Currently, the number of models of modern basic combat tanksequipped with automatic loading systems for tank guns (T-90, Leclerc, K-2, Type-90 and Oplot), exceeds the number of models whose crew includes a loader (Abrams, Leopard-2, " Challenger 2 "and" Merkava Mk.4 ").
The main reason for the transition to automatic loaders is the desire of designers to reduce the armor volume and thereby increase the degree of protection (ratio of armor weight to volume), without increasing the weight of the tank. The loader's workplace requires a volume of up to 2 cubic meters for free and safe access to the breech of the gun and ammunition, especially in the process of moving the tank at an increased speed over rough terrain. The charging person is subject to physical fatigue, which negatively affects the rate of fire of the gun - if at the beginning of the battle the pace of the loader exceeds the pace of the automatic loader, then at the end of the battle the situation changes to the opposite. The scheme of the Abrams tank shows that the workplace of the loader (indicated by the number 5) occupies a volume equal to the volume of the jobs of the commander and gunner taken together.
For the first time, a technical solution for the mechanization of reloading a cannon of a serial tank was implemented in France in the 1952 year as a semi-automatic loader of the light tank AMX-13. His gun was installed in the swinging tower with the removal of the breech of the gun outside the booking. To the left and right of the breech were revolving mechanized styling of unitary shots. When the gun was rolled back after the shot, a spring-loaded rammer was cocked, after which the gunner of the gun, rotating the steering wheel, had to ensure that one of two types of ammunition was selected and unload it into the feeder tray. After that, the shot was automatically sent to the barrel and the gun was ready to fire. After the semi-automatic loading of the ammunition was used up, the tank crew had to leave the tank and re-load the mechanized stowage from the stock of shots into the 20 units carried in the hull.
The first complete solution to automate the entire cycle of reloading the gun was implemented on the Soviet tank T-64. The tank was arranged according to the classical scheme with the location of the breech of the gun in the tower. A carousel-type automatic loader consisted of a rotating conveyor on which 28 horizontal trays for projectiles were installed, above them along the perimeter there was the same number of vertical holders for propelling charges of separate-loading shots. The charge was filled into a semi-flammable sleeve with cardboard walls, soaked with a thick, and a metal pan. The conveyor hinged on the inner crown of the shoulder strap tower supports. The commander and gunner were separated from the conveyor cabin, rigidly connected to the tower. In the slot of the cab there was a mechanism for lifting and discharging the projectile and the propellant charge into the barrel of the gun, as well as the catcher of the metal pan after the shot. The pallet was laid back in the conveyor to the vacant place. When the ammunition was consumed, the conveyor was replenished with shots from manual laying.
The autoloader mechanism was driven by a hydraulic drive. In case of his refusal, a duplicate manual drive was used. The minimum time of loading the gun in automatic mode was 6 seconds, the maximum (when turning the conveyor by 180 degrees in order to select a specific type of shot) - 20 seconds. In manual mode, the maximum loading time increased to 1 minutes.
A similar automatic loader is installed on the T-80, T-84 and Oplot tanks.
In the 1972, a new version of the carousel automatic loader with a horizontal arrangement of missile charges in the trays above the trays of shells appeared on the Soviet T-72 tank. With 1992, the specified automatic loader is installed on the Russian T-90 tank. Unfortunately, in comparison with its predecessor, the automatic loader has two significant shortcomings that have not been eliminated to the present:
- the conveyor relies not on the tower's epaulet, but on the bottom of the hull, therefore, with an external impact (a blow to the projection of the underlying surface or an explosion of a mine), the automatic loader fails;
- the capacity of the conveyor is six shots less due to the large diameter of the propellant sleeves located horizontally.
The conditional positive difference of the automatic loader is the lower (by 150 mm) height of the level of the propelling charges relative to the bottom of the hull, which reduces the likelihood of their being hit by a cumulative jet or an armor-piercing projectile when the hull penetrates in the area of the tank compartment. It should be noted that the conveyor is surrounded on both sides by internal fuel tanks, in the molded grooves of which shots are placed of hand-made ammunition, the level of which exceeds the upper level of the mechanized installation of the automatic loader. This completely eliminates the difference in the degree of security of the T-64 / T-80 and T-72 / T-90 from the ignition of propellant charges.
This assessment is confirmed by the practice of combat use of T-72 / T-90 tanks in local military conflicts, when crews load only automatic loader with ammunition. But this technique is possible only with actions in the immediate vicinity of the points of ammunition. During an army operation with tank raids in isolation from the supply bases, loading into tanks and flammable manual combat packs of shots to their standard number will be required.
The automatic loader T-72 / T-90 is driven by an electric motor and has a duplicate manual drive. The minimum shot time in automatic mode is 8 seconds, the maximum is 14 seconds due to the lower initial (in the first case) and higher final (in the second case) rotation speed of the electric motor compared to the uniform rotation speed of the hydraulic motor.
In response to the Soviet T-64 tank, the United States and the Federal Republic of Germany at the end of the 1960-s implemented a program to create an experienced MBT-70 tank armed with an 152-mm gun and equipped with an automatic loader. In connection with the large linear dimensions of large-caliber shots, an automatic conveyor-type was used, located in the developed aft niche of the tower. Its design included two conveyor conveyors, each of which consisted of horizontally arranged trays of shots, articulated between themselves, guide rollers and a central feed mechanism of shots into the barrel of the gun.
