Russian submarine Verkhoturye (K-51)

K-51 Verkhoturye (К-51 Верхотурье) is the lead submarine of the Project 667BDRM Delfin class (NATO reporting name: Delta IV) nuclear-powered ballistic missile submarines currently in service with the Russian Navy. It was built at the Sevmash shipbuilding company in Severodvinsk between 1981 and 1984 and was commissioned in 1984. It is named after the city of Verkhoturye.

Description
The K-51 Verkhoturye has a length of 167.4 m overall, beam of 11.7 m and draft of 8.8 m. It displaces 18200 t and can dive up to 550 - 650 m. It carries a complement of 135–140 sailors.

Two VM-4 180 MW pressurized water reactors power the submarine, and drive two shafts with seven-bladed fixed-pitch propellers. They propel the submarine to the maximum speed of 14 kn when surfaced and 24 kn when submerged.

The boat's primary armament are the 16 R-29RM Shtil submarine-launched ballistic missiles which have the range of 8300 km. It also has four 533 mm bow tubes which can launch RPK-7 Veter anti-ship cruise missiles, and up to 18 torpedoes or 24 mines.

Construction and service
Verkhoturye is the first submarine of the Delta-IV class. It was built at the Sevmash shipbuilding yard and launched under the name Imeni XXVI Siezda KPSS ("named after the 26th Congress of the CPSU") and was renamed as Verkhoturye in February 1999. The boat's keel was laid on 23 February 1981, it was launched on 7 March 1984 and was commissioned on 28 December 1984 into the Soviet Navy. The submarine was the test bed for the R-29RM submarine launched ballistic missile during 1985–1986. Between 2–29 September, it became the first submarine of the class to cruise to the Arctic Ocean while carrying missiles. After the Soviet Union's dissolution in 1991, the boat was transferred to the Russian Navy.

It underwent modernization twice, first in 1999, and then between 2010 and 2012. It re-entered service in December 2012 after the re-fit.