Creation of the "Circle" complex
At the beginning of 1958, according to a decree of the Council of Ministers and the Central Committee of the Communist Party, the creation of a new self-propelled anti-aircraft system begins with the provision of a prototype in 1961 for state tests. The main developer is NII-20. According to the terms of reference, it was required to develop the following sketch options:
- anti-aircraft guided missile with command guidance "3M8";
- anti-aircraft guided missile with combined guidance "3M10";
The last missile was supposed to be used at the final homing site. The option could not be implemented due to the insufficiently developed technical base of that time.
In addition to the missiles themselves, it was necessary to develop anew launchers, since the ones in service did not fit in many parameters - the missiles were supposed to use a liquid oxidizer and fuel, a complex implementation of refueling technology, short combat duty of fueled missiles, etc. The launcher was taken from the "Cube" air defense missile system being developed.
The development time is more than six years, the creation took place with enormous difficulties, it was especially difficult for the designers to create the rocket. At first, an anti-aircraft missile with a direct-flow TTD was developed by two teams from OKB-8 and TsNII-58:
- anti-aircraft guided missile KS-40 - OKB-8. Rocket weight - 1.8 tons;
- anti-aircraft guided missile S-134 - TsNII-58. The weight of the rocket is 2 tons, the development of its own PU - S-135 was carried out.
In mid-1959, the TsNII-58 team was united with the design bureau headed by S. Korolev OKB-1. Work on the creation of a missile defense system for the "Circle" complex is temporarily suspended.
Instead of TsNII-58, a team led by P. Grushin OKB-2 is involved in the development of the rocket and, in fact, the entire Krug anti-aircraft missile system. The Grushinsky team proposed to use one of the variants of the B-757 (S-75) missile for the Krug complex. In July 1959, according to the decree of the Council of Ministers of the Soviet Union No. 735-338 OKB-2, the development of the Krug air defense system under the 2K11M designation and missiles for the B-757 complex under the 3M10 designation began. Anti-aircraft missiles for the S-75 complex were created nearby at plant # 8. But in 1963, the development was recognized as unpromising and all work on the 2M11M complex was stopped.
The most successful option for creating the "Circle" complex is a complex with a KS-40 (3M8) rocket developed by OKB-8. The rocket is designed according to the aerodynamic design of the "rotary wing". The rocket receives such a scheme due to the unstable operation of the engines - some of the rocket maneuvers took place with overloads of up to eight units. The marching stage was a direct-flow supersonic engine (3Ts4). It is designed as a pipe with a central pointed body, having annular nozzles and combustion stabilizers. The 3N11 warhead weighing 150 kilograms with a radio fuse, an air accumulator cylinder and a seeker are placed in the recessed central body of the air intake. The ring body has taught the following units and equipment:
- kerosene tanks located from the beginning to the middle of the hull;
- steering gears with fenders, located in the central part of the body;
- onboard equipment and control system equipment in the rear of the hull.
The rocket was provided with a "launch stage" consisting of four solid-propellant launch boosters with charges (3Ts5 with 4L11). The charge is a solid-fuel single-channel checker weighing 173 kilograms and 2.6 meters long. The boosters were separated from the sustainer stage using aerodynamic surfaces located at the ends of the booster body.
Designers of OKB-8 also faced great difficulties in creating missiles:
- hardware and equipment failures;
- poor vibration resistance of the product;
- insufficient strength of structural elements;
- unsatisfactory operation and failures of the rocket ramjet engine.
Especially for testing the latest samples of anti-aircraft systems, a new test site was built in Kazakhstan in the early 1960s, measuring 300 by 100 kilometers. In the first half of 1963, state tests of a prototype of the Krug anti-aircraft complex took place at this test site. Of the 41 missile launches, of which 24 are combat-ready missiles, 26 were successful. From unsuccessful launches:
- wing flutter for 4 missiles;
- unsuccessful process of fuel combustion in 3 missiles;
- explosion of isopropyl nitrate in 6 missiles;
- failure of the radio caller to trigger 2 missiles.
The tests were generally recognized as successful, the radio command-type control system showed acceptable accuracy when aiming missiles at a target. In 1964, after eliminating the shortcomings, the complex is ready for mass production. 1965 - The Krug SD air defense missile system is being commissioned into the air defense system of the Soviet Union.
