rocket engine (expulsion charge) serves to give the grenade an initial velocity. In its design, it is a block of pressed gunpowder of the PPK-5 brand, the engine burns completely inside the launcher, which prevents the shooter from being hit by escaping gases when the main engine charge comes into action. The main engine charge is a bundle of tubular gunpowder. The powder gases formed during its combustion exit through a nozzle in the rear of the grenade.
The grenade is stabilized by a feather stabilizer, the wings of which fold back on their axes immediately after the grenade leaves the launcher barrel. In addition to the feather stabilizer, a certain role is played by tangential holes located in the transition bottom. The powder gases flowing through them impart a rotational motion to the grenade in flight, which improves the accuracy and precision of fire.
In 1981, the RPG-22 “NETTO” was adopted by the infantry as an unofficial anti-tank weapon. The objective reasons for its development and adoption were increased requirements for armor penetration, firing range, the need to reduce the time it takes to transfer the grenade to the combat position, and a simplified launcher design.
The PU sighting devices have not undergone any significant changes. However, the sighting marks of the front sight have divisions corresponding to 50, 150, 250 m to the target. On the outer dimensions of the front sight, on the division, multiple of 150 m, there are protrusions, the distance between which corresponds to the average width of the tank at a distance of 150 m. Some changes affected the trigger mechanism. The design of the grenade as a whole remained the same.
The RPG-18 and RPG-22 designs did not allow the grenade to be transferred from the combat position to the marching position. A grenade already prepared for firing, even if there was no need to fire, had to be discharged by firing towards the enemy. The author knows of cases where illiterate actions when handling the RPG-18 led to tragic results,
Almost immediately after the RPG-22, the RPG-26 “Aglen” was adopted by the USSR Armed Forces. The launcher design of the launcher is single-tube. The material for the pipe is fiberglass. The covers that close the launcher in this system are made in the form of burst rubber plugs that protrude significantly beyond the external dimensions of the pipe. This helps protect the launcher body from mechanical damage during storage or transportation. The front sight is made as a folding plate with marks in multiples of 50, 150 and 250 m. There is a protrusion in the upper part of the front sight, and a cutout in the upper part of the safety post to facilitate aiming at night up to 100 meters. The rear sight safety post is a cocking lever (in the vertical position) and a safety device from pressing the trigger lever (in the horizontal position). Three diopter holes located on the rotating plate constitute the rear sight. In this system, temperature ranges are significantly reduced, here they fluctuate within plus or minus 15 ° C. The trigger is cocked by moving the safety post to the vertical position. If there is no longer a need to fire, it is enough to lower it. As a result, the grenade will be moved to the traveling position. The sear is released from the combat platoon by pressing its lever.
In connection with the development of tank protection systems, it became necessary to develop RPGs capable of successfully destroying anti-cumulative protection systems. The best solution to this problem was the development of anti-tank rounds with a tandem warhead. The essence of the design is the arrangement of two cumulative charges in one round. In this case, the front (smaller) charge is designed to destroy the tank's dynamic protection unit, and the second (main) charge is designed to directly defeat the armor. One of these was the PG7VR round for the RPG-7 grenade launcher.
As for disposable grenades, the RPG-27 “Tavolga” design, adopted into service in 1989, was based on this principle. In this system, the launcher design remained practically the same as in the RPG-26. The differences affected only the configuration of the safety bar. In addition, in the rear part of the launcher there is a folding metal stop designed to ensure the shooter's safety from being hit by a jet stream when firing from a prone position or from cover. The design of the Tavolga's warhead has a tandem scheme, the caliber is significantly increased, and therefore the mass of the warhead. I think that today there are no tanks equipped with dynamic protection systems that could not be hit by “Tavolga”.
Experience of local conflicts of recent years has shown that in urban combat conditions, where the use of artillery and armored vehicles is difficult or impossible, the task of destroying enemy firing points or other defensive structures is easily accomplished with a sufficient number of anti-tank rocket launchers available to the unit. The effectiveness of this fire weapon can be judged by their performance characteristics, given below. At the same time, it should be noted that for ten years now, more advanced models of systems of this kind have not entered service. It must be assumed that the potential enemy has suspended the development of its tanks and anti-tank systems. Following us.
