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Tank ammunition. Soviet cumulative anti-tank ammunition during the war

IN game World of Tanks vehicles can be equipped different types shells, such as armor-piercing, sub-caliber, cumulative and high-explosive fragmentation shells. In this article we will look at the features of the action of each of these projectiles, the history of their invention and use, the pros and cons of their use in a historical context. The most common and, in most cases, standard shells on the vast majority of vehicles in the game are armor-piercing shells(BB) caliber device or sharp-headed.
According to Military encyclopedia Ivan Sytin, the idea of the prototype of current armor-piercing shells belongs to the officer of the Italian fleet Bettolo, who in 1877 proposed using the so-called “ bottom shock tube for armor-piercing projectiles"(before this, the shells were either not loaded at all, or the explosion of the powder charge was calculated on heating the head of the projectile when it hit the armor, which, however, was not always justified). After penetrating the armor, the damaging effect is provided by projectile fragments heated to a high temperature and fragments of armor. During the Second World War, shells of this type were easy to manufacture, reliable, had fairly high penetration, and worked well against homogeneous armor. But there was also a minus - on sloping armor the projectile could ricochet. The greater the thickness of the armor, the more fragments of armor are formed when penetrated by such a projectile, and the higher the destructive power.

The animation below illustrates the action of a chambered sharp-headed armor-piercing projectile. It is similar to an armor-piercing sharp-headed projectile, but in the rear part there is a cavity (chamber) with a TNT explosive charge, as well as a bottom fuse. After penetrating the armor, the shell explodes, striking the crew and equipment of the tank. In general, this projectile retained most of the advantages and disadvantages of the AR projectile, being distinguished by a significantly higher armor-protection effect and slightly lower armor penetration (due to the lower mass and strength of the projectile). During the War, the bottom fuses of shells were not sufficiently advanced, which sometimes led to a premature explosion of a shell before penetrating the armor, or to failure of the fuse after penetration, but the crew, in case of penetration, rarely felt better about it.

Sub-caliber projectile(BP) has a rather complex design and consists of two main parts - an armor-piercing core and a pallet. The task of the pallet, made of mild steel, is to accelerate the projectile in the barrel bore. When a projectile hits a target, the pan is crushed, and the heavy and hard pointed core, made of tungsten carbide, pierces the armor.
The projectile does not have a bursting charge, ensuring that the target is hit by fragments of the core and fragments of armor heated to high temperatures. Sub-caliber projectiles have significantly less weight compared to conventional armor-piercing projectiles, which allows them to accelerate in the gun barrel to significantly higher speeds. As a result, the penetration of sub-caliber projectiles turns out to be significantly higher. The use of sub-caliber shells made it possible to significantly increase the armor penetration of existing guns, which made it possible to hit even outdated guns against more modern, well-armored armored vehicles.
At the same time, sub-caliber shells have a number of disadvantages. Their shape resembled a coil (shells of this type and streamlined shape existed, but they were significantly less common), which greatly worsened the ballistics of the projectile, in addition, the lightweight projectile quickly lost speed; as a result, at long distances the armor penetration of sub-caliber projectiles dropped significantly, turning out to be even lower than that of classic armor-piercing projectiles. During World War II, sabot projectiles did not work well against sloping armor because the hard but brittle core easily broke under bending loads. The armor-piercing effect of such shells was inferior to armor-piercing caliber shells. Small-caliber sub-caliber projectiles were ineffective against armored vehicles that had protective shields made of thin steel. These shells were expensive and difficult to manufacture, and most importantly, scarce tungsten was used in their manufacture.
As a result, the number of sub-caliber shells in the ammunition load of guns during the war was small; they were allowed to be used only to hit heavily armored targets at short distances. The German army was the first to use sub-caliber shells in small quantities in 1940 during battles in France. In 1941, faced with heavily armored Soviet tanks, the Germans switched to the widespread use of sub-caliber shells, which significantly increased the anti-tank capabilities of their artillery and tanks. However, a shortage of tungsten limited the production of projectiles of this type; as a result, in 1944, the production of German sub-caliber shells was discontinued, while most of the shells fired during the war years were of a small caliber (37-50 mm).
Trying to get around the tungsten shortage problem, the Germans produced Pzgr.40(C) sub-caliber projectiles with a hardened steel core and surrogate Pzgr.40(W) projectiles with a regular steel core. In the USSR, fairly large-scale production of sub-caliber shells, created on the basis of captured German ones, began at the beginning of 1943, and most of the shells produced were of 45 mm caliber. The production of these shells of larger calibers was limited by a shortage of tungsten, and they were issued to troops only when there was a threat of an enemy tank attack, and a report was required to be written for each shell used. Also, sub-caliber shells were used to a limited extent by the British and American armies in the second half of the war.

