85 Mm Anti-tank Gun Zis-s-8 Technical Details
- Years of issue – 1944
- Total released – 5 units.
- Caliber – 85 mm
- Weight in firing position – 1765 kg
- Barrel length – 4650 mm
- The length of the threaded part – 3500 mm
- Calculation – 6 people
- Travel speed – up to 50 km / h
- Rate of fire – up to 20 rds / min
- The greatest firing range – 11 800 m
- Direct shot range – no data
- Shooting angles:
- Horizontal – 55 °
- Vertical – 4.5 ° + 30 °
85 Mm Anti-tank Gun Zis-s-8 Details
At the final stage of the Great Patriotic War, with the transition of the Red Army to strategic offensive operations, the belligerent units needed a new powerful divisional weapon. The increase in the caliber of such guns was associated with the appearance on the Eastern Front of the Germans of new tanks and self-propelled guns with thick armor.
In the course of development work, several design bureaus at once offered their versions of 85-mm divisional guns. In 1943, at TsAKB (Kaliningrad) under the leadership of the head and chief designer of the bureau V.G. Grabin, the 85-mm S-8 divisional gun with the ballistics of the 85-mm 52-K anti-aircraft gun of the 1939 model was created.
Even before the war in the design bureau of plant number 92 named. I.V. Stalin (Gorky) under the leadership of V.G. Grabin, work was carried out to create similar 85-mm guns: the F-30 divisional gun (later renamed ZIS-12) and the ZIS-23 anti-tank gun. However, with the beginning of the war, work on 85-mm divisional guns was curtailed. The prototype of the 85-mm cannon S-8 was manufactured at the factory
# 92 and therefore received the double index “85-mm anti-tank gun ZIS-S-8” in its designation.
The ZIS-S-8 cannon is made according to the classical scheme of an artillery gun. The barrel consisted of a monoblock pipe, a breech and a powerful two-chamber muzzle brake. Along with the active muzzle brake, a significant part of the recoil force was absorbed by the hydraulic recoil brake, the recoil brake was hydropneumatic. They were mounted above the barrel and, when fired, they rolled back together with the barrel, while the normal recoil length was 850 – 900 mm, the maximum one was 960 mm. The gun had a vertical wedge breechblock with a semiautomatic mechanical (copy) type.Its design and use of unitary rounds as ammunition ensured a rate of fire with aiming correction of 13-15 rounds per minute, and a maximum rate of fire without aiming correction – up to 25 rounds per minute. The barrel was housed in a cradle, which is a cast cylindrical clip attached to the upper machine of the gun carriage. With the help of a sector lifting mechanism, also mounted on the upper machine, the barrel, together with the cradle, could rotate in a vertical plane in the range of angles from -7 ° to + 35 °. The horizontal guidance angle provided by the rotary screw-type mechanism was – 54 °. The balancing mechanism is pneumatic. A panoramic sight or an optical sight was installed as sighting devices.
To protect the crew from small arms bullets and fragments of artillery shells and mines, a shield cover was fixed on the upper machine. On the lower machine of the carriage, two sliding box-shaped frames of a welded structure were mounted. The height of the line of fire was 815 mm. The undercarriage is two-wheeled, reinforced wheels from a ZIS-5 truck were used. The presence of torsion suspension allowed the gun to be towed by army trucks (6×6) along the highway at a speed of up to 60 km / h. The time for transferring the gun from the traveling position to the combat position and back did not exceed one minute.
The ammunition load of the ZIS-S-8 gun included unitary shots of the 85-mm anti-aircraft gun 52-K of the 1939 model. For testing at Plant No. 92, five prototypes of the ZIS-S-8 cannon were manufactured. Factory tests of the ZIS-S-8 cannon began at the end of 1943. The tests of the gun were carried out with armor-piercing shells weighing 9.2 kg and high-explosive fragmentation shells weighing 9.54 kg.
The ZIS-S-8 showed an initial velocity: with an armor-piercing projectile – 792 m / s, with a high-explosive fragmentation projectile – 655 m / s. The maximum firing range was achieved by a high-explosive fragmentation projectile – 11 800 m. Armor penetration at a distance of 500 m along the normal was 111 mm, at an angle of 30 ° – 90 mm, at a distance of 1500 m at an angle of meeting 30 ° – 75 mm. According to the conclusion of the GAU Art Committee of January 9, 1944, the gun did not pass the field tests.The main disadvantages identified during the tests of the ZIS-S-8 were the insufficient strength and reliability of the muzzle brake, as well as its strong sound effect on the gun crew; poor extraction of the sleeve and unsatisfactory operation of recoil devices during prolonged shooting; unsatisfactory operation of the lifting mechanism. After revision in 1944 – 1945, the ZIS-S-8 cannon passed field and military tests several times, but was never adopted for service.