For a long time, I did not compose any articles on my blog. This was due to both my private life and my commitment to writing texts for another media. Now I plan to return to writing articles here, and alternatively of general opinion-making texts I would like to focus more on my specialization, that is, the subject of peculiar armor and their applications in combat vehicles. In these articles, I would like to usage both a more or little accessible explanation on armour design, available information on armoring of individual vehicles, and, where possible, my experience with the plan of armour elements.
However, I reserve that all the information that will be provided in these articles has been obtained by me alone and is not the origin of any leak. So if you always complain about the content of my articles, I apologize, but in specified a situation you request to better defend any delicate information. At the same time, I besides point out that any speculation may be imprecise.
So let us decision on to the first article
-------------------------------------------------------------------------------------------------------------
In the fresh series I decided to take on the first fire of the presently tested Borsuk infantry car, which was developed by Huta Stalowa Wola. In the topic, I will present both the explanation related to the probable plan of the BWP-1 replacement shields, as well as the information I have been able to collect since 2017, erstwhile Badger was first shown. In any places this text will be subjective, so you do not gotta agree with my opinion absolutely. However, I would like you to find out what we're actually dealing with if we're talking about Badger.
However, it is not worth going consecutive to a simple, direct answer. specified an answer is frequently imprecise and at the same time can mislead. Therefore, it is better to break the full issue down into factors.
 |
| Badger Infantry Truck - photograph HSW |
What kind of hull is optimal for security?
If individual is talking about a well-armed infantry car, it most likely comes to head first the German combat car Puma. This 1 is characterized by a heavy armoured front of the vehicle, which was ensured by the usage of an inert reactive armour (also known as the NERA system), consisting of 2 steel sandwiches pre-greened with polymer rubber and a steel rear plate. The full strategy is tilted at an angle of about 65 - 70°, as specified inclination is optimal for the operation of this kind of shield. An equivalent solution has been implemented in another infantry combat vehicles, with a single steel sandwich mostly present in the layout as an easy disassembled additional armour.
However, the angles of tilting of the advanced front armor (generally mentioned 65 - 70°) proposed by any people were not chosen to accomplish advanced protection for the non-flowing "bewup". This slope of the armor is closely related to the optimal operation of the reactive armor present in the system. The puma in this case, however, is an exception - in another fighting infantry cars we are more frequently dealing with a cover in the form of a single steel plate or a steel-aluminium system.
In addition, the only advantages of reducing the slope of the advanced front plate are:
- improving the visibility of the driver (which is presently compensated by the usage of cameras)
and
- increase the angle of depression of the fast cannon (which for angles above 10° may look good, but this is not necessary).
 |
| Indicative cut of front armor bwp Puma |
The 3rd advantage, which was originally decisive erstwhile designing armored transporters, was to reduce the mass of steel plates used. However, composite casings are now used, which consist of many layers of different materials that can be lighter than steel. In addition, requirements for the protection of armoured infantry vehicles have increased importantly over the last 50 years. This makes it possible to aim for the protected surface of a combat infantry car to consist of as fewer walls as possible to effectively shield the combat vehicle. In addition, due to the usage of spatial and composite shields in the case of smaller tilt angles (15 - 40°) - which is inevitable in the case of the lower front armor - it is not possible to plan the armor in the same way as in the case of larger tilt angles (55 - 75°) in the advanced front armor. This, on the another hand, may lead to the creation of weakened areas with large surfaces, which will not warrant adequate protection against more effective anti-tank weapons (tank grenades, average caliber anti-tank ammunition). And at the very end, not everyone has specified experience in designing and utilizing NERA-type shields in combat vehicles as Germany.
 |
| Bwp AS21 Redback hull without additional armour |
It is primarily due to this that the optimal figure for the medium-armoured combat vehicle (a combat infantry car) turns out to be a lump more boxed, where we are dealing with a large lower front plate with a limited slope (15 - 40°) and a very powerfully tilted (about 80 - 82°) advanced front plate. A strategy with a lower slope can be designed both in the form of spatial / bulkhead armor (if lower levels of protection are met) or composite. Currently, unlike the systems utilized in the primary tanks, there is no request to supply passive protection against tank ammunition or tank grenades. This enables usage of armour systems based on metallic layers (steel-aluminium) or containing ceramics. However, in the event of specified demand, it is possible to make a front armor based on a dense but easy disassembled peculiar armor module, which would be tightened to the steel hull of a combat car. In this case, the combat infantry wagon AS21 Redback of South Korean Hanwha Techwin can be regarded as a precursor, but a akin solution can besides be found in the Indonesian-Turkish light tank Harimau Hitam.
Physics Magic
In this case, the subject will be 2 issues related to the construction of the Borsuk armor and its body. We are talking about ricochetting missiles and their fragmentation during the penetration process.
The ricocheting of anti-tank missiles is simply a substance known to those curious in the secondary war. The improvement of subcalibre ammunition (especially 1 with prolonged cores) has reduced the frequency of this phenomenon, but this process has not been eliminated. It's just that the angles of the bow of the armor at which this phenomenon occurs have changed. In the case of full-caliber planet War II ammunition, ricochets reached ricochets at an armor tilt of about 55 - 60°, while with modern anti-tank ammunition the required slope is already about 75 - 80°. The exact angle depends on the thickness of the metallic plate used, its mechanical strength and the characteristics of a given anti-tank missile.
In the case of Badsuk, this refers to the usage of advanced hardness armoured steel plates, the thickness of which is most likely 10 mm. For the advanced armor plate, the angle of its slope is about 80°. It is precisely due to the fact that for specified an angle there is simply a higher probability of ricocheting an anti-tank projectile than if the same plate were tilted at an angle of 65 to 72°, we could talk about optimizing a lump of an intermediate armored armored armored vehicle.
But what kind of missiles can ricochet specified a heavy inclined armor plate?