HEAT projectile(KS).
The operating principle of this armor-piercing ammunition differs significantly from the operating principle of kinetic ammunition, which includes conventional armor-piercing and sub-caliber projectiles. A cumulative projectile is a thin-walled steel projectile filled with a powerful explosive - hexogen, or a mixture of TNT and hexogen. At the front of the projectile, the explosive has a goblet-shaped recess lined with metal (usually copper). The projectile has a sensitive head fuse. When a projectile collides with armor, the explosive detonates. At the same time, the lining metal is melted and compressed by the explosion into a thin stream (pestle), flying forward at extremely high speed and piercing armor. The armor effect is ensured by a cumulative jet and splashes of armor metal. The hole of a cumulative projectile is small in size and has melted edges, which has led to a common misconception that cumulative projectiles “burn through” armor.
The penetration of a cumulative projectile does not depend on the speed of the projectile and is the same at all distances. Its production is quite simple; the production of the projectile does not require the use of large quantity scarce metals. The cumulative projectile can be used against infantry and artillery as a high-explosive fragmentation projectile. At the same time, cumulative shells during the war were characterized by numerous shortcomings. The manufacturing technology of these projectiles was not sufficiently developed, as a result, their penetration was relatively low (approximately the same as the caliber of the projectile or slightly higher) and was unstable. The rotation of the projectile at high initial speeds made it difficult to form a cumulative jet; as a result, the cumulative projectiles had a low initial speed, a short effective firing range and high dispersion, which was also facilitated by the non-optimal shape of the projectile head from an aerodynamic point of view (its configuration was determined by the presence of a notch).
The big problem was the creation of a complex fuse, which should be sensitive enough to quickly detonate a projectile, but stable enough not to explode in the barrel (the USSR was able to develop such a fuse, suitable for use in shells of powerful tank and anti-tank guns, only at the end of 1944 ). The minimum caliber of a cumulative projectile was 75 mm, and the effectiveness of cumulative projectiles of this caliber was greatly reduced. Mass production of cumulative projectiles required the deployment of large-scale production of hexogen.
The most widespread use of cumulative shells was by the German army (for the first time in the summer and autumn of 1941), mainly from 75 mm caliber guns and howitzers. The Soviet army used cumulative shells, created on the basis of captured German ones, from 1942-43, including them in the ammunition of regimental guns and howitzers, which had a low initial speed. The British and American armies used shells of this type, mainly in ammunition heavy howitzers. Thus, in the Second World War (unlike the present time, when improved shells of this type form the basis of the ammunition load of tank guns), the use of cumulative shells was quite limited, mainly they were considered as a means of anti-tank self-defense of guns that had low initial speeds and low armor penetration with traditional shells (regimental guns, howitzers). At the same time, all participants in the war actively used other anti-tank weapons with cumulative ammunition - grenade launchers, aerial bombs, hand grenades.

High-explosive fragmentation projectile(OF).
It was developed in the late 40s of the twentieth century in Great Britain to destroy enemy armored vehicles. It is a thin-walled steel or cast iron projectile filled with an explosive substance (usually TNT or ammonite), with a head fuse. Unlike armor-piercing shells, high-explosive fragmentation shells did not have a tracer. When it hits a target, the projectile explodes, hitting the target with fragments and a blast wave, either immediately - a fragmentation effect, or with some delay (which allows the projectile to go deeper into the ground) - a high-explosive effect. The projectile is intended primarily to destroy openly located and sheltered infantry, artillery, field shelters (trenches, wood-earth firing points), unarmored and lightly armored vehicles. Well-armored tanks and self-propelled guns are resistant to high-explosive fragmentation shells.
The main advantage high-explosive fragmentation projectile is its versatility. This type of projectile can be used effectively against the vast majority of targets. Another advantage is that it costs less than armor-piercing and cumulative projectiles of the same caliber, which reduces the cost of combat operations and firing training. In case of a direct hit in vulnerable areas (turret hatches, engine compartment radiator, ejection screens of the aft ammunition rack, etc.), the HE can disable the tank. Also hit by projectiles large caliber can cause destruction of lightly armored vehicles, and damage to heavily armored tanks, consisting of cracking of armor plates, jamming of the turret, failure of instruments and mechanisms, injuries and concussions of the crew.

In 1941, Soviet tank crews encountered an unpleasant surprise - German cumulative shells, which left holes in the armor with melted edges. They were called armor-piercing (the Germans used the term Hohlladungsgeschoss, “a projectile with a notch in the charge”). However, the German monopoly did not last long; already in 1942, the Soviet analogue of the BP-350A, built using the “reverse engineering” method (disassembling and studying captured German shells), - an “armor-burning” projectile for 76 mm guns. However, in fact, the effect of the shells was not associated with burning through the armor, but with a completely different effect.

Disputes about priorities

The term “cumulation” (Latin cumulatio - accumulation, summation) means the strengthening of any action due to addition (accumulation). During cumulation, due to a special charge configuration, part of the energy of the explosion products is concentrated in one direction. Several people who discovered it independently of each other claim priority in the discovery of the cumulative effect. In Russia - a military engineer, Lieutenant General Mikhail Boreskov, who used a charge with a recess for sapper work in 1864, and Captain Dmitry Andrievsky, who in 1865 developed a detonator charge for detonating dynamite from a cardboard sleeve filled with gunpowder with a recess filled with sawdust. In the USA - chemist Charles Munro, who in 1888, as legend has it, exploded a charge of pyroxylin with letters embossed on it next to a steel plate, and then drew attention to the same letters, mirrored “reflected” on the plate; in Europe - Max von Forster (1883).

At the beginning of the 20th century, cumulation was studied on both sides of the ocean - in Great Britain, Arthur Marshall, the author of a book dedicated to this effect, published in 1915, did this. In the 1920s, the famous explosives researcher Professor M.Ya. studied explosive charges with a notch (albeit without metal lining) in the USSR. Sukharevsky. However, to put the cumulative effect to work military vehicle The Germans were the first to succeed, who began the targeted development of cumulative armor-piercing projectiles in the mid-1930s under the leadership of Franz Tomanek.

Around the same time, Henry Mohaupt was doing the same thing in the United States. It is he who is considered in the West to be the author of the idea of metal lining a recess in an explosive charge. As a result, by the 1940s, the Germans already had such shells in service.

Deadly Funnel

How does the cumulative effect work? The idea is very simple. In the head of the ammunition there is a recess in the form of a funnel lined with a millimeter (or so) layer of metal with an acute angle at the apex (socket towards the target). The detonation of the explosive begins from the side closest to the top of the crater. The detonation wave “collapses” the funnel towards the axis of the projectile, and since the pressure of the explosion products (almost half a million atmospheres) exceeds the limit of plastic deformation of the lining, the latter begins to behave as a quasi-liquid. This process has nothing to do with melting; it is precisely the “cold” flow of the material. A very fast cumulative jet is squeezed out of the collapsing funnel, and the rest (pestle) flies from the point of explosion more slowly. The distribution of energy between the jet and the pestle depends on the angle at the top of the funnel: at an angle of less than 90 degrees, the energy of the jet is higher, at an angle of more than 90 degrees, the energy of the pestle is higher. Of course, this is a very simplified explanation - the mechanism of jet formation depends on the explosive used, on the shape and thickness of the lining.

