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6AKwsfK.jpg

 

Orginally polish second generation 120mm APFSDS-T ammo:

 

The designing of a new kinetic energy projectile for LEOPARD 2 tank 120 mm gun started in 2016. Development of a new kinetic energy projectile with a penetrator of boosted efficiency (by ca. 20% than currently manufactured ammunition) for piercing the RHA plate was the main goal of the project.  New generations of tungsten based


sinters with better mechanical characteristics were used to prepare the new design of the kinetic energy projectile, having a lower diameter and a length increased by
ca. 100 mm in comparison with projectiles currently manufactured and supplied to the army, under the procurement contracts for 2014-2017.

(...)

 terminal ballistics show that penetration depth of RHA plate is above 600 mm for the distance of 2000 m

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On 5.4.2018 at 9:24 PM, Ramlaen said:

According to CTA International their CT40 APFSDS will defeat 140mm of RHA at 1500m.  There is also an AHEAD style kinetic airburst to go along with their HE and HE airburst rounds.

 

Forgive me if this is old info and I was simply unaware.

Old news indeed. You shall perish!

 

Seriously though, does anyone with relevant knowledge on the topic can tell me what exactly is blocking the implementation of CTA technology into broader applications? The British, French, and Chinese seem to go ahead with this technology. About the UK there's no debate, but if the French and Chinese are doing something like this, surely it has some clear merits. 

What is blocking its implementation in high caliber (105mm-130mm) guns for tanks, or even small arms? Seems to conserve quite a bit of space for ammo, eases logistics, AND seems to get more penetration overall. 

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6 hours ago, Mighty_Zuk said:

Old news indeed. You shall perish!

 

Seriously though, does anyone with relevant knowledge on the topic can tell me what exactly is blocking the implementation of CTA technology into broader applications? The British, French, and Chinese seem to go ahead with this technology. About the UK there's no debate, but if the French and Chinese are doing something like this, surely it has some clear merits. 

What is blocking its implementation in high caliber (105mm-130mm) guns for tanks, or even small arms? Seems to conserve quite a bit of space for ammo, eases logistics, AND seems to get more penetration overall. 

 

I doubt it would improve large-caliber guns much.  I explained this a while back:
 

 

 

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I see now that the old link is gone, victim of the dreaded link rot.  So I will have to explain this all again.

 

Telescoped ammunition, like the way the G11's ammunition was constructed with the projectile buried in solid-cast propellant:

7BALMgu.png

Barely works for small arms and works less and less well as it is scaled up.

 

For any gun to work well the bullet has to seal with the bore and prevent gas from flowing past the projectile.  Gas that flows past the projectile and up the bore causes greatly accelerated bore erosion, and reduces performance because not only is that gas no longer behind the bullet to push it, but the gas is contributing the pressure in front of the bullet, which partially counteracts the pressure behind the bullet.

 

For normal, boring, conventional, functional ammunition, this is not a problem.  All the propellant is behind the projectile, and the surface of the projectile that seals the inside of the bore is jammed into the bore or very close to it.

 

5iEReZ0.png

 

No muss, no fuss.

 

But look at that G11 ammunition again.  The bullet is buried in the propellant.  More importantly, the full caliber part of the bullet that seals the bore is sitting behind the propellant, and a long, long way from the bore.  In order to seal the bore, the entire bullet is going to have to jump about half of its entire length before any of the propellant gas can get around it.

 

The telescoped ammunition is usually designed with a booster charge that breaks up the propellant and helps start the bullet down the bore, but in practice some of the propellant gas will make it around the bullet before it can seal.   As the design is scaled up, this problem gets worse and worse.  The inertia of the bullet scales with the cube of caliber and the distance it needs to travel before sealing is achieved scales linearly.  The amount of force at the base of the bullet only scales at the square of caliber, so it will take longer and longer for the bullet to jump a greater and greater distance, which means more time where the propellant is burning and simply going around the bullet and out the muzzle instead of pushing the bullet.

 

Large-caliber telescoped ammunition, such as the 25mm GAU-7 intended for the F-15, is complete garbage and burns the barrel out in a few hundred rounds, as well as burning much more propellant for the same ballistic performance as conventional ammo.

 

And like I said, if you look at a cross section of the new 40mm CT, they get around this problem by not actually being telescoped.  There is no propellant in front of the sealing ring of the projectile.  This sidesteps all the technical problems of telescoped ammunition, but it also means that the round enjoys no greater volumetric efficiency than conventional ammunition.

