In the context of the acquisition of fresh military equipment for the Armed Forces of the Republic of Poland, it is said and written that ordered and delivered weapons should be adequate to the threat of Russian military equipment after the current Russian-Ukrainian war. 1 of the topics related to this is the acquisition of combat infantry vehicles, which in our mechanized units will replace outdated BWP-1. A year ago, I presented to you in my blog what the possibilities of Huta Stalowa Wola's swimming combat car Borsuk, which was to verify all the information that had previously been made public.
Unfortunately, due to the launch of a full-scale Russian invasion of Ukraine and the related supplies of Polish military equipment, the Ukrainian side appeared in our MON, a purchasing fever which was frequently unfortunately devoid of logic and more sense. While the subject of the acquisition of the K9A1 self-propelled cannonhaubic or the planting of additional M1 Abrams tanks may make sense, the most controversial subject was the proposal to acquisition Korean combat infantry wagons AS-21 / PL-21, which would officially interact with the Badgers. This subject is out of date, and in return the Polish arms manufacture has received another chance to show its capabilities.
There is besides an academic discussion about how the armored infantry car should be and how the hull of specified a bewup should be shaped. Although Borsuk material I presented the advantages of front armor consisting of 1 wall with a limited slope, but it is evident in the discussion that unfortunately we are dealing with people who are not truly curious in the subject of reinforcement. possibly these people have not read my earlier survey on Badger, nor will they read what I wrote here.
And the following material, in which I will present the first more detailed information about the Russian subcalibre 3UBR11 anti-tank missile, will show you why trying to implement or copy Western solutions without any analysis can not always be cost-effective.
I will besides point out in advance that despite research, kind 3UBR11 ammunition did not enter the equipment of the Russian armed forces. According to unofficial information, the problem was identical to that of 3UBR8 ammunition, i.e. the exit brakes in the fast cannons did not work with the discarded subcalibre ammunition sabots. Additionally, 2A72 cannons, which operate on the rule of a long barrel recoil, may have had problem automatically reloading this kind of ammunition, resulting from a low mass of APFSDS kind missile. Norwegian NAMMO faced specified problems during the work on subcalibre ammunition 30 mm x 165 for the Finnish armed forces.
Russian subcalibre anti-tank rocket kind 3UBR11
Why did the Russians request 3UBR11?
At the time of implementation of the 2A42 rapid-fire cannon, which utilized 30 x 165 mm ammunition, the primary anti-tank cartridge for it became 3UBR6. 3UBR6 uses a full-caliber steel penetrator, which is capable of penetrating from a distance of 700 metres inclined at an angle of 60° 20 mm armored panels, or a vertical steel armour of 35 mm thickness. specified penetration was adequate to overcome the armour of most NATO armoured infantry vehicles (especially M113), whose bodies were usually made of aluminium alloys at the time.
However, already at the start of the 3BR6 it may have proved ineffective against the better armored infantry vehicles, which were developed in German-speaking countries. Both Marder and Swiss Tornado were the only NATO-wish bwps that continued to usage uniform steel shields, making them well protected against anti-tank ammunition. 14.5 mm. The main advantage, however, was the usage of a steel plate with a thickness of as much as 32 mm as the front armor of the lower. Its additional inclination at an angle of 23° (in Marder) or 30° (in Tornado) provided full protection against BS-41 (57-BZ-562) missiles containing the carbide core. In addition, specified thick armor provided 50% protection against hits of APCR missiles (DM43 type) cal. 20 mm at a distance of 800 meters.
Forward combat armor section Marder 1A3
The mention to DM43 is peculiarly crucial here, as this projectile is characterized by greater penetration of vertical steel armor than Russian 3BR6. This, on the another hand,
means that already at the start this rocket was ineffective against parts of the European armored infantry wagons. The problem did not happen in the case of U.S. M2 / M2A1 Bradley and YPR-765, where the primary criterion of protection (and not full met) was protection against hits by B-32 kal steel missiles. 14.5 mm from 300 metres.