Here, judaic designers from Plasan Sasa came to the aid, who tested this phenomenon for a 25 mm subcalibre APDS anti-tank missile. This kind of ammunition continues to usage the tungsten core or (better) uranium, but is characterized by a smaller ratio of the core dimension to its diameter. In this case, M791 missiles were utilized for the study, which until the mid-1990s were the primary anti-tank ammunition in American bwp M2 Bradley and wheeled armored transporters LAV-25. However, these are lighter missiles than Swiss PMB 073 missiles, which by 2012 were the mention kind of anti-tank ammunition for the verification of level 5 ballistic protection according to the STARAG 4569 standard.
 |
| Anti-tank missiles 25 x 137 mm (top): M791, PMB 090 and M919 The list lacks PMB 073 - not produced since the late 1990s. |
Based on the shootings, it was noted that the bullet ricocheted from a steel plate of 8 mm thickness inclined at an angle of 78 to 82 degrees. However, the exact critical angle depends on both the thickness of the steel plate utilized and its hardness. With Class 500 armoured steel (e.g. ARMSTAL 500), the optimal tilt angle for a board of 8 mm thickness is 81 degrees, but it is reduced to 79 degrees for a panel of 10 mm thickness or even 75 degrees utilizing a 15 mm thickness plate. An even better effect can be seen utilizing Class 600 armour steel, where the optimal angle of inclination was 82 degrees for the 8 mm thick plate. However, steel with specified advanced hardness (~600 HB) is not welded steel, so it can only be useful in the form of a tightened additional armor plate.
On the basis of this, it can be concluded that the 80° tilted advanced front armor of the BMP-1 and BMP-2 infantry vehicles - made of 500 (2P or BT-70Sz) class steel - can besides ricochete the subcalibre shells of 20 and 25 mm. However, what has been corrupted in the case proposed by WZMot. modernization of BWP-1, as the angle of inclination of the advanced part of the armor was reduced to 72°. And specified a reconstructed armor will no longer have specified abilities.
It is besides worth mentioning that during the ricochet, the tungsten core was crushed, so that the bullet was no longer specified a serious threat.
 |
| Visualisation of M791 ricochet on 8 mm thick steel plate (hardness: ~500 HB, angle of inclination: 81°) |
3UBR6 is simply a full caliber anti-tank rocket with a 400 gram steel core. This rocket was designed to overcome simple metallic (steel or aluminum) shields with a tiny angle of inclination (for steel up to 30°). The projectile itself officially pierces a 26-millimeter steel plate (probably ~300 HB) inclined at an angle of 60° at a distance of 300 metres. However, its effectiveness falls importantly erstwhile the mark is protected by simple spatial armor or more advanced composite shields. Taking into account the usage of the steel core and the low output velocity (970 m/s), it is likely that the biggest problems will gotta overcome composite shields containing ceramic layers. But I'm going to discuss this more thoroughly with another armored bullet.
Furthermore, authoritative data do not mention the ability to penetrate tilted shields at an angle of more than 75°, suggesting that, despite the usage of the 3UBR6 ballistic cap, it is simply a ricochet-like missile.
 |
| 30 mm kind 3UBR6 anti-tank missile |
The second of the Russian anti-tank missiles - 3UBR8 - is an APDS (Armour Penetrating, Discarded Sabot) subcalibre rocket utilizing a 222 gram tungsten core. It is characterized by the anticipation of penetrating a tilted (at an angle of 60°) steel plate with a thickness of 27 - 28 mm with a distance of 1000 meters. This is simply a much better value compared to 3UBR6 steel. It is besides a comparable value to the American M791, which pierces a 45 mm vertical steel plate from a distance of 1000 metres (which translates into the anticipation of penetrating a tilted steel plate with a thickness of 28 mm). However, this is worse than the Swiss PMB 073, which can pierce a 30 mm tilted steel plate from the same distance.
 |
| 30 mm kind 3UBR8 subcalibre anti-tank missile |
Interestingly, 3UBR8 is characterized by a lower penetration of armor from the Polish subcalibre kal missile. 23 mm, which is able to pierce at a distance of 1000 metres tilted (at an angle of 60°) a steel plate of 30 mm thickness, which is simply a consequence comparable to a Swiss missile. This is primarily due to the outlet velocity of both shells (1120 m/s for 3UBR8 and 1170 m/s for 23 mm APDS-T), the form of both missiles and the aerodynamics associated with it. It is besides worth mentioning that this projectile of kal. 23 mm is able to penetrate besides from a distance of 1000 metres the equivalent of the armor of the frontal combat vehicle BMP-3, which was designed to defend against 3UBR6 missiles fired from a distance of 200 metres.
However, the Russian maker gives a steel armour penetration value of 35 mm / 60° for a distance of 1000 metres. specified a value may be actual if it results from the usage of NATO-based MIL-STD-662 standard to find the permeability of the projectile alternatively than the Russian standard. The Western standard requires determining armor penetration for 50% of shells (that is, in fact, the average), while the Russians find armor penetration for 75% of cases. Therefore, the values for russian anti-tank ammunition may be undervalued. However, if the maker has not included this in its advertising brochures, it simply gives the incorrectness in this case. Furthermore, the value declared by him himself for 3UBR8 is, in fact, higher than that of APDS kal ammunition. 23 and 25 mm, but it is inactive lower than the penetration of APFSDS kal. 25 mm, which includes Swiss PMB 090 (now mention rocket for level 5 STANAG 4569) and American M919 (using uranium core).
 |
| Polish subcalibre anti-tank ammunition. 23 mm Photo by MESKO |
In order to penetrate the armor at all, the impact velocity of the anti-tank rocket must be higher than the limit velocity resulting from the relation between the protective material characteristics and the penetrator material. This is not due to the thickness of the protective material (if not very thin), but to its impact strength (i.e. hardness) and its density, as well as the hardness and density of the material from which the penetrator is made. In case the bullet does not exceed the limit speed, it is mushrooming. This effect is most frequently seen for lead shells, which is due to the fact that lead is simply a very soft metal.
