Frag Out! Magazine
Issue link: https://fragout.uberflip.com/i/1258433
fragmentation and small arms. The belt feeds supplying the ammunition and external elevation drives for the primary weapon are especially exposed to potential damage. Usually, the targeting systems in turrets as such also remain unprotected. Repairs, however, are easier, with the components being exposed. However, this is not done from the inside. The modules are usually inaccessible from the bottom, so the weapon malfunctions cannot be rectified in combat - this makes turrets as such unusable in a manner far more effective than the enemy would do. It is especially difficult to ensure low- temperature reliability. Some of the disadvantages listed above are not present in unmanned turrets with a closed design. The components are protected by the armor, and they are protected both from the adversary, as well as from the weather. Most of the systems as such can also be controlled from the inside, and malfunctions may also be removed by the crew, also from the inside. However, systems as such are quite large and heavy. Manned, two-man crew turrets are the most common nowadays. They are dominating the world of the IFVs around the world, even though this is a legacy of the design efforts of the 1980s. The potential disadvantages stem from the dimensions and weight. Furthermore, the crew is not separated from the ammunition. The most significant problem here stems from the fact that the turret basket takes up to 40% of the space available in the crew compartment. As a result, the vehicle has two seats less for the troops inside - these are taken up by the basket. These disadvantages are serious enough to push the designers towards the use of unmanned solutions. The designers of the Puma IFV were forced to do so, as the maximum weight of the vehicle was defined as 31.5 t. Similar limitations have been imposed upon the designers of the Kurganets-25 or the latest Stryker with a 30 mm gun. However, the total weight of the vehicle or the requirement for the vehicle to be amphibious becomes important enough to create weight reduction necessity, and a need to resign from manned turrets. Manned systems exhibit many advantages. The most important matter here is the higher situational awareness of the crew and the commander that could be created in a design that would be simpler and cheaper. The primary armament that would be powerful and coupled with a good fire control system both make it possible to create a vehicle that can attack moving targets at a level that is on par with contemporary MBTs, leaving the caliber of the primary weapon aside. This is why the British Ajax features a manned turret, despite the use of sophisticated FCS. The Korean K21 (amphibious one) also uses a manned turret. The same can be said about the successful Dutch CV9035MK3NL. Another issue that needs to be mentioned here is the fact that manned turrets usually can accommodate a large quantity of ammunition. Weapon malfunctions can be repaired in a manner that is quicker and safer, than in the case of the manned systems. A properly designed manned turret can also be protected by heavy armor. Swedish Stfr is a good example here. Summing it up, should a necessity emerge to minimize the weight and create more space for additional troops in the infantry compartment, remotely controlled turrets are the obvious way to go. Nonetheless, they also have some disadvantages. If no drastic weight cuts are expected, with regards to the IFV's components, with the simultaneous necessity to maximize the firepower and reliability of the weapons, then manned solutions are a good way to go still, and it may be expected that they would be still present on the newly developed vehicles in the future. Primary Weapons When primary armament is selected for the IFV, then four factors are relevant: caliber, the principle of operation, feeding system, and the ammunition available. All four matters are tied together. The caliber determines the ammunition performance. The larger it is, the better the fragmentation/armor-piercing/ explosive properties of the rounds are. However, the increased caliber results in a drastic reduction in the quantity of the rounds carried by the vehicle. If the quantity of ammunition goes below a certain value, the effectiveness of any gun that is theoretically superior (i.e. shooting a larger round) is significantly lower than in the case of guns of smaller caliber. Meanwhile, the guns of lower caliber have larger quantities of ammo at their disposal. 20 to 40 mm automatic guns seem to dominate the market now, in the IFV armament. It is commonly assumed that using a gun of a caliber that exceeds 60 mm (the Soviet 100 mm low-pressure gun included) is impractical for IFVs, given the low rate of fire, low quantity of ammunition available, increasingly more convoluted design - of both the turret, as well as of the vehicle. Please see Table 1 for the caliber range with the most common calibers nowadays. 20 and 25 mm rounds are gradually becoming less and less common, in IFV applications. Muzzle energy of the 20 mm rounds is as high as 109 kJ which translates into the ability to penetrate 80 mm of RHA (plate inclined at 60 deg) at a distance of 1000 m. MP-T round, meanwhile, carries only 30 g of explosives. Taking the aforesaid factors into account, such rounds exhibit too weak penetration performance to act against vehicles, the protection of which is increasingly better. The fragmentation and explosive effect also remain quite limited. The only advantage that both calibers have stems from the sheer quantity of rounds that the vehicle can carry - 1,250 each 20 mm rounds for the Marder 1A3 IFV and 900 each 25 mm rounds for the M2 Bradley platform. In the case of the NATO allies, as well as in the case of the Former USSR, the 30 mm caliber has become a „golden standard". The West adopted the 30x173 mm rounds, while the East is using the 30x165 mm rounds that are a bit weaker. The muzzle energy is as high as 210 kJ which translates into the ability to penetrate 110 mm of RHA at a distance of 1000 m. The projectile also carries around 40 gof explosives. Up until recently, 30 mm APFSDS-T rounds have been offering sufficient performance to act against vehicles and IFVs, meanwhile, the frag-HE performance was satisfactory when the targets were hit with a burst of around 20 rounds. The 30 mm rounds make it possible to store a sufficient quantity for immediate use. That quantity is usually around 200 rounds. The vehicles usually carried 400 rounds in total. One should admit though, BMP-2 seems to lead the pack here. 500 rounds are available immediately - 340 HEI rounds and 160 APDS/APFSDS-T rounds. www.fragoutmag.com