Developmental trends of accumulation heads (HEAT / SC)

wolskiowojnie.pl 3 years ago

Cumulative heads are the most widespread means of fire utilized in anti-tank ammunition. They are utilized in both hand grenades thrown by soldiers, fired grenade launchers and non-rejective cannons, anti-tank guided missiles, aircraft and artillery sub-ammunition cumulative-split, anti-tank mines, and specialized airheads and rocket blasters. Their evolution over the last 4 decades has been very violent and has given them fresh opportunities – undoubtedly worth presenting to Wolski about War.

The question of what is the cumulative charge and what is it? The simplest definition may be: The cumulative charge is simply a kind of explosive charge in which, as a consequence of an detonation hollowed out in the form of a cone or half-sphere of an explosive, a continuous cumulative stream from the insert filling the interior surface of the hollow occurs. The angle of beginning of the insert must be below 140 degrees. The resulting cumulative stream has a advanced ability to overcome the shields - depending on the diameter and material of the insert, the distance from the target, the kind of explosive used, the kind of detonator kind and the intent construction itself.

Regardless of construction, each cumulative charge has any common components, specified as: head/load body, explosive charge, cumulative insert, cumulative aperture, stimulant charge, bottom part of the fuse, ignition device. The cumulative flux formation mechanics is as follows: At the time of initiation of the detonator, there is an detonation that is transmitted to the explosive charge. The appropriate form of the cumulative aperture ensures the formation of the detonation wave in specified a way that the tip of the cone of the insert is not formed besides rapidly into a scrap. The detonation wave interacting with the cumulative cartridge (usually copper) crushes it into an axially symmetrical lump from which the cumulative stream is formed. It usually has a mass of 10-20 % by weight of the cumulative insert and its top (depending on the kind of load) reaches a velocity of 6 to 14km/s. The remainder of the stream reaches speeds below 2km/s. As a consequence of specified a large variation in speed, there is simply a crucial (up to 2000%) lengthening of the stream – along the rocket axis.

As a result, after a certain period, the stream becomes spaced or divided. According to the Swedish guidelines for diminution teams, the hazardous region in which it can decision into the air the decently created cumulative stream ranges from 1000m (50mm cartridge caliber) to 3500m (150mm insert caliber). However, these values should not be confused with the ability to overcome shields. This capacity is usually given in multiple cartridge calibers (CD-cone diameter) and is straight dependent on the distance to the target. usually the distance of more than 26 diameters of the burden from the mark causes the cumulative stream to be incapable to overcome the cover thicker than the diameter of the charge from which it was formed. This is due to this space of an extended stream. Therefore, the alleged "fired charge" is highly important, i.e. the optimal distance of initiation of the head in relation to the target. usually it is about 6-8 calibers of insert.

Reaching the goal.

It is interesting how the cumulative stream overcomes the monolithic steel target. At the minute the armor is hit by a cumulative stream, the force on its top exceeds 100GP – this is simply a value far beyond the toughest materials known today. As a consequence of the force on the armor stream, they begin to interact as if they were in a liquid state. The armor is virtually "exploded" on the basis of hydrodynamic erosion. Initially, the armor beats the top of the stream – at a velocity of almost 4km/s after being born to overcome it, it continues to proceed the further part of the stream – at a velocity of much lower than 1,5-2km/s. As a result, the effect on the mark is comparatively long-lasting, while the gross origin itself has a immense velocity which focuses on an highly tiny surface. The above description shows respective characteristics of peculiar cumulative loads. The most crucial thing is that they have very advanced theoretical penetration – in relation to the diameter of the cartridge and mass of the head in general. Theoretically, it makes them the perfect kind of anti-tank weapon. However, HEAT besides has measurable drawbacks. First of all, the process of forming the collamation charge is very easy to disrupt. Hitting a 5mm shard in the cargo body behind the cartridge reduces its penetration by 40%, hitting the copper cartridge by over 90%(!). Also, placing an object inside the insert will consequence in the same effect. Additionally, the spinning motion of the projectile causes disturbances during the formation of the cumulative stream from the cartridge - in utmost cases this reduced the penetration of test heads by almost 75%. Another issue is that only 10-20% of the mass of cartridges forms the core. So it has a tiny mass that only to any degree balances the velocity and tiny diameter of the stream. The elongated stream itself is highly delicate to continuity disorders. As a result, all armor effective against this threat is based on the semi-active distortion of the continuity of the cumulative stream.

Less murderous than it seems...

The final issue is that cumulative warheads, paradoxans, have rather a mild effect on the mark after defeating the armor. The penetration channel has a diameter of 5mm to 1cm, which together with a tiny mass of the sourced stream causes a weak penetration effect. The biggest threat is the alleged residual cumulative stream – i.e. 1 that defeated the armor and its velocity is inactive respective kilometres per second. It can origin an detonation of ammunition or its deflagration (in the case of LOVA) comparatively easy and a crew associate who is on its way will die. An equally serious threat is considered to be a cloud of shrapnel formed after armor penetration. It has the form of an expanding ellipse with an apex at the beginning formed in the armor and the base at the moving top of the cumulative stream. The maximum rate of distribution at the basis of the cloud is 90% of the velocity of the tip of the residual cumulative stream, while the minimum velocity is about 1400m/s.