One of the varieties of cumulative effect. To form an impact core, the cumulative notch has an obtuse angle at the apex (or a spherical shape). When exposed to a detonation wave, due to the shape and variable thickness of the walls (thicker towards the edges), the lining does not “collapse”, but is turned “inside out”. The resulting projectile with a diameter of a quarter and a length of one caliber (the original diameter of the notch) accelerates to 2.5 km/s. The armor penetration of the core is less than that of a cumulative jet, but it is maintained over almost a thousand recess diameters. Unlike a cumulative jet, which “takes away” only 15% of its mass from the pestle, the impact core is formed from the entire lining.

When the funnel collapses, a thin (comparable to the shell thickness) jet accelerates to speeds on the order of the explosive detonation speed (and sometimes higher), that is, about 10 km/s or more. This jet does not burn through the armor, but penetrates it, just as a jet of water under pressure erodes sand. However, during the formation of the jet, its different parts acquire different speeds (the rear parts are slower), so the cumulative jet cannot fly far - it begins to stretch and disintegrate, losing its ability to penetrate armor. The maximum effect of the jet is achieved at a certain distance from the charge (it is called focal). Structurally, the optimal armor penetration mode is ensured by the gap between the notch in the charge and the projectile head.

Liquid projectile, liquid armor

The speed of the cumulative jet significantly exceeds the speed of sound propagation in the armor material (about 4 km/s). Therefore, the interaction of the jet and the armor occurs according to the laws of hydrodynamics, that is, they behave like liquids. Theoretically, the depth of penetration of the jet into the armor is proportional to the length of the jet and square root from the ratio of the densities of the cladding material and the armor. In practice, armor penetration is usually even higher than theoretically calculated values, since the jet becomes longer due to the difference in the speeds of its head and rear parts. Typically, the thickness of the armor that a shaped charge can penetrate is 6-8 calibers, and for charges with linings made of materials such as depleted uranium, this value can reach 10. Is it possible to increase armor penetration by increasing the length of the jet? Yes, but often this does not make much sense: the jet becomes too thin and its armoring effect is reduced.

Pros and cons

HEAT ammunition has its advantages and disadvantages. The advantages include the fact that, unlike sub-caliber shells, their armor penetration does not depend on the speed of the projectile itself: cumulative ones can be fired even from light guns that are not capable of accelerating a projectile to high speed, and such charges can also be used in rocket-propelled grenades.

By the way, it is precisely the “artillery” use of cumulation that is fraught with difficulties. The fact is that most projectiles are stabilized in flight by rotation, and this has an extremely negative effect on the formation of the cumulative jet - it bends and destroys it. Designers are trying to reduce the rotation effect different ways- for example, using a special cladding texture (but at the same time, armor penetration is reduced to 2-3 calibers).

Another solution is used in French shells - only the body rotates, and the shaped charge mounted on bearings practically does not rotate. However, such shells are difficult to manufacture, and besides, they do not fully utilize the capabilities of the caliber (and armor penetration is directly related to the caliber).

The installation we assembled does not at all look like an analogue of the formidable weapon and mortal enemy of tanks - cumulative armor-piercing shells. Nevertheless, it represents a fairly accurate model of a cumulative jet. Of course, on a scale, the speed of sound in water is less than the speed of detonation, and the density of water is less than the density of the lining, and the caliber of real projectiles is larger. Our setup is excellent for demonstrating phenomena such as jet focusing.

It would seem that projectiles fired at high speed from smoothbore guns do not rotate - their flight is stabilized by the tail, but even in this case there are problems: at high speeds when the projectile hits the armor, the jet does not have time to focus. Therefore, shaped charges are most effective in low-velocity or generally stationary ammunition: shells for light guns, rocket-propelled grenades, ATGMs, and mines.

Another drawback is related to the fact that the cumulative jet is destroyed by explosive dynamic protection, as well as when passing through several relatively thin layers of armor. To overcome dynamic protection, a tandem ammunition has been developed: the first charge undermines its explosives, and the second pierces the main armor.

Water instead of explosives

In order to simulate the cumulative effect, it is not necessary to use explosives. We used ordinary distilled water for this purpose. Instead of an explosion, we will create a shock wave using a high-voltage discharge in water. We made the arrester from a piece of television cable RK-50 or RK-75 with an outer diameter of 10 mm. A copper washer with a 3 mm hole (coaxial with the central core) was soldered to the braid. The other end of the cable was stripped to a length of 6-7 cm and the central (high-voltage) core was connected to the capacitor.

If the jet is well focused, the channel punched in the gelatin is almost invisible, but with a defocused jet it looks like in the photo on the right. Nevertheless, “armor penetration” in this case is about 3-4 calibers. In the photograph, a gelatin block 1 cm thick is pierced with a cumulative jet “through and through”.

The role of the funnel in our experiment is played by the meniscus - it is this concave shape that the surface of the water takes in a capillary (thin tube). Desirable great depth“funnels”, which means that the walls of the tube must be well wetted. Glass will not work - water hammer during discharge destroys it. Polymer tubes do not wet well, but we solved this problem by using a paper liner.

Tap water is not good - it conducts current well, which will pass through the entire volume. We will use distilled water (for example, from injection ampoules), which does not contain dissolved salts. In this case, all the discharge energy will be released in the breakdown region. Voltage is about 7 kV, discharge energy is about 10 J.

Gelatin armor

Let's connect the spark gap and the capillary with a piece of elastic tube. Water should be poured inside using a syringe: there should be no bubbles in the capillary - they will distort the “collapse” picture. Having made sure that the meniscus has formed at a distance of about 1 cm from the spark gap, we charge the capacitor and close the circuit with a conductor tied to the insulating rod. In the area of the breakdown, high pressure will develop, a shock wave (SW) will be formed, which will “run” towards the meniscus and “collapse” it.

You can detect a cumulative jet by its poke into your palm, extended at a height of half a meter to a meter above the installation, or by spreading drops of water on the ceiling. It is very difficult to see a thin and fast cumulative jet with the naked eye, so we armed ourselves with special equipment, namely the CASIO Exilim Pro EX-F1 camera. This camera is very convenient for filming fast-paced processes - it allows you to shoot video at up to 1200 frames per second. The first test shootings showed that it is almost impossible to film the formation of the jet itself - the discharge spark “blinds” the camera.

