The Polish warships would receive the state-of-the-art Leonardo 76/62 SR MF STRALES guns that can fire standard rounds with programmable 4AP fuses, as well as DART guided projectiles that can be employed against highly maneuverable air threats, such as the anti-ship missiles.
PGZ confirmed, officially, that a contract as such was indeed signed in late 2023. The procurement would double the number of western-made 76 mm guns operated by the Polish Navy. 76 mm armament so far has been fitted onto the two legacy Oliver Hazard Perry frigates (US-made Mk 75 guns, license-manufactured variant of the Oto Melara 76/62 Compact), and the ORP Ślązak patrol corvette, using a much more modern counterpart of that gun - the Leonardo 76/62 Super Rapid.
All of those guns have been designed by the well-known Oto-Melara company, with a seat in La Spezia, in northern Italy. Thanks to the fact that Oto-Melara became a part of Finmeccanica (Leonardo later) on 1st January 2016, the said entity currently offers a broad range of naval artillery systems. The above also applies to 76 mm naval guns, still manufactured in La Spezia. The manufacturing plant itself has been subordinated to the Defence Systems Business Unit, and that unit is a part of Leonardo’s Electronics division.
Here, one should stress the fact that different 76 mm guns have been manufactured in Italy, as well as through license-manufacturing, in a number of more than 1,000 examples. They are operated by more than 50 fleets around the globe. The majority of those guns come in the Compact variant. Back in the 1980s, a new Oto Melara 76/62 Super Rapid model was developed, with the rate of fire going up from 80-85 to 120 rounds per minute. The enhanced performance here created a necessity to modify the feed mechanism and the munitions. Thus, a full conversion of the Compact model, so that becomes the Super Rapid, remains impossible. The manufacturer offers upgrade packages for the legacy guns, making it possible to attain a rate of fire of up to 100 rounds per minute.
Apart from the higher rate of fire which is the main distinguishing feature of the Super Rapid gun, it also features the MultiAmmo Feeding system, allowing the operator to automatically select one of several ammunition types fed from two automated carousel magazines housing 80 rounds in total, and arranged around the barbette. The device scans the rounds manually placed in the feeds, updating the location in the magazines of those rounds, based on the munitions movements. The system also features an intermediary drum that receives the given round from the respective carousel, and moves it further, to the vertical feed. The system allows the operator to change the munitions type mid-engagement, which is a major boost in the flexibility of employment for the gun, especially when multiple threats are countered at once, and circumstances emerge in which the target needs to be switched rapidly.
The drive to offer a broader spectrum of medium caliber guns to the customers resulted in the development of a system based on the Super Rapid gun, but also including several specific features. The birth of that gun is also dictated by the fact that the Italian Marina Militare, as the only Navy in the world of that size, does not use any CIWS solution on their ships (such as Goalkeeper or Phalanx).
The said system is named STRALES. Apart from the modified gun, it also employs new DART (Driven Ammunition Reduced Time-of-flight) munitions. It is distinguished by the shape of the projectile, resembling a dart, and fitted with a Simmel Difesa (currently owned by Nexter) microwave proximity fuse. The shape of the projectile has also become an inspiration for the system name, as Strales stands for “arrow” in Latin. The system may be delivered as a brand-new product, or as a conversion kit for Compact, or Super-Rapid systems.
DART projectiles have a high muzzle velocity of 1,200 meters per second. Compared to conventional rounds (275 meters per second) it is a major increase. This has been possible thanks to the freely rotating, slim sabot projectile. The sabot is a three-piece discarding element. The projectile weight with the sabot is 4 kilograms, and it is 670 mm long, as opposed to the 355-376 mm standard, for conventional munitions of this caliber.
The projectile is divided into four sections, by design. From the front, these sections are arranged as follows: guidance section (featuring servos that actuate the canard control surfaces), fuse section, warhead (where the discarding sabot is), and tail section (with six edge stabilizer surfaces, between them one can find the radio receiver that is used to receive the guidance commands).
The warhead is a pre-fragmented one, it includes tungsten submunitions, a steel body, and 2.5 kilograms of explosives. The warhead provides 100% fragmentation coverage across an area with a diameter of 20 meters. The detonation is initiated by the microwave proximity fuse. The fuse is a programmable, configurable device (can also be programmed in-flight, via the radio link) - either as a proximity, impact, or delay fuse.
Despite the fact that data on the guns that are to be installed on the brand-new, Polish frigates is scarce, the Leonardo 76/62 SR MF STRALES designation tells a lot. The guns come in the Super Rapid (SR) variant, with a rate of fire of 120 rounds per minute, and they have been coupled with the MultiAmmo Feeding (MF) system that feeds ammo from magazines underneath. The guns would employ a broad range of munitions, both in ABM, and DART variety, with the latter being the most important element of the STRALES system.
It may be concluded then that the Miecznik frigates would be fitted with a very modern medium caliber artillery system delivered by a reputable manufacturer, whose products are used by multiple navies, all over the world. It is a medium-caliber gun that can be used against naval, ground, and air threats, and it can also be employed in a missile defence role. The gun also offers more range than the conventional CIWS solutions.