Sierra II Class (Project 945A Kondor) Russian Nuclear-Powered Attack Submarine

The Sierra II Class (Project 945A Kondor) Russian Nuclear-Powered Attack Submarine is a follow-on to the Sierra I class. It was a small and expensive project. As well as its predecessors, the Sierra II class boats had titanium hulls. It has a considerably larger sail than the Sierra I class. Masts are offset on the starboard side to make way for two escape pods in the sail instead of one on the previous Sierra I class. The Project 945A has a considerably larger sail which is 5 m (16.4 ft) longer than the Sierra I class. The sail also has a curiously flat, square leading edge. The masts are offset on the starboard side to make way for two escape pods in the sail. The starboard side also has a 10-point environment sensor fitted at right angles to the front end of the sail. Also, the Sierra II class has a much larger pod on its after fin. The pod houses the Skat 3 passive very low frequency towed sonar array. Two titanium-hulled SIERRA-II nuclear-powered attack submarines serve with Russia’s Northern Fleet stationed near the Arctic Circle. The last Titanium-Hulled attack submarines completed, represent a premium design compared to the more numerous AKULA Class. The first of the original Project-945 SIERRA-I Class boats were laid down in 1979 and joined the Navy in 1984. Two SIERRA-Is were joined by two of the improved Project-945A SIERRA-II Class in 1986 and 1989. A single further improved Project-945AB SIERRA-III was laid down but abandoned at the end of the Cold War. Compared to the SIERRA-I, the -II model featured an enlarged sail with two rather than one escape pod in it. One of the pods is offset to port and the other to starboard. A more subtle improvement is an enlarged main sonar, the same MGK-501 Skat passive array fitted to the larger AKULA Class. The increased size of the sonar means that the large-diameter 650mm torpedo tubes had to be replaced by regular 533mm tubes. Like most modern SSNs the class is covered in sonar absorbing Anechoic tiles. These often fall off creating a pockmarked surface and disheveled appearance. The SIERRAs suffer from this more than most other classes, possibly due to difficulty attaching the tiles to the titanium hull.