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21 minutes ago, Mighty_Zuk said:

So then, what are the advantages of their design? Surely they had some reason to go for CTA rather than the existing Bofors 40mm guns.

 

Well even if they aren't true telescopic ammo, aren't they still somewhat more compact than regular ammo for a given rod length (taking the APFSDS as a reference)?

 

I mean the rod isn't completely buried into the propellant, but probably still more than with a regular ammo design.

 

5olwTwl.jpg

 

A sort of middle ground between the two?

Keeping the bottleneck of the case but inside the outer shell as opposed as a separate piece.

 

Another though, would it be possible that the bottleneck inside the CTA 40 only last for a short time (like it would melt or would be destroyed by the pressure), just long enough for the projectile to get an head-start on the expanding gas (hence the debatable denomination of telescoped).

Just asking.

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2 hours ago, Mighty_Zuk said:

So then, what are the advantages of their design? Surely they had some reason to go for CTA rather than the existing Bofors 40mm guns.

 

The autocannon breech and ammunition feed are both considerably less intrusive into the turret:

ZtebJV5.png

 

SE26x01.png?1

 

The cannon feeds through the trunnion, so the feed mechanism doesn't need to rotate with the cannon and can be pushed all the way to the front of the turret wall.

 

I'm not sure how well this design would scale up.  Certainly an MBT main cannon would present some serious problems, like the fact that the trunnions are buried in the frontal armor package.

 

The ammunition is somewhat more space efficient than 40mm L70 Bofors.  The outside diameter of the 40mm CTA is the same as the rim diameter of the L70 ammo, but the case only about 70% as long.  Ballistic performance somewhat favors the CTA.

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2 hours ago, Ramlaen said:

So the cased in cased telescoped refers to the propellant not protruding in front of the projectile?

 

Cased in this instance means not caseless.  There's a... I think it's polymer and metal, mixed contruction case keeping everything together.  The old G11 ammo was just a blob of propellant with the bullet, primer and booster inside.  The 25mm ammo for the GAU-7 was, if I'm remembering this correctly, of an absolutely bizarre configuration where each round was coated in a waterproof/fire resistant coating that was shucked off like a corn husk before each round went into the firing chamber.  

 

The "telescoped" is nearly meaningless, but it's basically the same configuration as the Textron small arms rounds that are also called "telescoped" even though they don't have any propellant ahead of the projectile either.

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30 minutes ago, Collimatrix said:

 

Cased in this instance means not caseless.  There's a... I think it's polymer and metal, mixed contruction case keeping everything together.  The old G11 ammo was just a blob of propellant with the bullet, primer and booster inside.  The 25mm ammo for the GAU-7 was, if I'm remembering this correctly, of an absolutely bizarre configuration where each round was coated in a waterproof/fire resistant coating that was shucked off like a corn husk before each round went into the firing chamber.  

 

The "telescoped" is nearly meaningless, but it's basically the same configuration as the Textron small arms rounds that are also called "telescoped" even though they don't have any propellant ahead of the projectile either.

 

One more question. Would the cased telescoped design handle chamber pressure better than a traditional design, similar to what Sturgeon described for Textron’s CT rifle?

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8 hours ago, Alzoc said:

 

 

Another though, would it be possible that the bottleneck inside the CTA 40 only last for a short time (like it would melt or would be destroyed by the pressure), just long enough for the projectile to get an head-start on the expanding gas (hence the debatable denomination of telescoped).

Just asking.

 

It might be that the bottleneck in the CTA is designed to be disposable.  The portion of the bore closest to the burning propellant usually takes the most damage, so if the cartridge case takes some of the damage instead of the bore throat, it could allow higher propellant burn temperatures without sacrificing barrel life.

 

But it's hard to say for sure from the information that I have if that's what they're trying to do.

 

1 minute ago, Ramlaen said:

 

One more question. Would the cased telescoped design handle chamber pressure better than a traditional design, similar to what Sturgeon described for Textron’s CT rifle?

 

I would need to see more of the exact design of the firing chamber to say for sure.

 

APysVCi.png

 

The design does have the advantage that it has no exposed case material, while the rimless ammunition used in small arms has a fair amount of exposed area.  The rimmed ammo used in tank guns has close to no exposure though, so the so-called "cased telescoped" ammunition only enjoys an advantage vs. small arms ammunition in that respect.

