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The main problem of the KV-1 was precisely in armament, since the 76.2-mm ZiS-5 cannon by the beginning of 1943 was practically powerless against the armor of the new German tanks Pz.Kpfw.V “Panther”, Pz.Kpfw.VI “Tiger ”And new modifications of the medium tank Pz.Kpfw.IV (with mounted armored screens). But as far back as 1940, the order was given on the construction and subsequent launch into mass production of KV-3 tanks equipped with a 107-mm ZiS-6 gun and KV-220 ( T-220) with an 85 mm F-39 instrument.

In terms of armoring and power of weapons, these combat vehicles were much better than the serial KV-1, but in the summer of 1941, due to the outbreak of war, work on them was suspended and then completely stopped. As a result, the tank armies of the Red Army until the fall of 1943 were forced to be content with the existing fleet of heavy tanks, inferior to the new German vehicles of a similar class. As a consequence, from August 1942, the KV-1s began to be phased out and completely stopped in December, temporarily replacing it with an “intermediate” heavy tank KV-85.

Such a large number on the designation of the next KV modification designated the caliber of the gun with which the tank was equipped. As has been repeatedly stated, one of the most significant shortcomings of the KV-1 was its short-barreled 76.2-mm cannon, which by the autumn of 1942 could not successfully deal with the enemy’s heavy armored vehicles. When selecting a new weapon, the emphasis was on defeating the 100-mm frontal armor of the German heavy tanks “Panther” and “Tiger”. The most effective in this regard were the 122 mm A-19 cannon, the 152 mm howitzer ML-20 cannon and the 85-mm anti-aircraft cannon 52-K, model 1939. It was the latter that was a prototype of the D-5T tank gun, which was developed completed in May 1943.

To speed up the tests and subsequent mass production, the hull, the undercarriage and the turret shifted from the KV-1s almost unchanged. The assembly of the KV-85 tanks began in August, but it was released in small numbers, since in the spring of 1944 a more advanced tank, the IS-2, was launched into mass production. For the same reason, the GBTU did not accept the option for serial constructionKV-122 with the gun D-25T caliber 122 mm.

Attempts to qualitatively improve the armament of a heavy KV-1 tank by installing an 85 mm caliber gun in its turret were made by Soviet designers back in 1941-1942. So, in December 1941, it was proposed to use the U-12 tank gun developed by the Uralmash design bureau (Yekaterinburg) by V.Ye. Sidorenko and A.V. Usenko. By the spring of 1942, the People's Commissariat of Arms of the USSR (NKV USSR) already had three projects of 85 mm tank guns: the TsAKB project, the chief designer - V.G. Grabin, design bureau of plant number 92 (Nizhny Novgorod), designer A.I. Savina and the design bureau of plant number 8 (Ekaterinburg), chief designer - L.V. Lyulyev. All three projects were created on the basis of the design of the 85 mm anti-aircraft gun arr. 1939 However, The leaders of the NKV rightly considered these developments premature, since The 76 mm tank guns in service at that time reliably hit virtually all samples of armored vehicles available in the Wehrmacht for that period.

Everything changed in January 1943, when on one of the sections of the Leningrad Front a serviceable prototype of a new German heavy tank Pz-VI "Tiger" with a set of documentation, which was passing military tests there, was captured. Comprehensively examining the captured machine during the tests, the specialists of the ABTU RKKA came to the disappointing conclusion that if the Pz-VI was adopted and the production organization started, the Soviet tank forces would not only lose their qualitative superiority, but would also seriously yield to the German tank units equipped with new tanks.

Really, the "Tiger" was a formidable opponent. Armed with 88 mm long-barreled cannon, having frontal armor thickness up to 100 mm, and airborne 62-82 mm, the brainchild of German designer E. Aders confidently hit frontal armor KV-1 and KV-1C already at ranges of 1000-1200m, KV also pierced PzKw-VI only from a distance of 200 m and then only in the lateral projection.

