There were times when designers believed that the best protection for a tank from a cumulative projectile was... an umbrella! Yes, yes, don’t be surprised, it was in the form of an umbrella put on the gun barrel that the original protection was made. It got to the point that they even planned to put it into service, and even tested it on a variety of Soviet tanks.
The successful use of anti-tank weapons with the cumulative principle of destroying armored targets during the Second World War pushed designers and scientists to further improve this type of ammunition. In the post-war years, the armor penetration of cumulative shells was almost doubled.
By this time, it became clear that the armor of the Soviet T-54, T-55, T-62 tanks did not provide protection against damage by the above ammunition. The thickness of the armor parts of our tanks was: upper frontal plate 100 mm at an angle of 60°, lower frontal plate 100 mm at an angle of 55°, hull sides 80 mm at 0° and turret forehead 170-90 mm at 23-55°. Therefore, to protect against an 85 mm cumulative projectile with a copper funnel, it was necessary to have a thickness of the upper frontal sheet of 215 mm, the lower frontal sheet of 250 mm, and the hull side of at least 250 mm at the same angles of inclination. When fired with 115-mm cumulative shells, these parameters should have been 260, 290 and 200 mm, respectively. Such an increase in the thickness of the armor parts of the tank hull would lead to an increase in their mass by 9-10 tons, which, for obvious reasons, was unacceptable.
Therefore, to solve the problem of protecting tanks in the direction of firing and the sides of the hull in the range of heading angles of 25° from cumulative ammunition of caliber up to 115 mm, complex screen protection ZET-1 was developed in 1964 and passed comprehensive tests. It consisted of a mesh windshield and solid side screens.
The properties of screens as protection against cumulative ammunition are based on the fact that when a cumulative projectile hits this same screen, it explodes before meeting the tank’s armor, as a result of which the formed cumulative jet, before reaching the tank’s armor, flies a considerable distance in the air. When moving in the air, the jet disintegrated, as a result of which its penetration ability sharply decreased, and it could not penetrate armor.
The weight of the mesh screen was 60 kg, the minimum distance between the screen and the armor was 1800 mm. The transfer time from traveling to combat position was 2-3 minutes, and to install the screen itself on the tank - no more than 15 minutes. The difference between the screens for the T-54/55 and T-62 tanks was only in the diameter of the base mounted on the gun barrel. The side screens were of a sectional type and made of duralumin. Their weight was about 200 kg, the minimum distance between the side of the tank and the screen section (with a rotation angle of the section to the tank axis of 30°) was 1500 mm. The transfer time from traveling to combat position was about 1 minute, and the installation time on a prepared tank was 3 minutes.
The main emphasis when testing the integrated protection was to determine its survivability during shelling, as well as the strength and reliability of the fastening during operation of the tank.
According to the developers of ZET-1, it was supposed to ensure the destruction of only one section of the screen when hit by an 85-mm projectile and two sections when hit by a 100-115-mm projectile. Fire tests carried out at the beginning of 1964 almost completely confirmed the designers' plans. Additionally, it was noted that replacing one section in the field took only 2 minutes.
An equally important stage of testing was checking the reliability of fastening the screens. For this purpose, the experimental T-55 and T-62 tanks underwent sea trials (500 km) overcoming various obstacles. Upon completion, it was noted that the fastening of both side and mesh screens was generally quite reliable.
In conclusion, the state commission noted “a significant increase in the effectiveness of tank protection when using the above protection,” and also recommended “accepting the ZET-1 frontal mesh screen for supply to the Soviet army.” Regarding the side screens, it was recommended to reconsider the method of attaching them to the tank.
However, mesh screens did not really “take root” - by order of the head of the Main Armored Directorate, their use was envisaged only in the “threatened period, immediately before the start of hostilities.” After the adoption of the T-64 and T-72 tanks with a fundamentally different armor structure (multi-layer) with increased projectile resistance, the need for mesh screens completely disappeared.
T-55 tank equipped with complex anti-cumulative screen protection (stowed position)
T-55 tank equipped with complex anti-cumulative screen protection (combat position)
T-62 tank, with complex anti-cumulative screen protection (stowed position)
T-62 tank, with complex anti-cumulative screen protection (combat position)
The hull of the T-54 tank, equipped with comprehensive screen protection and prepared for testing by shell fire
The T-62 tank, equipped with complex anti-cumulative screen protection, overcomes an area of small forest
T-55 tank equipped with complex anti-cumulative screen protection (combat position)
The condition of the ZET-1 screen and the upper frontal plate after the screen was hit by a 100-mm cumulative fragmentation projectile from the T-12 gun
View of the screen protection of the right side of the T-54 tank hull after four hits from an 85-mm cumulative projectile with a copper funnel
View of the screen protection of the right side of the T-54 tank hull after the first hit of an 85-mm cumulative projectile