 

The CT ammunition has the disadvantage that the cartridge case is completely cylindrical with, so far as I can tell, no taper to aid in extraction.  That could make getting the rounds out of the chamber at higher pressures harder.  On the other hand though, they are being pushed out of the chamber rather than pulled, and that may be a more positive way to get the spent case out.

 

From what I've read about the development of the British 110mm gun, the extremely high pressures required by tank guns necessitate a caseless or semi-caseless ammunition design.  The peak pressure is simply so high (120mm APFSDS peak pressure is about double that of rifle ammunition) that a conventional metal case will try to weld itself inside the chamber, and extraction becomes too unreliable.

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The CTA looks more an evolution of the H&K G11's rotating chamber concept than the LSAT LMG actually does, even though the latter is supposed to directly draw from G11's lessons (though I believe Textron primarily paid for the caseless ammo technology rather than the gun internals' patents, seeing that the LMG's rotating chamber is a bit different from the G11's --- as seen at 1:23 in the video below).

 

Spoiler

 

 

 

Dunno whether Textron's design, scaled up to AC size, would be better. At least the ammo wouldn't be forced to pass through the trunnion and it might be a bit easier to switch calibers without changing too many components (barrel and feeding system excluded).


EDIT: Didn't realize someone had posted the same video in the Small Arms thread - this is maybe unnecessary/redundant. :-/

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The HK G11 had a lot of specific technical solutions to problems that came up from the fact that it didn't have a cartridge case.  I'm thinking specifically of the propellant chemistry, which was quite different than conventional ammunition.  From what I've heard, they were still a long ways off from a completely practical weapon, but they got much further than anyone else ever has.

 

@Sturgeon knows more about the development of the G11 and Textron guns.

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DE 20 2016 104 939 U1 is a patent from Rheinmetall about the 130 mm smoothbore gun. In particular the patent is about a new gun with greater calibre designed to fit into the space of an already existing gun system such as the 120 mm smoothbore gun. The idea is that the design results in the room for the ammo storage being the limiting factor for gun upgrades. From the claims:

  • existing gun must be swappable/replaceable
  • new gun has a larger calibre
  • the maximum catridge diameter must be nearly the same (not to be confused with the calibre of the projectile)
  • the chamber of the new gun is longer
  • how much of the chamber is used is depending on the ammunition type and propellant charge (I suggest that might mean that HE ammo has shorter catridges?)
  • the new gun has a longer recoil path
  • the new gun is designed for a MBT

 

MYZa4tq.png?1

130 mm gun details.

R3yN10Y.png

120 mm and 130 mm chamber comparison.

 

So it seems that it is possible to upgrade the Leopard 2 with the 130 mm smoothbore gun, but it would require an autoloader and a new storage rack for the longer catridges.

ClbjE22WgAUh1Go.jpg:large

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On 4/17/2018 at 5:38 AM, Renegade334 said:

Like the risk of ammunition cookoff? That's one concern I often hear whenever the G11 (and true caseless ammo) is discussed.

 

I missed this response for the longest time somehow.

 

Yes, the caseless ammo in the G11 used high temperature propellant to reduce the risk of cookoff.  But there were other weird things about it too.

 

When the propellant in ammunition burns, the flame front propagates across the surface of the propellant.  The propellant is therefore usually shaped into extruded grains or flakes or rods, and the size and shape of these propellant grains can be used to control how much surface area is exposed to burning, and thus how quickly the propellant burns.

 

But the G11 ammo was different; the propellant was all consolidated into a single blob.  This was more space-efficient, but it meant that when the propellant needed to burn, it first needed to be shattered into smaller pieces by a booster charge.  Getting the main propellant charge to shatter in a relatively repeatable fashion was a major challenge.

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On 4/16/2018 at 8:16 PM, Collimatrix said:

It might be that the bottleneck in the CTA is designed to be disposable. The portion of the bore closest to the burning propellant usually takes the most damage, so if the cartridge case takes some of the damage instead of the bore throat, it could allow higher propellant burn temperatures without sacrificing barrel life.

At at the front of the 40CTA, you have a lubricant past to protect the bore when firing. 

