During World War II, heavy SPGs played an important role on the battlefields. It is not surprising that after its completion, the development of heavy self-propelled guns, one of the main tasks of which was the fight against enemy armored vehicles, was continued by designers from different countries. All the more surprising is the fact that only a few projects reached the stage of manufacturing in metal, and none of these formidable machines went into series. And the Soviet Union, in which the Object 268 heavy self-propelled gun was created, was no exception in this regard.
Weight limit
As in the case of heavy tanks, it was assumed that promising Soviet heavy SPGs would be very well protected vehicles with long 152 mm guns. The first requirements for such installations date back to 1945, although the real work began a year later. They were designed on the basis of the Object 260 (IS-7) and Object 701 (IS-4) tanks.
For the self-propelled unit based on the IS-4, which had the designation Object 715, it was supposed to use the 152-mm M31 cannon developed by the plant No. 172, which is the same in ballistics as the 152-mm high-power BR-2 cannon. The same gun was planned to be used for the project of a self-propelled installation of the Kirov plant in Leningrad. How exactly it was called is not completely clear. Some sources indicate the index Object 261, others call it Object 263.
Later, the design bureau of factory # 172 developed an even more powerful weapon, designated M48. In general, it repeated the design of the M31 and had a similar muzzle brake, but the muzzle velocity of its projectile was increased to 1000 m / s. For such a powerful weapon, the destruction of any enemy tank or bunker was not a big problem. The same gun was supposed to be placed in the Object 262 semi-open self-propelled gun.
The main obstacle in the way of all these plans was the delay in work on the IS-7 and problems with the development of serial production of the IS-4. The last activity on both SPGs dates back to 1947, after which the work was frozen "until better times." Which never came.
On February 18, 1949, the Resolution of the Council of Ministers of the USSR No. 701-270ss was issued, according to which the development and production of heavy tanks weighing more than 50 tons ceased. Naturally, after the IS-4 and IS-7, the development of self-propelled units based on them was ordered to live long.
According to the same decree, SKB-2 ChKZ and a branch of experimental plant No. 100 (Chelyabinsk) were given the task to develop a heavy tank with a combat weight of no more than 50 tons. The work, which received drawing code 730, led to the creation of the IS-5 heavy tank. A draft design of a new heavy tank was presented in April 1949, and already on September 14, ChKZ completed the assembly of the first prototype.
It was quite logical to develop an SPG on the same base, but the designers were in no hurry with this. The memory of how the work on self-propelled guns based on the IS-7 and IS-4 ended was still vivid. The go-ahead was given only at the moment when it became clear that the 730th object turned out to be quite successful, and its adoption was not far off.
In the literature on the T-10 and vehicles based on it, the start of work on the assault SPG is usually dated July 2, 1952. In fact, the chronology of events is somewhat different. The fact is that a self-propelled gun is usually made for a very specific artillery system. And the gun that ended up being “registered” on the machine known as the Object 268 was not even in the project for another 1.5 years after the start of work. But work on this weapon began much earlier.
From this point of view, the history of the new heavy self-propelled gun began in 1946, when, in parallel with the M31 and M48, the design bureau of factory # 172 began the development of the 152-mm M53 cannon. This gun with an initial projectile speed of 760 m / s was developed for the Object 116 SPG, known as the SU-152P. Both the gun and the installation itself were built in 1948. Tests showed insufficient accuracy of the system, and the project was closed. Nowadays SU-152P can be seen in the exposition of the Patriot park. So, it was this artillery system in a slightly modified form that was supposed to be the weapon of a promising self-propelled installation.
Work on the new machine, which initially did not have any designations, was initially headed by P. P. Isakov. The plant was developed by the team of the Special Design and Technological Bureau (OKTB) of the Leningrad Kirov Plant. The car was designed in three versions at once, two of which were noticeably different from the Object 268, which is now quite widely known. The fact that the design began even before July 1952 is eloquently indicated by the dates in the draft designs of the 2nd and 3rd options - April 25, 1952. By that time, the main parameters of the machine were already known. One of the main requirements for the self-propelled guns was the weight limitation: its combat weight should not exceed 50 tons.
Option number 2 of the projected heavy self-propelled guns provided for the aft placement of the fighting compartment. Due to this, the body length was reduced to 6675 mm. The entire nose of the car was occupied by the engine-transmission compartment, so there was no place for the driver-mechanic. He was put in the fighting compartment, where he was placed on the right in the direction of travel. With this arrangement, the driver's view was poor.
