The ZSU-23-4 and the SA-6 (Red Storm Rising)

I am bringing out 2 mainstays of the Soviet Air defense umbrella that were designed to stay with the armored formations.   We would study the Soviet Army and their Air Defense we had to look for were the SA-4/SA-6/SA-8 and the "ZSU",  those were high on the priority list, for if we went to war, we wanted to know where those were since we would be using combined air basically Helicopters and A-10's to counter the huge formation of Soviet armor descending down the Fulda gap.  These systems were designed to keep up with the Soviet formations in the field to protect them from our Air power, the Soviets had multiple systems that would overlap each other and provide complete coverage from low level attacks to the high atmosphere.    I am continuing my "Red Storm Rising" theme, in the book, the SAM systems were a major threat to the A-10's and the "Frisbee's" stealth fighters that were trying to slow and stem the Soviet advance.  In the book, the Soviet General had commented "We have done well with our technology, we can kill men instantly with missiles."

The ZSU-23-4 "Shilka" is a lightly armored Soviet self-propelled, radar guided anti-aircraft weapon system (SPAAG)

The acronym "ZSU" stands for Zenitnaya Samokhodnaya Ustanovka (Russian: Зенитная Самоходная Установка), meaning "anti-aircraft self-propelled system"; the "23" signifies the bore diameter in millimeters; the "4" signifies the number of gun barrels. It is named after the Shilka River in Russia. Afghan soldiers nicknamed it the "sewing machine" due to the sound of firing guns. It is also referred to by its nickname of "Zeus" which is a play on the first part of the name.

 T72M and a ZSU-23-4

The development of the ZSU-23-4 "Shilka" began in 1957 along with ZSU-37-2 "Yenisei" and the vehicle was brought into service in 1965, replacing all ZSU-57-2s in air defense units toward the beginning of the 1970s. The ZSU-23-4 was intended for AA defense of military facilities, troops, and mechanized columns on the march; originally, the more powerful guns of "Yenisei" were judged to be effective at covering the inner dead-zone of Soviet surface-to-air missile systems despite the increased weight of the vehicle, but commonality prevailed. Initially, tank regiments should have had the anti-aircraft artillery battalion of "Shilka" (consisting of two batteries, four ZSU-23-4s in each). At the end of the 1960s, one battery was equipped with ZSU-23-4s and the other with ZSU-57-2s. Motorized rifle and tank regiment standard anti-aircraft batteries consisted of two platoons later (one platoon was equipped with four ZSU-23-4s and another with four mobile surface-to-air missile systems 9K31 Strela-1 or 9K35 Strela-10). The ZSU-23-4 combined a proven radar system, the non-amphibious chassis based on GM-575 tracked vehicle, and four 23 mm autocannons. This delivered a highly effective combination of mobility with heavy firepower and considerable accuracy. The ZSU-23-4 outclassed all NATO anti-aircraft guns at the time, and it is still regarded as posing a major threat for low-flying fixed-wing aircraft and helicopters.
The system was widely fielded throughout the Warsaw Pact and among other pro-Soviet states. Around 2,500 ZSU-23-4s, of the total 6,500 produced, were exported to 23 countries. The Soviet Union's successor states continue to manufacture and supply variants of the ZSU-23-4, notably the Ukrainian "Donets" and Polish "Biala" variants.

ZSU-23-4 graphic.

ZSU-23-4 at Yad la-Shiryon Museum, Israel.

ZSU-23-4 units saw active service in the Yom Kippur War (1973) and other Arab-Israeli conflicts, the Iran–Iraq War (1980–1988), and the First Gulf War (1990). During the 1973 Yom Kippur War, the system was particularly effective against the Israeli Air Force. Israeli pilots attempting to fly low in order to avoid SA-6 missiles were often shot down by ZSU-23-4s as in Operation Doogman 5. During the Soviet-Afghan War ZSU-23-4 units were used widely and to great effect against mujahideen positions in the mountains, the ZSU-23-4's guns being able to elevate much higher than the weapons on BMPs, BTRs, T-55s, or T-62s. They were also used to suppress defensive positions around the presidential palace during the initial coup in Kabul at the start of the Soviet-Afghan war. The Russian Army used the ZSU-23-4 for mountain combat in Chechnya.
Initially fielded by the loyalist forces of the Syrian Arab Army as a fire support vehicle, a number of them were captured by different factions in the Syrian Civil War and they are normally fielded in a fire support role by all sides. There were no or at most very limited, attempts by the different opposing forces to use the Shilka in its original anti aircraft role against loyalist and international air forces operating in the area.