 

 

On 4/16/2018 at 8:16 PM, Collimatrix said:

The design does have the advantage that it has no exposed case material, while the rimless ammunition used in small arms has a fair amount of exposed area.  The rimmed ammo used in tank guns has close to no exposure though, so the so-called "cased telescoped" ammunition only enjoys an advantage vs. small arms ammunition in that respect.

 

The CT ammunition has the disadvantage that the cartridge case is completely cylindrical with, so far as I can tell, no taper to aid in extraction.  That could make getting the rounds out of the chamber at higher pressures harder.  On the other hand though, they are being pushed out of the chamber rather than pulled, and that may be a more positive way to get the spent case out.

The main problem was a sealing default. It’s now solved.

 

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Targets for the 30 mm APFSDS ammunition from Rheinmetall representing the BMP-3. Range 2,000 m, but the official effective combat range of the Puma's MK 30-2/ABM is listed as 3,000 metres.

 

0uYQUbB.png

 

The penetrator is optimized to remain intact after penetrating spaced armor arrays (which older types of medium calibre ammo couldn't do) and to create spall.

 

vUM5L20.png

 

In an older presentation, a 30 mm APFSDS managed to penetrated 15 mm HHA and 30 mm RHA in  a spaced configuration at 45° slope and 2,000 metres distance. The official armor penetration of the APFSDS-T PMC 287 is listed as 106 mm line-of-sight against a 60° sloped plate at a range of 1,000 m in Rheinmetall's flyers. The APFSDS-T PMC 359 round (with ECL instead of EL propellant) is listed with the same penetration value.

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On 10/27/2017 at 6:24 PM, Ramlaen said:

A quick comparison of the DM11, M339 Hatzav and XM1147 that I slapped together, since they are all programmable 120mm HE rounds that use tungsten pellets.

 

7A3qwhd.jpg

 

Thanks for making this. Any idea why ze germans chose a HEAT shaped design? Perhaps using existing shell design helped to speed up the design process because I cant imagine the shape is properly optimized to punch through concrete like the other HE rounds are designed to do. 

 

Does any round offer an advantage over the others or do they all the pretty much the same capability?

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50 minutes ago, Vicious_CB said:

 

Thanks for making this. Any idea why ze germans chose a HEAT shaped design? Perhaps using existing shell design helped to speed up the design process because I cant imagine the shape is properly optimized to punch through concrete like the other HE rounds are designed to do. 

 

Does any round offer an advantage over the others or do they all the pretty much the same capability?

 

Someone like @Bronezhilet could answer this better but the probe on the front of the DM11 has to do with the aerodynamic stabilization of the projectile and not a HEAT warhead mechanic. Note that with the two you can see a cutaway of the 'armor piercing' part is the shell wall between the pellets and the explosive filler.

 

I do not know the technical specs of each well enough to say one has an advantage or disadvantage over the others. As far as I am aware they are functionally equal.

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Well, that probe does act like an aerospike - it basically creates a bow shock (AKA detached shock) in front of the shell's body to reduce aerodynamic drag. You can even see the ring near the tip of the probe that helps form an optimal detached shockwave that doesn't enter in contact with the shell body.

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      aligned very cleanly and without "staggering" movement exactly on the cavity axis? However, this means that the slightest deviations from central symmetry must be avoided in the structure of the hollow charge. The whole rigor of this requirement is that it relates not only to the dimensions of the charge, but also includes the homogeneity of the materials used and that - as has already been shown - even differences in the size and orientation of the crystals in the explosive and in the copper of the liner have an influence. This requirement is even more stringent if one takes into account that the properties of the crystals mentioned above change over time, i.e. as they age, and that changes are also triggered during processing. A very sensitive influence can also be expected from the way the detonation is initiated.
      With the aforementioned and similar requirements with regard to precision, the production of hollow charges has set goals whose pursuit in the past has already brought about significant progress with regard to the generation of an undisturbed hollow charge jet during detonation, and in the future, through the tireless efforts of research and technology, even further perfection can be expected. In addition to this somewhat utopian-looking reference, however, it must be emphasized that the hollow charge principle is very flexible and includes a wealth of other possibilities for counteracting disturbances which oppose the effective targeted use of the explosive energy released during detonation. For example, it is not necessary for the hollow charge jet to dissolve into a number of particles as it progresses. Some of the irregularities in the behaviour of the particles will only develop during the tear-off process and can be avoided if the hollow charge jet is constructed in such a way that it does not tear.
      The reason for the dissolution of the hollow charge jet into a number of particles of different velocities is that the individual jet elements already have a different velocity when they are formed. In the case of the hollow charges currently in use, there is a velocity gradient in the beam from about 8-10 km at the tip to about 2 km at the end.The consequence is that the jet is constantly stretched as it progresses and eventually dissolves into more or less parts according to the strength properties of the material .2)
       