Such inconveniences were compensated for by the relatively small overhang of the gun for the vehicle dimensions - 2300 mm. The thickness of the front of the felling was from 150 to 180 mm, the sides were 90 mm. The upper frontal plate of the hull was only 75 mm thick, but its angle of inclination was 75 degrees. In short, the car had quite decent protection. The crew of the car consisted of four people. To facilitate the work of the loader, the shells were in a special drum behind the gun.
The third SPG version looked no less original. By and large, it was not even a self-propelled gun, but a tank, whose armor had to be reduced in thickness due to a more powerful and heavy weapon.
However, the difference between the Object 730 and the projected SU-152 (as this machine is designated in the documentation) is quite significant. The designers developed the turret for the self-propelled guns from scratch, and for the normal installation of a 152-mm gun in it, the shoulder strap diameter had to be increased from 2100 to 2300 mm. The maximum thickness of the turret armor reached 200 mm. The turret also housed ammunition, the size of which remained the same - 30 rounds. The main ammo rack was supposed to be placed in the aft niche, which made the loader's work a little easier.
Due to the new turret, the hull had to be changed, the length of which, in comparison with the 730, increased by 150 mm. The thickness of the upper side plates was reduced to 90 mm, and the lower - to 50 mm, this was done to maintain a combat mass within 50 tons. For the same purpose, the thickness of the upper frontal sheet and stern sheets was also reduced, to 60 and 40 mm, respectively. A coaxial machine gun on the self-propelled gun was not provided, but the anti-aircraft mount of the KPV heavy machine gun was to be installed at the top.
Thus, by the summer of 1952, the design of the SPG based on the 730 Object had not begun, but had already taken shape. The order of the Council of Ministers of the USSR of July 2, 1952 rather "legalized" the work on the machine, and also made a number of amendments to the design work already underway. Around the same time, the SPG received a drawing index of 268, and the theme itself became known as Object 268.
Soviet "Jagdtiger"
The literature indicates that a total of 5 variants of the vehicle were developed on the subject of Object 268. This is both true and not true. The fact is that the two options mentioned above were developed even before the final tactical and technical requirements were received. And they didn't even wear the 268 code.
Therefore, in fact, we are talking about three variants of the machine, two of which represented the evolution of previously developed draft designs. Both of these versions in a revised form were ready in December 1952. At the same time, the artillery system, which was supposed to be installed in these machines, was still being designed.
According to preliminary calculations, the muzzle velocity of its projectile should have been 740 m / s. The self-propelled gun M53 was taken as a basis, which was altered using separate units of the 122 mm M62-T tank gun. According to calculations, the total mass of such a system, which did not have an official designation, was 5100 kg.
The revised project of the second variant of the SPG, which received serial number 4, was prepared by the OKTB of the Kirov Plant by December 18, 1952. This time the car already had the code 268, and Zh. Ya. Kotin appeared as its chief designer. Outwardly, the 4th option was very similar to the 2nd, but in fact the differences turned out to be significant.
For starters, the length of the hull was increased to 6900 mm, that is, almost to the length of the Object 730. At the same time, the length of the extension of the barrel of the gun beyond the dimensions of the hull was reduced by 150 mm. The designers abandoned the beveled stern leaf of the cabin, which had a positive effect on the internal volume of the fighting compartment. Such changes were extremely necessary, since, according to the new technical specifications, the crew of the vehicle was increased to 5 people.
The new crew member was the second loader, located behind the commander. The commander himself received a new commander's cupola with a rangefinder, and a machine-gun mount with a "curved" barrel appeared in front of him. The driver's seat was also slightly altered, which received new viewing devices. The system with the "drum" remained in place, while the authors of the draft design emphasized that due to the large internal volume, it is possible to install more powerful weapons. In parallel with the increase in the volume of the fighting compartment, the armor protection increased. The thickness of the lower frontal hull plate was raised to 160 mm. The thickness of the front of the felling remained 180 mm, but the bevels with a thickness of 160 mm were made at a large angle. With all this, the mass of the car remained within 50 tons.
On December 10, 1952, a revised version of the 3rd variant of the ACS was completed, which received the 5th serial number. The length of its hull was reduced to the level of the 730th object (6925 mm), while the upper side plates were redone, which became bent. The forehead of the case has also changed slightly, but the thickness of these parts has remained unchanged. The preservation of the hull length within the base tank was due to the installation of the V-12-6 engine, which, by the way, eventually appeared on the T-10M heavy tank. Later, the enlarged turret ring also "migrated" to it.
The tower, designed for 4 people, also underwent alterations. The commander here also received a new commander's cupola, but the engineers of the OKTB of the Kirov plant gave the curved-barrel machine gun to the loader. By the way, both revised projects inherited the installation of the KPV anti-aircraft machine gun.