Fortunately, for crews, the shrapnel which carries with it are usually very tiny in weight and sizes, so they can easy be neutralized - past 97% of them are referred to as "minimum fatal". fewer fragments weighing more than 2g and speeds between 200 and 1400m/s are a much more serious threat – however, only about 3% are created. In total, during the penetration of a steel plate simulating e.g. the side of the fuselage, about 2000-2500 shrapnel of varying mass and velocity of gross crew compartments are formed. The average hazard was considered to be a flash accompanying the armor penetration and the blast of the detonation that is “outside” the armor. This corresponds to the Russian experience of both wars in Chechnya where attention was paid to the hazard of a wave of hypertension coming through open hatches if hit in their vicinity. Not a crucial threat was considered to be an increase in temperature, smoke and... the detonation and an increase in force inside the vehicle. The last issue needs to be developed. Over the years, the increase in force in a hit vehicle after penetration with a cumulative head was believed to be an crucial origin of the lethal. However, it turned out that this conclusion came first from the imperfections of the investigation methods of the 1950s and 1960s and the character of the heads of the time. In addition, it was attempted without deeper investigation to transfer the conclusions of the work on the death of detonation blasts in closed spaces into the interior of armored vehicles after penetrating the cover with a cumulative stream. As a result, the conclusions were powerfully drawn. In any cases, crews were advised to leave open hatches to prevent force from rising. It was not until 1989 that the US DEPARTMENT OF RESPIRATORY investigation DIVISION OF medicine concluded that it was “not entirely clear” the mechanics for the formation of injuries from the force wave inside vehicles, and that there was no broad data to explain the harm caused by the force wave inside the hit vehicle. The survey of the 1990 ’ s was only explained in parallel to the west and Russia. Their results were rather surprising. The force increase in the hit vehicle can only happen due to the action of a residual cumulative stream (very low mass and very advanced speed) and through a penetration channel with a diameter of 5 to 10mm. As a result, the increase in force in the vehicle has an impact on the crew, but it is not an crucial origin that threatens the crew, what is more – it turned out that open hatches carry a much greater hazard due to the fact that the blast of the detonation after hitting e.g. ppk is able to partially penetrate the crew compartment. Paradoxically, therefore, open hatches could have contributed to greater crew injuries than increased vehicle force after penetration.

Unfortunately, the story of the murderous wave of force and the supposedly beneficial influence of open hatches repents to this day among the crews of combat vehicles. It is explained due to the fact that there is simply a crucial increase in force in the hit vehicle, and the blast of a close detonation is able, for example, to break the hatch or open it, which besides gives the impression of "exiting" pressure. However, the results of the survey stand firm in opposition to the above "wisdom of the battlefield". In technological studies, it was considered not to have any effect on the death of battleships: toxic gases emitted after the armor was punctured and incidental flames. Have the above test results confirmed during the last 2 decades of tank participation in battles? Definitely so, with newer studies based on the experience of the battlefield from Iraq and Afghanistan even omit another gross factors of crew than the residual cumulative stream and shrapnel - the murderous increase in force in the hit vehicle is not even mentioned as a gross factor, like toxic fumes, flashes or external blasts of explosion. Generally, unless ammunition is ignited in a hit vehicle, only a crew associate standing on the residual cumulative stream way is usually killed. Crew members located at the other wall of armor of the vehicle may besides be offended by shrapnel sheaths, nevertheless most likely they will last the incidental without serious injury - especially if they wear a shrapnel and helmet vest, while the vehicle has an anti-split layer.

Some history.

The accumulation heads (GK) function in the Anglo-Saxon nomenclature as HEAT from Hight-Explosive Anti-Tank or SC from the Shaped Charge. Their genesis dates back to...1792 in Norway (Von Baader) and 1806 in Germany (Hausman) erstwhile it was noted that the powder charge with a symmetrical cylindrical depth utilized in mining allows to increase the blast force at little than usual amount of gunpowder. Of course, these were not cumulative charges in today's sense, but their immediate predecessors. However, the formation of this kind of weapon is due to the 3 names of engineers scientists from the late 19th century, of which prof. Cahrles E is best known. Munroe employed as a civilian in the US Navy, specifically in: United States Navy's Naval Torpedo Station, Newport, Rhode Island.

