T-34 at the time of its appearance in 1940 met the highest requirements for this type of weapon. The 76 mm cannon mounted on the tank hit all existing tanks in the world without any problems. During the war, German designers dramatically improved the armor protection of their tanks, to which Soviet designers responded by installing on the T-34 a more efficient and powerful gun of the D-5T model with a caliber of 85 mm.
First developments
However, it quickly became clear that the effectiveness of such a weapon was insufficient for the confident destruction of modern enemy tanks. The Soviet 85-mm cannon was noticeably inferior to the German 7.5 cm KwK 40 L / 70 in terms of armor penetration and accuracy of fire. In addition, German tanks began to be equipped with rangefinders and night vision devices, which put Soviet tanks with the D-5T in even more unfavorable conditions.
There was no potential for a further increase in power in the serial 85 mm gun. Attempts were made to create guns of the same caliber, but with greater power, in the framework of which experimental designs ZiS-1 and B-9 appeared. But both guns could not pass the tests and were rejected. The V-9K variant, which had a barrel tapering to a cone, also failed to test. This design of the gun provided an initial velocity of shells up to 1150 m / s. Because of this, by 1945, all work on guns of this caliber was discontinued. Therefore, many design teams of the USSR were engaged in the development of variants of the T-34, equipped with a larger caliber gun. The option of placing a 100 mm gun in a conventional tower is in the photograph.
Among these collectives were the designers of plant No. 183 (Uralvagonzavod, or UVZ) and design bureau No. 9. The employees of these design bureaus made an attempt to place the gun in the usual narrow tower T-34-85. However, already at the stage of conceptual work, it became clear that while maintaining the old diameter of the tower shoulder strap (amounting to 1,600 mm), it would not be possible to build a new artillery system. There was a proposal to use a turret from a heavy IS tank with a shoulder strap of 1850 mm. This option required a completely new housing design and was not accepted.
UVZ option
At that time, at the UVZ plant there were already prototypes of the T-44 model tank, which had an extended shoulder strap extended in diameter up to 1700 mm. It was such a tower that they decided to install on the body of a conventional T-34-85 tank. Due to the difference in the diameters of the epaulettes, the hull received some improvements and did not have a machine gun in the front sheet. Due to the lack of a machine gun, the crew of the car turned out to be reduced to 4 people.
Due to the wider overhead, it was necessary to change the layout of the fuel tanks - they were transferred to the control department. The suspension of the second and third balancer of the track rollers was performed according to the scheme similar to the first roller. A characteristic external difference was the use of drive wheels equipped with five rollers to drive the track. The T-34-100 in this version had a total weight of almost 33 tons and was assembled in February 1945.
Test
The machine was tested at the Gorokhovetsky training ground (near Gorky), as well as near Sverdlovsk. As the main armament, two artillery systems of various designs, the ZIS-100 or D-10T, were installed on the new Soviet T-34-100 medium tank. The transported ammunition consisted of 100 shells and 1,500 rounds for a single machine gun coaxial with the gun. The power plant and transmission did not differ from serial tanks and consisted of a 500-horsepower V-2-34 diesel engine and a five-speed gearbox. Photo T-34-100 with ZiS-100 below.
Cast tower had a thickness of frontal parts within 90 mm. The reservation scheme of the case remained the same and consisted of 45 mm frontal sheets, which had large angles of inclination:
- 60 degrees for the top sheet,
- 53 degrees for the bottom sheet.
Variants of the tank with the ZIS-100 and D-10T
The artillery system ZIS-100 was created by the design bureau of Plant No. 92 (Gorky, now Nizhny Novgorod). The gun with a caliber of 100 mm was a combination of the design of the serial gun ZIS-S85 (caliber 85 mm) and a new barrel of increased diameter and length. However, the recoil force of such an installation turned out to be too large, which adversely affected the transmission and chassis units of the tank. An attempt to reduce the impact by installing a muzzle brake (with a slotted circuit) did not bring any effect. The installation diagram of the guns in the tower is shown below.
The test results of the D-10T showed a low accuracy of the battle, although the indicators of loads on the nodes of the tank during firing were still outside the permissible limits. Despite this, representatives of the Red Army insisted on continuing work on the machine, which led to the creation of another version.
Tests option with LB-1
Around the same time, the design bureau of plant No. 92 created another gun with the designation LB-1 (short for Lavrentiy Beria). One of the goals of creating such a weapon was to reduce recoil force, which would allow the use of a gun on medium tanks.
It was proposed to install such a gun equipped with a muzzle brake in the T-34-100 turret with an extended shoulder strap. One of the shortcomings of the gun was a very long barrel, which went beyond the dimensions of the tank by more than 3.3 meters. At the same time, the total length of the tank was 9.15 meters, which impaired the geometric cross-country ability of the vehicle.
In April 1945, tests were carried out on a new version of the machine. The test site was the Gorokhovets training ground. According to the test results, the LB-1 system showed good results in accuracy of fire. In addition, the recoil force of such an instrument was much lower and was within acceptable limits. During the test, the gun fired about 1000 rounds without complaints about the design's working capacity. At the same time, the tank itself traveled over 500 km.
Final results
Despite the positive test results, the T-34-100 variant with LB-1 was not included in the series. The main reasons were the end of the war and the start of testing the first prototypes of the T-54 tank, which had a more modern design and powerful armoring.
At the same time, the LB-1 gun continued to develop further and in 1946-47 was used to equip the experimental versions of the T-44-100 and T-54. It did not show any noticeable advantage over the D-10T and was not mass-produced.