The idea of installing anti-aircraft guns on a self-propelled chassis is quite old. The first anti-aircraft guns on a self-propelled platform appeared during the First World War, and already during the Second World War they became widespread. The Germans achieved particular success in creating the ZSU, having created many different anti-aircraft guns on a mobile platform. They also began using the chassis of the mass production Pz4 tank to install various turrets with anti-aircraft guns on it. So at the end of the war, in small batches, the ZSU "Wirbelwind" (4x20-mm guns) and "Ostwind" (1x37-mm gun) got to the front. After the war, the idea of installing anti-aircraft guns on tank chassis was further developed. Further in the article, we will consider three ZSUs created on the basis of main battle tanks: the Soviet ZSU-57-2, the German Gepard ZSU and the somewhat exotic Finnish ZSU T-55 “Shooter”.
ZSU-57-2 (USSR)
In 1947, in the USSR, under the leadership of designer V. G. Grabin, they began to develop a paired 57-mm automatic anti-aircraft gun S-68, developed on the basis of the S-60 and intended for installation on a wheeled or tracked chassis. At the same time, the wheeled version of the installation was abandoned, leaving only the tracked one. The T-54 medium tank was taken as a base, the vehicle was named product 500, and in the army classification ZSU-57-2.
The ZSU-57-2 was a lightly armored tracked vehicle with a rotating turret, which made it possible to conduct circular anti-aircraft fire from automatic cannons. The armored corps was divided into 3 sections: control, combat and power. The control compartment was located on the left in the bow of the hull. It housed the driver's seat. The fighting compartment was located in the middle of the hull and in the turret, the power compartment was located in the stern and was separated from the fighting by a special armored partition. The hull was welded from light armor plates 8-13 mm thick. The crew consisted of 6 people: a driver-mechanic, commander, gunner, gunner-installer of the sight, two loaders for each of the guns, all of them, except for the driver, were located in the turret.
German SPAAG "Wirbelwind" during the Second World War
The tower, open from above, was welded and placed on a ball support above the cut of the turret sheet of the hull roof. There were 2 embrasures to mount the guns in the front of the hull. The rear wall of the turret had a window for ejection of cartridges and was removable, which facilitated the installation of guns. In the stowed position, the tower was closed from above with a folding canvas awning, in which 13 viewing plexiglass windows were mounted.
The S-68 automatic twin cannon consisted of two S-60 type assault rifles with the same device. In this case, the details of the right machine were a mirror image of the details of the left. The principle of operation of the automatics was to use recoil energy with a short recoil of the gun barrel. Their practical rate of fire was 100-120 rounds per barrel. However, in practice, the duration of continuous firing was 40-50 shots, after which the guns had to be cooled.
The twin gun was equipped with an automatic, anti-aircraft sight of the construction type. This sight was designed to solve the problem of determining the meeting point of the target with the projectile when firing. To do this, it was first necessary to determine and enter the following data into the sight: target speed (determined by the type of aircraft), heading angle (determined by the apparent direction of target movement) and slant range (determined by eye or using a rangefinder).
The anti-aircraft mount's ammunition consisted of 300 unitary cannon rounds, which were placed in special ammunition racks in the hull and turret. Most of the ammunition (248 shots) before loading into the ZSU was loaded into clips and kept in the turret (176 shots) and the bow of the hull (72 shots). The remaining 52 rounds were not loaded into the clips and were stored in a special compartment located under the rotating floor of the tower. Shots loaded in clips with armor-piercing shells were stacked in the rear of the tower to the right and left of the gun mount. The supply of clips to the guns was carried out by loaders in manual mode.
ZSU-57-2
The ZSU-57-2 was equipped with a 12-cylinder, V-shaped, four-stroke, liquid-cooled diesel engine. The diesel developed a power of 520 hp. and accelerated the installation on the highway to 50 km / h. The engine was installed perpendicular to the longitudinal axis of the ZSU on a special pedestal, which was welded to the bottom of the hull. The working volume of the engine was 38.88 liters, and its mass was 895 kg.
The car was equipped with 3 fuel tanks with a total capacity of 640 liters, the tanks were located inside the hull. Additional external tanks with a capacity of 95 liters were installed on the right along the ZSU on the fenders, the cruising range was 400-420 km. on the highway. A mechanical transmission with a stepped change in gear ratios was located in the rear of the hull. It included a five-speed gearbox, dry friction main clutch, two planetary swing mechanisms, two final drives, compressor and fan drives.
External communication of the ZSU-57-2 was carried out using the 10RT-26E radio station, and the internal communication using the TPU-47 tank intercom. The radio station installed on the self-propelled gun provided reliable communication when moving at a distance of 7-15 km., And in the stop mode at a distance of 9-20 km.
ZSU "Gepard" (Germany)
In the early 60s of the last century, the Bundeswehr became interested in the possibility of creating a new ZSU, which would be able to fight enemy aircraft at any time of the day. In the course of development, the designers and the military opted for a modified chassis of the Leopard-1 main battle tank and a coaxial 35-mm gun mount. The created combat vehicle 5PZF-B was also liked by the armies of Belgium and the Netherlands. As a result, the Bundeswehr ordered 420 ZSU 5PZF-B "Gepard", the Netherlands 100 5PZF-C equipped with its own radar, and Belgium 55 machines.