However, we have a somewhat different situation here due to the fact that the materials utilized are much tougher ceramics and tungsten alloy. nevertheless - given an example - in the case of silicon carbide-based ceramics (SiC) the limit velocity for tungsten is as much as 1200 m/s. However, in the case of steel due to its lower density this value is even higher. Comparing this consequence with the outlet speeds of 3UBR6 (970 m/s) and 3UBR8 (1120 m/s), it can be expected that the problem of mushrooming penetrations on ceramic shields may affect them. However, it must be remembered that the limit velocity depends on the material utilized and thus, for example, the corundum (Al2O3), which has a lower hardness than SiC, will have a lower limit velocity value. On the another hand, the problem with the exit velocity may affect all Russian mid-caliber anti-tank missiles, which is due to the construction of the ammunition utilized for high-speed cannons (the size of the casings, the material utilized for them, as well as the characteristics of the propelling material). besides in the case of a long-bore cannon of high-speed kal. 57 mm for its fresh anti-tank ammunition (APFSDS) marking 3UBM22 is expected to exit velocity around 1190 m/s.
 |
| The impact of the limit velocity on the penetration of ceramic armour by an elongated tungsten penetrator. The limit velocity for this case was previously estimated at 1210 m/s |
 |
| Anti-tank circular 30 mm BR type |
In addition, Russian sources mention the existence of as many as 5 another 30 mm anti-tank missiles. These are:
- BR, which is an APHE-type aircraft anti-tank missile, which is the primary kind of ammunition in Russian helicopters and combat aircraft,
- 9-A-4543, which is an APCR-type aircraft missile, besides utilized in Russian combat helicopters
- 3UBR7, which would be a (mythical) variant of the 3UBR8 rocket utilizing the uranium core,
- 3UBR10, which is simply a variant of the 3UBR6 rocket with polymer leading rings (their aim is only to reduce barrel wear, which takes place at the expense of the life of the projectile itself),
- 3UBR11, which is an APFSDS kind anti-tank missile,
There are besides indications of the existence of a kind 3UBR9, but it is not known what kind of rocket it is. However, it is worth mentioning a small bit about a 3UBR11 missile.
 |
| 30 mm kind 9-A-4543 |
This is the first confirmed Russian APFSDS kind rocket designed for high-speed cannons. His actual performance has not been given at this moment, so they are not known either the velocity of the exit or the penetration of this missile. However, any indications propose that 3UBR11 may be a copy of the Belgian M929, which was designed by MECAR (now part of Nexter) for usage in ammunition powered cannons 30 x 165 mm. Compared to 3UBR8 M929, it has a higher outlet velocity (1275 m/s), which can be effective in overcoming composite shields. In addition, it is able to pierce a tilted steel plate 45 mm thick with a distance of 1000 metres. However, it is not known how much this data can be compared to 3UBR11.
The second phenomenon, which will be discussed here, which is the fragmentation of anti-tank missiles, is linked to the application of the bulkhead strategy in Badsuk utilizing 2 layers of pre-green steel with a buoyancy fence.
The main problem with russian anti-tank missiles utilizing the steel core is their low efficiency in overcoming spatial shields or utilizing strong slope. While for the above mentioned 3UBR6, the critical angle of the armor can be estimated at about 30°, for rifles, anti-tank missiles can break as shortly as the armor is beaten at an angle of 18°. The hardness of the material utilized - especially armoured steel - besides influences this phenomenon. Here the effect is best seen utilizing advanced hardness steel, starting with class 500.
 |
| Fragmentation of B-32 anti-tank firearm shells 12.7 mm (left) and 14.5 mm (right) After passing through a thin, tilted steel plate. The plate on the left was 4.4 mm thick and on the right - 5 mm thick |
What's incorrect with Stanag 4569?
The basic standard utilized for ballistic protection tests of light and medium-armoured combat vehicles is the standard STANG 4569 (also known as AEP-55) introduced in 2002. Its 3rd variant is presently in force, which was implemented in 2014, but in its case the changes in the ballistic opposition test are sufficiently cosmetic that in this case the second version of 2011.
According to this standard, six levels of ballistic protection are distinguished, where the highest level provides immunity from subcalibre anti-tank ammunition. 30 mm. However, there is simply a clearly defined explanation of the results in the norm, which may lead to gaps in describing the actual protection of armoured vehicles. This, on the another hand, may lead to a decrease in the effectiveness of passive protection by entering it as a level of protection according to that standard.
In this case, there are 2 problems with standard 4569:
- deficiency of a level of protection to defend against ammunition 12.7 x 99 mm and 12.7 x 108 mm
- 30 x 165 mm ammunition protection is provided within level 6
However, it is worth describing why it is so important.
The STANAG 4569 standard has been "constructed" so that data safety levels consistent with this standard can theoretically warrant protection against all types of ammunition. Therefore, within Level 1, protection against 7.62 x 51 mm firearm shells with lead cores is required, while protection against the armored missiles of this caliber is required within Level 3. In between them - as a level 2 base - protection is required against anti-tank ammunition fired from automatic rifles. The full list of exact and theoretical requirements for each level of protection is given in the table below.
 |
| Requirements for ballistic protection according to STAG 4569 Ed. 2 |
As you can see, this standard omitted the request to defend against anti-tank ammunition. 12.7 mm, which is not as effective as ammunition. 14.5 mm, but it is more widely utilized due to the immense popularity of device guns specified as M2, DSZK or NSW, as well as the presence on the battlefield of anti-equipment rifles - besides known as large caliber selection rifles. Worse still, there are fewer standards for passive armour, which include opposition against Kal missiles. 12.7 mm. This is mainly due to the belief that the bulletproof vest will never supply safety against specified a missile, while armored vehicles are most frequently tested according to the standard phase 4569.
