In the early fifties, the Soviet defense industry began developing several projects of tactical missile systems. By the end of the decade, a number of new models of this class were adopted, differing from each other in various design features and characteristics. In addition, in the early stages of the development of missile systems, original versions of their architecture and principles of application were proposed. One of the most interesting options for a "non-standard" tactical missile system was the 2K5 "Korshun" system.
In the early fifties, an original proposal appeared concerning the development of promising tactical missile systems and was based on the characteristic features of systems of this class. At that time, there was no possibility of equipping missiles with control systems, which is why the calculated firing accuracy at long ranges left much to be desired. As a result, it was proposed to compensate for the lack of accuracy by various methods. In the case of the first domestic tactical missile systems, the accuracy was compensated by the power of a special warhead. Another project had to use different principles.
In the next project, it was proposed to use the approach characteristic of multiple launch rocket systems. The probability of hitting a single target was to be increased due to the salvo firing of several missiles. Due to such features of the work and the proposed technical characteristics, the promising complex was supposed to be a successful combination of MLRS and tactical missile system.
Complexes "Korshun" at the parade. Photo Militaryrussia.ru
The second unusual feature of the promising project was the class of the engine used. All previous missile systems were equipped with ammunition equipped with solid-propellant engines. In order to improve the main characteristics, it was proposed to complete the new product with a liquid fuel engine.
Work on a new liquid-propellant unguided ballistic missile started in 1952. The design was carried out by specialists from OKB-3 NII-88 (Podlipki). The work was supervised by the chief designer D. D. Sevruk. At the first stage of work, engineers formed the general appearance of a promising ammunition, and also determined the composition of the main units. After completing the preliminary design, the design team presented the new development to the leadership of the military industry.
Analysis of the submitted documentation showed the prospects for the project. The proposed tactical missile system, designed for salvo firing, was of certain interest to the troops and could find application in the armed forces. On September 19, 1953, a decree of the Council of Ministers of the USSR was issued, according to which OKB-3 NII-88 was to continue developing a promising project. In addition, a list of subcontractors responsible for the creation of certain components of the complex was stipulated.
Museum specimen, side view. Photo Wikimedia Commons
A promising tactical missile system received the code "Korshun". Subsequently, the Main Artillery Directorate assigned the 2K5 index to the project. The Korshun missile was designated 3P7. The system was supposed to include a self-propelled launcher. At various stages of development and testing, this combat vehicle received the designations SM-44, BM-25 and 2P5. The artillery unit of the self-propelled launcher was designated as SM-55.
In the course of preliminary work on the project, the main method of combat use of promising missile systems was formed. The Korshun systems were supposed to independently advance to the indicated positions, and then, using two or three batteries, simultaneously strike at the enemy's defenses at the required depth. The results of such attacks should have been a general weakening of the enemy's defense, as well as the appearance of corridors for the advance of the advancing troops. It was assumed that the relatively long firing range and power of the warheads would make it possible to inflict significant damage on the enemy and thereby facilitate the offensive of their troops.
The proposed method of combat use of the 2K5 Korshun complex implied the rapid transfer of equipment to the required firing positions, which made the corresponding requirements for self-propelled launchers. It was decided to build this technique on the basis of one of the newest automobile chassis with the required load-carrying capacity and cross-country ability. The best performance among the existing samples was shown by the three-axle all-wheel drive truck YAZ-214.
Vehicle feed and launcher. Photo Wikimedia Commons
This car was developed by the Yaroslavl Automobile Plant in the early fifties, but went into production only in 1956. Production in Yaroslavl continued until 1959, after which YaAZ was transferred to the production of engines, and the construction of trucks continued in the city of Kremenchug under the name KrAZ-214. The Korshun complex could use both types of chassis, but there is reason to believe that the serial equipment was built mainly on the basis of Yaroslavl vehicles.
