Staff Writer (Updated: 6/18/2015):
Design of the ZPU-1 is highly utilitarian and conventional. The system is essentially made up of three major components that include the barrel, gun mount and carriage - though the barrel and gun mount can be fitted to a vehicle for an improvised mobile weapons platform if desired. The air-cooled 14.5mm machine gun sits on a semi-flexible mounting that allows for engagement elevations of -8 to +88 degrees. Since the gun mount is fixed into the ZPU base carriage, the entire ZPU-1 system must be turned in order to achieve traverse. However, this does allow for traversal of a full 360-degrees. Maximum range of the gun system is out to 8,749 yards reaching aircraft as high up as 16,404 feet. However, the ZPU-1 remains most effective in engaging aircraft under 5,000 feet. A practical rate-of-fire for the 14.5mm machine gun is about 150 rounds per minute. The weapon base is fitted to a two-wheeled, rubber-tired carriage system with a tow arm for ground transport by light or heavy vehicles. A typical ZPU-1 crew is four personnel. The early optical sights of all ZPU-1s were updated in the 1950s. The 14.5mm barrel can be changed out when overheated.
The ZPU is cleared to fire a variety of ammunition types including an API (Armor-Piercing Incendiary), API-T (Armor-Piercing Incendiary - Tracer) and I-T (Incendiary - Tracer) type. The API (also known as the BS.41) features a full metal jacketed bullet that sports a tungsten carbide core. Penetration of this cartridge is out to 547 yards. The API-T (also known as the BZT) is a full metal jacketed round featuring a steel core and includes a tracer round during active firing for visually training the weapon system against a target. The I-T round is also known by the designation of "ZP". Typically, some 1,200 rounds of 14.5mm ammunition are supplied to a ZPU-1 crew though this may vary based on operator and ammunition carrier. ZPU ammunition was produced in Soviet factories as well as at facilities in Communist Bulgaria, China, Poland and Romania. Egypt also undertook production of ZPU cartridges for a time.
As the ZPU series was wholly Soviet in origin, it was not surprising to find it in the inventories of supported states and allied nations from in the Cold War years. The ZPU series was actively used throughout the Korean War by both North Korean and Chinese army troops against UN aircraft from 1950-1953. Additionally, the NVA utilized the weapon as a low-flying deterrent against the might of American Army helicopters in the upcoming Vietnam War of the 1960s-1970s. Saddam Hussein's forces were equipped with the ZPU types during the 1991 Gulf War. Most recently, examples of ZPU systems were recovered by coalition troops following the fall of Iraq in the 2003 American invasion showing that they were still in active use with the nation.
Major variants of the ZPU family line include the single-barreled ZPU-1, the double-barreled ZPU-2 and the quad-barreled ZPU-4. Each are easily recognizable and their designations clearly mark their respective versions based on number of barrels utilized. The ZPU has also been produced by the Chinese military industry under their own localized designations (Type 58/ ZPU-2 and Type 56/ZPU-4). The ZPU-1 and ZPU-2 are both transported on their integrated two-wheeled carriages while the ZPU-4 is moved by way of its four-wheeled carriage system. Additionally, the larger ZPU-2 and ZPU-4 systems require a standard operating crew of five personnel.
In the Russian Army inventory, the ZPU-1 has since been replaced by the more potent 23mm ZU-23 double-barreled air defense cannon system.