Such concerns (or caution) led to the improvement of a 3UBR8 cartridge in the late 1980s and 1990s containing a subcalibre APDS kind anti-tank rocket with core
Tungsten, which was already possibly effective against SPz Marder 1A1 and 1A2 armor. NATO knew about the work on this projectile, which resulted in modernisation packages for the Bradleys, Warriors and Marders, which contained elements of an additional steel armour designed to defend against this ammunition. However, the designation "3UBR"'"3BR"used in the USSR and Russia with full-caliber anti-tank ammunition may have confused about the real capabilities of this missile. Based on available information from that time, it can be concluded that in the West under the designation 3UBR8, a cartridge containing a full caliber APCR-type anti-tank rocket was expected. The implementation of specified ammunition for the equipment of the russian Army has been feared for a long time, which is why in the work on Leopard 2 and XM1 the criterion of full protection against specified ammunition (excluding the drive compartment), which was verified precisely by the usage of DM43 ammunition, appeared. specified a cartridge was indeed made beyond the east border, but its probable designation is 3UBR9. This ammunition will be described in another text.
Schedule of the German anti-tank rocket DM43 cal. 20 mm. In the United States, it is known as M602.
Returning to the subject, this mistake made Marder 1A3 and M2A2 Bradley full protected against 3BR6 steel missiles, but not so well protected against subcalibre ammunition with tungsten core. For both bwp the estimated minimum safe distance is about 700 to 1000 metres. From the position of the Russian-Ukrainian War, however, it is comforting that the Russians did not solve the problem of safely rejecting the sabot in having a 30 mm cannon outlet brake. As a result, the expected effective scope of this ammunition falls from ~2000 metres to only 100 metres, and thus this ammunition is not utilized by the Russians on the front line.
Western analysts, however, may have had a chance to rehabilitate, due to the fact that on the wave of the Yeltsinian thaw the construction of the 3UBR8 cartridge was revealed in 1994, so the Russians no longer had any secrets to hide. At that time, however, the first APFSDS missiles appeared in NATO to small-caliber fast-shooting cannons. Here we talk about the American M919 and Swiss PMB 090 for 25 mm and PMC 287 for the Mauser MK30 30 mm cannon. This made the Russians back late for the improvement of medium-caliber artillery ammunition against NATO states. In addition, in 1999, the STARAG 4569 standard was implemented in NATO, the highest level of protection (level 5) of which provided protection against 25 mm APDS ammunition, which was at the time comparable to the Russian 3UBR8 cartridge. These 2 issues may have been the reason why the existence of kind 3UBR11 anti-tank ammunition was first revealed in 2004.
Characteristics and criticism 3UBR11
Let's start rebuilding a 3BR11 subcalibre anti-tank rocket first.
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Visualisation of 3D subcalibre 3BR11 anti-tank rocket based on available images and graphics
The penetrator of this bullet actually consists of 3 drones. On the front we are dealing with 2 rollers - 1 with the diameter of the full penetrator (i.e. 10 mm) and the another with a smaller 1 with a diameter of 6 mm. The key is that we're talking about waltzes here. The roller-shaped penetrators are optimised to penetrate tilted armour guards. This is due to how an anti-tank rocket is eroding erstwhile penetrating a steel armour depending on whether it is tilted or not. As a consequence of friction of the penetrator against the crater walls, the form of the tip changes, yet aiming for the rounded form of the penetrator tip. Based on studies carried out on U-0.75Ti and tungsten alloy penetrators (probably 91%), it has been shown that a flat tip penetrator needs 6.5% lower velocity than a penetrator with a bevelled cone tip and 20% lower velocity from a penetrator with a conical tip to pierce a steel armour inclined at an angle of 70°. However, in the case of an untiltted armor, the flat tip penetrator needs respectively 4% and 11% higher velocity than the penetrators with a cut-off tip and a full cone. This difference in the required speeds is due to the penetration erosion process during armor penetration.
For comparison, NATO's primary anti-tank rocket is 30 mm, or American-Norwegian NM225 / Mk 258 has a tip in the form of a bevelled cone, making it more effective to pierce the unfitted armour. In the later version, the usage of tungsten carbide tip was considered, which clearly indicates at least an effort to evolve the projectile towards the fight against uncluttered composite shields containing ceramics.
