Rocket-Propelled Grenades [RPG]

The course of the Second World War proved the urgent need to use compact and at the same time powerful weapons to impress a wide range of armored targets on the battlefield. In the 1930s, the main means of combating tanks were large-caliber rifles and anti-tank artillery, and in many respects the reserve of improvement was exhausted.

Increasing the caliber of the systems led to an increase in their weight, which made them less maneuverable and, as a result, vulnerable to enemy fire on the battlefield. The way out was found in the creation of a new model of infantry weapons - manual anti-tank grenade launchers (RPG).

Manual anti-tank grenade launchers were designed according to the principle of "recoilless action". The RPG barrel was a pipe open on both sides. The front part of the pipe served as a barrel, and the breech section of the barrel served as a nozzle. When fired, the grenade moves along the barrel in the direction of the target, while the combustion products move in the opposite direction through the nozzle. In this way, the phenomenon of weapon recoil was eliminated, which made it possible to design the entire system relatively easily.

The first experiments on RPG design were carried out in the early 1930s, but due to low armor penetration, they were not adopted. The situation changed with the advent of cumulative munitions. A cumulative projectile uses a cumulative effect to penetrate armor. Cumulative effect (lat. ?umulo – intensify, increase) – the concentration of the explosion in a certain direction. To concentrate and direct the explosive flow in a certain direction, a funnel-shaped recess with the bell facing forward is arranged in the explosive and its surface is lined with 2-3 mm. layer of copper, steel or aluminum. When encountering an obstacle, the explosive is detonated, the metal shell is compressed and collapses, ejecting a red-hot metallized jet in the direction of the target, which "burns through" the armor at a speed of 10-12 m/s under a pressure of about 10 GPa. Cumulative shells made it possible to penetrate thick armor with a relatively small caliber.

The appearance of RPGs on the fronts of the Second World War dramatically increased the ability of infantry to independently repel massive tank attacks. At the same time, RPGs have become an irreplaceable means of supporting infantrymen in combined arms combat.

Modern RPGs use one of three grenade throwing schemes - a recoilless gun (the simplest or with a jet nozzle), jet, "Davis guns", and combined.

About the design of the grenade launcher according to the scheme of the recoilless gun, part of the powder gases formed during the combustion of the metal charge is ejected through the breech section of the barrel (launch tube) or through the nozzle, and the reaction of the jet compensates for the recoil. The grenade is designed in the form of a projectile with a sleeve. One of these samples is the Swedish "Karl Gustav" hand-held anti-tank grenade launcher.

When using a jet scheme, the grenade is launched using a jet engine in the tail of the grenade. Complete exhaustion of engine fuel can occur both in the middle of the barrel and during the flight of the grenade. The rocket engine allows you to accelerate the grenade to high speed, which provides a longer range for stability on the flight path. A significant drawback is the breakthrough of powder gases from the muzzle of the barrel and the exhaust of the grenade engine, which can cause serious burns to the shooter-grenade thrower. To eliminate this shortcoming, the grenade launcher itself is equipped with additional protective shields. Such are the aforementioned examples of anti-tank weapons of the Second World War - "Ofenrohr" and "Panzerschreck".

When designing a grenade launcher of the "Davis Cannon" type, a "counterweight" approximately equal to the mass and speed of the grenade is fired through the breech section of the barrel. The counterweight consists of many small plastic flakes or porous material that quickly crumble and lose speed in air. The danger zone remains, but is significantly reduced. According to this scheme, the German RPG "Panzerfaust"-3 and "Armbrust" were built. A characteristic feature of recent decades has become the desire for a low-speed launch of grenades (as well as rockets of portable missile systems) with subsequent acceleration on the trajectory. The low initial speed not only allows you to launch from closed spaces, but also reduces the unmasking signs of the RPG and the acoustic load on the grenade launcher.

Combined circuits use the principle of operation of non-return and reactive circuits at the same time. When using the combined scheme, the grenade is launched with the help of a starting charge, which pushes the grenade a certain distance. After the grenade has flown to a minimally safe distance from the grenade launcher, the marching main engine is turned on, which accelerates the grenade to the required speed. One of the most famous examples of the RPG of the combined scheme is the Soviet RPG-7.

RPGs are also classified into disposable and reusable samples. The latter are often called rocket grenades, since they are often the individual weapon of an infantryman (at that time, a reusable RPG usually serves a calculation of two or three soldiers). A single-use grenade launcher is a transport-launch container, equipped in factory conditions with a cumulative grenade. The container is hermetically sealed on both sides and simultaneously functions as a container for carrying and a launcher. Transport and launch containers are made of strong and at the same time light materials, such as reinforced plastic. This allows you to make containers lighter without losing strength.

Disposable grenade launchers can be equipped either with standard non-removable sights (usually mechanical sights) or equipped with brackets for installing optical or electronic-optical sights. After the shot, the sight is installed on a new transport and launch container. And the shot transport-launch container is thrown away. The effective range of their launch usually does not exceed 300 m. Such RPGs are the Soviet RPG-18 "Mukha", the British LAW-80, the American M72 and the French "APILAS".

The main combat units for RPGs remained cumulative, the armor penetration of which had to be increased. Increasing the efficiency of the cumulative warhead is facilitated by the increase in the accuracy of its manufacture and the optimization of the detonation time and the focal distance, that is, the distance to the obstacle at which the cumulative jet is formed. For this, contact head-bottom breakers are used with the appropriate removal of the head part forward (at a distance of approximately three gauges from the base of the cumulative funnel) on the fairing or pin or non-contact optical-electronic breakers.

The widespread use of dynamic defense caused the use of tandem cumulative shells. Unlike ordinary cumulative shells, tandems have two or more cumulative charges located one behind the other. One of the charges when hitting the target triggers the activation of active elements of dynamic protection, the second, as a rule, is more powerful – penetrates the main armor. Corresponding changes are also made in the production technology of the cumulative node. Metals are used to line the cumulative shell funnels, which, thanks to their properties, improve the penetrating characteristics of the cumulative projectile. For example, metal tantalum, which increases the length and penetrability of the cumulative jet, is being actively used alongside copper to line the funnel.

An interesting feature of the development of grenade launchers in a number of countries was the unification of grenades or their combat parts, which ensures equal effectiveness of RPGs of different types.

At the end of the 80s of the 20th century, the field of application of grenade launchers began to be expanded due to the introduction of shots with fragmentation and thermobaric warheads into the ammunition. Thus, RPGs from "specialized" anti-tank weapons turn into a multi-purpose means of supporting infantry units, capable of fighting various types of targets. So the very name "anti-tank grenade launcher" becomes conditional.

In partisan and other paramilitary formations, RPGs essentially replace artillery due to ease of operation, relative compactness and high mobility and combat effectiveness. Therefore, for the effectiveness of various types of combat operations, the presence of RPGs in a partisan unit is mandatory.

During raids and shelling, grenade launchers, destroying fortified firing points and important objects on the enemy's territory, essentially play a decisive role in the successful completion of the assigned task. Each partisan unit must have appropriately trained snipers and grenade launchers, as well as organize their training in field conditions and training centers. At the same time, all partisans, without exception, must possess the techniques and skills of shooting from grenade launchers.