YaAZ-214 was a three-axle bonnet truck with a 6x6 wheel arrangement. The vehicle was equipped with a YAZ-206B diesel engine with 205 hp. and a mechanical transmission based on a five-speed gearbox. A two-stage transfer case was also used. With its own weight of 12, 3 tons, the truck could transport cargo up to 7 tons. It was possible to tow trailers of a larger mass, including road trains.
During the restructuring according to the SM-44 / BM-25 / 2P5 project, the basic automobile chassis received some new units, primarily the SM-55 launcher. A support platform was attached to the cargo area of the car, on which a swivel unit with a hinge was placed to install a package of guides. In addition, at the rear of the platform there were lowered outrigger supports designed to stabilize the vehicle during firing. Another refinement of the base vehicle was the installation of shields on the cockpit, covering the windshield during firing.
Sectional view of the 3R7 rocket. Figure Militaryrussia.ru
The artillery part of the SM-55 launcher, developed in 1955 by the Leningrad Central Design Bureau-34, was a platform with mounts for a swinging package of guides. Due to the available drives, the platform could be directed horizontally, turning 6 ° to the right and left of the longitudinal axis of the combat vehicle. In addition, the possibility of vertical guidance of the package of guides with a rise to an angle of up to 52 ° was provided. At the same time, due to the small sector of horizontal guidance, firing was carried out only forward, "through the cockpit", which to a certain extent limited the minimum elevation angle.
A package of guides for unguided missiles was attached to the rocking device of the launcher. The package was a device of six guides arranged in two horizontal rows of three. On the outer surface of the central guides, there were frames necessary to connect all the units into a single block. In addition, the main power elements and guidance hydraulics of the package were located there. The guide package was equipped with an electrical ignition system controlled from a remote control in the cockpit.
As part of the SM-55 product, unified guides of a relatively simple design were used. To launch the rocket, it was proposed to use a device of ten clip-rings connected by longitudinal beams. On the inner racks of the rings, four screw guides were attached, with the help of which the initial promotion of the rocket was carried out. Due to the specificity of the distribution of loads during firing, the rings were located at different intervals: with smaller ones in the “muzzle” part and with larger ones at the “breech”. At the same time, due to the design of the rocket, the screw guides were not attached to the rear ring and were connected only to the next one.
After the installation of all the necessary equipment, the mass of the 2P5 launcher reached 18, 14 tons. With this weight, the combat vehicle could reach speeds of up to 55 km / h. The power reserve exceeded 500 km. The all-wheel drive chassis provided movement over rough terrain and overcoming various obstacles. The combat vehicle had the ability to move with ammunition ready for use.
Rocket and rail close-up. Photo Russianarms.ru
The development of the Korshun complex began in 1952 with the creation of an unguided missile. Subsequently, this product received the designation 3P7, under which it was brought to testing and serial production. The 3P7 was a liquid-propellant unguided ballistic missile capable of hitting targets in a fairly wide range of ranges.
In order to increase the firing range, the authors of the 3P7 project had to maximize the aerodynamics of the rocket. The main means of improving such characteristics was a large elongation of the hull, which required the abandonment of the worked out layout of the units. So, instead of concentric placement of the fuel and oxidizer tanks, it was necessary to use containers located in the body one after the other.
The 3P7 rocket was divided into two main units: a combat and a rocket unit. A conical head fairing and part of a cylindrical body were given under the warhead, and the elements of the power plant were placed directly behind it. There was a small compartment between the combat and reactive parts, designed for their docking, as well as to ensure the required weight of the product. During the assembly of the rocket, metal disks were placed in this compartment, with the help of which the mass was brought to the required values with an accuracy of 500 g. When assembled, the rocket had an elongated cylindrical body with a conical head fairing and four trapezoidal stabilizers in the tail. The stabilizers were mounted at an angle to the rocket axis. In front of the stabilizers, there were pins to interact with the screw guides.
The total length of the 3P7 rocket was 5.535 m, the body diameter was 250 mm. The reference launch mass was 375 kg. Of these, 100 kg fell on the warhead. The total mass of fuel and oxidizer reached 162 kg.