Tungsten penetrators for APFSDS kind PMC 287, photograph by Rheinmetall AG
It is peculiarly interesting to usage a tip with a smaller diameter. In 3UBR11, the usage of specified a drone results straight from the copying of the construction of the Swiss subcalibre PMC287 anti-tank missile, which was developed by Oerlikon Contraves (now Rheinmetall Waffe Munition) for the Mauser MK30 fast-shooting cannon.
Originally, the concept of utilizing specified a tip appeared in a subcalibre DM23 105 mm (known as M111). The intent of the usage of additional tungsten cylinders was to limit the process of ricocheting the projectile during the penetration of tilted steel armour. While the ricocheting itself is not as problematic as the full-caliber anti-tank ammunition, the anticipation of bending the penetrator during the penetrator gave emergence to quite a few complications, which was peculiarly evident during the penetration of steel bulkhead armour. However, loose mounted cylinders in the M111 did not solve the problem at all, as erstwhile the tilted armor was pierced and the aluminum ballistics cap was destroyed at the very beginning of the penetration, these cylinders were reflected by the surface of the armor itself. As a result, these played no function in the penetration process. However, the concept itself was right and was yet improved in the DM33 subcalibre missile, but 120 mm. The 3 loose cylinders present in the M111 were replaced by an elongated tip with reduced diameter, which was permanently connected to the remainder of the penetrator.
German subcalibre anti-tank rocket kind DM33 kal. 120 mm
However, it was crucial that a tiny area of reduced diameter, which acts as a carbu, was located between the tip and the right part of the penetrator. The stresses acting on the penetrator itself during penetration should make the tip separate from the remainder of the bullet, ricocheting simultaneously on the surface of the armor. The crater itself was formed after the ricochet, however, makes the remainder of the penetrator seamlessly enter the armor without hazard of buckling it.
The skillful usage of carbons in a subcalibre projectile allows to optimize the penetration process, which affects the penetration of composite armour
In the case of 3UBR11 – or at least its first version – we do not see the presence of the carbu. Instead, we are dealing with a simple narrowing of the front of the penetrator, which can function the same way as in the case of the presence of a carb, but so much as this warrant no longer exists. By the way, photographs of the penetrators utilized in PMC 287 indicate that, despite specified an oversight, this inactive looks like a direct copy of the solution developed by Oerlikon. As a result, an appropriate tungsten alloy heat treatment process plays a peculiar function in the effectiveness of the Russian subcalibre missile. If this 1 has not been selected properly, a bent armor can be bent or even crushed.
Let's decision at the very end to more dry data.
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The information I found on 3UBR11 indicates that it is characterized by the anticipation of penetration inclined at an angle of 60° of 45 mm thick armor plate with a distance of 1000 metres. This is simply a much worse consequence compared to NATO-narrow APFSDS missiles of the same caliber, which for comparison are able to pierce from the same distance inclined at the same angle of armor plates of 52 – 55 mm thickness. This at the same time indicates that the exit velocity of the 3BR11 rocket is about 1250 m/s. For comparison, the output velocity of NM225 and PMC 287 is 1405 – 1410 m/s. This difference is simply due to the limitations of the 30 mm x 165 cartridge comparative to the NATO-wish 30 mm x 173 cartridge, the consequence of which is the ability to accomplish much lower kinetic energy from western ammunition.
Continuing, based on pattern developed by 2 employees of the Swiss RUAG Land Systems, Walter Lanza and Willie Odermatt, it is possible to estimation the maximum penetration of this projectile at a glance. The consequence itself may be alternatively imprecise due to the form of the penetrator, but the value that can be obtained is 270 HB for armour steel, respectively:
- 50 mm at an angle of 60° (i.e. 100 mm)
- 77 mm at an angle of 30° (i.e. 89 mm)
- 86 mm without slope
Where advanced hardness armour steel (420 HB) is used, the values obtained shall be:
- 42 mm at an angle of 60° (i.e. 84 mm)
- 65 mm at an angle of 30° (75 mm)
- 72 mm without slope
Given the Russian trends in the plan of anti-tank missiles with dense metallic alloy penetrations, it can be clearly indicated that WNZ-90 alloy was utilized in the 3BR11 missile, which contains 90% tungsten, 7% nickel and 3% iron. This is an alloy developed inactive in the russian Union, by which it is of lower quality than Western tungsten alloys that previously could have been imported by the Russians. However, the usage of a newer WNŻ-10 alloy, which has a akin chemical composition, cannot be excluded, but thanks to the modified treatment, it has much greater mechanical strength. In addition, based on the mapping of the form of the full projectile, it can be indicated that the full mass of the projectile (without sabot) is 147 grams, of which 140 grams is the mass of the penetrator itself.