But you can film “armor penetration”. It will not be possible to penetrate the foil - the speed of the water jet is too low to liquefy aluminum. Therefore, we decided to use gelatin as armor. With a capillary diameter of 8 mm, we were able to achieve “armor penetration” of more than 30 mm, that is, 4 calibers. Most likely, with a little experimentation with focusing the jet, we could achieve more and even, perhaps, penetrate two-layer gelatin armor. So the next time the editorial office is attacked by an army of gelatin tanks, we will be ready to give a worthy rebuff.

We thank the CASIO representative office for providing the CASIO Exilim Pro EX-F1 camera for filming the experiment.

We present to your attention another material by Eldar Akhundov, an amateur expert of the Istiglal analytical group on armored vehicles, on the topic of cumulative ammunition. We are sure that readers will learn a lot of interesting and useful things for themselves, as is often the case in our section on weapons.

Currently, almost everyone who is interested in military equipment knows about the existence of so-called cumulative shells, missiles, mines, etc. But few people delve into the principle of operation and other similar details. In this article we will try to present in a more or less simple and understandable form the principles of operation and factors that determine the effectiveness of cumulative ammunition. All available information on cumulative projectiles would fill the size of several books, so this article is simplified.

The possibility of creating a shaped charge was first suggested in 1792 by the German mining engineer Franz von Baader. The assumption was that the energy of the explosion could be concentrated predominantly in one direction and over a small area with a special shape of the charge with a notch inside. This potential effect was planned to be used to punch deep holes in solid rock. However, in his experiments, Baader used black powder, which simply did not have the necessary properties (power, detonation wave speed, etc.). As a result, these experiments were not successful.

It was possible to demonstrate the effect of using a shaped charge only after the invention of the so-called. highly explosive explosives such as TNT or RDX, which have a high detonation wave speed. This was first done in the West in 1883 by the German military engineer, inventor and entrepreneur Max von Foerster. According to some reports, the Russian military engineer General Mikhail Matveevich Boreskov discovered the cumulative effect earlier, and back in 1864 he first used a charge with a notch for sapper work.

The cumulative effect was rediscovered, studied and described in sufficient detail in 1888 by the American Charles Monroe, and since then the cumulative effect has been nicknamed in scientific circles - the Monroe effect.

The first patents for armor-piercing cumulative ammunition were issued in 1910 in Germany and in 1911 in England.

Second World War laid the foundation wide application various types new and hitherto unknown deadly weapons. HEAT ammunition is no exception. And although, as we already know, they were created long before the Second World War, it was in it that they began to be widely used on the battlefields - quite logical in view of the role and place of armored vehicles on the battlefields from Stalingrad to the Ardennes.

The first and very successful use of a shaped charge took place in May 1940 during the assault by German paratroopers on the Belgian fortified fort of Eben-Emael. Powerful concrete firing points of the fort were destroyed by special sapper shaped charges. The factor of surprise, excellent reconnaissance, excellent training of German paratroopers, and of course new shaped charges (as well as the use of air gliders for landing) led to the fact that the fortress garrison capitulated a day after the start of the assault. By the way, despite being outnumbered several times.

Left: A concrete dome destroyed by a shaped charge explosion. Fort Eben-Emael. In the center of the explosion crater, a hole is visible, made by a cumulative jet. The exact mass of the charge used is unknown. Source (Wikipedia).Right: Caperial shaped charge weighing 13.5 kg. There were both light and heavier versions of this 50 kg charge. Folding legs for installation are visible. Legs are also needed to maintain the distance from the charge to the barrier being penetrated (the so-called focal length). More on this later. Sources: Wikipedia,HandbookofGermanMilitaryForces.

Most important acquired a shaped charge with the development of a lightweight portable anti-tank grenade launcher. And if previously the shaped charge was used only in sapper and artillery shells, as well as in aerial bombs, its processing into an infantry version opened new era in development anti-tank weapons. This significantly shifted the balance of the “armor-projectile” fight towards the projectile, since almost any trained boy armed with a simple and unpretentious grenade launcher already posed a serious danger to the tank.

The first such serial anti-tank grenade launcher was the American reusable grenade launcher Bazooka. The bazooka was the result of work to create anti-tank missile weapons in the United States, which began in the 1930s. It began to be used by the US Army against German tanks since 1942 in battles in North Africa.

M1 Bazooka (USA). There are two types of ammunition nearby: cumulative and high-explosive fragmentation. Source: Wikipedia.

Germany developed its grenade launcher, called the Faustpatron, in 1942, and first used it in 1943 on the Eastern Front. According to some reports, the Germans were impressed by the American Bazookas and decided to develop their own grenade launcher. According to other sources, which is more likely, the grenade launcher was created independently of the American design, since in Germany it was already for a long time Work was underway on anti-tank infantry weapons, and by the beginning of the war there were already certain theoretical and practical developments. This is also supported by the fact that, unlike the Bazooka, the Faustpatron is disposable and has a different and much simpler design. It was easier to use and did not require specially trained calculations. During World War II, Germany produced more than 8 million disposable grenade launchers of all models.

A family of disposable anti-tank grenade launchers manufactured in Germany during the Second World War.PanzerfaustKlein was originally called Faustpatron. One of its disadvantages was the ability to ricochet off sloping armor. In subsequent models, this drawback was eliminated due to the blunt-headed shape of the head. The digital number showed the aiming distance. The Panzerfaust 150 was a prototype version of the grenade launcher and was not mass produced. By the way, Soviet soldiers, not understanding the intricacies of the models, simply called all such grenade launchers Faustpatrons.

Anti-tank aerial bomb PTAB, 1942 (USSR).1 – explosive; 2 – cumulative lining. Source: Topwar.ru.

Further development of such weapons led to the creation of anti-tank guided missiles (ATGM) fired from anti-tank missile systems(ATGM). The first experiments in this direction were again carried out by the Germans in 1943-1944. After World War II, such missiles appeared on almost all possible weapons carriers, from armored vehicles to modern light attack drones and helicopters. Nowadays, cumulative ammunition is the main means of combating armored vehicles.