Professor Munroe may have been the first to not invent a cumulative charge – here German engineer Max Von Forester was 5 years faster – but no uncertainty he described and made experience of penetrating massive steel blocks through hollow loads with a cartridge. The thought of cargo of this kind was patented in Germany in 1910 and England in 1911, and in that second country it was attempted to usage specified warheads in torpedoes in 1913. However, the large War and then the postwar period did not bring about the popularization of specified warheads. In the navy, the warheads with highly energetic explosive material proved to be more effective, and the fight against the recently formed armored weapons ended on the shoulders of kinetic or demolition ammunition. However, this situation began to change in the second half of the 1930s and the breakthrough began in Nazi Germany in 1937. 2 scientists – H. Schardin and Thomanek developed and tested cumulative charges with a cartridge from another materials. Initially, it was glass, and they started researching average steel hardness and copper rather rapidly – which was considered optimal for this application. Both researchers besides described the issue of focal loads (the optimal distance of initiation from the target) and the precision of making cartridges. Their findings were patented on December 9, 1939. That's how the accumulation heads were born as we know them to this day. However, it should be mentioned that practically at the same time, and even earlier, akin patents were filed in France and later in Switzerland. beautiful rapidly due to the fact that already on October 18, 1940, in the US, a 2.36" M9A1 cumulative grenade was presented in action, which then evolved in conjunction with the rocket drive in M2A3 HEAT utilized in the celebrated Bazooki, which had already been fought in Africa in 1942.

World War II - promising beginnings.

However, definitely the widest usage of accumulation heads took place in the 3rd Reich. Interestingly, the characteristic feature of the German HEAT loads was the usage of soft steel sheet accumulation inserts – which was the consequence of material shortages and exceptional copper deficit. However, it should be considered that the hand-arms based on cumulative heads were in the 3rd A Reich applied truly massively and feltly to the battlefield. The first (Autumn 1942) was the hand-held Emulsive Emulsive Charge of the Haft-H3 with a weight of 3kg in the form of a cone and at the base of which there were 3 strong magnets that fixed the Haft-H3 to the tank. The 7.5-sdelay fuse initiated a cumulative charge that over 140mm of armor and created an beginning up to 5cm in diameter. Apart from the request to manually mount on the tank, it was a very effective weapon capable of beating any armor. Haf-H3 formed almost 554 1000 pieces. Another (spring 1943) was not a very successful hand-throwing cumulative burden of PWM(L) produced in 200 1000 pieces. But what truly strengthened the defence of Nazi troops was the introduction of Panzerschreck and Panzerfausts. The first was created as a creative copy of Bazook captured in November 1942. The American prototype defeated only 90mm of armor plates (with a perpendicular impact) but the Ni1emiecki Panzerschreck – 220mm steel in the same conditions, while the mark moving 30km/h was possible from a distance of as much as 150m. Although the armour was terrible in usage and susceptible to harm in combat, it was utilized massively – almost 290 1000 Pancershreck pieces and over 2.2 million missiles were created for it. There was besides inexpensive (cost of 70 reihsmarks) and fast (10 labour hours) in production. Thanks to the large scope of effective fire and rather effective accumulation grenades, it was a crucial reinforcement of the defence of the Papanc units of Wermahtu and Waffen-SS - and it was directed mainly for fighting in the south and west of Europe where the area allowed for better compensation of its deficiencies.

The most crucial cumulative weapon of II was, however, the German Panzerfaust – which has been produced since August 1943, undergoing constant evolution. The first versions (Faustpatrone, Panzerfaust Klein; Panzerfaust 30) defeated up to 150 and 200mm steel but their effective scope was only 30-40m. Subsequent versions – Panzerfaust 60 and 100 already covered 200mm of steel and their maximum scope was for stationary/moving for both 80/150m and 60/100m respectively. However, the effective ranges were almost halved. First of all, Panzerfausty was mass-produced – by the end of the 3rd Reich, 8.5 million of all versions (!) were created, and it was this weapon that contributed to the crucial immunisation of the German infantry against attacks of russian tanks - especially in the last year of war erstwhile there was a deficiency of armored, armored and tank guns. However, in only 1 case, the usage of Panzerfausts and Panzerschrecks had an operational dimension. In 1944, during the election-petrozavodic operation, the russian army broke the defensive positions of the Finns and in a very efficient operation won Wyborg on 20 June. The next day, the attack that would lead to the entry into the operating space was begun and consequently – to put Finland on its knees. As a result, the conflict of Tali-Ihantala occurred in which the last reserves of the Finns attempted to patch the breach in the front. 1 difference became a abrupt qualitative change in Finnish anti-tank capabilities. By mid-June, the Finns had only 1854 Panzerschrecks delivered from April 1944 (and 18 1000 missiles to them). It was besides thin a quantity that was not adequate to endanger the fast-moving fewer ppanc cannons and tanks and self-propelled guns. The Finns faced the problem of the inability to effectively fight Soviets he stormed armoured with artillery – despite the hard forestous terrain. However, as early as 19 June, German torpedo boats delivered 9 1000 Panzerfausts to fins and 3 days later Luftwaffe delivered another 5 1000 pieces. These supplies allowed to effectively reconstruct anti-tank capabilities, which together with determination and efficient command allowed to accomplish during the bloody and heroic conflict of Tali-Ihantala pata which together with the geopolitical situation and advancement of the Allies in Normandy contributed to the cessation of the Soviets' attack on 18 July and the start of negotiations which on 4 September turned into a ceasefire and on 19 September in a truce. This is most likely the only known example from the years of planet War II erstwhile a certain kind of weapon (in this case Panzerfaust) had a direct effect on the result of the fighting and as a consequence – the final result of the full operation.