In this regard, on May 5, 1943, the State Defense Committee issued Order No. 3289 “On Strengthening Artillery Armament of Tanks and Self-Propelled Units”, one of the decisions of which obliged the TsAKB and Design Office of Plant No. 9 (OKB-9, Yekaterinburg) as soon as possible to create projects of tank guns with ballistic 85 mm anti-aircraft gun 52-K for installation on heavy tanks KV-1C and the projected new heavy tank IS (later IS-85 or IS-1). In a strictly fixed time frame By June 14 of the same year, both design bureaus submitted prototypes of their designs.

CACB under the direction of V.G. Grabin developed a draft 85 mm tank gun C-31 by imposing on the cradle a 76 mm gun ZIS-5 barrel with the characteristics and ballistics of an anti-aircraft gun 52-K. OKB-9 designers under the guidance of F.F. Petrov was taken as the basis for the U-12 U-12 gun design, changed the design of semi-automatics and some knock-down devices (COI), created the D-5T tank gun (D-5C - option for ACS), which, however, also had 85 mm ballistics 52 -TO. Having reviewed both projects, the leadership of the NKV proposed J.I. Kotin, who was present at the examination, to build at the pilot plant No. 100 (Chelyabinsk) two prototypes of the KV-1C tank, one with the Grabinsky gun C-31, the second with the D-5T gun.

At that time, for SKB-2, the main theme was the development of the design of the new heavy tank IS-85. Faced with some difficulties in the design of components and mechanisms of the hull and chassis of the new tank, Kotin was aware that before December 1943 the IS would not go into series. Meanwhile, a heavy tank with more powerful weapons was needed by the troops, as they say, “just yesterday”, since enemy tank units continued to be equipped with a new technique at a fairly high pace. Chelyabinsk designers, on their own initiative, decided to install a cast turret designed for the IS-85 tank, an experimental prototype of which had already been manufactured at ChKZ, on a KV prototype designed for testing D-5T guns. The technical implementation of this solution seemed technologically rather difficult due to the fact that the KV-1C serial hull had a diameter of a turret shoulder strap of 1535 mm in size, and the new turret was designed for a new case with a shoulder strap with a diameter of 1,800 mm.

However, in SKB-2, in record time, a technology was developed that allowed the KV corps to be reworked under a shoulder-strap with a diameter of 1,800 mm in a simple way to broaden the hull by welding additional armor inserts on the hull in the area of the turret installation, but for this it was necessary to abandon one crew member in particular, the gunner-radio operator, whose workplace in the tank was located in the control compartment. This is the only case in the domestic tank building, when a larger diameter turret could be installed on the old hull without making major changes to its design. By July 20, 1943, the commission had been presented two tanks - " Object 238 "- with an S-31 cannon installed in the KV-1S standard turret and an" object 239 "with a D-5T gun mounted in the turret designed for the IS-85.

The prototypes of the KV were presented along with two prototypes of the IS tank armed with the same guns After inspecting the tanks and examining the project documentation by the commission, the object 238 was not allowed to factory tests due to extreme tightness in the fighting compartment, which significantly hampered the actions of the tank crew and significantly reduced the rate of fire and accuracy. Vodskaya test so successfully that their results have been counted as public and already August 8, 1943, he was adopted by Decree number 3891 GKO called heavy tank KV-85. On the 20th of August, at the Gorokhovetsky testing ground, at the insistence of the TsAKB leadership, comparative tests of the C-31 and D-5T guns were carried out. They were taken by KV-85 tanks, object 238 and two prototypes of IS-85. According to their results, the D-5T gun was recognized as the best compared to the C-31. It was smaller in weight and size, and was distinguished by ease of maintenance and better accuracy when shooting.

By design, the chassis, transmission, power unit, electrical and special equipment KV-85 are completely similar to those of the KV-1S tank. The following changes were made to the design of the KV-1S hull:

  • the diameter of the shoulder strap was increased to 1,800 mm;
  • extended turret box;
  • the design of the ammunition was changed;
  • the exchange gun became fixed in the front sheet of the case to the right of the driver’s workplace;
  • dismantled workplace shooter-radio operator.