Diagram of the 2K5 "Korshun" complex from a foreign reference book on Soviet weapons. Drawing by Wikimedia Commons
Initially, a C3.25 liquid engine, as well as fuel and oxidizer tanks, was to be located in the 3P7 jet part of the product. Such a power plant was supposed to use TG-02 fuel and an oxidizer in the form of nitric acid. The fuel vapor used ignited independently and then burned, providing the necessary traction. Even before the design of the rocket was completed, calculations showed that the first version of the power plant turns out to be too expensive to manufacture and operate. To reduce the cost, the rocket was equipped with an S3.25B engine using TM-130 non-self-igniting fuel. At the same time, a certain amount of TG-02 fuel was retained to start the engine. The oxidizing agent remained the same - nitric acid.
With the help of the existing engine, the rocket had to go off the launcher, and then go through the active phase of the flight. It took 7, 8 s to develop the entire supply of fuel and oxidizer. When leaving the guide, the rocket speed did not exceed 35 m / s, at the end of the active section - up to 990-1000 m / s. The length of the active section was 3.8 km. The impulse received during acceleration allowed the missile to enter a ballistic trajectory and hit the target at a distance of up to 55 km. The flight time to the maximum range reached 137 s.
To hit the target, a high-explosive warhead with a total weight of 100 kg was proposed. A 50 kg explosive charge and two fuses were placed inside the metal case. In order to increase the probability of hitting a target, a head contact and bottom electromechanical fuses were used.
The passage of the parade structure past the mausoleum. Photo Militaryrussia.ru
The rocket had no control systems. Targeting was to be carried out by setting the required guidance angles of the package of guides. By turning the launcher in a horizontal plane, azimuth guidance was performed, and the inclination of the systems changed the trajectory parameters and, as a result, the firing range. When firing at the maximum range, the deviation from the aiming point reached 500-550 m. It was planned to compensate for such a low accuracy with volleys of six missiles, including from several combat vehicles.
It is known that during the development of the Korshun project, 3P7 missiles became the basis for special-purpose modifications. In 1956, a small meteorological rocket MMP-05 was developed. It differed from the basic product in its increased dimensions and weight. Due to the new head compartment with the equipment, the length of the rocket increased to 7, 01 m, the mass - up to 396 kg. In the instrument compartment there was a group of four cameras, as well as thermometers, pressure gauges, electronic and telemetry equipment, similar to that installed on the MR-1 rocket. Also, the new rocket received a radar transponder to track the flight path. By changing the parameters of the launcher, it was possible to fly along a ballistic trajectory up to 50 km high. In the final section of the trajectory, the equipment descended to the ground using a parachute.
In 1958, the MMP-08 meteorological rocket appeared. It was about a meter longer than the MMP-05 and weighed 485 kg. The existing instrument compartment with the necessary equipment was used, and the difference in size and weight was due to the increased fuel supply. Thanks to the larger amount of fuel and oxidizer, MMP-08 could rise to an altitude of 80 km. From the point of view of operational characteristics, the rocket did not differ much from its predecessor.
Parade line. Photo Russianarms.ru
The development of the 3P7 unguided tactical missile was completed in 1954. In July 54, the first launch of an experimental product from a test bench took place. After the deployment of serial production of YaAZ-214 vehicles, the participants of the Korshun project had the opportunity to build an experimental self-propelled launcher of the 2P5 type. The manufacture of such a machine made it possible to begin testing the rocket complex in its entirety. Field tests have confirmed the design characteristics of the new weapon.
In 1956, according to the test results, the 2K5 Korshun tactical missile system was recommended for serial production. The assembly of combat vehicles was entrusted to the Izhevsk Machine-Building Plant. In 1957, contractor enterprises handed over to the armed forces the first production copies of launchers and unguided rockets for them. This technique entered trial operation, but was not put into service. On November 7, the Korshun complexes took part in the parade on Red Square for the first time.