What is the principle of operation of a cumulative projectile? In a cumulative projectile, the explosive is placed around an empty metal cone, also called a funnel or lining.

Design of a cumulative projectile: 1 - aerodynamic fairing. 2 - air cavity. 3 - facing. 4 - detonator. 5 - explosive charge (filled with melt or plastic). 6 - fuse. Source: Wikipedia.

Detonation starts from the top of the cone to its base. The enormous pressure of the explosion begins to deform ( squeeze) metal lining at high speed towards the central axis of the charge. The metal lining of the cone collides at the center of the cone. Due to the enormous pressure, which exceeds by many times all possible limits of strength and fluidity of the cladding metal, it loses its strength bonds in the structure and simply “flows” like a liquid in the form of a long and thin stream, which is called a cumulative stream. That is, in fact, the lining material at this moment behaves like a liquid, while not being a liquid itself. This state of matter is called a quasi-liquid. .

The lining metal, by the way, does not melt, because on average the temperature of the cumulative metal jet is about 300-500 degrees. The jet stretches in flight with a further decrease in its diameter. This happens because the head part of the jet has a speed of about 8 - 12 km/sec, and the tail part is about 2 km/sec and, accordingly, lags behind during flight. Most of the lining mass passes into the tail part (pestle).

The head part is involved in penetration, and the low-speed pestle has virtually no effect in this case. When the jet length is more than 5 - 8 funnel diameters (depending on the characteristics and design of the charge), the jet loses stability and begins to break up into separate fragments.

Schematic representation of the process of formation of a cumulative jet. Detonation - the beginning of the funnel compression - formation of a jet (extrusion of the funnel material outward) - stretching of the jet - the head thin high-speed part separated from the tail part and moved forward (10 - 12 km/sec) - the tail thicker part (pestle) is visible, but it moves at low speed (about 2 km/sec).Source: Popmech.ru.

The cumulative jet has enormous kinetic energy, and most of it is spent on penetrating armor. The contact pressure at the point of impact of the jet on the armor is enormous and creates loads many times higher than all possible strength limits in the metal of the armor. The armor metal at the point of impact behaves in the same way as the cladding metal, as already described above. It's flowing « . The usual characteristics of metals known to us in a static (quiet) state, such as hardness, flexibility or mechanical strength, simply cease to matter in such conditions. The metal of the armor does not burn through or melt, as it mistakenly seems, but is simply “washed out” (“splashes”) away from the point of impact. For this reason, the edges of the hole in the armor have a melted appearance.

By the way, for the same reason one of the old and erroneous names of a cumulative projectile is “armor-burning.”

Pulsed X-ray image of the moment of detonation of a shaped charge.

On the left - before the explosion. On the right is the moment of detonation.1 – armor. 2 – cumulative charge. 3 – cumulative recess (funnel) with metal lining. 4 – gaseous products of charge detonation and shock wave. 5 – tail low-speed part - pestle. 6 – the head high-speed part of the jet, which pierced the armor. 7 – removal of armor material to the sides from the point of impact of the jet.

Schematic representation of the moment of impact and penetration of a metal barrier by a cumulative jet.1 — Jet in flight and armor before contact. 2 - the jet hits the armor, you can see a kind of “splashing” of the material of the jet and armor to the sides and outwards. 3 - the process continues, the jet is already shorter in length as it is spent on overcoming the resistance of the obstacle, that is, it transfers part of its energy to the armor. 4 - you can see a hole made by the jet. The charge power in this example is not enough to penetrate the barrier, so the entire jet was simply used up to break through the recess. The remaining material from the cumulative jet is “smeared” on the inner surface of the punched hole. Source: Otvaga2004.ru.

Using a charge with a cumulative notch, but without metal lining, significantly reduces the cumulative effect and penetration. The reason for this lies in the fact that instead of a high-density metal jet, there is a jet of gaseous explosion products (a cumulative gas jet), which quickly dissipates in the surrounding space.

The main factors on which the effectiveness of cumulative ammunition depends are:

Explosive parameters. Here, for example, are the data from experiments with black powder and TNT, which were written about at the beginning of the article:

Table of properties of some explosives for shaped charges. Top table for pure substances. As can be seen from the tableCL20 is the most powerful explosive... and the most expensive.In shaped charges, as a rule, mixtures of various explosives are used with an admixture of other ingredients in various portions.

The mechanism of action of a shaped charge

Cumulative jet

Cumulative effect

scheme for the formation of a cumulative jet

The wave, propagating to the lateral generatrices of the cladding cone, collapses its walls towards each other, and as a result of the collision of the cladding walls, the pressure in the cladding material increases sharply. The pressure of the explosion products, reaching ~10 10 N/m² (10 5 kgf/cm²), significantly exceeds the yield strength of the metal. Therefore, the movement of the metal lining under the influence of explosion products is similar to the flow of liquid and is associated not with melting, but with plastic deformation.

Similar to a liquid, the lining metal forms two zones - a large mass (about 70-90%), a slowly moving “pestle” and a smaller mass (about 10-30%), thin (about the thickness of the lining) hypersonic metal jet moving along the axis. In this case, the jet speed is a function of the detonation speed of the explosive substance and the geometry of the funnel. When using funnels with small apex angles, it is possible to achieve extremely high speeds, but at the same time the requirements for the quality of the lining are increased, since the likelihood of premature destruction of the jet increases. IN modern ammunition funnels with complex geometry are used (exponential, stepped, etc.), with angles in the range of 30 - 60 degrees, and the speed of the cumulative jet reaches 10 km/sec.

Since the speed of the cumulative jet exceeds the speed of sound in the metal, the jet interacts with the armor according to hydrodynamic laws, that is, they behave as if they were colliding with ideal liquids. The strength of armor in its traditional sense in this case plays practically no role, and the density and thickness of the armor come first. The theoretical penetration ability of cumulative projectiles is proportional to the length of the cumulative jet and the square root of the ratio of the density of the funnel lining to the density of the armor. The practical depth of penetration of a cumulative jet into monolithic armor for existing ammunition varies in the range from 1.5 to 4 calibers.

