Fire control unit RPK-1

The RPK-1 Wasa fire control unit ( Russian Радиолокационно-Приборный Комплекс РПК-1 Ваза , Radiolokazionno-Priborny Kompleks RPK-1 “Wasa” ) is a Soviet radar device. It is used to direct the fire of a 57 mm anti-aircraft battery S-60 under the influence of active and passive radio interference. It replaced the gun alignment stations GRS-4 (СОН-4) and GRS-9 (СОН-9) as well as the command units 6-60 and E-2BD.

RPK-1 on truck Ural-375D

development

Electronic reconnaissance and target tracking of air targets day and night and under all weather conditions for anti-aircraft batteries had already become possible with the gun alignment station GRS-4 and its successor GRS-9. However, an additional command device was required to determine the lead point and the guide values for the anti-aircraft cannons. The electronic interference protection options as well as the dimensions and weights soon no longer met the requirements of modern combat. An analog computer of the type PUAZO-7 was therefore already integrated in the last GRS-4 built , which enabled the calculation of the lead point and the guide values for the guns of the anti-aircraft battery. The basic shortcomings of the two types mentioned could not be remedied.

Development of the RPK-1 began in the 1950s in the ZKB NII-20 (Russian: ЦАКБ НИИ-20 ) under the direction of MM Kositschkin ; state testing began in 1958 and completed in 1960. The RPK-1 was intended for fire control in anti-aircraft batteries, which were equipped with guns of caliber 57 ( S-60 ), 85 (KS-18) and 100 mm ( KS-19 ). The introduction into the Soviet Army began in 1961, the introduction into the NVA in 1968. Although the production of anti-aircraft missile systems in the Soviet Union had already started in the late 1960s, the RPK-1 was still in production until 1984. Compared to its predecessors, it is characterized by its significantly more compact design and improved interference protection options, which led to a significant increase in the combat value.

construction

With the RPK-1, all elements of a fire control complex were combined on one vehicle for the first time in the Soviet Union. The station consists of

the carrier vehicle Ural-375D

the radio measuring device 1RL35 (modifications M, N, M1)

the arithmetic unit 1A19 (modifications M, N, M1)

the identification device

the TV visor 9Sch13

the AB-16T / 230 / Tsch-400 electrical unit

the heating and ventilation system O30

An essentially unchanged Ural-375D truck is used as the carrier vehicle. The other components of the station are located in a box body with the designation product 932B (изделие 932Б). In the marching position, the antennas of the RPK-1 are inside the box body; in combat situations they are hydraulically swiveled upwards through a hinged hatch. With a length of 7.44 m, a width of 2.8 m and a height of 3.5 m, the total weight is 13.6 t. By combining all the components of the RPK-1 in one vehicle and choosing the Ural-375D as the carrier vehicle, it was ensured that the RPK-1 can follow the anti-aircraft battery without restriction, both on the road and off-road. The crew consists of a total of five people. It takes five to seven minutes to set up the station, plus a switch-on time of three minutes, which is due to the need to warm up the electronic assemblies.

The power supply is ensured by an AB-16-T / 230 / Tsch-400 electrical unit (modifications M1, M2). The unit supplies three-phase alternating current with a voltage of 230 volts and a frequency of 400 Hz with a nominal output of 16 kW. It is also in the box body during the march and is unfolded for operation.

The O30 heating and ventilation system supplies 120 m³ of fresh air per hour. Operation is possible while driving and when stationary.

The 1RL35 radio measuring device is used to clarify the airspace and determine the target coordinates. It works in the frequency range from 9.25 to 9.7 GHz. Furthermore, a training device for training the crew is integrated in the radio measuring device. A klystron with a pulse power of 360 kW was used in the transmitter , while the receiving part was implemented with traveling wave tubes . A circular parabolic antenna was used as the antenna for both reconnaissance operations and target tracking . Sending and receiving parts are built using electron tubes, since sufficiently powerful semiconductors were not available at the time of development.

In reconnaissance operations, an all-round search or a sector search can be carried out in a range from 18.5 to 22.5 °. With all-round search, the antenna can be swiveled at an elevation angle of 1.4 to 81.5 °, while with a sector search the minimum elevation angle is 14 °. Air targets can be detected up to a distance of 55 km, fighters typically up to a distance of 38 km. The air situation is shown on a panoramic device.

With automatic target escort, air targets can be escorted up to a maximum distance of 40 km, fighter planes typically up to a distance of 32 km. The deviation according to the distance is a maximum of 15 m, the error in the lateral or elevation angle is a maximum of 0.05 °. Flicker scanning is used as a functional principle . The disadvantage of this method, the susceptibility to angular response disturbances, is compensated for by the operation with main and secondary channels.

Comprehensive measures for interference protection have been integrated into the 1RL35 . To suppress passive radar interference one with two successive comes vacuum memory tubes operating system for the selection of moving targets (SBZ) with wind compensation for use. To protect against active interference, the transmission frequency can be changed automatically or manually. The station is protected against asynchronous interference through the possibility of wobbling the pulse repetition frequency , and against angular response interference through operation via the main and secondary channel. The runtime differences between the main and secondary channels are balanced out by a runtime chain. The interference protection is supplemented by an automatic amplitude selection of the response signals.