During the trial operation of new tactical missile systems, some disadvantages were identified that seriously impeded their use. First of all, the complaints were caused by the low accuracy of the missiles, together with the low power of the high-explosive warhead, which worsened the effectiveness of the weapon. A deviation of up to 500-550 m at maximum range was acceptable for missiles with special warheads, but a 50-kilogram conventional charge could not provide acceptable target destruction with such accuracy.
The parade line of the "Korshuns" accompanied by other types of equipment. Photo Russianarms.ru
It also turned out that the 3P7 rocket has insufficient reliability when used in some weather conditions. At low air temperatures, equipment failures were observed, up to explosions. This feature of the weapon sharply reduced the possibilities for its use and interfered with normal operation.
The identified shortcomings did not allow full use of the latest missile system, and also did not leave the opportunity to implement all its advantages in practice. For this reason, upon completion of the trial operation, it was decided to abandon the further production and use of "Korshuns". In August 1959 and in February 1960, two resolutions of the Council of Ministers were issued, stipulating the curtailment of the serial production of components of the 2K5 Korshun complex. In less than three years, no more than a few dozen self-propelled launchers and several hundred missiles were built.
In 1957, almost simultaneously with the beginning of the trial operation of the Korshuns, scientists "adopted" the small meteorological rocket MMP-05. The first operational launch of such a product took place on November 4 at a rocket sounding station located on Heiss Island (Franz Josef Land archipelago). Until February 18, 1958, the meteorologists of this station conducted five more similar studies. Meteorological rockets were also operated at other stations. Of particular interest is the launch of the MMP-05 rocket, which took place on the last day of 1957. The launch pad for the rocket was the deck of the Ob ship, which was abeam of the recently opened Mirny station in Antarctica.
The operation of the MMP-08 missiles began in 1958. These products were used by scientists from various meteorological laboratories, primarily located in high latitudes. Until the end of the fifties, polar weather stations used only rockets created on the basis of the 3P7 product. In 1957, three missiles were used, in the 58th - 36, in the 59th - 18. Later, the MMP-05 and MMP-08 missiles were replaced by newer developments with improved characteristics and modern target equipment.
Meteorological rocket ММР-05. Photo Wikimedia Commons
In view of the insufficient characteristics of the rocket and the complex as a whole, in 1959-60, it was decided to terminate the further operation of the Korshun 2K5 systems. Until that time, the tactical missile system had not been accepted into service, remaining in trial operation, which showed the impossibility of its full service. The lack of real prospects led to the abandonment of the complex, followed by the decommissioning and disposal of equipment. The cessation of the release of the 3P7 missiles also entailed a halt in the production of the MMP-05 and MMP-08 products, but the created stock made it possible to continue operation until the middle of the next decade. According to some reports, at least 260 MMP-05 missiles and more than 540 MMP-08 missiles were used until 1965.
Almost all of the 2P5 self-propelled launchers were decommissioned and sent for cutting or refurbishment. Ballistic missiles that were no longer needed were scrapped. According to available data, only one 2P5 / BM-25 vehicle has survived in its original form and is now an exhibit at the Military Historical Museum of Artillery, Engineering and Signal Corps (St. Petersburg). Together with the combat vehicle, the museum exhibits several mock-ups of 3P7 missiles.
Project 2K5 "Korshun" was an original attempt to combine in one complex all the advantages of multiple launch rocket systems and tactical ballistic missiles. From the former, it was proposed to take the possibility of simultaneously launching several missiles, which would allow hitting targets over a sufficiently large area, and from the latter, the firing range and tactical purpose. Such a combination of the qualities of technology of different classes could give certain advantages over existing systems, however, the design flaws of the 3P7 missiles did not make it possible to realize all the available potential. As a result, the Korshun complex did not come out of the trial operation stage. It should be noted that in the future, similar ideas were still implemented in new projects of long-range MLRS, which entered service later.
