Wednesday, September 6, 2017

New Polish AFVs revealed at MSPO

At the currently ongoing MSPO 2017 defence exhibition in Poland, a number of new combat vehicle prototypes were presented for the first time to the public. These vehicles include new main battle tank (MBT) variants, the Borsuk infantry fighting vehicle (IFV), that is currently being developed for the Polish Army, aswell as various wheeled vehicles such as proposed variants of the Rosomak (locally produced Patria AMV).

The PT-91M2 is a further upgrade of the PT-91 Twardy, incorporating many features of the PT-91M Pendekar
The PT-91M2 is an upgraded variant of the Polish PT-91 Twardy tank, although some sources suggest that the T-72 left in Polish Army service might be upgraded to this new configuration. Unlike the Polish Army PT-91 model, the PT-91M2 makes used of the Sagem SAVAN-15 fire control system from the French manufacturer Safran. This is also used on the Malaysian PT-91M Pendekar, currently the most advanced PT-91 version in service with the military of a nation, and is related to the SAVAN-20 system used on the French Leclerc MBT.
The system consists of a new primary sight for the gunner, a ballistic computer and sensors for the gun stabilization and automatic lead. The gunner's optic with two axis stabilization includes a direct daylight optic with 2x and 10x magnification, a thermal imager with two magnification levels and electronic zoom, aswell as a laser rangfinder. According to the manufacturer, the SAVAN-15 fire control system offers a high accuracy with a first-round hit probability of more than 90 percent and can also be used to fire at moving targets while the tank itself is moving.

The SOD is placed above thee OBRA-3 laser warning system
The protection of the PT-91M2 is enhanced by the use of a new version of the ERAWA explosive reactive armor at the frontal arc and most of the sides of the tank. The tank is covered by a mixture of the new ERAWA-3 ERA and the old ERAWA-1 armor, though the latter ERA tiles are apparently not used on the turret frontal section. Slat armor is used to protect the rear section of the MBT against simpler types of rocket propelled grenades (RPGs). The OBRA-3 laser warning system from the Polish company PCO SA is used to alarm the crew when being targeted by an ATGM launchers or by an enemy combat vehicle. Ontop of the OBRA-3 sensors, the modules of the new SOD situational awareness system are mounted. This system is similar to Rheinmetall's SAS and the Turkish YAMGÖZ close-range surveillance system (used on the Altay), consisting of multiple modules featuring thermal imagers and/or daylight cameras to observe the surroundings of the tank.

The SAVAN-15 gunner's sight
Aside of using a new FCS, the PT-91M2 offers another firepower enhancment. It is fitted with a new 125 mm smoothbore gun, which according to a spokesperson at MSPO is more precise than the previously used one. The exact model of the gun was not disclosed at the time of writing this pasage, it could be either a KBM-1M/KBA-3 gun from the Ukrainian company KMBD Morozov or an improved version of the 2A46MS of the Slovakian manufacturer ZTS Špeciál. Due to the limitations of the T-72's autoloader design and the still quite limited pressure and barrel length of said tank guns, the PT-91M2 is still not capable of reaching armor penetration levels similar to tanks fitted the latest 120 mm smoothbore guns; this is the reason why the PT-16 and the PT-17 exist as more potent upgrade and export options.

At the right side of the rear hull, an APU is installed.
The PT-91M2 is powered by the S-12U diesel engine from the Polish company PZL-Wola. This four-stroke multi-fuel capable engine has twelve cylinders and is watercooled. At a (dry) weight just below one metric ton, it provides 820 or 850 horsepower output. In the rear section of the tank at the right side, a new auxiliary power unit (APU) is located, which has been claimed to provide an output of 8 to 10 kW. This additional power system can provide electricity for the tank's electronics even when the main engine is not running, thus reducing the fuel consumption and enhancing the PT-91M2's thermal and accoustic stealth characteristics for ambushes.