ZSU "Gepard"
ZSU "Gepard", armed with a paired 35-mm anti-aircraft gun, was intended to combat low-flying air targets at inclined distances from 100 to 4,000 m and at altitudes up to 3,000 m, which fly at speeds of up to 350-400 m /with. Also, the installation can be used to combat ground targets at a distance of 4,500 m. The ZSU is designed to cover the mechanized units of the Bundeswehr on the march in open areas with difficult terrain. The chassis of the Leopard tank, which was the basis for the Gepard, contributed to the fulfillment of this task in the best possible way. ZSU was put into service in 1973.
The body of the ZSU "Gepard" was similar to the body of the main battle tank "Leopard 1", but it had light armor. The main difference was the installation of an additional 71 kW motor, which was used to provide power to the electrical equipment of the installation. The driver's seat was located in front of the right, to the left of it there was an auxiliary power unit, the tower was located in the center of the hull, and the MTO was in the stern. The machine had a torsion-type suspension, consisting of 7 double track rollers and 2 supporting, guide and rear drive wheels. The search radar, mounted at the rear of the tower, could be folded down if necessary. The target tracking radar is located in front of the tower.
The artillery unit of "Cheetah" consists of two 35-mm Oerlikon KDA guns and a double feed belt mechanism, which allows firing various types of shells. The cannons are mounted in a circular rotation tower and can be guided in a vertical plane in a sector from -5 ° to + 85 °. The drive of the guns is completely electric, but in case of failure, there are also drives for mechanical guidance. The total rate of fire of the installation is 1100 rounds per minute (550 per barrel).
Each gun has a special sensor that measures the initial flight speed of the projectile, then transmitting this data to the onboard FCS. The installation ammunition consists of 680 rounds, of which 40 are armor-piercing. In order to change the type of ammunition, the gunner needs only a few seconds. The shell casings are removed automatically during firing. The gunner can independently set the required firing modes and fire single shots, or bursts of 5 or 15 shots, or a continuous burst. When firing at air targets, the firing range does not exceed 4 km. Additionally, ZSU "Gepard" is equipped with two blocks of smoke grenades (4 grenade launchers in each), which are mounted on the sides of the tower.
ZSU T-55 "Shooter"
"Gepard" is equipped with two radars - target detection station MPDR-12 and target tracking radar "Albis". The range of their action is 15 km. In the second half of the 70s of the last century, a new version of the MPDR-18S target designation radar was also developed in Germany, with a detection range of 18 km. Both radars operate independently of each other, which allows independent tracking of the target selected for shelling and the search for new air targets. For firing in conditions of strong electronic suppression, the commander and gunner of the vehicle have optical sights with 1, 5 and 6 times magnification.
After the target has appeared on the screen, its identification takes place. In the event that this is an aircraft, then the target tracking radar located on the tower begins to track it. If necessary, this radar can be turned 180 °, thus covering it from the impact of fragments. The aiming of guns at the target occurs automatically, at the moment when the target enters the affected area, the ZSU crew receives the appropriate signal and opens fire, this mode allows you to save ammunition. It takes about 20 to 30 minutes to fully reload the gun magazines.
ZSU "Gepard" is equipped with navigation equipment, communication facilities, means of anti-chemical and anti-nuclear protection, as well as a mechanism for automatically bringing the vehicle from a traveling position to a combat position. Some of the ball machines are equipped with Siemens laser rangefinders.
ZSU T-55 "Shooter" (Finland)
ZSU T-55 "Shooter" was born as a result of close cooperation of several well-known European companies. This system was fully developed by the Italian company "Marconi", which in particular supplied its own radar for this SPAAG. The main armament was the Swiss 35-mm automatic cannon Oerlikon, the same ones installed on the German "Cheetah". The base for the ZSU was the Polish-made T-55AM tank. In the Finnish army, this ZSU received the ItPsv 90 index, where 90 is the year the ZSU was put into service. The vehicle is considered to be quite effective, its target hit rate is estimated at 52, 44%, which is very high for this kind of vehicles.
The very concept of the combat module used on the ZSU was developed in Great Britain in the 90s of the last century. This module could be installed on the chassis of the Chieftain tank, but the British army did not need such a ZSU. At the same time, the created module could be installed on a vast number of chassis of various tanks: the new Challenger, the export Vickers Mk3, the old Centurion, the American M48, the German Leopard 1, the Soviet T-55, the Chinese Type 59, and even the South African G6. But only the variant with the installation on the chassis of the Polish modification T55 - T55AM was in demand. Finland ordered 7 of these vehicles for its army.
ZSU T-55 "Shooter"
The main purpose of the ZSU T-55 "Strelok" is to fight low-flying enemy aircraft, helicopters and UAVs. The effective firing range is 4 km. At the same time, the Marconi radar station is able to detect targets at a distance of up to 12 km, track them from a distance of 10 km, and from 8 km. turn on the laser rangefinder. The rate of fire of the guns is 18 shots per second (9 shots per barrel). In addition to the main armament, each ZSU is equipped with 8 smoke grenade launchers.
In addition to fighting air targets, the installation is also able to hit lightly armored ground targets, for this it has 40 armor-piercing shells in its ammunition. The total ammunition reserve of the ZSU T-55 "Shooter" consists of 500 rounds. The created car was not easy at all. It significantly surpassed its donor, the T-55 medium tank. Unlike the T-55AM, which weighs 36 tons, the ZSU-55 "Strelok" has a mass of 41 tons. The increase in the mass of the car forced the developers to boost the engine to 620 hp. (the rated power of the T-55AM engine is 581 hp).