Detonation of the Panzerfaust head excavation.

The detonation effect of the head: as you can see, Panzerfaust had an highly lethal penetration effect, which resulted from a large penetration channel and a cumulative aluminium sheet insert.

The usage of hand-armed anti-tank weapons by the Allies seems to be devoid of specified spectacular results even though the decently utilized Bazooka and PIATs were effective weapons. However, regardless of the side utilizing specified a kind of weapon, its effectiveness depended on the tactics of the usage of armored weapons - i.e. how well trained were the crews of wagons and how large the support of infantry and artillery could number on. Of course, accumulation heads were commonly utilized besides in engineering measures and occasionally in others – even aircraft. However, their function as a very good glaring origin in the handguns of mpanc has been firmly established.

After the Second War – a ghost of HEAT supremacy?

On both sides of the “iron curtain” the appearance of cumulative ammunition was appreciated. Although its penetration was straight dependent on the diameter of the cartridge - and thus the caliber of the bullet - it seemed to be above the possible cover of any tank - both average and heavy. With the improvement of rocket technology and guidance, this resulted in the emergence of the first ppk which rapidly began to displace anti-tank cannons. The usage of this kind of warheads in more and more hand grenades and hand grenades – specified as RKG-3 – has besides been established. This kind of head has besides begun to be utilized in aerial means of destruction. The efficiency of HEAT seemed to be advanced adequate that any tank designers sacrificed the shield for another parameters of the vehicle – assuming that it was impossible to effectively shield the vehicle from this threat. As the communicative of so-thinking French and Germans showed, they made a large mistake due to the fact that at the same time on both sides of the iron curtain in the 1960s fresh types of armor were developed effective against cumulative heads.

In the United Kingdom, the conflict Vehicle investigation and improvement Centre (FVRDE) during an armor survey with increased opposition to cumulative heads, a breakthrough was made and in 1964, a shell model was developed which was twice as effective against cumulative heads as a homogeneous steel armour of the same weight with a akin opposition to kinetic ammunition. This was a breakthrough in the construction of armored weapons to an degree not noted since the 1930s. The fresh kind of cover was named (from the inventor) "Harvey's armor" and the full program gained the code name "Burlington". The peculiar armour of this kind consists of a number of slanted packages, each of which consists of 2 steel plates and a layer intermediate between them. The outer layer is thicker and more plastic steel, while the interior layer is made of thinner steel of very advanced hardness. Between them is the intermediate layer which has the form of elastomer, polymer, or rubber. At the time of hitting the gross origin (e.g. cumulative stream) into the outer ( thicker) steel plate and its perforation occurs the deformation and displacement of the plate. Through the intermediate layer, then the energy is transferred to the bottom layer of the package (thinner) which is put into motion. Shifting it causes the constant appearance of fresh material on the way of the cumulative stream, tearing its continuity (space) and the formation of lateral stresses.

In the USSR, the first functional ERA in the planet was developed. In 1968, the tank armor КДЗ-68 was successfully tested, which consisted of a monolithic cast of the front top of the hull (variable thickness from 67 to 105mm counting perpendicularly to the surface) with a scope open from the top of the pockets. Each of them contained a layer of explosive that closed from the top with a steel plate mounted with a massive screw. specified a constructed passive-explosive armor protected practically completely against 115mm cannon ammunition and Falang's ppk heads. Despite the very promising results, it was considered that the base armor T-64 and then T-64A protected adequate against more than 85% of the weapons of the NATO countries, while the problems with the KDZ-68 operation and the necessity of cyclical replacements of explosives in the armor all decade discouraged the USSR generalization and the full program closed down with a powerful primary armor and a conspect of active protection systems. However, it was interesting that engineer G. Blazer, who immigrated to Israel in 1970, where he continued his investigation into the usage of ERA armor with prof. Held of Germany...

Both British "Burlington" and russian KDZ-68 effective guards against cumulative heads but both were implemented in their improvement versions only 1.5 decades later. British armor along with Leopard 2, M1 Abrams and Challenger 1 from 1979 to 1984, and russian ERA as Contact 1 (4s20) from 1982 to 1984. Until then, there were no measures that full effectively allowed solutions to the problem of very advanced HEAT penetration capabilities. This has resulted in a crucial spread of cumulative heads which were commonly utilized in the 1970s in:

hand grenades (e.g. RGB-3/3M/3EM)
cap grenades (e.g. M433 HEDP, PGN-60)
multi- and disposable hand grenade launchers (e.g. M72 LAW, rgppanc)
anti-tank mines (e.g. MKU)
anti-tank guided missiles (e.g. Milan, HOT)
heavy guided aircraft rockets (e.g. Maveric, Ch-23M)
tank shells for smooth-bore cannons (e.g. BK-14M, DM-12)
Artillery and aeronautical cumulative-particle sub-ammunition DPICM (e.g. M483 M509)
bombardments for cutting steel structures

