The Shilka ZSU-23-4 [ZSU = Zenitnaya Samokhodnaya Ustanovka - Anti-aircraft Self-Propelled Gun] is a Self-Propelled Anti-Aircraft Gun (SPAAG) featuring a prominent radar dish that can be folded down mounted on a modified PT-76 chassis. ZSU 23-4 Shilka, is capable of acquiring, tracking and engaging low-flying aircraft (as well as mobile ground targets while either in place or on the move). Employed in pairs 200 meters apart, 400 meters behind battalion leading elements, it is commonly used to suppress ATGM launch sites, such as TOW vehicles. The armament consists of four 23mm cannon with a maximum slant range of 3,000 meters. Ammunition is normally loaded with a ratio of three HE rounds to one AP round. Resupply vehicles carry an estimated additional 3,000 rounds for each of the four ZSUs in a typical battery. Recent (October 1997) information details ZSU-23-4 updates/modernization being offered by the Ukrainians that include: a new radar system replacing the GUN DISH radar, plus a sensor pod believed to include day/night camera, and a laser rangefinder; and mounted above radar/sensor pod is a layer of six fire-and-forget SAMs, believed to be Russian SA-18/GROUSE.
The ZSU-23-4 is a fully integrated, self-propelled antiaircraft system with four liquid-cooled 23-mm automatic cannons mounted on the front of a large, flat, armored turret. The chassis has many components borrowed from other Soviet armored vehicles, and the suspension system resembles that of the PT-76 and ASU 85 (six road wheels and no track support rollers). The driver sits in the left front of the hull, and the rest of the crew (commander, gunner, and radar operator) are located in the turret. The GUN DISH fire control radar mounted on the rear of the turret can be folded down during travel.
A number of different ZSU-23-4 models have been produced. These are primarily distinguishable externally by the types of stowage boxes on the turret and minor modifications in the mounting of the guns.
A platoon of four ZSU-23-4s is assigned, along with four SA-9/GASKIN SAM systems, to the antiaircraft battery of motorized rifle and tank regiments to cover the deadspace of the SA-6/GAINFUL in the division air defense umbrella. Two ZSU-23-4s usually will be in support of each of the two first-echelon battalions, each weapon normally separated by 200 meters, typically traveling 400 meters behind the battalion’s leading elements.
The ZSU-23-4 is not amphibious, but has a fording capability of just over one meter. During river assault operations, the ZSU-23-4s would be ferried to the far bank immediately after the leading companies.
The ZSU-23-4 has the capability to both acquire and track low-flying aircraft targets, with an effective AA range of 2,500 meters. It also is capable of firing on the move because of its integrated radar/gun stabilization system. The high frequency operation of the GUN DISH radar emits a very narrow beam that provides for excellent aircraft tracking while being difficult to detect or evade. However, such a frequency also dictates a limited range, which can be compensated for by linking the system to other long-range acquisition radar in the area. The ZSU-23-4 also can be used against lightly armored ground vehicles.
The four guns are water cooled and have a cyclic rate of fire of 800 to 1,000 rounds per minute each. However, the guns are normally fired in bursts (2-3 rounds per barrel) to reduce ammunition expenditure and prolong barrel life. Each ZSU-23-4 carries about 2,000 rounds onboard. Supply trucks, which follow the ZSUs at a distance of 1.5 to 2.5 km, carry an estimated additional 3,000 rounds for each of the four ZSUs. Electronic target acquisition, tracking, and ranging are automated, and an onboard computer determines super-elevation and azimuth lead. Conventional optical sights also are available. Two types of ammunition normally are mixed at a ratio of three Frag-HE-T rounds per one API-T round. An HEI-T round also may be fired.
TheZSU-23-4can be airlifted bytheAN-22 or II-76. The crew of the ZSU-23-4 is afforded a degree of protection by the thin armor (maximum thickness 9.4 mm in the hull, 8.9 in the turret). Collective NBC protection is provided by a radiation detection and warning system and an air filtration and overpressure system.
