The United States and the Soviet Union each took possession of both the technology and the engineers from the V-2 missile at the end of World War II. This knowledge laid the foundations for both nations' subsequent development of strategic ballistic missiles for the delivery of atomic and nuclear warheads. Similarly, they used the knowledge acquired from the German V-1 program as the basis for developing their own land-attack cruise missiles that, initially, were more attractive than ballistic missiles because it was easier to endow them with longer reach. Both navies quickly appreciated the advantage of deploying land-attack missiles aboard submarines, since it offered the potential for launching weapons against their opponent's homeland from a stealthy platform.
The Soviet Navy exploited the concepts of the German V-2 missile launch canisters to develop a design for a very large submarine capable of firing both ballistic and cruise missiles against land targets. In the 1949 preliminary design the 5,400-ton (surfaced) Project P-2 boat could carry twelve R-1 ballistic missiles (the Soviet production version of the V-2) and additional cruise missiles, but its engineers were unable to solve a host of development problems, leading to the project's termination. The same design bureau began work the following year on Project 624, a 2,650-ton (submerged) cruise missile submarine powered by a closed-cycle Walter steam turbine based on the plant designed for the German Type XXVI boat. When that, too, was halted, work began on Project 628, a cruise missile-armed development of the wartime Series XIV design, but the Soviet Navy's rejection of its missile terminated efforts in 1953.
Thereafter, the Soviet Navy simultaneously pursued the development and deployment of both cruise and ballistic missile submarines. The diesel-electric Project 611A class (NATO- designated Zulu-IV) submarine B- 62, with a single launch tube, was the first to fire an R-11 ballistic missile (NATO-designated Scud) on 16 September 1955. The succeeding Project 611AB class (NATO-designated Zulu-V) were the first operational ballistic missile submarines, the first boat (the B-67) commissioning on 30 June 1956. These six boats could launch their two R-11FM missiles from vertical tubes in the sail and retained the torpedo capabilities of their conventionally armed sisters. They were followed by 22 Project 629 class (NATO-designated Golf) boats armed with three improved R-13 missiles and 9 similarly armed nuclear-powered boats of the Project 658 class (NATO-designated Hotel).
Meanwhile, after trials with two boats between 1955 and 1959- a Project 611 (NATO-designated Zulu) and a Project 613 (NATO-designated Whiskey)-two series of operational conversions based on the Whiskey design entered service from 1960, as the six Project 644 class (NATO-designated Whiskey Twin Cylinder) and the six Project 665 class (NATO-designated Whiskey Long Bin). Soviet designers also pursued development of nuclear-powered cruise missile submarines, initially exploring a modified version of the fleet 's first nuclear-powered attack boat as Project 627A and then a much larger 7,140-ton (submerged) type as Project 653, both optimized for submerged operation. But problems with the P-20 missiles for those vessels halted development. Instead, a new nuclear- powered design, Project 659 (NATO-designated Echo I), which featured a conventional hull form to maximize stability while launching missiles on the surface, entered service from 1961. On 14 December 1959, however, the new Strategic Rocket Forces were established. That arm of service took control of all land-based strategic missiles, downgrading the importance of the navy's cruise missile boats and leading to the decision to concentrate efforts on sea-based ballistic missiles and focus cruise missile efforts on anti-ship warfare.
Soviet ballistic missile submarines were initially very vulnerable during launch, because they had to surface to fire their missiles. On 10 September 1960, the B-62 of the Project 611AB class successfully fired a ballistic missile while submerged. The new D-4 launch system it tested replaced the earlier D-2 system originally fitted in the Project 629 and Project 658 classes of ballistic missile submarines that began entering service in 1960. The upgraded Project 629A and Project 658M boats carried three liquid-fuelled R-21 ( NATO-designated Sark) missiles with a range of 870 miles (twice that of the earlier R-13 weapons) in vertical tubes and recommissioned beginning in February 1962.
The Soviet Union was slower than the United States in developing ballistic missile submarines capable of carrying heavy loads of these weapons. In part this was attributable to an attraction toward deploying cruise missile boats, since cruise missiles seemed to offer greater and less complex development potential than ballistic weapons and the submarines would be capable of undertaking a broader range of missions. The emergence of a politically powerful rival for funding in the form of the Strategic Rocket Forces also inhibited development of boats matching the weapons capabilities of U.S. strategic submarines. The disappointing results of efforts to field long-range, heavily armed cruise missiles and the success in overcoming difficulties in developing solid-fuelled ballistic weapons led the Soviet Fleet to develop and deploy a large force of powerfully armed strategic missile submarines: 34 of the Project 667A class (NATO-designated Yankee) followed by 43 of the various versions of the Project 667B type (NATO-designated Delta), which entered service between late 1967 and early 1986.
Both the United States and the Soviet Union continued to develop longer-range, more powerful ballistic missiles, which therefore were larger, and the bigger submarines required to accommodate them. For the United States the new missile was the Trident-substantially larger than the Poseidon-which led to the design of the Ohio-class submarines, the largest in the world at that time. They embarked 24 of the new weapons, an arrangement regarded as a considerably more efficient use of submarine platforms. The first of 18 boats, the Ohio, commissioned on 11 November 1981. All remain in service, although four are being converted to launch up to 154 cruise missiles via 22 vertical tubes, rather than ballistic missiles, with more possibly converting in the future. The Soviet Union countered with its Project 941 class ballistic missile submarines (NATO-designated Typhoon), the first, the TK- 208, commissioning on 12 December 1981. They use an unusual double pressure hull form, are even larger than the Ohio class, and thus are the world's largest submarines, although they carried only 20 R-39 ballistic missiles (NATO-designated Sturgeon) in vertical tubes. The six boats of the class remain in service.