The middle of the twentieth century went down in history as a time of revolutionary technological breakthroughs in all areas of technology, science and even culture. As soon as this period is not called: the age of cybernetics, the era of astronautics and even the era of rock and roll. In the USSR, at the end of the forties, the world's first nuclear power plant was put into operation, this happened four years after Hiroshima. An icebreaker with a nuclear power plant was also built in the USSR (1957). And three years earlier, the Nautilus nuclear submarine was solemnly launched in the United States. The era of the nuclear submarine fleet began. It was thought that diesel submarines were forever a thing of the past. But it turned out that in some cases there is no replacement for them. An example is the world's quietest submarine of Project 877 Varshavyanka.
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The advantages of nuclear-powered submarines are obvious. They do not need to regularly float to the surface to recharge their batteries, the radius of operational use is almost unlimited, as well astime at depth. It is only required to load food into the holds and pump drinking water into tanks (however, there are also desalination plants). Inside the compartments it is spacious, the living conditions of the crew are quite comfortable, and the combat capabilities are such that one unit is enough to arrange dozens of Hiroshima. But there are also some problematic points. The reactor can only be shut down in case of an accident, so the boat is constantly making noise. It’s almost impossible to “lay low” and sit quietly.
No matter how safe the power plant is, but the cooling of the thermal circuits requires pumping outboard water, which then, though weakly, but “fonit”, and on this trail the ship can be “calculated” using sensitive instruments. In addition, any nuclear submarine (nuclear submarine) is of considerable size, and therefore there are restrictions on walking in the shallow areas of the oceans.
Why was a diesel submarine needed
After the appearance in service of the fleets of probable opponents of these cruisers invisible on the surface, similar ships began to be built for the Soviet Navy. It soon became clear that the samples of domestic nuclear submarines differ from foreign ones, and not for the better. Acoustic means of detection quickly spotted them by the noise of propellers and engines. This problem was solved later, and in the late sixties and early seventies it was decided to give an asymmetric response to external threats. In 1974, Rubin Design Bureau received from the Commander-in-Chief of the Navy S. G. Gorshkov TK, which listed the main requirements for the new ship: smallvisibility, a wide functional range and a reduced number of crew members. Four years later, the first Varshavyanka left the stocks in Komsomolsk-on-Amur. The submarine met all the points of the technical assignment, and in many respects even surpassed the parameters specified in it.
Submarine device
Submarines usually consist of two hulls located one inside the other (according to the "matryoshka" principle).
The light shell serves as a fairing, under which the so-called TsGB (main ballast tanks) and TsVB (auxiliary) are hidden. The main ballast is designed to create positive or negative buoyancy, that is, it ensures the ascent and immersion of the ship. Auxiliary tanks create a trim (that is, the longitudinal horizontal tilt of the hull) on the bow or stern, and also serve to equalize the roll.
The crew, armament, all the necessary machines, including the electric motor, batteries, GKP (main command post) equipment, the galley and much more are enclosed in a strong hull divided into compartments. Is no exception and "Varshavyanka". The submarine is divided into six compartments. Usually the first and last of them are called torpedoes, but the Project 877 ships have these weapons only in the bow, along with a sonar post equipped with a special retractable (down) shaft. But the design features do not end there.
Design oddities
Yuri Kormilitsin, General Designer of Rubin Design Bureau, gavethe shape of the ship, the outlines characteristic of a nuclear missile carrier. In cross section, it is almost round, unlike other diesel counterparts, flattened along the sides. The frames, which, according to the classical scheme, were located inside the strong hull, were moved into the inter-hull space, due to this original solution, a lot of space was freed up, which made it possible to significantly improve the living conditions for the crew and place the equipment in the most rational way. The submarine of the Varshavyanka project has become the most modern ship of the Soviet Navy in terms of automation, mechanization and cybernetics, which reduced the load on the crew - with its smaller number - and leveled the notorious human factor in many situations.