       
      The programmed shaped charge jet

      By special selection of the parameters of a hollow charge (type and density of the explosive, dimensions and shape of the cavity, wall thickness and material of the cavity lining, shape as well as wall thickness and material of the casing, position and extension of the ignition elements) it can be achieved that differences in the velocity of the individual elements of the jet are prevented at all.
      The relationship between the distribution of mass and velocity in the jet and the charge parameters was already known shortly after the discovery of the
      the lining of the cavity achievable effect by Thomanek quite detailed results. 3)
      This connection is achieved by following each individual sub-process during the detonation of the charge and the deformation of the liner by calculation. When the detonation front reaches the individual zones of the liner body, the material there enters a state of flow under the influence of the detonation pressure and is accelerated inwards. The speed at which the lining elements are accelerated depends on how long the pressure remains at the zone under consideration or, which comes to the same effect as how far the outer surface of the detonator is from this point. Thus, the influence of the width of the explosive coating on the velocity of a panel is obtained.
      For example, consider a cylindrical charge with a cone as a cavity and a diameter of 8 cm. The time required for the dilution wave to reach the top of the cone from the outer surface is then 4 cm/approx. 800000 cm/sec, i.e. approx. 5 microseconds; in the central zones of the cone with an explosive coating of 2 cm, this time is only half as long and the impulse transmitted to the lining elements by the detonation pressure in this time is therefore half as large.
      Of course, the speed also depends on the wall thickness of the lining body at this point and the density of the lining material.  The initial velocity of the lining elements can be specifically influenced by a suitable choice of the wall thickness and it can change at will between the tip and base of the lining cone. One speaks of "progressive" or "degressive" liners, depending on whether the wall thickness increases or decreases towards the base. The influence of the liner's wall thickness/explosive coverage ratio then has a further effect on the jet elements that are emitted when the liner zone converges on the cavity axis. In addition, the mass and velocity of the jet elements formed depend on the angle at which the convergence takes place, i.e. the opening angle of the cavity. Peak angles result in high velocities for small masses, and the opposite is true for obtuse angles.
      The previous remarks should serve to explain, at least by way of indication, how it is possible to determine the dependence of the distribution of mass and velocity in the jet on the charge parameters. With the knowledge of these interrelationships, it now seems possible to create projectile-like structures from the cladding bodies, in which the initial length and the distribution of mass and velocity over this length are predetermined, i.e. the hollow charge jet can be programmed.
       
      Up to now, almost all attempts have been made to obtain a jet with the greatest possible penetration capacity. This led to the familiar design forms: cylindrical on the outside, cavity for example 60° cone with copper liner, initiation of the detonation now often by detonation wave deflection at the rear edge of the detonator, whereby better use of the explosive volume and higher beam tip velocities are achieved (compare also Figure 16). The resulting beam is then a constantly stretched structure with a velocity of up to 10 km/sec at the tip and about 2 km/sec at the end, which is followed more slowly by the rest of the cladding mass, the so-called "slug". 4)
      As already mentioned several times, the differences in the velocity of the individual beam elements cause the initially coherent structure to be broken up into a sequence of particles. Nevertheless, very good results have been achieved with the described type of charges, especially against massive targets.
      Penetration depths of up to 6 charge diameters have been achieved. In contrast, when using targets with air gaps, the distance travelled in the massive parts of the target is greatly reduced. In the future, requirements for the performance of hollow-charge ammunition should be geared to these reduced amounts; this would mean that modern hollow charges should be developed to penetrate structured targets rather than exaggerated penetration performance in massive targets. An attempt should be made to program the hollow-charge jet, i.e. to adapt it to the structure of the target.
      In the following we will try to explain by means of examples that there are many possibilities to modify the beam of the currently used hollow charge.