The turret of a new design was a shaped casting of a streamlined shape with a wall thickness of 100 mm. Its front part of a spherical shape was cast separately and welded to the turret. Its design included an embrasure for mounting the gun. The mask of the gun was made of a bent armor plate and had three embrasures - for the installation of the gun, the paired machine gun and the sight. On the roof of the turret was mounted a double-wing hatch for landing and disembarking crew members and a cast commander's turret with a wall thickness of 82 mm, equipped with a hatch and providing all-round visibility.

The turret was located on the left rear of the vehicle and was equipped with surveillance devices MK-4. The turret was installed on the hull epaulette, was fixed with grippers and was equalized with respect to the axis of rotation. The jobs of the tank commander and gunner were located to the left of the gun, the loader's workplace was on the right and was equipped with the MK-4 surveillance device. In the central front of the turret, an 85-mm tank gun D-5T was installed, to the right of it was a 7.62 mm DT machine gun. The gun was a tank artillery system with a monoblock barrel. Valve wedge, vertical, semi-automatic copier type. LCPs included a hydraulic brake of the recoiling parts of the spindle type, an in-line hydropneumatic type and were located at the bottom of the barrel. The ammunition of the gun consisted of 85 mm shots of a 52-K anti-aircraft gun. Shots with O-365 fragmentation shells, armored piercing caliber ones with projectiles BR-365 and BR-365K, armor piercing subcaliber with a projectile BR-365P were used.

The production of the KV-85 was organized at ChKZ from August to the end of October 1943, when it was replaced on the production line by the IS-85 tank. At the same time, the KV-1S was being assembled at the Chelyabinsk Concrete Plant, which continued through December of the same year. In total, the troops received 147 tanks of the model in question. In total, according to the order of NKTP No. 530 of September 7, 1943, the industry should have shipped 63 KV-85 in September and 63 in October, after which their release was planned to stop in favor of the IS tank. But according to the report of the People's Commissariat, 148 KV-85 tanks, produced in parallel with the KB-1S, were handed over to the customer. In December 1943, the release of the latest machines of the KB family was discontinued.

A few examples of the use of KV-85 tanks showed that the 85-mm cannon is an effective weapon against German heavy machinery and should be installed on an average T-34 tank, which was subsequently made. Even during the operation to liberate the Crimea, the commanders of the mobile prosecution detachments complained that the KV-85 and SU-152 were not fast enough and lagged behind the trucks with infantry. It is understandable, because the KV-85 is a heavy tank. However, its lower maneuverability and dynamism had to be compensated by powerful armor and weaponry. And if the KV protection was considered quite adequate at that time, then the gun required much more powerful, in order to hit German equipment from maximum distances.

According to the results of the KV-85 combat operations, the designers and the military concluded that the further modernization of the KV family tanks was not practical, that the 85-mm cannon was sufficient to counter German tanks, but it was significantly inferior to the artists of the latter in terms of armored penetration when shooting from long distances Soviet heavy tanks are weaker armored than their German counterparts, and therefore the concept of medium and heavy tanks (T-34 and KV), armed with a single-caliber gun, was outdated.

In total, according to the order of NKTP No. 530 of September 7, 1943, the industry should have shipped 63 KV-85 in September and 63 in October, after which their release was planned to stop in favor of the IS tank. But according to the report of the People's Commissariat, 148 KV-85 tanks, produced in parallel with the KB-1C, were handed over to the customer. In December 1943, the release of the latest machines of the KB family was discontinued.

The KV-85 was mainly delivered to the recruitment of individual Guards heavy breakthrough tank regiments (OGVTPP). Despite the relatively small number of built KV-85s, their appearance on the fronts to some extent helped to compensate for the emerging qualitative lag of Soviet armored vehicles from the enemy’s armored vehicles.

After the war, the first released copy of the KV-85 was installed on a pedestal as a monument in Avtovo, St. Petersburg. Another experienced KV-1s tank, re-armed with the 85-mm S-31 experimental weapon, is on display in the Armored Museum in Kubinka. Another KV-85 tank is located on the territory of the Chelyabinsk Railway Plant, near the factory's clinic.

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Page last modified: 09-03-2019 17:59:45 ZULU