In short, we don't usage another standards, due to the fact that we have a standard of 4569. It's time for CS.
Fortunately, there is simply a little-known German standard in the European Union that describes the opposition to both individual armor and passive armor of combat vehicles. It is simply a standard of VPAM-APR 2006, which was implemented on 13 October 2006. Its 3rd amendment is presently applicable, which has been in force since 14 May 2009. According to this standard, there is simply a level of 13 and 14 ballistic protection, which guarantees immunity against ammunition 12.7 mm and 14.5 mm. However, the requirements for these levels of protection are more excessive than the standard phase 4569.
In both cases, the armor must withstand hits with at least 16 kal shells. 12.7 mm (for level 13) or 14.5 mm (for level 14) fired at a distance of 10 metres from the target. However, the standard recommends investigating utilizing 20 to 30 rounds of a given caliber fired towards a single test object.
In this case, the level 13 requirements are rather balanced and centred between the level 3 requirements of STANAG (22 hits with 7.62 mm at 30 meters distance) and the level 4 of STANAG (12 hits with 14.5 mm at 200 meters distance). This makes it possible to reasonably test the opposition of passive armor against kal missiles. 12.7 mm. On the another hand, VPAM level 14 in this case exceeds the requirements of STANG level 4 4569. True, in this standard for level 14, the velocity of 911 m/s is entered, which corresponds to the distance of 200 meters for a 14.5 mm bullet, but this can most likely be treated ambiguously. This allows you to check the better designed additional armor (or base armor) with 14.5 mm ammunition for level 4 STARAG.
 |
| SWISS P anti-tank missile caliber .338 Lapua Magnum |
In addition, the supporting VPAM-APR standard is rather liberal in terms of ammunition, which is allowed for certification. According to this standard, armor opposition can be checked, among others, utilizing Swiss firearm ammunition 7.5 x 55 mm, German hunting ammunition 8 x 64 mm, 12 caliber breneks, or anti-tank ammunition utilizing .338 Lapua Magnum cartridges. The second pierces steel armor 12 mm thick from a distance of 600 meters, so it can be effective in relation to armor gathering level 3 requirements. For comparison, STAG 4569 strictly imposes the kind of ammunition that can be utilized for certification, for example, for level 1 certification requires the import of 5.56 mm ammunition from Belgian, American or German production to make the test valid.
For this reason, the implementation of the German VPAM standards may be beneficial for the Polish arms industry. It can make greater usage of the possible of 12.7 mm and 14.5 mm ammunition for ballistic tests, while at the same time introducing greater freedom to usage test ammunition.
The second problem with 30 x 165 mm ammunition is that only 3UBR6 kind steel projectile was allowed for usage according to STANAG 4569. More specifically, his Slovak copy is now produced in NATO, making the Russian first not allowed to be tested according to this standard. The main problem with this projectile is that it is characterized by a much lower penetration than NATO-wst ammunition of 30 x 173 mm APFSDS type. And yet both missiles were aligned within 1 and the same level of ballistic protection.
In addition, there is simply a stupid mistake in the average state. The standard specifies that armor gathering the level 6 requirements must defend against ammunition 30 x 165 mm fired from a distance of 500 meters. However, the velocity of impact on the mark (which is 810 m/s) for the Slovak copy 3UBR6 corresponds to a distance of 750 metres. This could mean that NATO has identified a weak, full-caliber anti-tank rocket 40 years ago as a greater threat to their armored vehicles than modern, western sub-caliber ammunition.
There is besides the 3rd problem of this standard, which is frequently carefully overlooked. The requirements for each level of ballistic protection are further geared within levels between 3 and 5. This is because:
- level 3 is the highest level of protection, which requires opposition against hits from a crucial tallness (e.g. in urban fights, the opponent is located in a tall building)
- Level 4 is the highest level of protection which requires opposition against hitting perpendicular to the side and rear of the armored vehicle. In addition, in this respect, a given level can be met if both the sides and the rear of the vehicle are protected.
- Levels 5 and 6 are enforced only by hitting the front of the vehicle or its sides, but at an angle not exceeding 30° from the vehicle symmetry axis
This together means that a combat infantry car which is protected:
- in front of kind 3UBR6 and 30 mm kind 3UBR8 anti-tank missiles,
- on the sides in front of 14.5 mm-caliber anti-tank missiles, and possibly 23 mm-caliber 3UBR1,
- at the rear before 12.7 mm anti-tank missiles
actually meets the requirements for level 4 phase 4569 for front armor and level 3 phase 4569 for protected areas of combat vehicle.
Why is that? I'll remind you again in a nutshell.
Anti-tank ammunition of types 3UBR6 and 3UBR8 is characterized by worse armor penetration from 25 x 137 mm APFSDS kind ammunition. It is so possible that the shield will halt the Russian kal missile. 30 mm, but it won't halt the western kal missile. 25 mm. In this case, this shield meets the requirements for Level 4 (resistance against large caliber firearm ammunition) alternatively than Level 5 or 6. At the same time, level 4 is the highest level of protection of sides and rear combat vehicle. That means the side armor can halt the kal missile. 23 mm or even 30 mm, but it will inactive be marked as gathering the requirements for level 4. On the another hand, the 360° level of protection must be ensured on both sides and back. If the side armor stops the 14.5 mm cal bullet (corresponding to level 4), but the rear armor will no longer halt it, then the armor is marked as gathering level 3 requirements (resistance against tiny caliber anti-tank ammunition) alternatively than level 4.
Without the aid of computer simulations (or the usage of Badger in war conditions) we will never truly know what protection the successor of BWP-1 actually guarantees. investigating shields utilizing non-normative anti-tank means costs, and with limited resources for development, the manufacturer's primary nonsubjective is to quit unnecessary costs associated with working on his product. Instead, we are dealing with the definition of levels of protection that do not truly specify the actual protection of Borsuk against anti-tank weapons.