At the same time, in the 1960s and 1970s, the fast evolution of cumulative charges continued – through their optimised ones. This process took place mainly in France and Germany where it was decided to importantly improve the performance of cumulative heads without expanding their diameter. To this end, compositions (for stronger) of the explosive were changed in the cargo bodies and better cumulative apertures were developed. They were besides taught to produce highly precise copper inserts, and to equip missiles and rockets with lighters in the outer ballistic caps / probes, which guaranteed optimal focal dimension of loads. As a result, ppk Milan 1 of 1973 beat 530mm steel (input of 96mm diameter) while its improvement version from the end of production (1983) reached more than 600mm penetration at the same diameter. A certain disadvantage was the increase in the cost of production of heads. Another way went Americans for whom a larger caliber of the head was expected to supply even so adequate penetration with a simpler and so cheaper plan of the head. The consequence was a harsh profession due to the fact that it turned out that BGM-71A (1970) and M47 Dragoon (1975) beat up to 450mm of steel - which was a value lower than the opposition of the front towers T-64A, T-72A and T-80B. The 1980s is another fast evolution of the ppk heads – this time, in addition to further optimization of the heads, their caliber was besides increased. A good example here is HOT 1 (1978) and HOT 2 (1985). The first 1 has a 136mm diameter head which has a copper cartridge with a wall thickness of 3mm beginning angle of 60 degrees, an explosive charge weight of 2.930kg (Hexolit), a ballistic cap having a dimension of 1.8 caliber head. HOT 2 already has a 150mm diameter head with a 2.75mm copper insert with a 50 degree beginning angle, and a burden weight of as much as 4.06kg (Octolit), and definitely the form of the cumulative aperture was different. The ballistic cap had a different form and dimension of 1.46 caliber. Despite the larger angle of beginning the insert and the lower distance to the fuse the change in the cargo structure (including diameter) caused a drastic increase in penetration – with 720mm RHA in HOT 1 up to over 800mm (according to any sources over 900mm). Soon, however, the construction of the heads had to undergo another evolution.

ERA – Changing Game Rules?

Despite any problems with opposition to harm and the tightness of covering the “complex of dynamic protection” 4s20 Contact 1 introduced in 1983 provided an unprecedented increase in vehicle immunity. The simplification in the penetration of 50-80% cumulative heads (according to Russian data) meant the theoretical immunity of 1 T-72A, T-64B and T-80B tanks to this means of destruction. Worse still, until mid-1987, there were no NATO's dedicated rocket anti-tank weapons down to defeat the cover of the russian ERA without a crucial decline in the ability to overcome the armor. Additionally, in the USSR, the said forging program for armoring hulls of machines manufactured before 1982 was introduced, while in the machines of each of the 3 families produced after 1982, the compositions of the hull armor were completely altered so that its opposition equaled the opposition of towers. Of course, despite the usage of the ERA, the real effectiveness of the shield was not "total" for 2 main reasons. First of all, only 60-70% of the vehicle's front surface was protected by the ERA – this very fact already gave a chance to accomplish at least 1/3 effective hits from customs. Secondly, the sensitivity of the Contact-1 to harm in the fight anticipated the fast formation of many unscreened ERA tank areas during the following days of fighting. However, it is hard to recognise that this situation is acceptable to NATO producers of Ppanc ammunition. Worse – in 1988 a fresh kind of cover was mass-mounted on russian tanks – ERA 4s22 Contact 5. However, it should be remembered that acceptance for weapons and trial operation took place already in 1985.

According to Russian sources, the effectiveness of the armor implemented in 1985 Contact-5 is estimated to be an average 20% simplification in the capabilities of penetration of subcalibre anti-tank missiles and from 50 to 80% simplification in the anticipation of penetration of single accumulation heads. another estimates of NII Stali reported that 4s22 resists equal to subcalibre missiles as an additional 120mm steel and cumulative missiles like 500-600mm steel. At the time of introduction at the end of 1987, the first ppk equipped with an effective precursor (TOW-2A) decided to upgrade the ERA cassette. The fresh T-72B production series (sometimes known as the ‘model 1989’) has received Contact-5 modules with a partially neutralising primitive precursor of ppk and even more effectively combating the ‘long cores’ of APFSDS missiles. The changes have been introduced since the end of 1988. As a result, 2 versions of the fresh russian ERA tapes were introduced almost simultaneously. The first – for trial usage and for serial T-80U and T-80UD tanks and the second – was utilized on fresh T-72B series produced since 1988. Detailed data on the effectiveness of the modification Contact-5 known from T-72B since 1988 are not known. The usage of larger cassette components was intended to accomplish efficiency of more than 20% against subcalibre missiles. More importantly, the fresh 4s22 modules were to partially neutralize the simple precursors known for e.g. TOW-2A. Another construction of ERA modules, the distance from the tower's armor or the size of the elements was intended to let the “catch” of the main cumulative stream by the working ERA elements despite their initiation with a precursor. Of course, the effectiveness of ERA in this case would be very limited and dependent on the location of the hit, but not zero - as in the case of the older 4s20.