The automatic loader conveyor makes it possible to include it in the design of new and modernized tanks with the lowest cost and place shots of caliber up to 155 mm in it. In this regard, he was most prevalent in tank building. At the moment, the main battle tanks Leclerc (France), K-2 (South Korea) and T-90 (Japan) are equipped with conveyor automatic loaders of almost identical design.
The aft niche of the tower is an attractive place to place other types of automatic loader. In addition to the lack of restrictions in increasing the overall dimensions of the niche, it eliminates the risk of a tank failure in the event of ignition charges or explosive detonation in shaped, high-explosive, concrete-cutting or shrapnel shells. The niche is equipped with an armored partition between the fighting compartment and the automatic loader, the automatically opening and closing shots delivery hatch and the upper expelling panels that operate when the internal pressure increases and divert the fire and shock wave from the fighting compartment.
In the Russian experimental tank “Object 640” (“Black Eagle”), the feeding area was made in the form of a removable armored module with an automatic loader conveyor located inside.
It was assumed that the process of replenishing the tank ammunition will be simplified by replacing the modules in the field.
One of the options for upgrading the main battle tank Abrams (USA) is to install a turret automatic loader in the rear alcove, consisting of two conveyor drums, the entire internal volume of which is filled with shots, in contrast to the conveyor conveyor. This allows you to increase the ammunition stored in the automatic loader, at the cost of increasing the vertical envelope of the tower.
The original modernization project of the main battle tank “Leopard-2” (Germany) is based on the idea of a substantial increase in the length of the aft niche and, accordingly, the size of the ammunition set stored in the automatic loader racking unit equipped with a gripper that moves in two central racks divided by sections with cells in which unitary shots are placed.
Along with the listed advantages, the option of placing the automatic loader in the aft niche of the tower has one significant drawback, which devalues the very idea of excluding a tank crew charging from the composition in order to reduce the tank's armored volume - this way of placing the machine leads to the exact opposite result:
- free unused volume of the fighting compartment appears in the tank hull, since the commander and gunner are located on both sides of the gun with the maximum approximation to the optical observation devices located on the roof of the tower;
- the volume of the tower increases more than twice;
- a large area of the frontal projection of the tower makes it impossible to use powerful and heavy armor;
- maneuvering a tank on the battlefield relative to the frontal direction of attack within safe angles + -30 degrees embedded in the design of the frontal armor, combined with the rotation of the turret when the gun is horizontally aimed at the target displays the weakly protected lateral projection of the turret from the specified limits until reaching the angle 60 degrees.
Therefore, the most appropriate solution is to place the automatic loader in the turmoil space, first implemented in T-64. In addition to reducing the amount of armored vehicles and increasing the level of protection of the tank, such a layout solution allows taking the next step in improving the design of the main battle tanks in the near future - to move to an unmanned fighting compartment when the entire crew is accommodated in the control compartment, which is hermetically sealed from the rest of the tank.
Uninhabited fighting compartment with a carousel automatic loader provides an additional bonus - the possibility of placing four corners of the internal fuel tanks in the corners of the compartment in a volume that is not swept over by the cylindrical conveyor body. As a result, it will be possible to separate the crew and the fuel into separate compartments, while not carrying it into the nose, the most shelled part of the hull, as it has been briefly done in the main Merkava Mk.4 battle tank (Israel).
With the size of the compartment 2х2х1 meters, the total volume of internal tanks will be about one cubic meter. The fighting compartment can be filled with inert gas (nitrogen or carbon dioxide), which will completely prevent the ignition of the fuel under any circumstances. The risk of mass ignition of missile charge shots (containing fuel and oxidant) can be eliminated by returning to the use of metal shells. Even with the initiation of burning of a propellant charge by a cumulative jet or an armor-piercing projectile, the fire will be localized by specific liners subjected to mechanical impact.
The project of a similar tank with the installation of a weapon in a swinging turret is presented in the title of this article. The shots are placed in a three-level carousel loader. In each level in the same plane are the shells and shells with missile charges to them. The total ammunition in the automatic loader is 42 shot, 14 in each tier.
But in the case of an uninhabited fighting compartment, a swinging tower and a carousel automatic loader with a horizontal arrangement of shots are not the most effective solution, since:
- raising the shot from the tank body to the breech of the gun passes through an open, unprotected space;
- the process of loading the gun is possible only in one of its position relative to the horizontal axis of the body; in this position, each time you reload, you have to turn a heavy inertial turret, and then return it back to the aiming line, unlike the existing carousel machines that adapt to the current position of the turret.
The use of the classic tower in conjunction with the three-tier automatic loader is impossible, since the breech of the gun, which descends at large elevation angles, requires free space under it. The length of the most modern armor-piercing feathered sub-caliber shells reached 924 mm, i.e. almost the radius of the circle carousel loader. As shown in the attached diagram of the dependence of the penetrability of armor-piercing shells on their speed, length, elongation, weight and firing distance, the most low-cost measure is to increase the length while maintaining the diameter of the armor-piercing rod (penetrator).
In this regard, it seems advisable to use a high-capacity carousel loader with a vertical arrangement of shots and free space in the center of the type of machine used in the 1983 year in the ASM Block III experimental tank (USA).
As the experience of the development of the last Soviet promising tanker "Boxer / Hammer" shows, this or that design of the automatic loader for the first Russian promising tank Armat will largely determine its future as the main strike force of the Russian Army.