Besides, the military itself does not require specified additional tests from the manufacturer. Otherwise, specified a request as protection against Russian ammunition. For 30 mm would be determined by the military. An example of a decision with an additional request are ballistic protection requirements for a fresh Czech infantry combat car. It is not only essential to defend against anti-tank ammunition. 30 mm, but besides before Russian anti-tank ammunition. 57 mm. It is actual that the penetration of both types of ammunition is akin (due to the obsolescence of larger caliber ammunition), but that specified a request has been created, it must be enforced from the maker and verified. Furthermore, specified a request as protection against 3UBR6 missiles can be verified by purchasing a single fast-shooting cannon utilizing 30 x 165 mm ammunition and the usage of anti-tank ammunition from Slovak production, which is produced there on the basis of documentation provided by the russian Union in the mid-1980s. Be even by utilizing the air cannon and specially modified ammunition of a given type.
Another word of digression - the above data does not necessarily mention to Borsuk. That's why it's time to present what it might look like in his case.
Let's cut to the chase.
It should be borne in head that all aspects of the plan of the Borsuk armor mentioned by me are the sum of the assumptions envisaged and unforeseen by the designers of the successor BWP-1. Thanks to this and "dry" numbers it can go to the mark discussion of the ballistic opposition of Badsuk. This is mainly possible thanks to the inept OPSEC from the producer, or Huta Stalowa Wola.
The basic and overall most crucial information is that Borsuk's plan primarily uses advanced hardness armour steel (class 500) in the form of 10 mm thick plates.
I managed to measurement this thickness on the technology demonstration presented on MSPO 2017, which was later rebuilt to the function of the first prototype. This is important, that in the case of a separate construction of a technology and prototype demonstrator in the former, it is not essential to effort specifically for the thickness of the individual elements of the hull, as it is intended to execute only a visual function in the demonstration itself. Moreover, Badger on MSPO 2017 was deprived of additional buoyancy modules that appeared a year later. This is due to the increase in the mark mass of the combat infantry car, which was initially expected to be 25 tonnes and yet increased to 28 tonnes, while it was essential to keep the same water mobility. This, however, allowed me to accurately measurement the thickness of the outer armor plates. It is besides worth mentioning that the same steel plates (and of the same thickness) are utilized for the production of Opal III, which is present in the Polish Army in the form of artillery command wagons in self-propelled artillery squadrons armed with self-propelled Krab cannons and a single SMG120 Rak mortar, which serves in the Toruń Artillery and Armoured Training Centre. It may be suspected that specified a decision may consequence from reasons of saving money in the improvement of Borsuk and its subsequent serial production.
As far as the supplier of this steel is concerned, this is simply a secondary issue from the point of view of ballistic resistance, since specified armoured steel with a hardness of ~500 HB must meet the requirements of the American MIL-DTL-46100 standard. At least that is the case for most armored steel, as I will discuss in the next article in this series. This makes it possible to use:
- Swedish ARMOX 500 armour steel, which is entirely imported into Poland,
- Finnish armoured steel Miilux PROTECTION 500, which is heat-treated and mechanically operated in the Miilux plant in Tarnowskie Mountains,
- Polish armored steel ARMSTAL 500, which is produced in the Quality Steel Huta in Steel Wola - the direct neighbour of HSW,
- or possibly another Polish armored steel MILAR 480, for which Huta Częstochowa was responsible
However, unlike Rosomak, HSW is not convinced to usage Polish armoured steel in its products, deciding in return to import armoured steel from Sweden. On the another hand, MILAR 480 steel is not produced in series due to financial difficulties of Huta Częstochowa. Unofficially, however, due to problems with fresh steel investors, Węglokoks and PZZ were besides to be offered for 1/6 of its value. The very usage of Class 500 steel is unique to our reinforcement industry. In the West, for the construction of combat vehicles, the class 450 steels are used, which is better balanced between its hardness and plasticity, and at the same time is easier for welding.
The standard 46100 itself is public, so we can find the ballistic opposition of specified a single armor plate. However, due to the requirements of this standard, armor opposition is tested at an angle of 30°, while the consequence itself means a minimum compliant rocket impact velocity at 50% hits. In the case of a 10 mm thick plate, this velocity exceeds the output velocity for the M2 cal. 7.62 mm anti-tank rocket (.30-06 Springfield), which means complete protection against this kind of projectile. However, for the M2 anti-tank rocket 12.7 mm (.50 BMG) the minimum impact velocity is 652 m/s, corresponding to a distance of 550 metres.
Let us now decision on to the issue of the steel armor strategy utilized in Badger. In this case, 2 pictures will aid in the explanation of the text - 1 of my photographs made on MSPO 2018 and the another published in the monthly Military-Technik- Defence Report. My photograph will aid describe Borsuk's side armor, while the photograph from Altair will aid describe the front armor of this combat vehicle.
 |
| Photo of the bwp Borsuk body published in monthly RWTO (No. 9 / 2020) - photograph by Marcin Deptula |
In this picture, you can see a cross section of the advanced and lower Borsuk armor. In the case of the lower cover we are dealing with 2 steel plates in the spatial system, with the plate at the front being tilted at an angle of about 30° in the mediate part and about 50° in the lower part. The thickness of both plates may be suspected to be 10 mm. At the same time, the distance between these discs is large adequate that steel penetration missiles can be easy crushed between them. Officially according to the manufacturer, Borsuka's front armor provides level 4 passive protection (i.e. immunity from 14.5 mm ammunition), which in this case is actually provided by specified a spatial system.