The gravity of the situation has been rapidly assessed in NATO countries and multi-track actions have been launched to reconstruct the effectiveness of cumulative anti-tank weapons. In countries where extended investigation has been carried out and own ERAs (Germany, France) have been developed, a comprehensive approach has been put into place and fundamental heads have been developed capable of overcoming ERA despite the work of its elements and of creating "non-initiating" precursors. What is symptomatic – in countries that had their own highly developed work on reactive armor, it was rejected to make "simple" precursors with a tiny cumulative charge to initiate an ERA bone detonation before the initiation of the primary charge for these precursors not activating ERA components. This approach required time for investigation and investigating and specified loads to appear in Germany and France only around 1991-1993. In a word, the gap in the effectiveness of the next generations of Milans and HOTs was about 7 or 9 years... The Americans followed a different, faster path. Agreeing with a possible fast decrease in the effectiveness of the adopted solution, they developed a fresh version of the ppk BGM-71E TOW-2A with a head with a higher penetration rate and a probe with a simple precursor. This was effective against Contact 1 solution. This kind of production was mass-produced in mid-1987, so it can be assumed that the gap in the efficiency of ppk was about 3 and a half to 4 years for the US Army. In addition, dense work on fresh types of warheads capable of overcoming Burlington armor and any ERA was started.

Trends in the improvement of accumulation heads currently

Since the early 1990s, trends in HEAT improvement have been focusing around respective interrelated areas: the increase in penetration, the increase in the compactness of heads, the defeat of ERA, NERA, SLERA and Burlington armor, multitasking and the increase in the safety of weapons.

Increased penetration is simply a constant trend in the improvement of accumulation heads. Since the 1990s, however, it has been achieved through a combination of 3 major changes: the composition of the explosive of the head, changes in the material of the cumulative insert and changes in its geometry. The oldest of the cold warheads were elaborated with materials specified as TNT (trotyl), followed by a transition to Hexolite (RDX) or blend of TNT, Hexogen and admixture of aluminium with calcium chloride. Since the 1980s, the heads began to be filled with Oktogen (HMX) while in 1991 the CL-20, or material, became available by 14% more energetic than HMX. 2 fresh materials were created on the basis of it rather rapidly – LX-14 and LX-19. However, the disadvantage remains the price due to the fact that a kilo CL-20 costs about $1,500. However, this was not the end of the changes due to the fact that already in 2005 the heads from PBXW-11 were tested (by the Swiss RUAG), or a cast mix of Oktogen with aluminum powder and the mentioned LX-14, explosives based on CL-20 were besides adopted in the US. Another change was the insert material – here the aim was to increase the density of the insert material while maintaining efficient cumulative stream formation. Copper proved to be possible to replace costly molybdenum or improved by thickening and very careful profile of the double cartridge. The changes of its geometry – mathematical modeling allowed for the creation of more effective cumulative apertures – as a consequence the same permeability of the charge could be as much as 1/3 shorter. Another was the form of the insert itself. How serious was the effect of these changes? Typical accumulation charges from the late 1980s pierced armor equal to about 6 -7 of their diameters, producing a cumulative stream with a highest velocity of 6500 to 8000 m/s. Modern optimised loads, utilizing molybdenum or optimised copper cartridges and fresh LX-14/LHX-19 explosive devices, let to make the velocity of the top of the cumulative stream from 10500 to 12000 m/s, while the armor penetration capacity reaches more than 10,5 diameters of the cartridge. As a result, there was a very large increase in the penetration of blasting agents equipped with specified heads. The accumulation grenade fired from a disposable M72 LAW grenade launcher (66mm caliber) has a 60mm diameter cartridge. It defeated 360mm steel (6 diameter insert). The fresh M72EC Mk.II grenade already beats 540mm steel (9 diameters). This besides applies to ppk. Russian PPk Kornet heads ( 152mm caliber) with a 146mm cartridge calibre in the mid-1990s were able to beat between 1000 and 1100mm steel (7,5 mm diameter). The same caliber of Western cartridges tested in the mediate of last decade have already reached 1500mm penetration (10.5 mm diameter insert) – mainly thanks to molybdenum as a cartridge material. In fact, you can compose about 30% increase in the penetration of cumulative heads over the last 2 decades.