Both of these options, however, did not go further than sketch studies. In January 1953, the projects were submitted to the scientific and technical committee of the Main Armored Directorate (GBTU) and the Ministry of Transport and Heavy Engineering (MTiTM). Having studied them, the members of the STC came to the conclusion that these projects provide for the need for a serious alteration of the hull of Object 730 and therefore are not suitable.
The commission approved for further work a completely different, much more "calm" project, which required minimal alterations to the base chassis. Of the major changes in it, only the installation of a slightly more compact V-12-6 engine was required, which, by the way, was also envisaged in version No. 5.
A revised version of the project was presented in June 1953. A wooden model at a scale of 1:10 was also presented to the commission. And on August 25, on the subject of Object 268, a conclusion was given, signed by Colonel-General A. I. Radzievsky.
Several sources indicate that design work stalled at this stage, but this is not the case. Of course, the self-propelled work was somewhat influenced by the adoption on November 28, 1953 of the Object 730, which later became the T-10 tank. Nevertheless, work on the car continued. NM Chistyakov, who had previously worked in Nizhny Tagil as head of the new design sector, became the lead engineer of Object 268. There, under him, work began on the Object 140 medium tank, but for a number of reasons the designer left Nizhny Tagil and moved to Leningrad. The general leadership fell on N. V. Kurin, a veteran of the Kirov plant and the author of a number of self-propelled units.
There was, however, another reason that slowed down the work on Object 268, which some researchers do not take into account. The fact is that the gun that was supposed to be installed on the SPG was still at the design stage. Meanwhile, the staff of the plant No. 172 did not sit idly by. Following the 122-mm M62 cannon, proposed for installation in the promising Object 752 and Object 777 tanks, the Perm gunsmiths at the beginning of 1954 finally reached the 152 mm caliber.
7 years have passed since the design of the M53, a modified version of which was supposed to be installed on Object 268, and the development of artillery in these years did not stand still. As a result, a 152-mm gun project was born, which received the designation M64. The muzzle velocity of its projectile was almost the same as that of the M53 (750 m / s), but the barrel length was noticeably reduced. Given the fact that the fighting compartment of Object 268 was located approximately in the same place as the fighting compartment of the T-10, this was very important. For comparison, the modified M53 had a total horizontal length from the turret rotation axis to the muzzle brake tip of 5845 mm, and the M64 had 4203 mm. With the new gun, the barrel overhang was only 2185 mm.
Officially, the technical design of the M64 was reviewed by the Main Artillery Directorate (GAU) in August 1954. In fact, the team of the OKTB of the Kirov plant received information on the new weapon earlier. The already mentioned thesis that design work on Object 268 had stalled by the fall of 1953 sounds a little strange given that the drawing documentation for the car was dated June 20, 1954.
The drawings (in total, the design documentation contained 37 sheets) shows a machine that is most similar to the Object 268, which was later built in metal. Conceptually, the vehicle closely resembled the German self-propelled gun Jagdtiger, which was maximally unified with the Pz. Kpfw heavy tank. Tiger Ausf. B.
The fundamental difference between the two machines was that the Soviet engineers managed not only to fit into the dimensions of the T-10 hull, but also to maintain the same combat weight. And in height, the Object 268 was even slightly lower than the T-10. The vehicle inherited the commander's cupola with a rangefinder from previous projects. As in the case of its predecessors, the thickness of the hull from the sides and stern had to be reduced, but the thickness of the sides of the wheelhouse increased to 100 mm. The frontal protection of the felling was also quite impressive - 187 mm. Due to the fact that the wheelhouse was expanded to the total width of the hull, it turned out to be quite spacious.
Between the past and the future
The final estimate for Object 268 was completed in March 1955. At the same time, the timing of the production of prototypes was approved. According to plans, the first sample of Object 268 was expected to be received in the first quarter of 1956, two more copies were to be produced in the fourth quarter. Alas, it was during this period that work began on heavy tanks of a new generation, Chistyakov headed work on the Object 278 heavy tank, and this directly affected the readiness of the ACS.
As for factory # 172, he completed the creation of a prototype 152-mm M64 gun in December 1955. And in February 1956, after a program of factory tests, the gun with serial number 4 was sent to Leningrad, to the Kirov plant.
The delay in work led to the fact that the first prototype of the Object 268 was completed only by the fall of 1956. In general, the car corresponded to the design documentation, although some changes did take place. For example, it was decided to abandon the convex roof of the deckhouse. Instead, the SPG received a roof that was easier to manufacture. The machine did not have a machine gun with a "curved" barrel, in its place the prototype had a plug. The shape of the stern leaf of the felling became simpler, which they decided not to make bent. This part was made removable, since it was used to mount and dismantle the tool.