The radar-guided ZSU-23-4 "Shilka" SPAAG, with its four 23 mm (0.90") autocannons, was a revolutionary SPAAG, proving to be an extremely effective weapon against enemy attack aircraft and helicopters under every weather and light condition. The ZSU-23-4 has a very high density, rate and accuracy of fire, as well as the capability for each of the four autocannons to fire its own type of projectile from separate belts. While it is technically possible that each cannon shoots different type of ammunition, there were two types commonly used in late 1970s: OFZT incendiary fragmentation and BZT armour-piercing tracer, which were to be loaded in 3:1 ratio—three OFZT, then one BZT, every 10th BZT round equipped with so-called "copper remover" and marked. Operators were strongly discouraged from shooting from a single barrel.

The appearance of the "Shilka" caused significant changes in NATO tactics in aircraft use at low altitude over the battlefield. Despite its present obsolescence as a modern short-range anti-aircraft weapon, the ZSU-23-4 is still deadly for enemy light armoured vehicles, infantry and firing points as an infantry-support vehicle. With its high rate of accurate fire, the ZSU-23-4 can even neutralize tanks by destroying their gun sights, radio antennas, or other vulnerable parts. ZSU-23-4s, especially late models, have excellent performance and good systems reliability.
Based on the GM-575 tracked vehicle chassis, which used components from the PT-76 light amphibious tank, the ZSU-23-4 mounts an armored turret holding four liquid-cooled 23 mm (0.9") 2A7 autocannons linked to an RPK-2 "Tobol" radar (NATO designator: "Gun Dish"). The vehicle weighs 19 tonnes (late modifications up to 21 tonnes), has a movement range of 450 km (280 mi) and a top speed of 50 km/h (31 mph). Additional firepower of late modifications can be supplied by a roof-mounted pod of six short-range SA-18 SAMs, or side mounted SA-16s.
The crew numbers four: driver, commander, gunner and radar operator. The driver's compartment is located in the nose part of the vehicle. The fighting compartment is in the center, and the engine compartment is in the rear part of the vehicle.

Each water-cooled 23 mm 2A7 autocannon has a cyclic rate of 850–1,000 rounds per minute for a combined rate of fire of 3,400–4,000 rounds per minute. The welded turret has a race ring transplanted from a T-54 medium tank with a 1,840 mm (6') diameter. The 360° rotating turret is fully stabilised and capable of firing on the move. The turret rotation and autocannon elevation mechanisms provide very good speed and guidance accuracy. The hydraulically driven aiming mechanisms have been proven to be very reliable. Manual aim is used against ground targets. The quad automatic anti-aircraft gun AZP-23 "Amur" has a range of elevation from -4° to +85°. The GRAU designation for ZSU-23-4 turret with 23 mm (0.9") AZP-23 "Amur" quad automatic gun is 2A10. An armoured plate inside the turret protects crew members from fire and explosive gas during intense firing.

Ammunition capacity is 2,000 rounds stowed aboard (520 rounds per each upper autocannon and 480 rounds per each lower autocannon) loaded in 50-round or shorter belts.  A typical loading of each ammunition belt contains 40 OFZT and 10 BZT rounds. They can be fired to a maximum horizontal range of 7 km (4.3 mi), and a vertical range of 5.1 km (3.2 mi). The effective vertical range is 1.5 km (0.93 mi) at a direct range to target of 2.5 km (1.6 mi) and target speed of 250 m/s (up to 500 m/s if a modern fire control system is used). The usual autocannon burst consists of 3–10 projectiles and target lead angle is calculated for each burst (fire without adjustment) by computer. In attacking targets on the ground, its effective range is around 2.5 km (1.6 mi). The short range of its 23 mm autocannons and relatively low explosive effect of its small-calibre projectiles mean it is less able to engage threats such as jet attack aircraft and cruise missiles than modern systems like the 9K22 Tunguska armed with more powerful 30 mm autocannons and integrated missile armaments. A special 23 mm round with composite projectiles was developed for a modern variant of SPAAG (ZSU-23-4M4) to be used against cruise missiles.