The computing device 1A19 is used to determine the shot values of the guns of the battery. It is assumed that the air target moves in a straight line with constant speed and in any plane during the hold-up time. By the radar 1RL35 determined spherical target coordinates are converted into rectangular target coordinates, and taking into consideration the course and speed of the air target, as well as the propellant temperature, the parallax and the wind direction or speed at different elevation levels, the azimuth angle to the lead point determined and the pipe increase. These values are transmitted to the guns via cables. The aiming of the guns takes place fully automatically according to the values of the computing device. Propellant temperature, parallax and wind direction or speed must be entered manually into the computing device. The computing device can also be coupled with the 9Sch13 television sight . The distance to the target can either be determined by the radio measuring station; alternatively, the distance is determined on the basis of a set height without radiation from the radar device. Furthermore, inertia support is possible if the air target is lost by the radar station. The target coordinates are extrapolated by the computing device for a maximum of 10 seconds. This operating method can also be used if, for tactical reasons, the radiation from the radar station is to be briefly interrupted. The transmitter of the radar station is not switched off, but rather the transmission power is diverted to a resistor, the so-called equivalent, instead of to the antenna. This operating mode also serves to increase interference protection. It was first introduced in a Soviet fire control system on the RPK-1. A similar solution is available in the 1RL33 radar unit of the Fla-Sfl ZSU-23-4 . In terms of design, the arithmetic unit is an analog computer , which is mostly built up with electron tubes, resolvers and resolvers . The advantage of this design lay in the significantly higher operating speed of analog computers compared to digital computers at the time of development and in the simple implementation of the differential equations to be solved by rotating electrical machines.

The 9Sch13 television sight is used to observe the airspace and to determine the angular coordinates of the air target during the day and with a clear view. The system essentially consists of a television camera with a zoomable lens and a screen for display in the cabin. The television camera is arranged axially parallel to the antenna, so that it is possible to switch quickly between operating the radar station and the television sight. The use of the television sight also increases the interference protection of the weapon system, since radiation can be avoided when the distance is determined by the computing device. However, the accuracy of the shot values is lower, and use is limited to appropriate weather conditions. The RPK-1 was the first Soviet weapon system to use such a television sight.

The identification device is part of the Kremni 2 complex . The operating principle is based on sending and receiving a coded pulse train. A total of twelve manually changeable code filters are available. The dipole antenna of the identification device is arranged above the parabolic antenna.

Working method

The components of the RPK-1 enable several working methods that allow adaptation to the respective tactical situation.

An automatic all-round search can be carried out to clarify the target, an adjustable sector is automatically searched in the elevation angle. Due to the design, several revolutions of the antenna are necessary to completely cover the height range. Alternatively, an automatic sector search can be carried out in the lateral and elevation angles. If the direction and distance of the air target to be scouted are roughly known, the antenna can also be directed manually. The aerial target can also be assigned using a TZK anti-aircraft telescope or an autonomous radar station; the antenna is directed parallel to the TZK or the coordinates transmitted by the radar station.

Perceived targets can be accompanied automatically according to the angular coordinates; automatic, semi-automatic or manual distance monitoring is possible. If the radiation is to be minimized, a semi-automatic accompaniment can be carried out according to the angular coordinates determined by the television sight. The television sight is aimed at the target in the air, the distance is determined either by the radar station or by the computing device according to a fixed elevation angle. In the event of intentional or unintentional loss of the air target by the radar station, the angular coordinates can be extrapolated by the computing device for a limited period of time.

commitment

Soviet Army

The introduction of the system began in 1961 in the Soviet Army. There the RPK-1 replaced the gun straightening stations SON-9 and SON 9a in the anti-aircraft batteries, which were equipped with the 57-mm automatic anti-aircraft gun S-60 . In principle, one RPK-1 was provided for each firing battery. Since larger-caliber anti-aircraft cannons were replaced by anti-aircraft missile systems, rifled anti-aircraft cannons of smaller caliber by anti-aircraft and anti-aircraft missile systems, use was restricted to the S-60 weapon system. With the replacement of the S-60 by the 2K12 Kub and 9K33 Osa anti -aircraft missile systems , the RPK-1 was separated from the active units in the 1970s.

National Peoples Army

The introduction to the NVA began in 1968 and could not be completed until 1975. The RPK-1 replaced the GRS-9a in the anti-aircraft regiments equipped with the S-60. As early as 1976, however, the air defense regiments of the NVA began to replace the S-60 with the 2K12 anti-aircraft missile system , which was completed in 1983. The anti-aircraft regiments of the active divisions and thus the existing RPK-1 were assigned to the mobilization divisions of the NVA and remained there until the NVA was dissolved. After the dissolution of the NVA, the RPK-1 were scrapped or given away. Due to the long introduction period, the modifications RPK-1A, RPK-1M and RPK-1N were available in the NVA.

Other states

The RPK-1 was delivered to practically all states that also procured the S-60. In Belarus, Ukraine, Yugoslavia, Romania, Angola and Iraq, it was still in use after 2000.

During the Second Gulf War , an Iraqi RPK-1 demonstrated the system's interference protection capabilities. After an AGM-88 HARM tactical anti-radar missile interlocked with the station's signal, it was switched to equivalent. The HARM lost its target and switched to a radar station AN / TPQ-36 , which also operated in the frequency range 9.3–9.7 GHz. The Q-36 was successfully fought by the AGM-88.

Individual evidence

↑ Designation in the NVA, the transliteration SON-4 is also in use

↑ see Зенитный артиллерийский комплекс С-60 (Russian)

↑ see Dawydow ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice.@1@ 2Template: Dead Link / azrp.ucoz.ru
↑ Five minutes standard time in the NVA, see radio measuring fire control unit RPK-1N, use in the NVA and in the FR-11 , seven minutes after Dawydow.
↑ Parallax here means the shift in the position of the guns in relation to the position of the radar station
↑ Radio measuring fire control unit RPK-1N

Web links

literature

Collective of authors: Handbook for air defense gunners. Military publishing house of the GDR, 4th edition 1975.
Wilfried Copenhagen: The land forces of the NVA. Motorbuch Verlag, 1st edition 1999.

[1] Designation in the NVA, the transliteration SON-4 is also in use

[2] see Зенитный артиллерийский комплекс С-60 (Russian)