Pr.1244.10
The Pr.1244.1 program grew out of a 1980s in-house development for a small missile ship by the Almaz design office. The long-range anti-ship missiles of the new generation that were to be the ship's main weapon required over-the-horizon targeting, most reliably obtained by an on-board helicopter. Integrating a helicopter deck and hangar turned the 1000-ton small ship into a 2000-ton light frigate. Such a ship would become a
bona fide target for enemy submarines, and the requirement grew to include self-defense ASW weapons and sensors. A multi-role helicopter was already planned to be carried, and the hull sonars and ASW vectors were progressing by leaps and bounds in the late 1980s, so a massive under-bow active sonar was integrated, while on-board weaponry turned towards the RPK-9 Medvedka light torpedo-carrying missile system then in development. It out-ranged and out-paced all torpedo- and rocket-based systems then in service, and promised to make good use of the on-board and helicopter sensors.
The design, now clearly in frigate territory, was clearly lacking in air defense. Of the current systems, the Uragan developed for the Pr.956 destroyer was too heavy and cumbersome, and lacked the reaction time and flexibility to counter saturation attacks, while the Kinzhal mounted on the Pr.1155 and Pr.1154 was considered too expensive and lacking in range to counter high-velocity threats. A new AAW system clearly had to be developed to keep up with the overall high technology content of the design. At that stage, the Pr.1244, now projected to displace 3500 tons, was unceremoniously re-packaged as a multi-role first-rank frigate, and pushed to the Soviet Navy procurement committee as a replacement for the various 1960s-vintage hulls tasked with blue-water air defense and sub-hunting.
While most of the projected systems were mature or nearing readiness, the linchpin of the program was the new and ambitious air-defense system. Envious of the US Aegis integrated air-defense system and fearful of ongoing high-velocity anti-ship weapons in development in NATO countries, Soviet brass pushed for a full-fledged integrated air-defense system (IADS), centered around a smart multi-function AESA radar array (leaping one generation ahead of projected NATO systems) and a compact single-stage SAM marrying autonomous active radar guidance and a 75km baseline range. In order to hasten entry in service, construction of the ships was started before all systems had been tested.
The Oniks and Medvedka systems had already been trialed on different platforms and their integration posed no major problems. On the other hand, neither the Redut missile nor the associated radar were available to be mounted on the first of class as it was launched in 1996. A forward-thinking attempt at concurrent engineering soon ground to a halt, with one ship completed and three blocked during fitting out before the situation was solved.
After much waffling, the class lead was completed and rushed into service in late 1998 without any the planned air-defense systems. A single AK-630M2 CIWS was fitted as originally planned, leaving the ship bristling with offensive weapons but woefully undefended. Luckily, the single ship of vanilla Pr.1244.1 would not spend a long time so defenseless.
No satisfying alternative design was available at the time, and the Soviet Navy could ill afford to wait for a new frigate program. Completing the following ships in the class would require re-thinking the AAW systems from the ground up.
It would take nearly 10 more years to bring the planned Pr.1244.1 configuration to fruition.
Pr.1244.1R
The second and third ships of Pr.1244.1 were still being completed when the lead unit was commissioned without any air defense system. At that stage, an interim solution had been selected: the Soviet Air Defense Forces (PVO) had commissioned a land-based SAM system based around a straightforward adaptation of the third-generation R-77 air-to-air missile. There was little doubt that this move was inspired by the NATO ARMSAM/NASAMS-III experiments, but the mission was as different as the client force. Instead of protecting mobile land forces, what would become the S-350P Nadim (the -P suffix being added once Navy interest was made official) was to provide high-density medium-range cover to the large long-range SAM batteries protecting the Soviet airspace, and to the ubiquitous radar systems supporting them.
Since a folding-wing R-77 version was already under development for internal carriage on the 5th-generation stealth fighters, modification for cold-launch canisters was straightforward. The same series of missiles was put into production for both the VMF and the PVO, with different guidance variants to help overcome low-observable targets and swarming attacks. The extended flight envelope, high maneuverability and smart seekers of the 5V77K missile family provided a welcome replacement to the defunct Redut system, albeit at no small cost. As its air-to-air forebear, the new missile used chiefly active radar guidance, and was thus exponentially more expensive than the earlier command-guided missiles used by both the PVO and the VMF. For once in Soviet design history, the cost of the projectile had surpassed the cost of the platform.
While this felt like a good investment to some in the naval staff - after all, no one required that all launch canisters be filled, and the ships would be that much cheaper - others considered it a risky departure from the timeless Soviet philosophy of always preparing to fight a long war of attrition. Keeping weapons dumb and cheap had so far allowed to plan for surge production in case of escalation.