      A completely different motion sequence of the particles of the beam from this type of charge can be obtained by replacing the centrally symmetrical ignition by a (one-sided) eccentric one.The individual beam particles then no longer move one behind the other on the cavity axis, their paths point in a fan-like manner in different directions (compare Figures 8a and b) 5) The following example is intended to show how even a slight change in the cavity shape can noticeably influence the beam and its effect.  Figure 9a shows a cladding body whose shape can be roughly described as a cone which ends at the base in a spherical zone. Figure 9b shows the penetration channel of an externally cylindrical charge produced using this liner.
       
      [Figure 8 and figure 9]
       
      The explanation for the peculiar shape results from the velocity distribution in the hollow jet. The front part of the jet comes from the cone-shaped part of the cavity and corresponds to the jet from a cone, which stretches as it advances. For the subsequent jet elements, which originate from the spherical zones at the base, it is decisive that the tangent at the cavity becomes steeper and steeper towards the base. The consequence is that the successive jet elements become faster and faster towards the rear, thus approaching each other and leading to a thickening of the jet in this rear area. On impact, the effect is increased in the form of a widening of the penetration channel.
      While with the hollow charge described above, a concentration of energy occurs in the rear jet section, it is also possible to achieve this in the front jet section. For this purpose, the cavity must be spherical at the apex and end in a cone at the base (see Figures 10a and b). The penetration channel is wide at the top and has the shape of a hemisphere followed by a narrow conical part. 6)
      If the cavity, which is essentially delimited by a cone, is spherical at both the apex and the base, the penetration channel will consist of a wide part at the armour surface, followed by a narrow conical part and a further widening at the end. Following these examples, it should be considered possible that the effectiveness of the individual sections of the hollow charge jet can be determined in quite a different way, especially if it is taken into account that other parameters of the hollow charges can also contribute to this by their specific choice.
       
      [Figure 10]
       
      As explained in the previous section, other velocity distributions are possible in addition to the velocity gradient in the jet of the commonly used hollow charges that leads to rupture. It is also possible to achieve that all beam elements have the same velocity, provided that the relevant charge parameters are adjusted to it in each zone of the cavity. If, for example, the wall thickness of the cladding is selected in such a way that it is in the same ratio to the corresponding width of the explosive coating for all zones, the cladding elements of all zones receive the same initial velocity on detonation and thus also all the beam elements that are separated from them when flowing together on the cavity axis.
      As a result, the jet is represented here by an "overlong projectile" with a rather high velocity. A sketch of the principle of such a charge is shown in Figure 11. The nozzle-shaped body attached to the base has the purpose of preventing the decomposition by-products from coming into direct contact with the free atmosphere when the base zone is accelerated, thus avoiding a premature drop in pressure. In a similar way, other causes of disturbance are to be avoided, whereby a number of experiments are always necessary before a principle path can be realized.
       
      [Figure 11]

      Instead of a single rod-like projectile, a sequence of several such rods can be obtained in which the individual elements have the same velocity, with the velocity of the rods differing from each other.
      In addition, from the special solution of the identical velocity of all beam elements, transitions to the common hollow charge with the large velocity gradient in the beam can also be developed. In particular, the case can also be realized in which the difference in the velocity of the following beam elements is so small that the beam is only broken when all obstacles of the target have been overcome. How such a continuous beam reacts to protective measures that disturb a particle-dissolved jet is still to be investigated. In any case, the disturbances caused by the rupture process are avoided here (compare Figure 12).
       
      [Figure 12]

      Also, the range of possible variations in the structure of the shaped charge jet is so wide that an adaptation to very different target compositions seems possible. Not insignificant is the fact that the energy of the effect carriers from a hollow charge can be distributed in a targeted manner to mass and velocity, i.e. the jet can obtain a greater mass at the expense of the velocity of its elements and vice versa.
      As investigations have shown, the protective effect of certain materials depends on the speed of the projectiles. 7) However, such measures need not refer to the entire jet, but can be limited to parts of it, for example to the front or rear parts of the target.
      A special group of shaped charges has not been mentioned so far, namely those with a flat, especially blunt conical cavity. ln contrast to the pointed conical cavity, the attainable velocities are lower here. The speed of the structure previously referred to as the jet is no longer very different from that of the so-called following slug. It can be achieved by methods which will not be discussed in detail here, that the jet and slug components - i.e. the entire mass of the liner - merge into an at least temporarily coherent structure. lf the difference in the speeds of the front and rear parts is sufficiently small, it is absorbed by internal expansion work, and a projectile with a uniform speed of about 2000 m/sec is created. Figure 13 shows a series of such projectiles from charges with a flat cavity, using X-ray flash images.
       
