How the dinosaurs died out - the last heavy tanks (part 3)

2024 Author: Matthew Elmers | [email protected]. Last modified: 2023-12-16 21:49

The IS-4 heavy tank is the last of the Stalinist family

Long before the end of World War II, the teams of several design bureaus were developing a promising heavy tank "for the final stage of the war and for the subsequent time." Among them was the design bureau of the Kirov plant, which began designing in December 1943. The main task was seen as a sharp increase in the tank's security, in particular, resistance against new 88mm long-barreled anti-tank guns (the Red Army had already become familiar with the self-propelled version of which, Ferdinant, during the Battle of Kursk). In addition to thickening the frontal armor plates, the entire design of the bow was seriously redesigned, compared to the previous IS tanks, the increased mass of the tank required a more powerful engine, which led to the lengthening of the hull and the addition of a seventh road roller on board to the chassis. The hull was assembled by welding rolled armor plates, while the tower was completely cast, with the exception of a part of the roof - a large plate held by bolts was a hatch for dismantling the gun. In April 1944, a GKO decree ordered ChKZ for the production of two prototypes of the "object 701" (this was the name of the new tank in the factory documentation, which is interesting - the order for it was received earlier than for the IS-3, which had the index "703") … The first prototype, designated "701 №0", entered the factory tests in May of the same year, which lasted a month and a half.

"Object 701" # 1

"Object 701" No. 3

The result of the work to eliminate the identified shortcomings was the release of the following two prototypes - "Object 701" No. 1 and No. 3, differing in armament (it was supposed to use 100mm S-34 or 122mm D-25T guns). Tests of the modified samples followed, which lasted more than a month, and the conclusion of the commission - the tank is certainly good, but requires refinement. The plant was to produce the next two prototypes and re-submit them for testing. In August 1944, the first detailed information was received about the new German Tiger-B tank with a weapon similar to the Ferdinant, and work on new tanks was accelerated. In particular, they conducted experimental firing at the body of the "Object 701" with both domestic and captured guns. The result was expected, and pleasantly pleased the testers - the hull reliably protected the tank when fired by 88mm long-barreled guns from +/- 30 ° course angles at all distances. The tower showed slightly worse resistance - safe angles were +/- 15 ° for it, but this is acceptable, since the tower is more often deployed towards the enemy and receives hits on the forehead at low course angles. Prototype No. 4 goes for testing in September, but again the work of the units, and in the first place the transmissions, does not satisfy the commission, and two months later, Object 701 No. 5 enters the state tests, which were carried out at the NII BT test site in December-January. The tank is recommended for service, and undergoes two additional tests from January 1945 to March, and from March to April. The commission considers the tank to have passed the tests and confirms the initial decision to enter service. Moreover, in April "Object 701" No. 6 was tested in Chelyabinsk, and in its conclusions the commission noted that the reliability of the units is satisfactory, and their testing in serial production is sufficient for a recommendation for adoption. In a letter to the People's Commissar of the Tank Industry V. Malyshev, the ChKZ management asks to approve the program for the serial production of the tank from the summer of 1945, bringing the production rate to 100 vehicles per month by August! But … At this time, it was already put into service and launched into the Object 703 series under the name IS-3, and there was simply no money left for two heavy tanks.

heavy tank IS-3.

The story of "seven hundred and first" would have ended on this, especially since the war was won, and the center of gravity of interests shifted towards the restoration of the national economy, but the unexpected happened - at the beginning of 1946, the IS-3 tank, which made a splash at the Victory Parade, was removed from production. The shortcomings and unsuccessful shape of the bow revealed during operation undermined the confidence of the military in the car, the MCN program (elimination of design flaws) cost almost as much as the tank itself, and the IS-3 was sent to the repair bases directly from the factory workshops. The final point in the fate of the IS-3 was put by the shelling test of the tank, when a 100mm projectile hit the welded seam passing in the middle and fastening the two upper frontal parts. The result was disastrous - the tank literally collapsed, bursting at all the seams. The weakened zone was known earlier, but no one could have imagined that getting into it would cause such dire consequences. And now, the country suddenly finds itself without the production of heavy tanks! In this situation, having considered all the options, the Council of Ministers of the USSR in April of the same year made a decision to adopt the "Object 701" with the assignment of the IS-4 index to it. The release was supposed to start by the end of the year, but the documentation required for this was not ready. More than 80 additional changes were made to the design, and the first two serial IS-4 tanks entered ministerial tests only in April 1947. The conclusion of the commission turns out to be categorical - the tanks did not stand the test! Reliability did not meet the requirements of peacetime (it was no longer possible to turn a blind eye to the resource of the main units of the power unit and transmission in tens of hours, as it was, say, in 1942, because the tank would die anyway before the resource was exhausted), the complexity of management and maintenance required special training of drivers, not to mention such "trifles" as the impossibility of using the radio station on the move and high noise (in calm weather, the howling of fans was heard … for 7-8 kilometers!). The modified tanks are tested again in the summer, but they receive another list of 121 points of shortcomings. The tank was seriously reworked, new solutions were tested on 25 vehicles of the pilot batch, and on October 8, 1947, the final drawings for the serial production of the IS-4 were approved.