However, specified a shield will besides be able to defend the armored vehicle from anti-tank ammunition. 23 and 30 mm utilizing steel cores. This is surely ensured in terms of crew and landing protection due to the fact that this is separated from the drive compartment by additional steel plates. It is simply a disputed issue, but it is likely to supply specified opposition without hazard of harm to the drive compartment. The warrant of failure to harm the engine or another components of the drive, on the another hand, does not be in case of usage against the 3UBR8 Badger with a tungsten penetrator. This may not have been taken into account due to the fact that the STARAG 4569 standard allows the dismantling of the powerpack and another components of the vehicle not being elements of the armor for ballistic tests.
As far as the advanced front armor is concerned, it can be noted that the steel structure is no different from what the Badger looks like. It can so be suspected that the advanced armour consists of a single steel plate with a thickness of 10 mm ~80°. As I mentioned earlier, specified a evidence can not only halt the ammunition of the kal. 14,5 mm, but besides ricochet APDS kind ammunition. 20 - 30 mm. In this area, it can be protected from 3UBR8 missiles without taking into account additional factors. Additional anti-slip layers, which are present on the top plate, may paradoxically have a affirmative effect on Borsuka's anti-slip resistance.
Why was Badger not tested to meet the requirements of Level 5 of STARAG?
The reasons are three:
1. The Polish Army does not usage 25 x 137 mm ammunition, which is utilized to meet the requirements of level 5 - for investigating armor at this level would request a dedicated Oerlikon KBA or M242 cannon, which in Poland does not exist, or a pneumatic cannon designed to fire the equivalents of the Kal projectiles. 25 mm. However, sending Badsuk abroad would require the approval of MON.
2. utilized in the Polish Army undercalibre missiles of kal. 23 mm may be counted as equivalent (but not equivalent) to APDS kal. 25 mm. Today, however, immunity from APFSDS kal-type missiles is required to meet level 5. 25 mm with greater penetration.
3. In case of powerpack dismantling for Borsuk ballistic tests, it may not meet the level 5 requirements.
 |
| Bok of the Bwp Borsuk demonstrators - photograph by Piotr Zbies You can perfectly see the individual armour plates and retardant foam |
In the case of side armor, you can see very well the section of the displacement bulkhead (which was not on the 2017 demonstration) and individual steel plates. Thanks to measurements from 2017 and visible changes (eliminating the slope of the side armor and adding easy disassembled floats) it is possible to find the exact side section, which was shown in 2018.
 |
| Cross-section of the side armor of the bwp Borsuk demonstrators. The plate of 8 mm thickness was located outside the vehicle. |
Such a cover - and more specifically its later version - was classified by the maker as gathering the requirements of level 3, i.e. protecting against anti-tank ammunition. 7.62 mm. In fact, however, due to the anticipation of firearm ammunition with carbon core, this shield is equally effective in protecting against large caliber firearm ammunition. The cover gathering the minimum level 3 requirements may defend against caliber-based anti-tank missiles:
- 12.7 mm fired at right angle from 100 meters
and
- 14.5 mm fired at an angle of 30° at 200 meters
It is known, however, that in the case of 14.5 mm projectiles specified ballistic protection can be achieved at 50% of the hits even erstwhile fired from a distance of 100 meters at an angle of 20°. However, given the usage of the spatial system, where steel plates are 80 mm apart, the actual effectiveness of this armor may be even higher. The above results are possible erstwhile the distance between steel plates is 30 mm.
However, due to the Gestapo's reservations regarding the width of the Badger, which was 340 cm and not 320 cm, as originally decided by the manufacturer, the plan of the side armor of the fighting infantry car was changed. This is rather a clever game erstwhile it comes to intelligence security, but the summarum details of the side armor plan could not have changed much.
The main changes that can be seen are the greater thickness of floats, which can improve the effective protection of the spatial armour and the presence of another thin, tilted steel plate, which can improve the opposition to firearm ammunition hits and increase its likelihood of crushing during penetration.
However, in the case of anti-tank ammunition protection from fast-shooting 23 and 30 mm guns, the opposition to hits shall be based at least 60° for the time being.
In the case of 30 mm 3UBR6 caliber missiles, Borsuk's side armor may be suspected to defend against hits at an angle of 60° at a distance of 500 - 700 meters and at an angle of 65° at a distance of 300 metres.
On the another hand, a kind 3UBR1 23 mm projectile fired at a distance of 700 metres is characterized by a 1/4 lower penetration of steel armor than a larger 3UBR6 projectile. On the basis of this, it can be assumed that the side armor protects against 23 mm hits at an angle of 60° with a distance of 250 - 300 metres.
A completely separate issue is besides the anticipation of utilizing a composite additional armor. At this point, this problem goes beyond the current possibilities of describing this problem. For it is up to both the military and the maker to find whether the Badger will receive heavier additional armor, what additional armor it will be, and how well it will protect. There are a fewer national extra armor proposals, and I hope to describe them all someday. curious producers from abroad who want to propose their solutions in Badger may well appear. The full issue of the usage of additional armor is discussed further in the article.
Protection of ZSSW-30
A completely different communicative is to supply ballistic protection for an unmanned combat tower. Since it is not crewed, it did not seem essential to supply adequate armor at first. For this reason, the first unmanned towers were open-type structures, i.e. structures de facto without their own hull. However, due to the vulnerability of specified towers to weather conditions and harm from branches, stones, etc., the closed-type unmanned towers were gradually implemented for sale and service. Since we are talking about unmanned towers, their armoring remains a secondary issue. due to this, there are not many structures in the planet whose passive armor provides opposition exceeding level 3 around the tower, not to mention reaching level 5 or 6 in front of the tower.
