T-54

The T-54 (GBTU index - Object 137) is a Soviet medium tank[3]. Adopted by the Soviet Army of the USSR Armed Forces in 1946, it entered serial production from 1947, and was constantly modernized. Since 1958, a modification called the T-55, adapted for combat operations in conditions of the use of nuclear weapons, was produced. Between 1961 and 1967, it was mainly replaced in production and in the tank forces of the USSR by the T-62 tank, created on its chassis, but production of the T-55 at OZTM continued until 1979. A number of countries also produced the T-54 itself, or its modernized or adapted to local conditions variants.

The T-54 was exported and served in the armed forces of many countries worldwide, serving in most local conflicts after World War II. The tank became renowned for its exceptional reliability and simplicity, praised by many experts. Throughout the Afghan War, the T-55 and T-62 were the primary tanks in the tank units of the Limited Contingent of Soviet Forces in Afghanistan (OKSVA). Despite the presence of a sufficient number of more modern and powerful tanks in the USSR Armed Forces at that time and the constant modernization of light armored vehicles, they were not sent to the motorized rifle and airborne units of the OKSVA, the tank fleet of the OKSVA remained unchanged for all 9 years of the war, which was due to the highest reliability of the engines of these tanks when used in high-altitude conditions against the T-64, which performed poorly there, and to a lesser extent, as a result of the first factor, a cheaper option for using these tanks in Afghanistan, and the lack of modern tanks in the units of the USSR Armed Forces on the southern borders of the USSR and the limited number of anti-tank weapons of the Afghan mujahideen [4].

History of creation
The T-54's immediate predecessor was the T-44, developed in 1943-1944. In its early stages, the T-54's development was inseparable from the T-44's, as both tanks were developed in line with the general trend of Soviet armored vehicle development at the time, and initially, the T-54, as built, was a significantly modernized version of the T-44.

Developed in 1943-1944 by the Uralvagonzavod design bureau under the direction of A. A. Morozov, the T-44 was intended to replace the T-34 as the Red Army's primary medium tank. The T-44's main innovation was its unique layout for its time. By reconfiguring the engine compartment and mounting the engine and transmission transversely, it was possible to significantly reduce its length and height, and shift the turret to the center of the hull, reducing the load on the front road wheels. This, coupled with the elimination of the radio operator/gunner, also significantly reduced armor volume and, while weighing less than the production T-34-85, significantly increased armor protection.

According to the requirements for the protection of a prospective medium tank from 75-mm and 88-mm shells formulated by TsNII-48 back in late 1943[5]:

a) the upper part of the hull and the front of the turret must be completely invulnerable;
b) the upper half of the hull side must be completely invulnerable within certain course angles;
c) the side of the turret must be completely invulnerable within a range of course angles approximately twice as large as the same range for the side of the hull;
d) the range of the course angles of invulnerability of the wing liner can be taken as the average between the range for the side of the turret and the range for the side of the hull.
These requirements, although not fully met, were implemented on the T-44, the first modification of which had 75 mm of frontal armor and sides 45 mm thick at the bottom and 75 mm at the top. On the first large-scale production modification, the T-44A, the frontal armor thickness was increased to 90 mm, and the side armor to 75 mm across the entire height.

However, despite all these advantages, the T-44's armament remained the same as that of the T-34-85—the 85mm ZIS-S-53 gun with a 56-caliber barrel, which was already considered unpromising for a medium tank in 1944.[6] There were two ways to increase firepower. The first was to create guns with a higher muzzle velocity by lengthening the barrel and increasing the propellant charge. However, experiments with 85mm guns of this type ("high-power" in the terminology of the time), conducted in 1944, demonstrated the problematic nature of their production using the existing technological base. In addition, an analysis of the results of gunfire tests showed that light, high-velocity projectiles were less effective in penetrating armor positioned at significant angles than the low-velocity but heavy projectiles of 100mm and 122mm guns.[6] As a result, the second path was chosen: increasing artillery power by increasing the caliber.

The T-54 (GBTU index - Object 137) is a Soviet medium tank[3]. Adopted by the Soviet Army of the USSR Armed Forces in 1946, it entered serial production from 1947, and was constantly modernized. Since 1958, a modification called the T-55, adapted for combat operations in conditions of the use of nuclear weapons, was produced. Between 1961 and 1967, it was mainly replaced in production and in the tank forces of the USSR by the T-62 tank, created on its chassis, but production of the T-55 at OZTM continued until 1979. A number of countries also produced the T-54 itself, or its modernized or adapted to local conditions variants.

The T-54 was exported and served in the armed forces of many countries worldwide, serving in most local conflicts after World War II. The tank became renowned for its exceptional reliability and simplicity, praised by many experts. Throughout the Afghan War, the T-55 and T-62 were the primary tanks in the tank units of the Limited Contingent of Soviet Forces in Afghanistan (OKSVA). Despite the presence of a sufficient number of more modern and powerful tanks in the USSR Armed Forces at that time and the constant modernization of light armored vehicles, they were not sent to the motorized rifle and airborne units of the OKSVA, the tank fleet of the OKSVA remained unchanged for all 9 years of the war, which was due to the highest reliability of the engines of these tanks when used in high-altitude conditions against the T-64, which performed poorly there, and to a lesser extent, as a result of the first factor, a cheaper option for using these tanks in Afghanistan, and the lack of modern tanks in the units of the USSR Armed Forces on the southern borders of the USSR and the limited number of anti-tank weapons of the Afghan mujahideen [4].

History of creation
The immediate predecessor of the T-54 was the T-44 tank, created in 1943-1944. In the early stages, the development of the T-54 was inseparable from the T-44, since the development of both tanks was carried out in the general direction of the development of Soviet armored vehicles of those years,