Appointment 2K11
The main purpose of the 2K11 anti-aircraft missile system is to defeat / destroy any enemy aircraft with a speed of less than 700 m / s at a distance of 11 to 45 kilometers and at an altitude of 3 to 23.5 kilometers, in any weather from a spot. This is the first military air defense system in service with the SV ZRBD as a means of the army or front-line level. He provided group cover in his area of responsibility for military and other formations.
The troop composition of the Krug air defense missile system
The Krug SD air defense missile system was the main weapon of the front-line or army air defense missile system. In turn, the ZRDN, which are part of the ZRBR, consisted of:
- target detection station SOTS 1S12, target designation reception cabins K-1 "Crab" and a little later (after 1981) a combat command post from the ACS "Polyana-D1". All equipment was included in the control platoon;
- three anti-aircraft batteries consisting of: SNR 1S32 missile guidance station, three SPU 2P24 (each with two 3M8), a technical battery consisting of KIPS 2V9, a transport vehicle TM 2T5, TZM 2T6, a tanker and equipment for refueling missiles.
In addition to the transport-loading vehicle, all other solutions for 1965, which are part of the ZRDN, were made on an all-terrain caterpillar track. The maximum speed of the anti-aircraft missile battalion is up to 50 km / h at a distance of up to 300 kilometers (full fuel supply). When reaching a given point, he provided a two-hour combat alert of the air defense.
The ZRBR consisted of the following solutions (control battery): P-40 target detection radar, P-12/15, PRV-9A meter and decimeter range detection radar, Crab cabin (since 1981, the command post from the Polyana -D1 ).
Device and design
Station SOTs 1S12 - radar with all-round visibility (see range) for detecting enemy air targets, identifying and issuing a control center for guidance stations 1S32. SOTs 1S12 plus radio altimeter PRV-9A - P-40, known as "Bronya", was in service with radar units of the air defense of the ground.
Main characteristics:
- KS-41 caterpillar chassis;
- detection of air objects at a distance of less than 180 kilometers, an altitude of no more than 12 kilometers. (70 kilometers with an enemy aircraft flying at a height of not more than 500 meters);
- power - 1.7-1.8 MW;
- overview - circular, four beams in the vertical plane (two in the upper and two in the lower part of the plane);
- switching beams - electromechanical.
Station SNR 1C32 is a station for searching for targets according to the issued CU (SOC 1C12), auto-tracking and issuing calculated data to launch SPU 2P25. Carries out radio command control of missiles in flight. The station is equipped with an automatic electronic rangefinder. The principle of operation is the method of monoconic covert scanning by angular coordinates. Radar of cm-range of coherent impulse action. Antenna post - design of circular rotation with antennas. The largest of these is the target channel antenna. Next to it are the missile channel antennas (narrow and wide beam) and the command-transmitting antenna. At the very top is the reticle camera. The computing-decisive equipment of the station calculated the boundaries for launching missiles and other data necessary for launching missiles based on the real coordinates of the targets. The data came to the launchers, after which the launchers came into motion and turned in the direction of the target. When entering the affected area, the missiles were launched. After the launch, the rocket was captured to accompany the missile channel antenna and after the target channel. Data for charging the radio fuse and control commands were transmitted via the command-transmitting antenna.
Main characteristics:
- chassis - self-propelled tracked chassis from SU-100P;
- weight - 28.5 tons;
- engine - diesel A-105V;
- engine power 400 hp;
- cruising range - up to 400 kilometers;
- maximum speed up to 65 km / h;
- power - 750 kW;
- beam width - 1 degree;
- target acquisition max / min - up to 105/70 kilometers;
- range / coordinates error - 15 meters / 0.02 degrees;
- calculation of the station - 4 people.
The 3M8 guided anti-aircraft missile is a two-stage missile. Marching stage with an air-jet ramjet engine. Fuel is kerosene. The starting stage is four detachable solid propellant boosters. A high-explosive fragmentation warhead with a radio fuse detonation. If it was impossible to hit the target, the missile defense system self-destructed. Rocket control - 3 points method (half straightening).
Main characteristics:
- wingspan 2.2 meters;
- the span of the stabilizers - 2.7 meters;
- length - 8.4 meters;
- diameter - 85 centimeters;
- starting weight - 2.4 tons;
- weight of the sustainer stage with the warhead - 1.4 tons;
- kerosene - 270 kilograms, isopropyl nitrate - 27 kilograms;
- undermining warhead - up to 50 meters to the target (radio fuse).
