ZU-23-2

The ZU-23-2, also known as ZU-23, is a Soviet towed 23×152mm anti-aircraft twin-barreled autocannon. ZU stands for Zenitnaya Ustanovka (Russian: Зенитная Установка) – anti-aircraft mount. The GRAU index is 2A13.
The ZU-23-2 was developed in the late 1950s. It was designed to engage low-flying targets at a range of 2.5 km as well as armoured vehicles at a range of two kilometres and for direct defence of troops and strategic locations against air assault usually conducted by helicopters and low-flying airplanes. In 1955, KBP presented the single-barrel ZU-1 and the twin-barrel ZU-14. While the former was eventually dropped, the ZU-14 was selected and, after some modifications, entered series production.
In the Soviet Union, some 140,000 units were produced. The ZU-23 has also been produced under licence by Bulgaria, Poland, Egypt and the People's Republic of China.
Development of this weapon into a self-propelled anti-aircraft gun led to the ZSU-23-4 Shilka.
The ZU-23-2 (2A13) mounts two 23 mm autocannons on a small trailer which can be converted into a stationary mount for firing the guns. While in this position the wheels are moved aside. The autocannon can be prepared for firing from the march position in 30 seconds and in emergency can be fired from the traveling position. The weapon is aimed and fired manually, with the help of the ZAP-23 optical-mechanical sight which uses manually entered target data to provide limited automatic aiming. It also has a straight-tube telescope T-3 for use against ground targets such as infantry as well as unarmored or lightly armoured vehicles. The ammo is fed by a conveyor belt from two ammunition boxes. Each of the ammunition boxes is located on the side of the twin autocannon and each carries 50 rounds. The fumes created by firing the weapon are partially removed through the side openings in the barrels.
Normally, once each barrel has fired 100 rounds it becomes too hot and is therefore replaced with a spare barrel. Each weapon is normally provided with two replacement barrels as part of its standard equipment. Tulamashzavod Joint Stock Company is offering to upgrade the 2A14 guns to the 2A14M standard with a barrel life of 10,000 rounds instead of 8,000 rounds.
The cannon carriage is based on the earlier ZPU-2 anti-aircraft twin heavy machine gun, which mounted two KPV 14.5×114mm heavy machine guns. ZU-23-2 can be identified by different placement of the ammunition boxes (at right angles to the gun carriage) and by muzzle flash suppressors. In another similarity to the ZPU series, single-barrel and four-barrel versions of the ZU-23 were also developed. However, these versions never entered service.
The ZU-23-2 can be towed by a number of different vehicles. In USSR and later Russia the most frequently used towing vehicles for it were GAZ-66 4x4 trucks and GAZ-69 4x4 light trucks.
The weapon is known in the Finnish forces colloquially as Sergei.
The 23 mm AA gun utilizes the same 23x152B case as the wartime VYa aircraft autocannon. Due to different loadings and primers the ammunition is not interchangeable, however: ammunition of the anti-aircraft cannon can be identified from its steel casings, ammunition for the aircraft cannon having brass cases instead. The following table lists the main characteristics of some of the available 23x152B ammunition used in 23 mm AA guns:
Not only the gun itself but also the ammunition is produced in several countries. In Bulgaria, the company ARCUS Co. produces rounds and fuses for the 2A7 and 2A14 guns.
The ZU-23-2 first entered service with the Soviet Army in 1960. The gun is often mounted on trucks for use in both anti-aircraft and direct fire support roles. It can also be mounted on the roof of the MT-LB multi-purpose tracked APCs. A specially modified three-legged ZU-23-2 autocannon is used as the base for the BTR-DG airborne SPAAG. Cheap, easy to operate and still effective, the ZU-23-2 is still used by the Russian Army and by more than 20 other armies.
From 1965 onwards, the Soviet Union began supplying the Democratic Republic of Vietnam with large shipments of weapons. The 23 mm ZU-23-2 was, along with the 37 mm M1939, the most frequently encountered anti-aircraft gun in Vietnam. Given that 83% of the USAF losses came from ground fire, the ZU-23 was probably responsible for shooting down hundreds of aircraft.
During the Soviet–Afghan War, the Soviet forces placed ZU-23-2 sets in the occupied areas to secure their positions, employing them in both the static defense and direct fire support roles. In the later Afghan Civil War, the main belligerents, the Taliban and the Northern Alliance forces also employed ZU-23-2 autocannons mounted on BMP-1 and BTR-70 APCs or GAZ-66 and ZIL-131 trucks, along with SA-7 Grail or Stinger Missiles, as their primary air-defense and direct fire support weapons.
The ZU-23-2 was extensively employed during the Lebanese Civil War, mounted on a variety of civilian and military vehicles, including M113 and BTR-152 APCs, Dodge Ram (1st generation) pickup trucks, AIL M325 Command Cars, Toyota Dyna U10-series trucks, Dodge W600 medium-duty trucks and M35A1/A2 trucks. They proved very useful in urban combat, being employed in the direct fire support role by the Syrian Army, the Palestine Liberation Organization (PLO) guerrilla factions and the various Christian and Muslim Lebanese militias. In late 1983, the ZU-23-2 was used on attacks against dug-in positions held by U.S. Marine ground units serving with the Multinational Force in Lebanon (MNF II). At the time, a Marine spokesman described such antipersonnel use of the weapon as a violation of the laws of war; however, writing for the Marine Corps Gazette in 1988, Maj. W. Hays Parks dismissed this allegation as incorrect.
During the Gulf War of 1991, it was a favorite weapon of the Iraqi Army, albeit used more often against ground targets such as infantry and light enemy vehicles. They tended to use it more against ground targets as the ZU-23-2 is ineffective against fast-moving jet aircraft, though later on it was proven to be relatively ineffective as it inflicted few casualties throughout the war.
The ZU-23-2 also saw usage during the Georgian Civil War and at least one kill was claimed by a ZU-23-2, when Georgian forces shot down a Sukhoi Su-25 fighter-bomber jet on 4 June 1993.
The ZU-23-2 had seen widespread use by both sides in the Libyan Civil War, being often mounted on technical pickup trucks. The weapon has also been heavily used in the Syrian Civil War, being installed on pickup trucks and is credited for bringing down several Syrian Air Force helicopters. Technicals equipped with ZU-23-2 autocannons have also been frequently employed against moving ground targets. During the Yemeni Civil War, ZU-23-2 autocannons are said to have engaged Saudi tanks.
On 4 May 2020, ZU-23 was used by Ethiopian troops stationed in Somalia as part of the African Union Mission to Somalia (AMISOM) to mistakenly shoot down an Embraer EMB 120RT Brasilia transporting medical supplies and mosquito nets while on approach to Bardalee, Somalia, killing all six people onboard. The confusion arose from the fact the airplane was approaching from the west, instead of the usual easterly landing direction, and overflew the airfield at a low altitude due to animals on or in the vicinity of the runway. Ethiopian soldiers interpreted these facts as indicative of a suicide plane looking to strike targets within the base camp, and responded with fire.