 The RPK-2 "Tobol" a.k.a. 1RL33 radar operates in the J band and can detect aircraft up to 20 km (12 mi) away. It has excellent target tracking capability and is relatively hard to detect by the enemy. However, the radar picks up many false returns (ground clutter) under 60 m (200 ft) of altitude. The radar antenna is mounted on collapsible supports in the top rear of the turret. There is an optical alignment sight. The RPK-2 radar proved to have good protection against enemy passive electronic radar counter-measures. Nevertheless, the radar system of the ZSU-23-4 has a short detection range during target search, depending on weather conditions (mainly dependent on rain and snow conditions). It is hard to automatically track the target at ranges less than 7–8 km (4.3-5.0 mi) because of the high angular speed of the target at close distances. The radar needs to be reset quite often because of the unstable parameters of electronic cathode-ray tubes of the target selection system. The absence of an automatic laser range finder requires a skillful commander and gunner.

Soviet doctrine supplied the vehicle since 1965 in an anti-aircraft artillery battery of two, four-vehicle platoons for anti-aircraft defence of motor rifle and tank regiments. At the end of the 1960s one platoon was equipped with ZSU-23-4 SPAAGs while another one was still equipped with ZSU-57-2 SPAAGs. ZSU-57-2 was completely replaced with ZSU-23-4 by the beginning of the 1970s. In the 1970s, Soviet motor rifle and tank regiments were equipped with an anti-aircraft missile artillery battery consisting of two platoons, one equipped with four ZSU-23-4 SPAAGs and the other with four 9K31 Strela-1 (SA-9 Gaskin) or later with four 9K35 Strela-10 (SA-13 Gopher) short-range surface-to-air missile systems which cover the dead zones of 2K12 Kub (SA-6 Gainful) surface-to-air missile systems belonging to the divisional level. Since the 1980s Soviet motor rifle and tank regiments were equipped with an anti-aircraft artillery battalion of three batteries (one was equipped with ZSU-23-4 or 9K22 Tunguska SPAAGs, the second one was equipped with 9K35 Strela-10 (SA-13 Gopher) short-range surface-to-air missile systems and the third battery with 9K38 Igla man-portable surface-to-air missiles on IFVs or APCs.
The ZSU-23-4 is very vulnerable to enemy anti-tank missiles, cannons and heavy machine guns; the armor is thin (not exceeding 15 mm) and the exposed wheels, tracks, radar, and gun barrels can easily be damaged in combat. Firing positions of ZSU-23-4 SPAAGs are typically placed near the forward edge of the battle area (FEBA) but behind the main forces, usually 600–1000 m behind objectives when on the defensive or 400–600 m behind the leading tanks on the offensive. ZSU-23-4 SPAAGs are divided evenly along the troop columns on the march.
At first each ZSU-23-4 operated in combat autonomously, without target marking from regimental or divisional air defense. In 1978, the PPRU-1 (mobile reconnaissance and control post) was passed into service of the Soviet Army. The PPRU-1 ("Ovod-M-SV") vehicle is based on MT-LBu armored tracked chassis and it was intended for control of motor rifle or tank regimental anti-aircraft unit equipped with ZSU-23-4 SPAAGs and 9K31 "Strela-1M" mobile surface-to-air missile systems. The PPRU-1 is equipped with "Luk-23" radar and an automatic fire control system associated with the divisional air defense system.

ZSU-23-4 photo.