When the conical shell collapses, the velocities of individual parts of the jet turn out to be different and the jet stretches in flight. Therefore, a slight increase in the gap between the charge and the target increases the penetration depth due to the elongation of the jet. At significant distances between the charge and the target, the jet breaks into pieces, and the penetration effect is reduced. The greatest effect is achieved on the so-called “ focal length" To maintain this distance, various types of tips of appropriate lengths are used.

The use of a charge with a cumulative notch, but without metal lining, reduces the cumulative effect, since instead of a metal jet there is a jet of gaseous explosion products. But at the same time, a significantly more destructive armor effect is achieved.

Impact core

Formation of the “shock core”

To form an impact core, the cumulative notch has an obtuse angle at the apex or the shape of a spherical segment of variable thickness (thicker at the edges than in the center). Under the influence of a shock wave, the cone does not collapse, but is turned “inside out.” The resulting projectile with a diameter of a quarter and a length of one caliber (the original diameter of the notch) accelerates to a speed of 2.5 km/s. The armor penetration of the core is less than that of a cumulative jet, but it remains at a distance of up to a thousand calibers. In contrast to the cumulative jet, which consists of only 15% of the lining mass, the impact core is formed from 100% of its mass.

Story

In 1792, mining engineer Franz von Baader suggested that the energy of an explosion could be concentrated in a small area using a hollow charge. However, in his experiments, von Baader used black powder, which cannot explode and form the necessary detonation wave. The effect of using a hollow charge was first demonstrated only with the invention of high explosives. This was done in 1883 by the inventor von Foerster.

The cumulative effect was rediscovered, studied and described in detail in his works by the American Charles Edward Munro in 1888.

In the Soviet Union in 1925-1926, Professor M. Ya. Sukharevsky studied explosive charges with a notch.

In 1938, Franz Rudolf Thomanek in Germany and Henry Hans Mohaupt in the USA independently discovered the effect of increasing penetration power by using a metal lining of a cone.

For the first time in combat conditions, a shaped charge was used on May 10, 1940 during the assault on Fort Eben-Emal (Belgium). Then, to undermine the fortifications, German troops used two types of portable charges in the form of hollow hemispheres weighing 50 and 12.5 kg.

X-ray pulse photography of the process, carried out in 1939 - early 1940s in laboratories in Germany, the USA and Great Britain, made it possible to significantly clarify the principles of operation of a shaped charge (traditional photography is impossible due to flashes of flame and a large amount of smoke during detonation).

One of the unpleasant surprises of the summer of 1941 for tank crews of the Red Army was the use of cumulative ammunition by German troops. Damaged tanks showed holes with melted edges, which is why the shells were called “armor-burning” shells. On May 23, 1942, at the Sofrinsky training ground, tests were carried out of a cumulative projectile for a 76-mm regimental gun, developed on the basis of a captured German shell. Based on the test results, on May 27, 1942, the new projectile was put into service.

In the 1950s, enormous progress was made in understanding the principles of cumulative jet formation. Methods for improving shaped charges with passive inserts (lenses) have been proposed, optimal shapes of shaped craters have been determined, methods have been developed to compensate for projectile rotation by corrugating the cone, and more powerful explosives have been used. Many of the phenomena discovered in those distant years are still being studied to this day.

Notes

Links

The theory of the process of armor penetration of cumulative and sub-caliber projectiles Tank power
V. Murakhovsky, “Courage 2004” website Another cumulative myth.

Wikimedia Foundation. 2010.

- oh, oh. cumulatif, ve adj., cumulativ lat. cumulatio increase, accumulation. Rel. to cumulation. Andrey viewed his case as a providential cumulative effect. October 2003 2 67. This is competition with other definitions... ... Historical Dictionary of Gallicisms of the Russian Language

This term has other meanings, see Cumulation. Sectional view of a unitary shot with a cumulative projectile... Wikipedia

Other, obsolete meaning the term “projectile” device, device, design ... Wikipedia

projectile- ▲ ammunition for (what), shoot a projectile ammunition for shooting. bullet. bullet. dum dum. fraction. Buckshot. shrapnel. cumulative (# projectile). armor-piercing. mine ammunition for firing from smoothbore guns... Ideographic Dictionary of the Russian Language

Sectional view of unitary cumulative ammunition Cumulative effect, Monroe effect (English: Munroe effect) enhancing the effect of an explosion by concentrating it in a given direction. The cumulative effect is achieved by using a charge with a cumulative notch ... Wikipedia

A; m. 1. Type of ammunition for firing guns. Aviation, anti-aircraft, anti-tank. Dalnoboiny village Oskolochny village Shell explosions. 2. Device, device for sports exercises. S. for throwing. Projectiles for vaults.... ... encyclopedic Dictionary

Artillery shell- the main element of an artillery shot, designed to hit various targets and perform other tasks (lighting, smoke, training, etc.). Consists of a body, equipment and a fuse. By caliber they are divided into small, medium and... Glossary of military terms

At the dawn of the practical use of cumulative ammunition, during the Second World War, they were quite officially called “armor-piercing”, since at that time the physics of the cumulative effect was unclear. And although in the post-war period it was precisely established that the cumulative effect has nothing to do with “burning through”, echoes of this myth are still found in the philistine environment. But in general, we can assume that the “armor-burning myth” has safely died. However, “a holy place is never empty” and one myth regarding cumulative ammunition was immediately replaced by another...

This time, the production of fantasies about the effects of cumulative ammunition on the crews of armored vehicles was put on stream. The main postulates of dreamers are as follows::
— tank crews are allegedly killed by excess pressure created inside an armored vehicle by cumulative ammunition after penetrating the armor;
— crews who keep the hatches open supposedly stay alive thanks to a “free exit” for excess pressure.

