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 commissioned , 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 into the United States. The era of the nuclear submarine fleet began. It was thought that diesel submarines were forever in 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.
Nuclear submarines - advantages and disadvantages
The advantages of nuclear-powered submarines are obvious. They do not need to regularly float to the surface to recharge the batteries, the radius of operational use is almost unlimited, as well as the time spent at depth. It is only required to load food into the holds and pump drinking water into the tanks (however, there are also desalination plants). It is spacious inside the compartments, 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 some problem points. The reactor can be turned off only in case of an accident, therefore the boat is constantly noisy. It’s almost impossible to “go to the bottom” and sit quietly.
No matter how safe the power plant is, the cooling of the thermal circuits requires pumping outboard water, which then, though weakly, “fonits”, and from this track the ship can be “calculated” using sensitive instruments. In addition, any nuclear submarine (nuclear submarine) has considerable dimensions, and therefore there are restrictions on walking in the shallow areas of the oceans.
Why was a diesel submarine needed
After the arming of fleets of probable opponents of these invisible cruisers on the surface, similar ships began to be built for the USSR Navy. It soon became clear that the samples of domestic nuclear submarines differ from foreign ones, and not for the better. Acoustic means of detecting them quite quickly detected by the noise of propellers and engines. This problem was solved later, and in the late sixties - early seventies, external threats were decided to give an asymmetric answer. In 1974, Rubin Design Bureau received from the Commander-in-Chief of the Navy S. G. Gorshkov TZ, which listed the main requirements for a new ship: low visibility, wide functional spectrum and a reduced number of crew members. Four years later, the first Varshavyanka came off the slipways in Komsomolsk-on-Amur. The submarine met all points of the technical specifications, and in many respects even surpassed the parameters indicated in it.
Submarine device
Submarines usually consist of two hulls located one in the other (according to the "nested doll" principle).
The light shell serves as a fairing, under which are hidden the so-called pulp and paper cylinder (tank of the main ballast) and pulp and paper (auxiliary). The main ballast is designed to create positive or negative buoyancy, that is, provides ascent and sinking of the ship. Auxiliary tanks create a trim (i.e. longitudinal horizontal inclination of the hull) on the bow or stern, and also serve to level the roll.
The crew, armament, all the necessary machines, including an electric motor, batteries, equipment of the Civil Defense Command (main command post), a galley, and much more are enclosed in a durable case, divided into compartments. “Varshavyanka” is no exception. The submarine is divided into six compartments. Usually the first and last of them are called torpedo, but for Project 877 ships this weapon is only in the bow, along with a hydroacoustic post equipped with a special retractable (down) shaft. But this design features are not limited.
Constructive unusual
Yuri Kormilitsin, general designer of the Rubin design bureau, gave the shape of the ship the outlines characteristic of an atomic missile carrier. In cross section, it is almost round, unlike other diesel counterparts, flattened on the sides. The frames, which, according to the classical scheme, were located inside a solid hull, were taken out into the inter-hull space, due to this original solution a lot of space was freed up, which allowed to significantly improve the living conditions for the crew and place the equipment in the most rational way. The Varshavyanka project submarine became the most modern ship of the USSR Navy in the aspect of automation, mechanization and cybernetics, which reduced the load on the crew - with its smaller numbers - 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 Stells system, the means to reduce the visibility of submarines are mainly based on reducing the reflectivity of the surface. Such special material is protected by Varshavyanka. The submarine is covered with a special sound-absorbing layer, which reduces the noise coming from the vehicles and mechanisms of the ship, and at the same time absorbs the signals of a hostile sonar.
The turbulence and cavitation, which inevitably arise near the rudders, prompted the designers of Rubin to shift them closer to the mid-range (center of the hull).
But to ensure low visibility, it is not enough to be a "black hole" (as Project 877 was called the sonar acoustics of NATO fleets). After all, it was not for idle walks on the sea that the Varshavyanka was created. The submarine itself must hunt for enemy ships, and for this it needs “eyes” and “ears”. Finding the enemy before he can see you is the crew’s main task. Sonar can be of two types: active and passive. The first 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, it is more difficult to use them, but safer. The Varshavyanka class submarine has both types of sonars and, in addition to them, an advanced system for processing the information received on the basis of the onboard computer. The technology of the “acoustic tunnel” is applied, which reduces the side radiation of the sonar.
Chassis
To recharge the batteries, this submarine does not need to float to the surface, it is enough to raise the RPD (they are also called snorkels) to provide access to outside air and the removal of fuel combustion products. The diesel is used low-smoke, which reduces the visibility of the ship in the open sea.
Other innovations are used. The main diesel engine (5.5 thousand liters. From.) 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 above-water position, the engine provides an economical engine (with a capacity of 130 liters. From.), And two more (102 liters. From.) Are reserve-shunting. The kinematic scheme is such that all three engines operate on one screw. It is also special, six-blade, which allows you to rotate it at a lower speed (250 rpm.), Producing, respectively, less noise.
Living conditions
Diesel boat service conditions were always considered difficult. In addition to the psychological burden, the crew experienced a large number of inconveniences associated with a lack of space and limited autonomy. Submarines like Varshavyanka differ from other ships of this class in much better conditions. Team members do not have to sleep on torpedoes; there are comfortable cabins for this. There are also showers, a cinema hall and an outpatient clinic.
Varshavyanka today, project 636
Despite the considerable age of the project, the need for Varshavyanka class boats remains urgent, and the ship also has considerable export potential. The Indian Navy has a dozen units of these submarines in service, two fly under the Algerian flag, and the Polish Navy also has them. China also buys them for its Navy. After the destruction of the world socialist system, the Warsaw Collective Security Treaty ceased to apply (after which the project was named), many samples of Soviet technology, including the most modern ones, ended up in the arsenals of NATO countries. In order to maintain the potential of submarine forces at the proper level, an urgent modernization of the material part of the fleet was required. Since the general scheme and concept of the ship seems successful, no significant changes were made to the general design. The Novorossiysk submarine of the Varshavyanka project of a new type was laid down in St. Petersburg at the Admiralty Shipyards in August 2010, marking the beginning of a series of advanced projects that received 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 remaining submarines will also be named after the cities of military glory. The new units are intended to strengthen the Black Sea Fleet of the Russian Federation. Their design takes into account the entire experience of shipbuilding and applies the latest achievements of navigation, acoustic and computer technology. Submarines of project 636 Varshavyanka will be armed with Caliber cruise missiles with a combat radius of up to 2,500 km.
Technical data and weapons
The total displacement of Varshavyanka in the submerged state is 3036 tons, in the surface position - 2300 tons. Like nuclear boats, it goes faster under water, up to 17 knots (versus 10 under diesel). Extreme project 636 substrates can be immersed 300 meters. The length of the ship is almost 73 meters, its width is 10. In the surface position, the draft, depending on the load, is from 6.2 to 6.6 meters. The crew consists of 52 people, autonomous navigation is maintained for 45 days. The boat is armed with six 533 caliber torpedoes and four cruise missiles.