The PT-17 is a new tank variant broadly similar to the PT-16 prototype from last year.
A more severe upgrade for the T-72 and PT-91 designs is the new PT-17 main battle tank. This tank is the result of a closer cooperation between a number of Polish and Ukranian companies. While the hull seems to be still largely based on last year's PT-16's hull, the PT-17 features a new turret compared to its predecessor.
While some web-forums claim that this turret is identical to that of the T-72-120 prototype, there are several reasons to question such statements. It rather appears that some of the T-72-120 components were taken and integrated into a barebone PT-91/T-72 turret. For example the lack of roof-mounted ERA (aswell as the lack of mounting points for such armor tiles), the different shape of the add-on armor and the fact that the tank is fitted with composite armor rather than explosive reactive armor are all indicators for this not being the turret of the T-72-120 prototype. Furthermore four modules of the Obra-3 laser warning system from PCO SA are installed on the turret, which can detect the laser wavelengths commonly used in rangefinders and for laser-beam guided missiles. 

The gunner's sight of the PT-17 is made by the Polish company PCO SA
The PT-17 utilizes the same optics and fire control system as the earlier PT-16 prototype MBT. This means the commander is provided with a GOD-1 Iris sight mounted ontop a small and fixed mast on the turret, while the GOC-1 Nike serves as the gunner's main sight. The GOD-1 Iris is an independent optitc for the commander with 360° traverse, which also provides (depending on configuration) -20° depression and +60° elevation in the vertical plane. It includes a thermal camera (operating in the 8 to 12 µm wavelength), a set of daylight TV cameras and an eyesafe laser rangefinder. The digital camera offers two field of views (FoVs), a wide 10.7° by 8° field of view (WFOV) for target spotting and a near 3.3° by 2.5° field of view (NFOV) for better aiming and target identification. According to the manufacturer, these sights allow detecting tank-sized targets at 5,500 and 12,500 metres distance (WFOV and NFOV respectively), recognizing the targets at 1,800 and 4,800 metres and identifying them at up to 900 and 2,500 metres distance respectively. The thermal imaging unit provides two similar, but slightly smaller field of views: a wide 10° by 8° and a near 3.1° by 2.5° option. The ranges for target detection, recognition and identification are slightly smaller, sitting at 4,950 & 11,000 m, 1,600 & 4,800 m and 800 & 2,400 metres respectively. The thermal imager sensor array has a resolution of 640 by 512. The laser rangefinder has a wavelength of 1.54 µm and a maximum range of 10,000 metres, while its accuracy is ±5 metres. The gunner's GOC-1 Nike is fitted with the same thermal imager, day TV camera and eyesafe laser rangefinder as the commander's Iris sight.

The KBM2 tank gun is compatible with NATO standardized ammunition.
The PT-17 is armed with a 120 mm KBM2 smoothbore gun of Ukranian origin. This tank gun is chambered in the NATO standardized 120 x 570 mm calibre and has a barrel length of 50 calibres (6,000 mm), being slightly longer than the average 120 mm L/44 (M256) gun barrel. The maximum supported chamber pressure at 7,200 kgf/cm² (706 MPa) is however just average, other modern tank guns such as the Rheinmetall L/55 gun can sustain higher pressures. In order to install the KBM2 tank gun in a T-72-like turret, the recoil mass and recoil path have to be limited. This is why the smoothbore gun offers a recoil path of 260 to 300 mm, with a hard stop at 310 mm. The recoil path of a Rheinmetall L/44 and L/55 gun is slightly longer at 340 mm, which should result in slightly lowered effects from the recoil force.
The KBM2 gun is fed by a bustle mounted autoloader, which can store up to 22 rounds of main gun ammo. The ammunition magazine is separated from the crew, thus a penetration of the turret armor is less likely to result in a lethal explosion and a flying turret due to ammunition cook-off. The secondary armament of the PT-17 appears to be identical to the PT-16. Aside of a coaxial-mounted machine gun, a further MG is located in a remotely controlled weapon station (RWS). In theory this RWS can also accept a 30 mm or 40 mm automatic grenade launcher.