Here are examples of such statements from various forums, sites of “experts” and printed publications(the original spelling has been preserved; among those cited there are very authoritative printed publications):

“- Question for experts. When a tank is hit by cumulative ammunition, what damaging factors affect the crew?
- Excessive pressure first. All other factors are related”;

“Assuming that the cumulative jet itself and fragments of pierced armor rarely affect more than one crew member, I would say that the main damaging factor was the overpressure... caused by the cumulative jet...”;

“It should also be noted that the high destructive power of shaped charges is explained by the fact that when a jet burns through the hull, tank or other vehicle, the jet rushes inside, where it fills the entire space (for example, in a tank) and causes severe damage to people...”;

“The tank commander, Sergeant V. Rusnak, recalled: “It’s very scary when a cumulative projectile hits a tank. “Burns through” armor anywhere. If the hatches in the turret are open, then a huge pressure force throws people out of the tank..."

“...the smaller volume of our tanks does not allow us to reduce the impact of INCREASED PRESSURE (the shock wave factor is not considered) on the crew, and it is the increase in pressure that kills them...”

“What is the calculation made, why actual death should occur, if the drops did not kill, let’s say, a fire did not occur, and the pressure is excessive or it simply tears into pieces in a confined space, or the skull bursts from the inside. There's something tricky about this excess pressure. That’s why they kept the hatch open”;

“Sometimes an open hatch can save you because a blast wave can throw a tanker out through it. A cumulative jet can simply fly through a person’s body, firstly, and secondly, when in a very short time the pressure increases very much + everything around heats up, it is very unlikely to survive. From eyewitness accounts, the tank crews’ turret is torn, their eyes fly out of their sockets”;

“When an armored vehicle is hit by a cumulative grenade, the factors that affect the crew are excess pressure, armor fragments and a cumulative jet. But taking into account the measures taken by the crews to prevent the formation of excess pressure inside the vehicle, such as opening hatches and loopholes, armor fragments and a cumulative jet remain the factors affecting personnel.”.

There are probably enough “horrors of war” presented by both citizens interested in military affairs and the military personnel themselves. Let's get down to business - refuting these misconceptions. First, let's consider whether it is in principle possible for the appearance of supposedly “lethal pressure” inside armored vehicles from the impact of cumulative ammunition. I apologize to knowledgeable readers for the theoretical part, they may miss it.

PHYSICS OF THE CUMULATIVE EFFECT

The principle of operation of cumulative ammunition is based on the physical effect of accumulation (cumulation) of energy in converging detonation waves formed when an explosive charge having a funnel-shaped recess is detonated. As a result, a high-speed flow of explosion products—a cumulative jet—is formed in the direction of the excavation focus. An increase in the armor-piercing effect of a projectile in the presence of a notch in the explosive charge was noted back in the 19th century (Monroe effect, 1888), and in 1914 the first patent for an armor-piercing cumulative projectile was received.

Rice. 1. Tandem cumulative ammunition of the German RPG “Panzerfaust” 3-IT600. 1 – tip; 2 – precharge; 3 – head fuse; 4 – telescopic rod; 5 – main charge with a focusing lens; 6 – bottom fuse.

Rice. 2. Pulsed X-ray image of shaped charge detonation. 1 – armored barrier; 2 – cumulative charge; 3 – cumulative recess (funnel) with metal lining; 4 – charge detonation products; 5 – pestle; 6 – head part of the jet; 7 – removal of barrier material.

The metal lining of the recess in the explosive charge makes it possible to form a high-density cumulative jet from the lining material. The so-called pestle (the tail part of the cumulative jet) is formed from the outer layers of the cladding. The inner layers of the cladding form head part jets. A lining made of heavy ductile metals (for example, copper) forms a continuous cumulative jet with a density of 85-90% of the material density, capable of maintaining integrity at high elongation (up to 10 funnel diameters).

The speed of the metal cumulative jet reaches 10-12 km/s at its head. In this case, the speed of movement of parts of the cumulative jet along the axis of symmetry is not the same and amounts to up to 2 km/s in the tail part (the so-called velocity gradient). Under the influence of the velocity gradient, the jet in free flight is stretched in the axial direction with a simultaneous decrease in the cross section. At a distance of more than 10-12 diameters of the shaped charge funnel, the jet begins to disintegrate into fragments and its penetrating effect sharply decreases.

Experiments on trapping a cumulative jet with a porous material without destroying it showed the absence of the recrystallization effect, i.e. the temperature of the metal does not reach the melting point, it is even below the point of first recrystallization. Thus, a cumulative jet is a metal in a liquid state, heated to relatively low temperatures. The temperature of the metal in the cumulative jet does not exceed 200-400° degrees (some experts estimate the upper limit at 600°).

When meeting an obstacle (armor), the cumulative jet slows down and transfers pressure to the obstacle. The jet material spreads in the direction opposite to its velocity vector. At the boundary between the materials of the jet and the barrier, pressure arises, the magnitude of which (up to 12-15 t/sq.cm) is usually one or two orders of magnitude greater than the tensile strength of the barrier material. Therefore, the barrier material is removed (“washed out”) from the area high pressure in the radial direction.

These processes at the macro level are described by hydrodynamic theory, in particular, the Bernoulli equation is valid for them, as well as that obtained by M.A. Lavrentiev. hydrodynamic equation for shaped charges. At the same time, the calculated depth of penetration of an obstacle does not always agree with experimental data. Therefore, in recent decades, the physics of interaction between a cumulative jet and an obstacle has been studied at the submicrolevel, based on a comparison of the kinetic energy of impact with the energy of breaking interatomic and molecular bonds of the substance. The results obtained are used in the development of new types of both cumulative ammunition and armored barriers.

The armor-protecting effect of cumulative ammunition is ensured by a high-speed cumulative jet that penetrates the barrier and secondary armor fragments. The jet temperature is sufficient to ignite powder charges, fuel vapors and hydraulic fluids. Lethal effect cumulative jet, the number of secondary fragments decreases with increasing armor thickness.

HIGH-EXPLOSIVE EFFECT OF CUMULATIVE AMMUNITION

Now let's talk more about excess pressure and shock waves. The cumulative jet itself does not create any significant shock wave due to its small mass. The shock wave is created by the detonation of an explosive charge of ammunition (high-explosive action). A shock wave CANNOT penetrate a thick-armored barrier through a hole pierced by a cumulative jet, because the diameter of such a hole is negligible and it is impossible to transmit any significant impulse through it. Accordingly, excess pressure cannot be created inside the armored object.