The launcher of the tracked type 2P24 is used to install two fueled combat 3M8s on it, transport and launch on detected and tracked air targets. To ensure the safety of launches, the calculation had to be inside the SPU. The artillery part of the installation is a support beam with an arrow at the rear on hinges. The boom is raised by hydraulic cylinders and brackets that have supports for installing missiles. To launch the rocket, the front support is removed (for the passage of the lower stabilizer). When moving (transporting), the rockets are additionally reinforced with supports, also placed on the boom.
Main characteristics:
- chassis - tracked chassis from SU-100P;
- weight - 28.5 tons;
- engine - diesel V-54, power 400 hp;;
- cruising range up to 400 kilometers;
- maximum speed up to 65 km / h;
- angles of missile launch - 10-60 degrees.
- height - more than 4 meters;
- installation time of missiles on SPU - about 4 minutes;
- Launch calculation - 3 people.
Equipment and machinery of subdivisions provided with the Krug air defense system
K-1 called "Crab" is an automated command and control system. Purpose - automated fire control of anti-aircraft units (regiments) armed with S-75/60 complexes and a little later the Krug air defense system.
Complex composition:
- KBU (for the brigade), located on the chassis from the Ural-375;
- control center (for the division), located on the chassis from the ZIL-157;
- "Grid-2K" - transmission line for radar information;
- topographic snapper GAZ-69T;
- equipment and power supply units.
The complex provided display on the brigade commander's console of data on the air situation from radar stations of the P-12/15/40 type. Operators could provide simultaneous detection and tracking of up to 10 targets at a distance of 15 to 160 kilometers, followed by entering the coordinates of the target into the calculating device for further processing and issuing the control center at the missile guidance station of the divisions. He could also receive data from the command post of the army or front for two purposes. The time required for processing the data and issuing the control center was 32 seconds. Working out reliability - not less than 0.9.
During the operation of the "Crab" complex with the C-75/60 complexes, quite serious shortcomings were revealed, which led to the fact that the fire capability of units equipped with the "Krug" air defense system was reduced by 60 percent. Therefore, the complex was used in less than 50 percent of combat missions.
In 1981, the ACS was adopted for conducting combat operations by a brigade - "Polyana-D1", which consisted of:
- command post of the 9S478 brigade (PBU-B);
- PBU-D - divisional point;
PBU-B - BU 9S486 cabin, 9S487 interface cabin and two diesel power plants. PBU-D - BU 9S489 cabin, diesel power plants and 9S488 maintenance cabin. Command posts were installed on the chassis from the Ural-375. The topographic marker was installed on the UAZ-452T-2.
The use of "Polyana-D1" immediately increased the number of targets processed at the ZRBR command post to 62 units and doubled the simultaneously controlled target channels. For the command post of the division, the number of controlled channels has doubled, and the number of targets processed has increased to 16 units. In the ACS, for the first time, they implement automated coordination of the actions of subordinate units for independently selected air targets. The use of "Polyana-D1" increased by 20 percent the number of targets hit / destroyed while reducing the consumption of missiles by almost 20 percent.
The main characteristics of the SAM SD 2K11 "Circle":
- range of destruction - from 11 to 45 kilometers;
- target height - from 3 to 23.5 kilometers;
- the speed of the targets hit is not more than 800 m / s;
- the probability of hitting a target with one missile - 0.7;
- response time no more than 60 seconds;
- weight of one rocket - 2.45 tons;
- the time of transfer to the stowed / combat position is no more than 5 minutes.
- the main chassis of the complex is of the caterpillar type.
Modifications
Since the complex was a fairly new and complex type of technology, it was constantly modernized and improved. Improvements were carried out to reduce the "dead" lower zone of the air defense system. Foreign counterpart - SAM "Nike Hercules". It had the best indicators of range and height of destruction. He practically did not have mobility (the time for transferring from field to combat was up to 6 hours).
- "Krug-A" - modification of the 1967 air defense system. The lower boundary (height) was lowered to 250 meters;
- "Krug-M" or 2K-11M - modification of 1971. The range is increased to 50 kilometers, the altitude limit of the defeat is up to 24.5 kilometers;
- "Circle-M1 / M2 / M3" - M1 modification of 1974. The "dead" zone in height dropped to 150 meters, hitting targets at a distance of up to 20 kilometers on a catch-up course.
Export - Bulgaria, East Germany, Czechoslovakia, Hungary, Syria, Poland. Discontinued after the start of serial production of the S-300V.
