Kashalot-class submarine
The Kashalot-class submarine, Soviet designation Project 1910, is a class of research and special operations submarine constructed by the Soviet Union during the late 1970s and early 1980s.
Two boats of the class were constructed, AS-13 and AS-15, with the first boat of the class being laid down in 1977 and commissioned in 1986, the second being laid down in 1983 but not commissioned until 1991. A third class boat, AS-12, reached the fitting-out stage before being cancelled in 1998.
Displacing 1,580 tons submerged, the Kashalot class was constructed using a single titanium hull design, and is powered by a nuclear reactor; they were the first Soviet nuclear-powered submarines to have a single hull. The boats each have a crew of 36 officers and men. AS-13 and AS-15 were reported active as of 2016. In 2021 it was reported that AS-15 was being returned to active operations in conjunction with the submarine Belgorod.