No little serious challenge was the defeat of ERA, SLERA, or Burlington armor. Here 2 methods have proved effective. The first were precursors and the second – the mentioned increase in cumulative stream speed. The second of these issues became at any point as crucial as the increase in the pierceability of the heads – the bulk of the penetration capacity of the stream amounts to the first 30% of its dimension (counting from the top). Reaching a velocity of more than 9km/s means that ERAs in the early 1990s have a ‘too slow’ shift of metallic elements during their work – they are incapable to ‘catch’ and break the continuity of specified a fast cumulative stream. This includes Burllington armor and derivatives from the first half of the 1980s. However, the main method of overcoming ERA has become precursors. Initially, they were simple (e.g. in TOW-2A) and were expected to simply activate earlier reactive armor cubes so that the merging of its executive elements (steel plates) did not disrupt the main cumulative stream. Since ERA manufacturers began to usage double layers of elements alternatively rapidly or to manoeuvre sometimes their initiation, the effectiveness of specified solutions proved to be tiny – e.g. even comparatively simple Polish ERAWA-2 despite this kind of precursors is able to reduce the penetration of primary heads inactive by about 50%, which was confirmed during the tests of Panzerfaust-3T, HJ-8 and others. The answer to this was originally to be "fired" precursors whose improvement was, however, abandoned for another solution – alleged non-initiating precursors. They produce from non-metallic accumulation cartridges a low-speed granular stream (below 5km/s) that does not initiate ERA components, but creates a large size beginning in them. The publications presented investigation results showing the ability to overcome 2 layers of ERA shielded by 14 mm armor plate without their initiation. This kind of precursor allows practically immediate initiation of the main load, and the usage of various types of interlayers and delays in the movement of dense armour components may not be effective. Again, the effectiveness of specified solutions can be shown on the example of native tests – while the aforementioned ERAWA-2 effectively protected against PzF-3T and partially from prototype PzF-3IT600 with a "classical precursor" the fresh serial PzF-3IT600 equipped with a non-initiating precursor passed through the Polish ERA in rule without decreasing penetration capabilities... specified precursors have since half a 1000 years become widely utilized in the west in ppanc, ppk, and aero ammunition grenade launchers.

Another issue was the effort to reconcile conflicting requirements for the demolition of different targets. While it has always been a precedence in the accumulation weapon to overcome the armor, as far as the end of the Cold War was concerned, the importance of combating the armored targets has been reduced, but the number of shootings into the force of the surviving opponent in the open space or fighting soldiers in buildings has increased. Initially, the usage of specialized heads was a necessity but besides a logistical nightmare and economical nonsense. It was rather rapidly possible to reconcile the combating of armoured targets with improved demolition of surviving force – the heads' bodies received simply pre-fragmented tantalum coats (Hellfire IIK) besides changed the impact point in combating soft targets. Eventually, however, in the latest types of weapons, all requirements were combined. A good example here is Hellfire R "Romeo" which has an effective non-initiating precursor, and optimised primary heads with a fresh cumulative cartridge, different from its typical shape, and high-energy explosive. As a result, a cartridge with a calibre of about 145-150mm is able to beat more than 1500mm of steel. In addition, the head body is pre-fragmented so that it is very effective to cover a given area with shrapnels – which importantly helps the option of practically vertical diving for the intent of the version "Roemo". In addition, the head’s head’s head’s head’s head and beginnings are made of rather thick hardened steel – so that it can overcome the “thin” iron concrete (“houses from a large plate”) or more than 1m brick walls. Although then there are deformations that harm the cumulative cartridge, the effect of an detonation of a warhead with a pre-fragmented body is devastating. A akin concept, but somewhat better in individual solutions is the head of the British Brimstone.

Probably, however, the future is among the intermediate forms between the heads forming the cumulative stream and the EFP penetrator. They are based on the formation of a copper cartridge with a slow extending cumulative stream (slow streching jet) of large diameter, weight and penetration. This anticipation emerged with the mastery of asymmetric initiation of cumulative charges. In typical cumulative loads, this is an undesirable phenomenon resulting in a nonlinear stream run and a drastic drop in penetration. As a consequence of the mastery of the production technology of highly material-clean copper inserts and the optimization of their shape, charges with a cartridge twice as thick as standard cumulative charges were developed, nevertheless forming an ultra-fast copper penetrator which is an intermediate form between the EFP and the stream. It has a dimension equal to 150% of the diameter of the load, a piercer than the EFP, but it behaves likewise (little sensitive) to reactive armor. In addition, it produces a penetration channel with a circumstantial diameter of EFP – erstwhile utilizing this kind of head as precursors it is an crucial advantage. A good example of the usage of this kind of burden is the fresh universal JAGAM rocket equipped with a CSSJ precursor operating on the "slow stretching jet" principle. It allows not only to combat targets shielded with ERA armor but besides (in cooperation with the dual operation of the primary head) to combat bunkers and indoor facilities. The switchable mode can work like a simple cumulative head or with an armored front burden (with an beginning for the "release" of the cumulative stream) as a penetration head entering the interior of the object through an beginning made by CSSJ.