The new air-defense missile system was nevertheless adopted in 2000 as the 4K77D system, aka S-350F Redut-2. Though overshadowed in the public eye by more glamorous systems like the Fort and the Krepost, its versatility and low support requirements made it an ideal candidate for extending the size of the self-protection bubble of major units, where it complemented handily the shorter-ranged Kinzhal/Kolchan family. The Redut-2 with its original non-phased-array data-links would be fitted to a few lighter combatant classes, but would never really find its place in this role.
Vertical-launch missile silos were hastily fitted into the slots reserved for the original Redut in the fore-deck. The original CIWS fit of a single AK-630M2 was no less inadequate when backed up by a SAM battery, and was deleted and covered by further VLS packs for the Redut-2, while the Redut emplacements around the hangar were replaced by a pair of combined-weapons Palma-S CIWS with much better coverage.
Since no tracking phased-array was available to support the new missile system, a crash program yielded a compact data-link antenna to lead the missiles to a small enough engagement box around the targets detected by the on-board radars. In this regard, the interim radar fit still let to be desired, as the Podberyozovik C-band plate lacked the scan rate and accuracy, and the Pozitiv the power, to provide target data out to the full range of the missiles.
Pr.1244.1M
The ambitious Redut-R multi-function phased-array radar concept was torn apart and drastically simplified. In an attempt to work around the complexities of the AESA array, work concentrated on a high frequency scan-only passive array that could enter service in the short term. While not as flexible as an active array, this system allowed accurate medium-range scanning and tracking of targets with a virtually unlimited refresh rate. The added weight was a trade-off for a much better ability to track fast-moving and low-altitude targets.
The 3Ts90 Kometa-1 X-band phased-array radar system was also integrated on the Pr.1102 destroyer, but would soon be replaced by more capable versions.
The installation of this array atop the deck-house of the Pr.1244 allowed the removal of the Pozitiv target-acquisition radar atop the hangar. Still, this early PESA array lacked the smarts to guide even radar-active SAMs all by itself, and the data-link antennas developed for Pr.1244.1R were retained. This new configuration gave the last four ships of Pr.1244.1 a better chance of exploiting the full range of the S-350F missiles. The missile data-link antennas of Pr.1244.1R were retained, since the integration of their function in the radar array was still several years away.
Space for a fixed radar array was allocated at the bottom of the mainmast since the beginning of Pr.1244.1, so the integration of the relatively compact Kometa-1 array was a straightforward affair. Outside of the radar fit, the ships of Pr.1244.1M were mostly identical to the Pr.1124.1R. Both factors made the two production variants of Pr.1244.1 visually very similar. Still, priority for new-build ships and the low availability of the radar arrays meant that the earlier Pr.1244.1R ships would never be back-fitted with the Kometa arrays. Their already respectable AAW capabilities and the rapid entry in service of more advanced designs in the following years meant that the original Pr.1124.1R could soldier on as ASW platform and missile trucks.
Pr.1244.2
The definitive version of the series would require another major step in Soviet fixed phased-array radar systems. Completion of the Kometa-1 scan-only cleared the way for more complex and smarter arrays, starting with its 3Ts91 Kometa-2 descendant. This new version combined the scanning ability already established with a near-instantaneous track creation able to generate guidance solutions against fast and maneuvering targets, while integrated secondary arrays handled IFF interrogation and long-range 2D detection of low-observable contacts in L-band. This assembly would represent the bulk of built-in PESA arrays in Soviet surface combatants well into the 2010s.
The new array was noticeably taller than the simpler Kometa-1, and required a complete re-design of the upper deck-house and mainmast. In order to save weight and reduce radar signature, the latticed mast was at last replaced with a massive slanted mast made of carbon composite.
All in all, a lot of the original systems were updated during the transition between variants, making the Pr.1244.2 almost unrelated to its elder cousins. Externally visible were: new and lighter radars for 3D air search and surface target indication, an expanded visual/IR detection and countermeasures suite, and a new EW suite. Nearly nothing of the original weapons suite was retained, with the Oniks launchers at last replaced with the UKSK universal VLS, and the original RPK-9 system re-wired to the URK-11K standard. Both missile arrays gave the ships a respectable 40 tubes for a mix of land-attack, anti-ship and ASW missiles, although the higher missile density of the UKSK made loading all cells with 3-ton Oniks or 3M14 LACMs a perilous proposition in choppy seas.
The integration of all these new systems made the Pr.1244.2 the standard production variant of the series, with 13 hulls turned out in the Yantar and Zaliv shipyards between 2006 and 2011.
Ships would later be upgraded with newer sub-systems, though the overall outline of the ships would mostly stay true to their mid-2000s iteration.