The guns are useful against low-flying aircraft and lightly protected ground targets. Due to its effectiveness against ground targets, ZSU-23-4s have been used in urban environments (e.g., Afghanistan, Abkhazia, Chechnya, Syria and Lebanon). This is primarily because the guns can elevate much higher than a tank or APC cannon, enabling armored units equipped with ZSU-23-4s to return fire against ambushes from above.
A small number of ZSU-23-4 SPAAGs are still in use by the Russian Naval Infantry (specifically the 61st and 175th brigades of the Northern Fleet and the 336th brigade of the Baltic Fleet).

   You noticed that both systems share the same chassis...

The 2K12 "Kub" (Russian: 2К12 "Куб"; English: cube) (NATO reporting name: SA-6 "Gainful") mobile surface-to-air missile system is a Soviet low to medium-level air defence system designed to protect ground forces from air attack. "2К12" is the GRAU designation of the system.
Each 2K12 battery consists of a number of similar tracked vehicles, one of which carries the 1S91 (SURN vehicle, NATO designation "Straight Flush") 25 kW G/H band radar (with a range of 75 km (47 mi)) equipped with a continuous wave illuminator, in addition to an optical sight. The battery usually also includes four triple-missile transporter erector launchers (TELs), and four trucks, each carrying three spare missiles and a crane. The TEL is based on a GM-578 chassis, while the 1S91 radar vehicle is based on a GM-568 chassis, all developed and produced by MMZ.

The development of the 2K12 was started after 18 July 1958 at the request of the CPSU Central Committee. The system was set the requirements of being able to engage aerial targets flying at speeds of 420 to 600 m/s (820–1,170 kn) at altitudes of 100 to 7,000 m (330 to 22,970 ft) at ranges up to 20 km (12 mi), with a single shot kill probability of at least 0.7.
The systems design was the responsibility of the now Tikhomirov Scientific Research Institute of Instrument Design (NIIP). In addition to NIIP several other design bureaus were involved in the creation of the Kub missile system including the now JSC Metrowagonmash (former MMZ)which designed and produced the chassis of the self-propelled components. Many of the design bureaus would later go on to co-operate in the development of the successor to the 2K12 "Kub", the 9K37 "Buk"
First trials of the missile system were started at the end of 1959 to discover a series of problems:

• low power for the missile radar seeker and badly designed nose cone,
• missile air inlets design failure,
• low quality of heat shield inside the afterburner chamber (titanium was replaced by steel).

Those failures resulted in some 'orgchanges': In August 1961 Toropov was replaced by Lyapin as the Chief Designer of Vympel and in January 1962 Tikhomirov was replaced by Figurovskiy as the Chief Designer of NIIP. Still, the work wasn't intensified. Before 1963 only 11 of 83 missiles fired had the seeker head installed, only 3 launches were successful.
Kub downed its first ever air target on February 18, 1963, during the state trials at Donguz test site, Orenburg Oblast. It was an Ilyushin Il-28 bomber.
The system entered an extended testing period between 1959 and 1966, after overcoming the technical difficulties of producing the 2K12 "Kub" the system was accepted into service on 23 January 1967 and went into production that same year.
It is sometimes claimed that the SA-N-3 Goblet naval system is a version of the 3M9 but this is not the case, as the M-11 Shtorm is a separate system and, unusually for Russian surface-to-air missiles, has no land-based variant.

The 2K12 system shares many components with the 2K11 Krug (SA-4) system. In many ways they are designed to complement each other; 2K11 is effective at long ranges and high altitudes, 2K12 at medium ranges and intermediate altitudes.
The system is able to acquire and begin tracking targets using the 1S91 "Самоходная установка разведки и наведения" (SPRGU - "Self-propelled Reconnaissance and Guidance Unit" / NATO: "Straight Flush" radar) at 75 km (47 mi) and begin illumination and guidance at 28 km (17 mi). IFF is also performed using this radar. It can only guide one or two missiles to a single target at any time. The missile is initially command guided with terminal semi-active radar homing (SARH), with target illumination provided by the "Straight Flush" radar. Detonation is via either the impact or proximity fuze. On the latest models, this vehicle is also fitted with an optical tracking system which allows engagement without the use of the radar (for active RF emissions stealth reasons, or due to heavy ECM jamming) in which case the effective altitude is limited to 14 km/46000 ft. The optical tracking method also allows engagements to altitudes below that where the radar is able to track targets. Maximum target speed is around Mach 2 for head-on engagements and Mach 1 for tail-chase engagements. Top speed of the missile is approximately Mach 2.8.
In contrast to the elaborate Patriot missile or even the simpler Hawk system fielded by US forces, most of the system rides on two tracked self-propelled vehicles, rather than towed or mounted on trucks, and either the launcher or control vehicle can be set to launch in only 15 minutes after changing location.