Rice. 3. Inlet (A) and outlet (B) holes punched by a cumulative jet in a thick-armored barrier. Source:

The gaseous products formed during the explosion of a shaped charge are under a pressure of 200-250 thousand atmospheres and heated to a temperature of 3500-4000°. Explosion products, expanding at a speed of 7-9 km/s, strike the environment, compressing both the environment and the objects in it. The layer of medium adjacent to the charge (for example, air) is instantly compressed. Trying to expand, this compressed layer intensively compresses the next layer, and so on. This process propagates through an elastic medium in the form of a so-called SHOCK WAVE.

The boundary separating the last compressed layer from the normal medium is called the shock wave front. At the front of the shock wave there is a sharp increase in pressure. At the initial moment of formation of the shock wave, the pressure at its front reaches 800-900 atmospheres. When the shock wave breaks away from the detonation products that lose their ability to expand, it continues to independently propagate through the medium. Typically, separation occurs at a distance of 10-12 reduced radii of the charge.

The high-explosive effect of the charge on a person is ensured by the pressure in the front of the shock wave and the specific impulse. The specific impulse is equal to the amount of motion carried by the shock wave per unit area of the wave front. Human body behind short time the action of the shock wave is affected by the pressure in its front and receives an impulse of movement, which leads to contusions, damage to the outer integument, internal organs and skeleton.

The mechanism for the formation of a shock wave when an explosive charge is detonated on surfaces differs in that, in addition to the main shock wave, a shock wave reflected from the surface is formed, which is combined with the main one. In this case, the pressure in the combined shock wave front almost doubles in some cases. For example, when detonating on a steel surface, the pressure at the front of the shock wave will be 1.8-1.9 compared to the detonation of the same charge in the air. This is exactly the effect that occurs when shaped charges of anti-tank weapons detonate on the armor of tanks and other equipment.

Rice. 4. An example of the affected area by the high-explosive action of a cumulative ammunition with a reduced mass of 2 kg when it hits the center of the right side projection of the turret. The zone of lethal damage is shown in red, and the zone of traumatic damage in yellow. The calculation was carried out according to the generally accepted methodology (without taking into account the effects of the shock wave flowing into the hatch openings).

Rice. 5. The interaction of the shock wave front with a dummy in a helmet during the detonation of a 1.5 kg C4 charge at a distance of three meters is shown. Areas with excess pressure over 3.5 atmospheres are marked in red. Source: NRL's Laboratory for Computational Physics and Fluid Dynamics

Due to the small dimensions of tanks and other armored vehicles, as well as the detonation of shaped charges on the surface of the armor, the high-explosive effect on the crew in the case of OPEN HATCHES of the vehicle is ensured by relatively small charges of shaped ammunition. For example, if it hits the center of the side projection of a tank turret, the path of the shock wave from the point of detonation to the hatch opening will be about a meter; if it hits the front part of the turret, it will be less than 2 m, and if it hits the rear part, it will be less than a meter.

If a cumulative jet hits the dynamic protection elements, secondary detonation and shock waves arise, which can cause additional damage to the crew through the openings of open hatches.

Rice. 6. The damaging effect of the "Panzerfaust" 3-IT600 RPG cumulative ammunition in a multi-purpose version when firing at buildings (structures). Source: Dynamit Nobel GmbH

Rice. 7. M113 armored personnel carrier, destroyed by a Hellfire ATGM hit.

The pressure at the shock wave front at local points can either decrease or increase when interacting with various objects. The interaction of a shock wave even with small objects, for example with the head of a person in a helmet, leads to multiple local changes in pressure. Typically, this phenomenon is observed when there is an obstacle in the path of the shock wave and penetration (as they say, “flowing”) of the shock wave into objects through open openings.

Thus, the theory does not confirm the hypothesis about the destructive effect of excess pressure of cumulative ammunition inside the tank. The shock wave of cumulative ammunition is formed when an explosive charge explodes and can penetrate inside the tank only through hatch openings. Therefore, hatches SHOULD BE KEEPED CLOSED. Those who do not do this risk receiving a severe concussion, or even dying from a high-explosive action when a shaped charge is detonated.

Under what circumstances is a dangerous increase in pressure inside closed objects possible? Only in those cases when the cumulative and high-explosive action of an explosive charge makes a hole in the barrier sufficient for the explosion products to flow in and create a shock wave inside. Synergistic effect is achieved by a combination of a cumulative jet and the high-explosive action of a charge on thin-armored and fragile barriers, which leads to structural destruction of the material, ensuring the flow of explosion products behind the barrier. For example, the ammunition of the German Panzerfaust 3-IT600 grenade launcher in a multi-purpose version, when breaking through a reinforced concrete wall, creates an excess pressure of 2-3 bar in the room.

Heavy ATGMs (type 9M120, Hellfire) when hitting a light-class armored fighting vehicle with bulletproof protection, with their synergistic effect, can destroy not only the crew, but also partially or completely destroy the vehicles. On the other hand, the impact of most wearable PTS on armored fighting vehicles is not so sad - here the usual effect of the armor effect of a cumulative jet is observed, and the crew is not damaged by excess pressure.

PRACTICE

We had to fire from 115-mm and 125-mm tank guns with a cumulative projectile, from a cumulative grenade at various targets, including a stone-concrete bunker, self-propelled unit ISU-152 and armored personnel carrier BTR-152. An old armored personnel carrier, full of holes like a sieve, was destroyed by the high-explosive effect of the projectile; in other cases, no allegedly “crushing effect of the shock wave” was detected inside the targets.

Several times I examined damaged tanks and infantry fighting vehicles, mostly damaged by RPGs and LNG. If there is no explosion of fuel or ammunition, the impact of the shock wave is also imperceptible. In addition, no concussion was noted among the surviving crews whose vehicles were damaged by RPGs. There were wounds from shrapnel, deep burns from metal splashes, but there were no concussions from excess pressure.

Rice. 8. Three hits from cumulative RPG shots in an infantry fighting vehicle. Despite the dense grouping of holes, no breaches are observed.

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