Heavy machine gun fire can penetrate the hull and turret. Tread and road wheels are vulnerable to artillery fire. HE fragmentation can penetrate the armor, destroy the radar dish, or rupture the liquid coolant sleeves of the 23-mm cannons. The system also is vulnerable to ECM.
ZSU-23-4 “Shilka” (1964) – pre-production and then initial production models.
ZSU-23-4V “Shilka” (1968): modernized variant with enhanced reliability of some details, ventilation system case located on the right side of the hull. Commander vision device was added.
ZSU-23-4V1 “Shilka” (1970) – modernized variant with enhanced reliability of radar system and other details, ventilation system cases located on front bilges of the turret. Guidance-system computer was improved (as well as accuracy and efficiency of anti-aircraft fire on the move at 40 km/h). It is fitted with a slightly improved diesel engine V-6R-1.
ZSU-23-4M “Beryoza” (1973) – armed with modernized autocannons 2A7M. The pneumatic loading was replaced with pyrotechnic loading (unreliable compressor was removed), welded tubes of coolant outlet were replaced with flexible pipes which increased autocannon barrel life from 3500 rounds to 4500 rounds.
ZSU-23-4MZ “Beryoza” (Z stands for “zaproschik” — “inquirer”) (1977) – equipped with identification friend-or-foe system “Luk”. All ZSU-23-4M were upgraded to ZSU-23-4MZ level during scheduled repairs. It should be noted that army unofficially continued to use the name “Shilka” for all variants of ZSU-23-4.
ZSU-23-4M2 (1978) – so-called “Afghan” variant. Reequipment performed during the Soviet War in Afghanistan for mountain combats. The radar system was removed and a night-sight was added. Ammunition increased from 2,000 to 4,000 rounds.
Russian Federation and Belarus
ZSU-23-4M4 and ZSU-23-4M5 (1999) – modernized variants, armed with two additional paired man-portable air-defense systems “Igla” on each side of the turret and equipped with 81mm smoke grenade launchers, laser emission sensors, electro-optical vision devices (including television system for driver) and improved weapon radar system. The mechanical transmission was replaced with hydrostatic transmission, hydraulic boosters were installed. Mobility increased to the level of main battle tanks. This upgrade was first shown during the exhibition MAKS-99 in Zhukovsky and was carried out by the Minotor Service Enterprise and Peleng Joint Stock Company from the Republic of Belarus, and the Ulyanovsk Mechanical Plant of Russia. The Ulyanovsk Mechancial Plant is also offering ZSU-23-4 upgrade packages independently.
Donets (1999) – This is a Ukrainian modernization developed by Malyshev Tank Factory in Kharkov. It has the modified turret from the ZSU-23-4, armed with two additional paired man-portable air-defense systems “Strela-10″ installed on the hull of the T-80UD main battle tank. Ammunition for 23 mm autocannons increased two times.
ZSU-23-4MP “Biała” (2000) – Polish upgrade with Grom anti-aircraft missiles and fully digital passive aiming devices instead of the radar.
ZSU-23-4 upgrade – This version was developed by Bharat Electronics Ltd (BEL) of India in cooperation with Israel Aircraft Industries (IAI). The upgraded systems will feature a solid-state radar and computers, electro-optical fire control systems, a new Caterpillar 359 BHP diesel engine and a new APU. The upgraded systems must be able to operate despite enemy jamming, must be able to pick up targets more than 15 km away, and must function in temperatures between 55º Celsius and minus 40º Celsius. The gun must be able to shoot down targets flying up to 450 miles per hour up to 1,500 meters and out to 2,500 meters. The purpose of the upgrade would be to extend the life of the air defence system by 15 years. In December 2004 it was reported that the Indian Army awarded a USD $104 million contract to upgrade 48 ZSU-23-4 air defence systems of the Indian Army.
ZSU-23-4 upgrade (1998) – As a private venture, Hollandse Signaalapparaten company (now Thales Nederland) of the Netherlands, obtained a number of ex-East German Army ZSU-23-4V1s and developed an upgrade package. The main part of this upgrade is the modernisation of the radar and fire-control system. The first prototype was completed in mid-1998. The upgraded vehicle is equipped with the ASADS Ka-band target tracking radar and the PAGE I-band surveillance radar