The fairly large missiles have an effective range of 4–24 km (2.5–15 miles) and an effective altitude of 50–14,000 m (164–45,931 ft). The missile weighs 599 kg (1,321 lb) and the warhead weighs 56 kg (123 lb). Top missile speed is approx. Mach 2.8. The combined propulsion system 9D16K included solid fuel rocket motor which, when burned out, forms the combustion chamber for a ramjet in a pioneering design putting this missile far ahead of its contemporaries in terms of propulsion.
The missile was fitted with a semi-active radar seeker 1SB4, designed by MNII Agat, which was able to track the target by Doppler frequency since the start. Later upgrades (3M9M3 missile) could do this before the start. Chief Designer of the seeker head was Yu.N. Vekhov, since 1960 – I.G. Akopyan.
In 1977 a new version, the 3M9M1 (DoD designation SA-6B) was created with three missiles fitted onto a different chassis (the same as that of the 9K37 "Buk" (NATO reporting name "Gadfly" / DoD SA-11 ), the 2K12 effective replacement) with an integrated "Fire Dome" missile guidance radar. For comparisons between the 2K12, 9K37, see the 9K37 Buk entry.
An earlier incremental upgrade saw the 2K12 missiles replaced with the 2K12E versions and this system was known as Kvadrat ("Квадрат", meaning square). This name was derived from the most common arrangement pattern of the military vehicles of the 2K12 complex, when the 1S91 radar is located at the center and 4x2P25 TELs at the vertices of a square around the radar.

SURN 1S91 vehicle included two radar station – a target acquisition and distribution radar 1S11 and a continuous wave illuminator 1S31, in addition to an IFF interrogator and an optical channel.
While 1S31 antenna was installed on the upper section of the superstructure and the 1S11 on the lower, they could turn around independently. To make the height of the vehicle lower the central cylinder was able to hide inside the prime mover.
The acquisition range of the radar was reported as 50 km (31 mi) for the Phantom II type target.
Total weight of the 1S91 vehicle with a crew of 4 was 20.3 tonnes and 2P25 vehicle with 3 missiles and a crew of 3 was 19.5 t.

 "Spoonrest, and a "Thin Skin" with a "Fansong SA-2" system in the background.

The 2K12 can also be used at a regimental level, if used as such it can be accompanied by a number of additional radar systems for extended air search at longer range and lower altitude, to supplement the 1S91 "Straight Flush". These systems include the:

• P-12 "Spoon Rest", a VHF early warning radar (also used by the SA-2), with a 200 kilometres (120 mi) range.

• P-40 "Long Track", an E band early warning radar (also used by the SA-4 and SA-8), with a 370 kilometres (230 mi) range.
• P-15 "Flat Face A", a UHF early warning radar (also used by the SA-3, with a 150 kilometres (93 mi) range.
• "Thin Skin" or "Side Net" E band height finding radar (also used by the SA-2, SA-4 and SA-5, range 240 km/148 miles)
• "Score Board" IFF radar

The "Spoon Rest" and "Thin Skin" are mounted on a truck, "Long Track" on a tracked vehicle (a modified AT-T) and "Flat Face" on a van. It is unknown what kind of mounting the "Score Board" has.
Without the P-40 "Long Track" mobile radar vehicle, the 2K12 is unable to track aircraft at high altitudes.