Project 1083.1 Paltus / Nelhma
Project 10831 Norsub / Nor-Sub-5

To develop new technical solutions in the field of combat submarines of the new generation, on 16 July 1990 "nuclear deep-water station 1 rank" AS-12 - Research Project 10831 submarine was laid in Severodvinsk. On 26 August 1995 the ship was launched, and in 1997 joined the Northern Fleet, devoid of weapons. The submarine received the designation in the West NORSUB-5, made of titanium alloy and designed for diving depth of more than 1000 m. The Main power plant rated capacity of 15,000 KW, with one reactor and one screw.

These small deep-diving nuclear-powered submarines were probably designed for covert underwater intelligence collection [ "research" or "ocean engineering"). Reportedly yet another small submarine intended for special operations on the sea floor, equipped with two manipulators forward. Essentially the Soviet equivalent to the US NR-1. Numbers of exactly how manv Paltus class submarines exist are not readily available; indeed, there may well be only a single craft in service.

Paltus is of a similar size to the X-Ray, which is a very small research submarine built at Sudomekh Yard, St Petersburg in 1984. Originally thought to be nuclear-powered. Based in the Northern Fleet and probably associated with deep diving seabed operations associated with an Echo II SSGN. Paltus was launched at Sudomekh in April 1991. Also originally thought to be nuclear-powered and is associated in seabed operations with the Yankee Stretch SSAN. The 'Yankee Stretch' conversion probably serves as a "mother ship" for transport and support of these craft.

Bellona reported in 1997 that the Northern Fleet had one active mini-submarine of this class in service called AS-12. According to Bellona it appeared to be generally similar to the Project 1851 X-Ray, though slightly larger in dimensions and displacement. Some sources give the Paltus class as Project 1851.

The "Paltus" nomenclature is also associated with the entirely unrelated Project 877 submarines designated "Kilo" by NATO. Paltus is Russian for turbot or halibut. The Arrowtooth Flounder (Atheresthes stomias) is also known as the Arrowtooth Halibut, Turbot, and Paltus. To make it more marketable, arrowtooth is often sold on the West Coast as turbot, although it is not related to the true turbot (Psetta maxima), a highly-valued fish caught off Europe. The Pacific Halibut (Hippoglossus stenolepis) is also known as the Alaskan halibut, Common halibut, or Whitesided paltus. Close to 100% of the halibut landed in the U.S. is Pacific halibut. The main sources for Pacific halibut are the U.S. and Canada.