 |
| Photo of the ZSSW-30 tower body published in RWTO monthly magazine (No. 9 / 2020) - photograph by Marcin Deptula |
ZSSW-30 in its present form - this is simply a tower designed for KTO Rosomak - does not break out of this scheme. On the basis of my own analysis, which I will describe more accurately, it can be estimated that within the tower structure itself protection at level 3 (immunity against anti-tank ammunition 7.62 x 51 mm) has been provided, and in areas weakened and located outside the tower itself - at level 2 (immunity against ammunition 7.62 x 39 mm). The steel structure of the tower itself (without additional armor) was designed to defend at level 1 (resistance against lead and lead-steel ammunition).
 |
| Panzer cover of the old kind commander during ballistic trials |
This is straight due to the thickness of the steel plates, which were bolted to the tower and the fact that the structure of the tower was tilted at an angle of about 30°. The usage of steel in the function of additional armour was most likely due to the savings that were to be achieved in the production of prototype towers. However, this does not preclude the usage of another additional armour systems made of another materials and gathering another passive protection requirements. It is worth mentioning, however, that HSW decided to place a thin layer of polyethylene fabric (the production of German Dyneema) between the steel structure of the tower and steel additional plates.
 |
| Cross-section of the old panorama of the commander at ZSSW-30 |
This solution allows partial depreciation of the additional armour and the effort to destruct defects resulting from the armor structure of at least 2 adjacent steel layers. In the absence of a absorbent layer (polyethylene fabric or rubber lining), the ballistic opposition of specified armor strategy is lower than the opposition of a single steel plate with a full thickness. In addition, the absorbent layer itself increases armor opposition against artillery fragments. The presence of the absorbent layer in the structure of the ZSSW-30 armour was revealed by WITU in 2015 at the First Polish-Brazilian Conference on discipline and Technology organized jointly by the Institute of Aviation and University of Brasilia. Moreover, due to the nature of the fabrics, this layer can be seen sometimes on the ZSSW-30, especially within the lowered shield protecting the spare sight (between the cannon optoelectronic module and the cannon).
 |
| Visible layer of Dyneema in the rear viewfinder cover |
An crucial part of discussing the ZSSW-30 armor is, however, the presentation of the additional armor structure protecting the Spike-type ppk launcher, which are located on the right side of the tower. This structure is likely to disagree from the shield protecting the remainder of the tower, while at the same time due to the indiscretion and defective plan of this shielding, it is possible to describe the structures of this part of the additional armour.
 |
| Unmanned tower and close-up to visible (left) bright ceramic component on the tower - photograph HSW |
As you can see, in this part of the armor is visible a ceramic layer made of corundum (Al2O3) advanced purity (more than 99%) with magnesium oxide (MgO) acting as sintering modifier. This is easy to identify due to the colour of this material akin to that of ivory. If calcium oxide (CaO) or lower purity of the material, the colour of alumina would be more akin to that of white. In addition, it can be noted that the armor module consists of a single layer of ceramics with a thickness of between 6 and 10 mm, meaning that it was designed to meet the requirements of level 3 according to the standard STANAG 4569. In the case of armor designed under level 2, ceramics are not profitable, while at level 4, 2 layers of armoured ceramics or a single, thick layer of tiles or ceramic barrels are required.
On the another hand, the flaw in the construction of these panels is the failure to usage metallic frames to defend ceramics against possible harm and defend the full armor strategy from the eyes of curious people. Moreover, the metallic frame reduces the degree of harm to the ceramic layer during armor penetration and increases the integrity of the already pierced armor. The second missing component of the armor is the fugue, which plays the top function in reducing the damaged armor surface during the puncture. The usage of fugue in ceramic armour is the cheapest way to accomplish multiple hits resistance, which is so required in STARAG 4569. It can be more than convinced that specified errors erstwhile designing armor consequence from the fact that usually during a test fire, the intent of which is to test armor ceramics, neither frame nor fugue is utilized (although not always for the latter).
 |
| Comparison of the size of corundum layer harm after hitting 7.62 mm From the top: 1. large, single ceramic plate 2. Ceramic tiles with empty gaps between them 3. Ceramic tiles in aluminium honeycombs |
Interestingly, the plan of the full additional armor on the ZSSW-30 is akin to the plan of the composite armor proposed in the patent EN 219768 B1 from the WITU. peculiar attention is paid to the ZSSW-30 strips, which defend towers on the edges of the additional armor module. Furthermore, thanks to this patent, it is possible to describe the structure of the additional ceramic armour on the ZSSW-30.
 |
| Potential ceramic armor cut to ZSSW-30. The layout is devoid of frames, fugs, or absorbent layers, which makes its effectiveness questionable. It is besides distant from the 1 shown in the patent. |
The presence of ceramics only within the shield protecting the double anti-tank rocket launcher may be due primarily to the desire to reduce the cost of working on additional armor, as well as the fact that the Polish defence manufacture has not yet cooperated with Polish factories with competence in the manufacture of armour ceramics. Instead, it was decided to usage ceramic tiles produced outside the EU and NATO to make this additional armor. However, national cooperation in this field would be useful in the close future to make lightweight composite shields for Borsuk and ZSSW-30 gathering the requirements of level 4 or even the old level 5. The worst part, however, is that there was absolutely no effort to plan the appropriate composite-ceramic armour for the Polish unmanned tower. 1 can only hope that serially produced towers will be better protected in this respect.
Badger as a modular armored vehicle
The fundamental issue that is forgotten in the context of the Badger is that it was designed as an armored vehicle utilizing modular armour kits. This means that depending on the customer's willingness and needs, this vehicle can be adapted to a given level of ballistic resistance, including opposition to anti-tank grenades with ERA. You can besides manipulate the width of "bewup". In the base version (i.e. without additional floats) Borsuk is only 320 cm wide, which makes it 1 of the fewer caterpillar combat vehicles that are located in the Czech rail gauge (maximum vehicle width: 329 cm). At the same time, with our transport capabilities, you can increase its width to 355 cm or up to 400 cm. Railway wagons intended for the carriage of dense military vehicles were designed to carry tanks from the T-72 family, which are 355 cm wide, even the rail gauge in our country allows the carriage of vehicles up to 4 meters wide.