The PT-17 tank has a roof-mounted RWS (covered under tarp)
Like the PT-16, the PT-17 is offered with various engine configurations. The variant on display at the MSPO 2017 is supposedly powered by a S-1000R diesel engine from PZL-Wola; the same engine is also found on the Malaysian PT-91M tanks. This engine provides an output of 1,000 horsepower, but other powerpack alternatives with an output of up to 1,200 hp are also possible. In case of the PT-16, it was mentioned that engines from the German manufacturer MTU and from the Swedish company Scania can also be used on customer's demand. The engine is coupled to an unspecified German-made transmission, but it is most likely a ESM 350 transmission from SESM/Renk, which would be the same powerpack as used on the Pendekar.

Armor coverage is poor at the center of the turret.
In some aspects the PT-17 appears to be a downgrade compared to earlier Polish main battle tanks. The amount and type of smoke grenade launchers - a key reason why people believe it uses the same turret as the T-72-120 - is different from the PT-91 and PT-91M(2). The PT-17 has only two banks, each holding six smoke grenade launchers (one at the left and one at the right side of the turret), which are covered by sheet metal. Compared to the Polish and Malaysian PT-91 variants this is a clear step back; those tanks offered 24 smoke grenade dischargers spread in two groups, each group containing two banks of six grendes. The Leopard 2A5 and Leopard 2PL, the backbone of the Polish Army, both offer 16 smoke grenade dischargers, using four banks of four smoke grenade launchers.
A further questionable aspect of the PT-17 is armor protection; while probably better than the PT-91(M2) based on thickness and coverage, the tank appears to be worse armored in several aspects compared to the previous PT-16 prototype. The PT-17 is protected by Ukranian-made composite armor on the turret and unknown - probably Polish-made - applique armor on the T-72-derived hull. The new turret armor is thinner than the PT-16's armor; although it must be noted that thickness alone doesn't say anything about armor protection. However it doesn't include a composite armor module for the gun mantlet and has a very large and weird cut-out at the turret front, leaving a large zone of the tank's center with inferior protection. The new armor modules also don't extend as far back as on the PT-16, covering less of the turret sides.

The Borsuk features a dual-launcher for Spike-LR ATGMs aswell as a 30 mm autocannon.
The Borsuk is a new infantry fighting vehicle currently being developed for the Polish Army by OBRUM. First 3D renderings of the design already found its way on the internet last year. At MSPO 2017 the first prototype of the Borsuk (Polish for badger) IFV was presented to the public for the first time. The new vehicle is meant to replace the Soviet-designed BMP-1s (locally known as BWP-1) in the Polish military.
The Borsuk is one of the few modern IFVs designed with amphibious capabilities, using two sets of water blades for propulsion in water. This key requirement of the Polish Army affects all other aspects of the vehicle's design. The Borsuk has a rather larger hull with a larger UFP and a relatively high roof height, in order to provide enough buyoancy for swimming through water. Moreover the weight of the vehicle is limited to only between 24 and 25 metric tons in the amphibious configuration. In order to achieve a lower weight, the vehicle can be fitted with rubber band tracks, which save about one metric ton of weight compared to conventional steel tracks. The Borsuk is fitted with the unmanned ZSSW-30 turret from HSW, which provides further weight reductions compared to a manned turret. The vehicle is manned by a crew of three (commander, driver and gunner) and can transport a six men infantry squad.

The ZSSW-30 turret being installed on the Borsuk prototype hull
The ZSSW-30 turret is fitted with variants of the same GOC-1 Nike and GOD-1 Iris sights as found on the PT-17 main battle tank, allowing the vehicle to fight at night and in a hunter-killer mode. The main armament consists of a 30 mm Mk 44 Bushmaster II chain gun made by the US company Aliant Techsystems. This gun has a rate of fire of 200 rounds and can be altered to fire the more powerful 40 x 180 mm Super Forty round by swapping out the barrel. The turret contains 200 rounds of ready-to-fire ammunition in the 30 x 173 mm calibre, aswell as 400 7.62 mm bullets for the coaxial UKM-2000C machine gun. A twin launcher for the Spike-LR anti-tank guided missile (ATGM) is mounted on the right side of the turret, allowing the Borsuk to combat even heavily armored vehicles.