Lessons for Us
In light of all this, we have had a long-standing discussion about a heavy-armoured infantry car. Given the improvement trend of the passive shields of the infantry cars, it can be concluded that the request to defend a heavier infantry car will be able to address immunity from 3UBR11 kind anti-tank ammunition.
Comparison of information widely available on the net with those you have had the chance to read here, at the same time indicates that the penetration of 3BR11 can be overestimated and, furthermore, the pedigree of Russian ammunition itself may be mistakenly indicated. Contrary to the belief of 3UBR11, it was based on Swiss PMC 287 for cannons utilizing 30 mm x 173 ammunition, alternatively than Belgian M929, which uses the same cartridge. M929 – developed by MECAR (now Nexter Arrowtech) – was created on the basis of the M928 cartridge from the same maker and was only tested by Slovaks in 2019. There is so no chance that the missile, which was created at the latest in 2004, would be based on the rocket tested only in 2019. For us, this is of large benefit, due to the fact that PMC 287 ammunition was utilized to test the armor of the German Puma infantry car. And that besides means that Puma is immune to 3BR11 hits with a large surplus.
Anti-tank ammunition kind M929 on tests in Slovakia, photograph Miroslav Gyurosi
At the same time, the analysis of the 3UBR11 ammunition plan indicates that the recommended peculiar armor plan may be the deficiency or slight inclination of the armor, while simultaneously utilizing ceramic layers and bulkhead armour components. As I pointed out, a roller-shaped penetrator needs a velocity of ~11% higher than a cone-shaped penetrator, which translates into a difference in kinetic energy of up to 23%. possibly low mechanical strength of the tungsten alloy utilized can make the penetrator delicate to the usage of steel layers in the spatial system, and this in combination with the low first velocity of the projectile makes 3UBR11 highly ineffective against ceramic shields.
Thanks to Russia's free approach to OPSEC, we can learn a lot about the construction of Russian anti-tank missiles, as I demonstrated to you on the example of 3UBR11. Moreover, it has been possible for a short time to explain the plan of another fresh anti-tank missile. This is due to the fact that it is simply a kind 3UBM22 ammunition for S-60 and S-68 kal. 57 mm, which in the latest edition was demonstrated on the 2S38 self-propelled anti-aircraft armat and heavy-duty BMP-T-15 infantry car. And I think it could be another, but shorter text.
Bibliography
- I'm sorry.Tankograd: 30 mm x 165 Cartridges
- MIL-STD-662F, Department of Defense. Test method standard. V50 Ballistic Test for Armor, 18.12.1997
- patent RU 40461 U1, Унитарный малокалиберный патрон, W.W. Amanov, B.M. Butajev, A.I. Kosichin, A.S. Korobkov, O.T. Cziżewski, W.O. Czmytenko, announced and awarded 10.09.2004
- patent RU 2265791 C1, Стреловидный бронебойный снаряд, W.W. Amanov, B.M. Butajev, R.U. Esiev, A.I. Kosichin, A.S. Korobkov, O.T. Cziżewski, W.O. Czmytenko, announced 20.10.2005, awarded 10.12.2005
Miroslav Gyurosi, Mecar's M929 APFSDS-T ammunition undergoes Trials in Slovakia, 17.05.2019
- Wendy Leonard, The effect of noseshape on depleted uranium (DU) long-rod penetrations, U.S. Army investigation Laboratory, ARL-TR-1505, September 1997