heavy tank IS-4 (Object 701-6)

The release went sluggishly, and despite the improvements, the tank did not meet the requirements of the army until the end. It came to a ban on accepting tanks from the factory on January 10, 1948 - a "raised tone" proceeding followed between the military and the Ministry of Transport Engineering, with the involvement of the USSR Council of Ministers (not the last in the fate of the tank, as it turned out), which resulted in two orders: to continue acceptance and development of a program to eliminate the identified defects, with the modernization of all previously delivered tanks. But already in August, a second conflict arises, exactly repeating the previous one, with similar conclusions. Acceptance is resumed, only it is meticulous and methodical. The result of all the altercations and mutual recriminations was the decision on January 1, 1949, to discontinue production of the tank. A total of 219 serial IS-4 tanks and six prototypes were produced. The service of the tank was painfully similar to the previously considered M103 and FV214 Conqueror - most of the vehicles were "sent" to the Far East, where they were quickly taken out of service for long-term storage, and later removed from service. The only complete copies that have survived to this day are the IS-4 from the exposition of the Museum of Armored Weapons and Equipment (Kubinka near Moscow) and a monument in the village of Zabaikalye, Chita Region.

heavy tank IS-4 (Object 701-6).

The IS-4 tank was designed according to the classic layout with a rear engine compartment. The control department housed a driver-mechanic, whose workplace was located along the axis of the tank. Access was through a round sliding hatch, in which viewing devices were mounted (two periscopic MK-4, they had to be removed to open the hatch). The engine of the tank is a 12-cylinder, V-shaped diesel engine V-12, which is a further development of the V-2. Forcing up to 750 hp produced by the introduction of a driven centrifugal blower, in addition to this, many other design changes were made. Of interest is the transmission of the tank, which consisted of a single planetary-type gear and turns mechanism. The role of the checkpoint was performed by a two-row planetary mechanism with three friction elements and a reverse, this provided the tank with six forward speeds and three backward. The turning mechanism of the 3K type with multipliers was developed in 1935-36, but due to its complexity it was not mastered by the industry at that time. On the one hand, it provided a stable straight-line movement in any conditions, but when turning, the speed of the tank's center of gravity significantly decreased and the engine was overloaded. The undercarriage consisted of 7 support and 3 support rollers, torsion bar suspension. The tank hull was welded from rolled armor, the turret was cast. The armament of the tank includes a 122mm D-25T rifled cannon with 30 separate loading rounds of ammunition, and two large-caliber DShKM machine guns - coaxial and anti-aircraft. It is worth noting the way of storing shells in the tank - all 30 shells are located in the rear of the tower in individual cassettes, which were designed for a specific type of shell. It had 12 cassettes for armor-piercing shells and 18 for high-explosive fragmentation shells; for convenience, their handles were painted red and yellow, respectively. Cartridges with charges were stored mainly in the case. The machine gun ammunition consisted of 500 rounds - 250 in five boxes (two are already installed on the machine guns) and 250 in the factory packs. The gunner, as in other Soviet tanks, was located to the left of the gun, in front of the commander. At his disposal was a telescopic "breaking" sight TSh-45 and a periscope observation device. Behind the armor plate for dismantling the gun were the hatches of the tank commander and the loader, they were supplied with periscopic observation devices (for the commander - TPK-1, for the MK-4 loader), the commander's cupola was absent, as were the prismatic observation devices for the all-round view.

The advantage of the tank was its powerful armor, which protects against the main anti-tank guns of that time, but in terms of armament it had no advantages over the IS-2 and IS-3. Low reliability, complexity in management and operation, insufficient mobility and maneuverability did not allow this heaviest of all serial Soviet tanks to take a worthy position in the troops.