Weapons

ZSU-23-4 Shilka

The high-frequency operation of the fire control radar emits a very narrow beam that provides excellent aircraft tracking while being difficult to detect or evade. However, such a frequency also dictates a limited range; linking the system to other long-range acquisition radars in the area can compensate for this. This system can also engage lightly armoured ground vehicles. The four guns are water-cooled and each have a cyclic rate of fire of 800 to 1000 rounds a minute. However, the gunner normally fires them in bursts of 2 to 3 rounds a barrel, to reduce ammunition expenditure and prolong barrel life. Each ZSU-23-4 carries about 2000 rounds onboard. Ammunition supply trucks, carry an estimated additional 3000 rounds for each of the four guns.

Electronic target acquisition, tracking, and ranging is automated; an onboard computer determines super elevation and azimuth lead. Conventional optical sights also are available. The onboard load normally mixes two types of ammunition at a ratio of three HEI-T rounds per one API-T round. An HEl round is also available. The HEI-T and HEl rounds are intended for defeating aircraft by fragmentation, blast, or incendiary effect. They may also be used against personnel in a ground role. The API-T round can penetrate lightly armoured ground targets & aircraft and can defeat them by an incendiary effect. Tracers facilitate correction of fire.

The ZSU-23-4 is not amphibious, but has a fording capability of just over one meter. During river assault operations, it would be ferried to the far bank immediately after the leading companies. The crew also receives protection from its thin armour; 9.4mm in the hull and 8.9mm in the turret. A radiation detection & warning system and an air filtration & overpressure system provide collective NBC protection. The latest variant, the ZSU-23-4M, features large ammunition panniers mounted on the turret sides with three access ports on each side of the hull and an armoured cover for the guns. It also has a digital computer, an improved fire control radar and can be linked to off-carriage radar and fire control equipment if required.

The fire control radar on the ZSU-23-4M is capable of being used independently in the search mode whereas on previous versions it had been slaved to the gun tubes. There is also a modified ZSU-23-4M with protrusions on the right & left sides of the fire control radar dome and vanes down its center. The vanes are side-lobe clutter-reducing devices and the protrusions are IFF receivers. The most significant changes include a major change to the air cooling supply system as well as the radio & electronic systems of the vehicle. These changes have improved the overall reliability of the system. An improved ventilation system for the fighting and crew compartments has been installed.

Note:

Defence News reported in December 2004, that the Indian Army awarded a USD $104 million contract to Bharat Electronics Limited (BEL) and Israel Aircraft Industries (IAI), to upgrade 48 ZSU-23-4 air defence systems of the Indian Army. The Chairman of BEL, Y Gopala Rao, stated that the trials were conducted on two upgraded prototypes and the remaining 46 systems are to be upgraded by 2005. IAI assisted BEL with the system integration. It is also reported that the upgraded systems will feature a solid-state radar and computers, electro-optical fire control systems, a new engine and overhauling of all subsystems. 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 35º Celsius and minus 40º Celsius. The gun must be able to shoot down targets flying up to 450 miles per hour up to 1500 meters and out to 2500 meters. The purpose of the upgrade would be to extend the life of the air defence system by 15 years.

Note:

Defence News reported in July 2006, that the Indian Army rejected an upgraded prototype of the ZSU-23-4 air defence system, as the system was inaccurate and had insufficient range and has requested the Ministry of Defence to expedite the purchase of a replacement system.