      Figure 14 shows a section through a captured specimen of cohesive projectiles. Such projectiles are particularly characterized by stable flight at long distances and have already found 'a versatile application today, especially as a replacement for natural fragments (see also cover picture and Figure 15).
       
      [Figure 13, figure 14 and figure15]
       
      In connection with the efforts to combat future targets, which may be unknown at present, it should be mentioned that it is possible and possibly very useful to arrange projectile-forming hollow charges in a special way one behind the other. If this is done taking into account all the side effects of the detonation, and if such an arrangement is ignited appropriately, one obtains a sequence of projectiles flying one behind the other at fairly high speed, the mass of which is considerably greater than that of particles of the hollow charge jet.
      It is also possible to combine a projectile-forming charge with a jet-forming charge with an acute-angled cavity. Figure 16 shows such a charge, also known as "tandem charge".
      It was designed to create a strong follow-on effect inside the tank. On detonation, the jet from the rear charge penetrates through an opening in the apex of the front flat-cone charge. Only after this has been done is this charge also detonated; the flat liner body is formed into a projectile which follows the jet from the rear charge through the channel created by it and comes into effect there depending on the intended purpose.
       
      [Figure 16]
       
      These examples are intended to show that there are almost no limits to the imagination when it comes to exploiting the potential inherent in the principle of forming effective projectiles by transferring explosive energy to inert materials. There are many ways to develop explosive charges that can be effective against complex targets and do not necessarily require a gun to reach the target, but can be used in warheads of missiles. Of course, there will always be possibilities to achieve sufficient protection by suitably constructed armour. What should be particularly emphasized here, however, is the view that there is hardly likely to be a miracle cure for all types of shaped charges and that, apart from a temporary predominance on one side or the other, there will probably continue to be mutual efforts to perfect shaped charges on the one hand and protective armour on the other.
       
    • By Ronny
      I see many knowledgeable members here so i decided to make an account to ask some question
      According to many historical accounts, the armor of WW II battleship is very thick: can be between 410-650 mm of steel
      Thick enough that they can even resist penetration  from 12-16 inch canon 


       
      Compared to these massive round, it is probably obvious that missiles such as Harpoon, Exocet will do little or nothing against the armor belt: No penetration and probably nothing more than a small dent.
      Anti tank missiles such as AGM-65, AGM-114 or Brimstone can penetrate the armor but all their warhead will do is penetrating a tiny hole into the massive battleship, it likely will hit nothing significant given that a battleship have massive volume of space). Furthermore, i heard space armor is extremely effective against HEAT warhead as well).
       
      But what if the two are combined? HEAT + explosive warhead: aka BROACH.
      With a frontal shape charged and secondary follow through bomb
      This is the working principles of the system:


       
      BROACH was designed to help small cruise missile penetrate bunkers. So i have some question:
      1- Because concrete and soil are very brittle, unlike steel, I think the precursor charge likely much drill bigger hole in them than it can drill on steel armor belt of a battleship, so even if we use missile with BROACH warhead to hit a battleship, it won't drill a hole big enough to allow the secondary warhead to pass through. Is that a correct assessment?
      2-  Looking at the cutaway of the missiles. How come the detonation of the frontal shaped charge doesn't damage/destroy the secondary warhead or at very least propel it to the opposite direction? 
       
      3-  Can supersonic missiles such as Agm-88 (Mach2) , Asmp-A (Mach3) , Rampage , Asm-3 (Mach 3) , Hawc (Mach 5) penetrate the armor belt of a battleship? or they simply don't have enough velocity and density?
       
       
       
    • By Molota_477
      M1 CATTB
      pic from TankNet.
      I feel uncertain whether its cannon's caliber was 140mm or not, I found a figure at the document AD-A228 389 showed behind, which label the gun as LW 120.But in many ways I've found its data in websites all considered to be 140mm.

      AFAIK,the first xm291(140)demonstrator was based on xm1 tank, and the successor was the''Thumper'' which was fitted with a new turret look like the CATTB but still m1a1 hull(Maybe it was CATTB's predecessor? )

      I will really appreciate if anyone have valuable information to share
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