The Soviet Navy expanded considerably following the close of World War 2 (1939-1945), evolving from a relatively contained shallow water force to a deep water global naval power to rival the strengths of Britain, France, and the United States. The Delta I-class served the Soviet Navy as an eighteen-strong group of ballistic missile submarines from the early 1970s into the early 1990s. Their ballistic missiles provided a long range reach that would have proven important in the event of total war with the West. Construction of the group began at Severodvinsk and ended at Komsomolsk in the Soviet Far East, the class used to succeed the outgoing Yankee I-class boats.
The Soviet government approved work on a new ballistic missile submarine (Project 667B "Murena") in 1965 and work commenced thereafter before submarine "K-279" was the first boat commissioned in December 1972. The vessels displaced at 7,800 when surfaced and 10,000 tons when submerged. Their length was 456 feet with a beam reaching 39.3 feet and a draught down to 29.5 feet. Power was served through nuclear means by way of 2 x pressurized water-cooled reactors fueling 2 x steam turbines which, in turn, drove a pair of shafts at the stern at 52,000 horsepower output. Surfaced speeds reached 12 knots while submerged speeds topped at 25 knots. Dive depth reached 390 meters. Range was essentially unlimited due to the nuclear fuel and limited primarily by onboard food stores and crew fatigue. The crew numbered 120 personnel. Her outward configuration was mostly traditional, though its sail was set well-forward on the spine and its dive planes installed at the tower.
The Delta I-class held the capability to field 12 x R-29 "Vysota" (NATO: SS-N-8 "Sawfly") Submarine-Launched Ballistic Missiles (SLBMs) through D-9 series launch tubes featured along the dorsal spine of the vessel, aft of the conning tower. Additionally, the class was outfitted with 4 x 533mm (21") torpedo tubes at the bow. The missile armament gave the Delta I boats a long range capability against land-based enemy targets, allowing the vessel to operate outside of known enemy sonar trap areas. Additionally, the vessels could launch their missiles while moving, albeit slowly at about 5 knots, but moving nonetheless which added a "shoot-and-scoot" capability and tracking was through a more advanced navigation system.
Of the eighteen Delta I boats eventually built, half of those were out of service by 1991. Decommissioning of the remaining boats began in 1994 and all were out of service by the end of 1998, facing the scrapman's torch during the next decade. The Delta I-class submarines were eventually succeeded themselves by the four-strong Delta II-class submarines which were more or less interim boats based on the Delta I - their hulls lengthened to add four more missile tubes and their crew complement increased to 130. The boats were heavier and held a deeper diving depth of 450 meters. The work on these new submarines spanned 1972 to 1975 and the line was active until decommissioning began in 1996.
The Project 667B Murena boat design was not exported to Soviet-aligned customers.