The Krivak class, Soviet designation Project 1135 Burevestnik (storm petrel), are a series of frigates and guard ships (patrol boats) built in the Soviet Union primarily for the Soviet Navy since 1970. Later some sub-branches, like the Nerey (Nereus) were designed for coastal patrol by the KGB Border Troops. Until 1977, the ships in the class were considered to be large anti-submarine warfare vessels. These ships are commonly known by their NATO reporting class name of Krivak and are divided into Krivak I, Krivak II, Krivak IV (navy), and Krivak III (coast guard) classes. History The frigates were designed as a successor to the . The design started in the late 1950s and matured as an anti-submarine ship in the 1960s. The first ship was that was commissioned in 1970. A total of 40 ships were built, 32 ships for the Soviet Navy and 8 modified ships of the Nerey (Krivak III) subclass for the KGB Maritime Border Guard. Currently 2 vessels of the Nerey subclass are in service with the FSB Coast Guard and one was the flagship of the Ukrainian Navy (scuttled in 2022 to avoid capture). The ship's unique features — the bow missile box, the stack and the angled mast, earned it a rap-like nickname among U. S. sailors that comes from their foreign ship silhouette identification training — "Hot dog pack, Smokestack, Knife in the Back, two Guns in the Back — Krivak." The Indian Navy ordered six frigates of upgraded Krivak III class as the . Three ships were delivered in 2003–2004. Three more were delivered in 2011–2012. On 12 October 2010, it was announced that the Yantar Shipyard at Kaliningrad had won a contract for construction of three new warships for the Russian Navy. The construction of the frigates for the Russian Navy will be carried out in parallel with the construction of the same-type frigates for the Indian Navy. Variants Project 1135 Burevestnik (Krivak I): Design process started in 1956 as an anti-surface frigate successor to the Riga-class frigate. The role changed to an anti-submarine ship powered by gas turbines and armed with the SS-N-14 missile. The main building yards were Zhdanov Yard (now known as Northern Shipyard) (Leningrad), Yantar Yard (Kaliningrad) and Kamysh Burun Yard, (Kerch, Crimea). NATO referred to these ships as Krivak I-class. (21 ships built). Project 1135M Burevestnik M (Krivak II): This group of ships were fitted with