Low visibility
Sonar works on the same principle as conventional radar. Sonar emits short pulses of sound frequency, which, reflected from underwater objects, create a picture of the situation. As in the Ste alth system, the means to reduce the visibility of submarines are mainly based on reducing the reflectivity of the surface. Varshavyanka is protected by this special material. The submarine is covered with a special sound-absorbing layer that reduces the noise coming from the ship's machinery and mechanisms, and at the same time absorbs hostile sonar signals.
Turbulence and cavitation, which inevitably occur near the rudders, prompted the Rubin designers to move them closer tomidship frame (hull center).
But to ensure low visibility, it’s not enough to be a “black hole” (as Project 877 was called by the hydroacoustics of NATO fleets). After all, Varshavyanka was not created for idle walks on the sea. The submarine itself must hunt enemy ships, and for this it needs "eyes" and "ears". Finding the enemy before he can see you is the main task of the crew. There are two types of sonar: active and passive. The former emit acoustic impulses, they act at a greater distance, but at the same time unmask the ship. The latter use the results of other sonars and sea noises, they are more difficult to use, but safer. The Varshavyanka-class submarine has both types of sonars and, in addition to them, a perfect system for processing the received information based on an on-board computer. Acoustic tunnel technology has been applied to reduce side sonar emissions.
Chassis
To recharge the batteries, this submarine does not need to surface, it is enough to raise the RDP (they are also called snorkels) to provide outside air access and removal of fuel combustion products. Diesel is low smoke, which reduces the visibility of the ship on the high seas.
Used and other innovations. The main diesel engine (5.5 thousand hp) does not serve to set the vessel in motion, its purpose is only to set in motion the rotor of the battery charging generator. In the surface position, the course is provided by an economical motor (with a capacity of 130 hp), and two more (102 hp each) are back-upshunting. The kinematic scheme is such that all three engines operate on one propeller. It is also special, with six blades, which allows it to rotate at a lower speed (250 rpm), producing, accordingly, less noise.
Living conditions
The service conditions on a diesel boat have always been considered difficult. In addition to psychological stress, the crew experienced a large number of inconveniences associated with lack of space and limited autonomy. Submarines of the Varshavyanka type differ from other ships of this class in much better conditions. Crew members do not have to sleep on torpedoes; there are comfortable cabins for this. There are also showers, a cinema room and a dispensary.
"Varshavyanka" today, 636th project
Despite the considerable age of the project, the need for Varshavyanka-class boats remains urgent, moreover, the ship has considerable export potential. The Indian Navy is armed with a dozen units of these submarines, two fly under the Algerian flag, and the Polish fleet also has them. China also buys them for its Navy. After the destruction of the world socialist system, the Warsaw Treaty of Collective Security ceased to operate (after which the project was named), many samples of Soviet equipment, including the most modern ones, ended up in the arsenals of NATO countries. In order to maintain the potential of the submarine forces at the proper level, an urgent modernization of the materiel of the fleet was required. Since the general scheme and concept of the ship seem to be successful, significantno changes were made to the overall design. The Novorossiysk submarine of the Varshavyanka project of a new type was laid down in St. Petersburg at the Admir alty shipyards in August 2010, marking the beginning of a series of improved projects that received the index 636. Five more such ships are planned to be launched in the coming years. The next will be Rostov-on-Don and Stary Oskol, the rest of the submarines will also be named after the cities of military glory. The new units are designed to reinforce the Black Sea Fleet of the Russian Federation. Their design takes into account all the experience of shipbuilding and applies the latest achievements in navigation, acoustic and computer technology. Project 636 Varshavyanka submarines will be armed with Caliber cruise missiles with a combat radius of up to 2,500 km.
Technical data and weaponry
The total displacement of the Varshavyanka submerged is 3036 tons, while on the surface it is 2300 tons. Like nuclear boats, it goes faster under water, up to 17 knots (against 10 under diesel). Project 636 substrates can dive up to 300 meters. The length of the ship is almost 73 meters, the width is 10. In the surface draft, depending on the load, it is from 6.2 to 6.6 meters. The crew consists of 52 people, autonomous navigation is supported for 45 days. The boat is armed with six 533-caliber torpedoes and four cruise missiles.