The Borsuk has a very high bow
The new Polish IFV is powered by a MTU 199TE20 six-cylinder engine coupled to an automatic transmission with four forward and two reverse gears. The Polish defence news website Defence24.pl claims that this powerpack is providing an output of 600 kW (~804 hp); however there seems to be a conversion or writing error, as MTU's own database mentions an output of only 450 kW, which is equal to approximately 600 horsepower. The Borsuk's drivetrain consists of six pairs of roadwheels and a suspension of currently unknown type.

The current Borsuk prototype lacks any sort of modular applique armor
OBRUM has not released any data on armor protection yet, however the unmanned turret is protected only according to STANAG 4569 level 2 in the basic variant. The version used on the Borsuk is fitted with bolt-on armor, which can boost the protection up to level 4 (all-round protection against 14.5 mm AP ammunition from 200 m distance). The hull of the prototype is fitted with no add-on armor modules at all and therefore might not even feature special armor on most of the surface; only the lower front plate seems to be fitted with an armor module or attachment points for such. It seems likely that the basic configuration of the Borsuk reaches only ballistic protection according to STANAG 4569 level 3 or 4 at most. The high ride of the vehicle and the belly plate are designed to increase protection against mines and IEDs, but no performance data has been revealed yet.
The Polish Army recently decided to shift the focus of new vehicles more towards armor protection, affecting the Borsuk development. Therefore an additonal armor package making use of materials such as resin and ceramic can be installed on the vehicle, boosting the weight to 30 metric tons. Active protection systems of unknown type are also considered for installation on the vehicle, though no system has yet been fitted. The vehicle is designed with a further growth potential of two additional tons.

5 comments:

  1. In addition to Borsuk. It will have 720 hp MTU engine. Hydropneumatic suspension will be provided by Hortsman, which allows to increase the max weight of the already existing prototype up to 35-40 tons(the chassis can handle it).
    Since the program is still in it's early stage(the vehicle it's pre prototype and introduction date is estimated for 2023), and MOD's decision to shift toward protection was very recent, the produder didn't have much time to make substantial changes in the chassis. This also means that HSW has a lot of time to make some changes or even redesign the whole thing, give up amphibious capabilities and be more armor effective.

    http://www.horstman.co.uk/products/inarm_hydrogas/index.html

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  2. I use the secure (German) web browser Cliqz. When I try to connect to below-the-turret-ring with it I receive the error message: "The owner of www.below-the-turret-ring.blogspot.com has configured their website improperly. To protect your information from being stolen, Cliqz has not connected to this website.

    This site uses HTTP Strict Transport Security (HSTS) to specify that Cliqz may only connect to it securely. As a result, it is not possible to add an exception for this certificate.

    Learn more: https://support.mozilla.org/en-US/kb/what-does-your-connection-is-not-secure-mean" (Cliqz is a secure, pared-down Firefox derivative, so they use Mozilla's online support library.)

    I have to come in through a different browser to get here. I thought you might like to know about the error.

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  3. About the pressure on the KBA-2M, I don´t see 706 MPa being "average". As far as I know the data for the Rheinmetall L55 is +580MPa, the 2A82 cannon has +600MPa...Is somewhere a error?

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    Replies
    1. This is the maximum supported chamber pressure of the KBA-2M gun. The corresponding value for the L55 gun from Rheinmetall is 725 MPa and for the future 130 mm gun even 880 MPa.

      The value you cite for the Rheinmetall L55 gun is the effective pressure achieved with ammunition at +21°C. This value is lower than the maximum supported chamber pressure, because otherwise the gun chamber (or barrel) would burst when the round is fired in the desert (pressure generated by explosions increases with lower exterior pressure AKA higher temperatures).

      The 2A82 tank gun might have a maximum pressure of only ~600-700 MPa, but it has a larger diameter and therefore is not directly comparable (a larger diameter means that the a propellant charge of equivalent size will generate less pressure, but still move/generate the same amount of gases).

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    2. M.M.

      Thank you very much for your help and your great blog!

      Kinds regards

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