Paradoxically, however, Borsuk's buoyancy could have another benefit. In addition to utilizing modular armour kits, it would be possible to adjust the "bewup" to the installation of interior peculiar armor modules. This is an different issue in the case of combat infantry vehicles, and not many primary tanks usage specified facilities. However, it cannot be excluded that the implementation of specified an option would only be feasible if the Borsuk hull was somewhat redesigned and adapted to specified changes. On the basis of a photograph of the bare Borsuka body, however, it can be suspected that the free space in front of the propulsion strategy is suitable for the function of "pockets" for additional armor.
The second aspect you can manipulate in Badger is its mass. This is usually limited to the strength of the suspension applied. In the case of Borsuk, it was decided to apply hydropneumatic suspension alternatively of an old torsion-based suspension. In this case, 12 Horstman InArm suspension modules of British-German production of Horstmann were used.
 |
| Horstmann Hydropneumatic Suspension Demonstrator built on Bradley M2 chassis |
This suspension did not become as popular as utilized in Rosomak and the proposed Hydrostrut suspension in LPG. The only serial-produced combat vehicle utilizing this kind of suspension is the single-singapore fighter car Hunter, whose serial production began in 2019. The reason for this low popularity is that this kind of hydro-pneumatic suspension was designed for deleted projects of the fresh American bwp (FCS) and the British combat reconnaissance vehicle (FSCS) while the German Pumas utilized a more proven hydro-strut suspension.
However, the actual scope of this suspension was to be demonstrated with the bwp proposed by BAE Systems in the GCV programme. There, 14 InArm suspension modules were to supply the maximum fighting mass of the vehicle, which was to be up to 76 tonnes. The same suspension is besides presently proposed for M2 Bradley's combat infantry wagons, where 10 suspension modules are intended to supply a burden capacity of up to 45 tonnes. In the case of Badsuk, Horstman's suspension was configured under a combat mass of 28 tonnes. However, the advantage of this kind of suspension is that it interferes to a tiny degree in the construction of the hull of the combat vehicle, especially in the construction of its bottom, while at the same time the process of replacing the suspension modules is simpler compared to the process of replacing the suspension based on torsion bars. In addition, the burden capacity of the suspension can be changed by selecting force in a chamber filled with compressed nitrogen. As can be seen, therefore, there are no limits to the possibilities of the hydropneumatic suspension applied.
The only limit for expanding the amount of armor on our "bawup" is the engine used. The drive unit from Friedrichshafen, which is presently utilized in Borsuk, can accomplish up to 815 hp in another variant. The maximum fighting mass of Borsuka would be 35.9 tonnes, while utilizing the origin from BWP-2 this value increases to 38.8 tonnes. However, this is simply a much higher value than the current Borsuka combat mass, which only shows that if the BWP-1 successor's buoyancy is discontinued, the possible for expanding the mass exists and can be utilized well. Given the current combat mass, which with full equipment is 28 tonnes, we can see that the power supply in the propulsion strategy utilized allows an additional 8 to 11 tons of armor to be added. Of course, at the expense of Borsuk's buoyancy. This adapted Badger could be much better armored, starting with the provision of level 4 STARAG around the vehicle and level 5 for the front armor.
But what's the ceiling for a 38-ton combat car?
At this point, with the current achievements of material engineering, it is possible to supply protection against hits of APFSDS 30 mm caliber from a distance of 1000 meters. Both front and side. However, it will be a subject for another articles that will appear on this blog.
Bibliography
- NATO Standardization Agency, AEP-55, Volume 1 (Edition 2), Procedures for evaluating the protection level of armed vehicles. Volume 1. Kinetic energy and artillery three, 31.08.2011
- Marcin Deptula, New BWP: Half-century programme, Military-Technik- Defence Report, 9 / 2020, pp. 4 - 11
- V. Paris, A. Weiss, A. Vizel, E. Ran, F. Aizik, Fragmentation of armor piercing steel projects upon oblique perforation of steel plates, DYMAT 2012 - 10th global Conference on the Mechanical and Physical Behaviour of Materials under Dynamic Loading, EPJ Web of Conferences, No. 26, 2012
DYMAT 2012 - 10th global Conference on the Mechanical and Physical Behaviour of Materials under Dynamic Loading
- J.C. LaSalvia, B. Leavey, H.T. Miller, J.R. Houskamp, R.C. McCuiston, Recent results on the fundamental performance of a hot-pressed silicon carbide impacted by a subscale long-rod penetrations, Advances in Ceramic Armor IV, pp. 89 - 97
- A. Weiss, A. Borenstein, V. Paris, M. Ravid, N. Shapira, Evaluation of critical ricochet Englishs for 25 mm APDS-T projectile on metallic targets - modeling and verification, Procedures of the 2019 Hypervelocity Impact Symposium, pp. 82 - 88
- Adam Wiśniewski, Paweł Żochowski, Add-on passive armour for light armed vehicles protection, Weapons Technology Problems, 1 / 2013, pp. 17 - 24
Adam Wiśniewski, CAWA composite armour casesettes for protection of land objects against of impacts, diary of Polish-Brazilian discipline & Technology, 1 / 2015, pp. 214 - 218
Adam Wiśniewski, Modular layered passive composite armour, patent PL 219768 B1, announced 09.12.2013, granted 31.07.2015
- Peter Zbies, Standard non-comparable - ballistic verification of armor and anti-tank ammunition, fresh Military Technique, 11 / 2020, pp. 38 - 44
Z.N. Zhao, B. Han, F.H. Li, R. Zhang, P.B. Su, M. Yang, Q. Zhang, Q.C. Zhang, T.J. Lu, Enhanced bi-layer mosaic armor: experiments and simulation, Ceramics International, 15 / 2020, pp. 23854 - 23866