In addition, despite a tiny diameter of about 100mm, the precursor proved on the tests the anticipation of beating 2 types of ERA and a steel plate corresponding to the T-55 (210-230mm RHA) armor thickness. The above penetration capacity of CSSJ retains to a distance equal to 50 burden diameters (5m) although due to the base burden of the typical cumulative head, the precursor is utilized on a minimum permissible distance equal to 1 insert diameter. Another example of this kind of solution, this time in stand-off weapons is the MEPHISTO head of the TAURUS maneuvering missile. It places a 355mm diameter precursor based on the rule of indirect action between EFP and HEAT creates a stream capable of breaking a gap in diameter of 20cm in more than 2 metres of reinforced thickness of reinforced gel through which penetrates a specially designed anti-concrete penetration charge. In total, the MEPHISTO head is able to overcome the almost six-metre failure of ferrobetone.

Cost of modernity.

The fast improvement of accumulation heads brings 2 major drawbacks. The first is the cost – modern optimised heads elaborated with CL-20 based material with molybdenum inserts are expensive. They are even very costly – so that the cost may exceed respective times the cost of a "normal" head. Secondly, the retention time of ammunition has been drastically reduced. It is now around a decade and a half, which is almost twice as short as the “classical” Elaborated TNT heads. As a result, modern solutions are respective times more costly than in the 1980s. It is besides worth remembering that modern accumulation heads are not a wonderful remedy – they have a worthy opponent in the form of increasingly newer generation of armor so effective that hits on the front surfaces of the tower and hull of modern tanks will alternatively consequence in a triumph of armor. Even despite hitting the monster diameter with cumulative heads – specified as Korneta or HOT-2. besides modern hand-held anti-tank grenade launchers – specified as RPG-29 or PzF-3IT600 may not defeat modern "asymmetric" side armours specified as the American TUSK with tandem cartridges ERA M31 and M32 or German IBD solutions which already in 2008 presented photographs from tests where the side armor module with a thickness of about 550-650mm and partially spatial construction was able to halt the 800mm RHA test head equipped with a precursor. However, the fact is the undisputed effectiveness of the top-attack attack performed by ppk specified as Javelin, MMP, Hellfire, JAGM or Brimstone – modern precursors and 1300-1500mm steel heads make it impossible to shield the ERA tank tower ceiling from specified a threat. Therefore, active vehicle protection is required, which is simply a full triumph for anti-tank weapons designers and proves the advanced efficiency of modern western dense ppk. Cumulative heads are besides inactive utilized in a number of another types of ammunition and there is no good substitute for them – penetrating heads for aerial means of handling, demersal anti-tank mines, artillery sub-ammunition cumulative – shrapnel (DPICM), bomb charges – all of these applications will be based on cumulative charges for decades to come.

ARTICLE INCLUDED BY THE SUPPORT OF PATRONS:
Jakub Klech, Paweł Clocktowski, William Błasiak, Paweł Staufer-Kamiński ,Pawel December, Jacek Popiołek, Master of Pupets, Tomasz Sobiechowski, Piotr Skoczen, Bartłomiej Czerwiński, Radosław Pachowicz, Mateusz Żaba, Piotr Przedwojski, Martin Schoch, Monika Kamińska, Jarosław Kaczyński, Łukasz Karcz, Lwszek Skrzyniarz, specified One, Radosław Wójciga, Krzysztof Polakowski, Radoslaw Jarecki, Mateusz Gębala, Paweł Królak, Marcin Dębicki, Paweł Gos, Michał eL, Krzysztof Piszczek, Ziutek Wadowski, Marcin Michaluk, Wojciech Cymbalak, David Dyrcz, Maciej Kolinski, Krzysztof Wójcik, Tomasz Sąt, Piotr Klimecki, Paweł Małacki, Tomasz Bartkowik and 7 wishing to preserve the anonymity of the Patrons.

In addition to the above mentioned supporting Patrons of the article are:

Kamil Oleksiak, Darek Kowalski,I mvc, Karol Kościak, Krzysztof Książek, Mariusz Złotocha, Artur Powroźnik, Marcin Martyn, Mateusz Dażerling, Hubert Raich, Artur Gemula, Grzegorz Taramina, Andrzej Fidut,Tomasz Gach, Jacek Kazimierczak, Mikołaj Jakub Barski,Grzegorz Borecki, Pawel Skrzypek, Jan Mączynski, Przemek Szynkar,Mariusz Rolik, Michał Gropej, Edward Sloska,Piotr Milczak,Mateusz Bryniak, Marek Sobolewski, Juliusz Śniadewicz, Piotr Pekal, Jurek Morito, Mariusz Gomulski, Przemysław Sawicki,Daniel Kubas, Jarosław Potoczny, Jacek Bach, Krzysztof Dziadowski, Paweł Dziadowski, Paweł Dziadowski, Paweł Dziadowski, Krzysztof Dziadowski, Paweł.
Paweł Pawlak, Daniel Buslowicz,Marcin Kwasnik,Slawomir Mariat,Mar Kan,Tomasz Stachowicz, Morhun Varsik

I besides thank 20 others who want to stay anonymous – Patrons.

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