Interestingly the Soviet Union managed a greater submarine fleet than Germany did heading into World War 2 (1939-1945). however, the communist nation did comparatively little with this undersea force during the conflict which pitted the two rivals against one another from June 1941 on. After the war, there fell a greater focus on the submarine force by Soviet authorities during the arms race with the West - the submarine became the spearhead of the Soviet Navy and many of its early forms were heavily influenced by captured German wartime designs. As such, they generally lagged behind their contemporaries in terms of capability and technology until about the 1970s when more and more designs appeared that began to outshine anything available in the West.
In the immediate post-war years, the Soviet Navy undertook a massive building program of a large group of submarines known as "Project 613" (NATO codename of "Whiskey- class"). Up to this point, the Navy had completed some 56 of the S-class boats during the Soviet 1930s rearmament period and even 88 of the Shchuka-class boats preceded them. The Whiskey-class went on to number 215 boats (21 also added to this total from local Chinese production) across five major variants - though a far cry from the 340 boats originally sought by Soviet authorities.
Design work on the new group began in 1946 and involved modification of the German wartime Type XXI boat (detailed elsewhere on this site). Construction of the class spanned from 1949 to 1958 and, as finalized, the boats displaced 1,080 tons when surfaced and 1,350s submerged with dimensions that included a length of 76 meters, a beam of 6.3 meters, and a draught of 4.9 meters. A standard crew complement numbered 54 personnel (increased in some later versions).
Propulsion was conventional and involved a combination diesel-electric arrangement in which the diesel units carried the boat during surface running and the electric motors powered the boat underwater. This required the boat to surface to charge its battery packs and expel any built-up CO2 gas. Surfaced speeds reached 18 knots and submerged speeds fell to 7 knots - a common trait of early submarines (later generation submarines reversed this trend by offering faster underwater speeds with reduced surface-going speeds). Operational range was out to 13,500 nautical miles when surfaced and 6,000 miles when submerged - enough provisions were on hand to supply the crew on 40-45 day long patrols. As designed, the Whiskey-class was primarily intended for coastal patrolling though its role would expand throughout its service tenure.
In terms of armament, the Whiskey-class continued established attack submarine tradition by being fitted with 6 x 533mm (21") torpedo tubes arranged in four bow (forward facing) mountings and two stern (rear facing) mountings. This allowed the frontal four tubes to be used to attack forward targets and the pairing at the rear to engage trailing targets. Twelve torpedo reloads were carried though this could be substituted with twenty-two naval mines as needed. Like other World War 2-era attack submarines, the Whiskey-class carried surface deck guns originally made up of a 25mm weapon. Later models of the group introduced a 57mm gun and still later versions showcased support for SS-N-3 series cruise missiles when that technology was made available to Soviet subs - this conversion occurred primarily during the 1950s and 1960s.
The major variants of the Whiskey-class were known as "Whiskey I", "Whiskey II", "Whiskey III", "Whiskey IV", and "Whiskey V". Whiskey I were the original Whiskey boats with 25mm deck armament followed by the Whiskey II with its up-gunned 57mm gun. The Whiskey III lot saw all of its deck armament removed and Whiskey IV brought along with it a snorkel capability. Whiskey V boats had no deck armament but were seen with snorkels and given more streamlined sails.
While conventional vessels through-and-through during the early going of the Cold War, it was not until the line was upgraded to become guided missile carriers (Project 644) that the Whiskey-class grew into its own as a notable threat to the West. Work on the conversions began in 1956 and saw a single vessel serve as prototype. A launch tube was added aft of the conning tower housing 1 x SS-N-3 cruise missile and six boats followed to this standard from 1958 into 1960 - the major difference with this group was two missile launch tubes which made them known as Whiskey "Twin Cylinder" submarines. Despite their launch tube configuration, the modified boats were still required to surface to launch their missile ordnance at land-based targets (a requirement no longer observed by modern missile attack submarines). From 1960 to 1963, the line was once again attended to when the sail of the boat was lengthened to accommodate up to four cruise missiles. Their lengthening brought about the name of Whiskey "Long Bin" (Project 655) in the West. Other special mission submarines were created as needed including a form modified to serve in special forces insertion/extraction actions.
The Whiskey-class was sold to various Soviet-aligned nations including Albania, Bulgaria, China, Egypt, Indonesia, North Korea, and Poland - some 45 believed to have operated under non-Soviet flags and all having been retired as of this writing (2015). Chinese versions included five received from the Soviets directly and twenty-one boats added from local production - the model was known as "Type 03". Soviet Whiskey-class boats soldiered on into the end of the Cold War (1991) after which all were given up amidst the chaos that followed the collapse of the Soviet Union and its various service branches which, adding insult to injury, saw little or no funding for modernization or replacement.
The Whiskey-class was eventually superseded by two new groups in the Romeo-class and the Juliett-class arriving in the 1950s and 1960s - the former was used to replace the standard Whiskey patrol boats and the latter replacing the Whiskey missile carriers.