The crew of the car remained the same and consisted of 5 people. Thanks to the successful layout, it was not at all crowded inside the car, even a very tall person could work in it. And this despite the fact that the ammunition load of the large-caliber gun was 35 rounds. The convenience of the crew was due, among other things, to the design features of the gun. Firstly, the M64 had an ejector, thanks to which it was possible to minimize the ingress of powder gases into the fighting compartment. Secondly, the gun received a loading mechanism, which greatly facilitated the work of the loaders.
Factory tests of the prototype Object 268 began in the fall of 1956 and ended in the spring of 1957. In general, the car showed characteristics close to the calculated ones. In terms of driving performance, the Object 268 almost coincided with the T-10, including its maximum speed.
Soon after the tests, the SPG went to the NIIBT proving grounds in Kubinka. Shooting tests showed that the factory # 172 had not in vain delayed the development of the gun. The M64 in terms of accuracy of fire was clearly superior to the ML-20S, which was installed on the ISU-152. The new gun turned out to be the best in terms of the initial velocity of the projectile, and in terms of firing range, and rate of fire.
Alas, all this no longer played any role. It was decided to abandon the construction of two more prototypes of Object 268, and the first prototype of the machine went to the museum at the NIIBT proving grounds. Now this specimen is on display in the Patriot Park. Recently, the museum staff managed to bring the ACS into a running state.
Had Object 268 appeared five years earlier, its chances of going into production would have been very high. The car turned out to be successful, quite comfortable for the crew and well protected. But by 1957, a whole series of events had taken place, which together made the launch of a series of such SPGs meaningless.
To begin with, in 1955, the development of a new generation of heavy tanks (Objects 277, 278, 279 and 770) began, which had a significantly higher level of armor protection. Even the M64 cannon was no longer enough against them. The GBTU was well aware that the designers of armored vehicles abroad also do not sit still. It turned out that a promising self-propelled gun is armed with an artillery system, which is already outdated.
In addition, just in the mid-50s, a program to modernize the ISU-152 began, which significantly extended the service life of these machines. Unlike the Object 268, which was just about to be put into production, these self-propelled guns were already here and now. Yes, the ML-20 was inferior to the M64 in all respects, but not so significantly.
Finally, the production of the T-10 was extremely slow. Loading the Kirov Plant and ChTZ also with self-propelled units meant further narrowing the already not wide stream of T-10s entering the troops. In addition, factory # 172 needed to master a new cannon for the production of a new ACS.
There was one more reason, which largely coincides with why the British put an end to their heavy self-propelled guns FV215 and FV4005 around the same time. The fact is that in 1956, work began on projects for anti-tank guided missile systems. On May 8, 1957, the USSR Council of Ministers authorized work on the development of tanks and self-propelled units armed with guided missiles.
Many will immediately remember the "bad Khrushchev", but let's face it. An anti-tank missile launcher is much more compact than a cannon. Launching a rocket is much easier, and most importantly, it can be controlled in flight. As a result, with a similar power of the charge, the rocket turns out to be an order of magnitude more effective. Unsurprisingly, Object 268 was the last Soviet heavy assault SPG with cannon armament.
The work on SPGs based on the T-10 did not stop there. In the same 1957, the OKTB of the Kirov plant began developing a vehicle that received the designation Object 282. It is often called a tank, but in fact it was a heavy tank destroyer. It was created with the expectation of being armed with 170-mm anti-tank missiles "Salamander", but due to the fact that the team of NII-48 could not bring them to mind, the weapons were changed. In the final configuration, the vehicle, indexed Object 282T, was to be equipped with either 152-mm anti-tank missiles TRS-152 (ammunition for 22 missiles) or 132-mm missiles TRS-132 (ammunition for 30 missiles).
The vehicle, which was launched for trials in 1959, was strikingly different from the previous SPGs. Despite such an impressive ammunition capacity and a crew of 2-3 people, the tank became somewhat shorter than the T-10. And most importantly, its height was only 2100 mm. The frontal part of the tank has been redesigned. In addition, the designers moved the fuel tanks forward, separating the crew from them with a 30-mm partition. The vehicle received a forced V-12-7 engine with a capacity of 1000 hp. Its top speed increased to 55 km / h.
In a word, it turned out to be an extraordinary machine, which in the end was destroyed by weapons. Tests have shown that the Topol control system installed at Object 282T is not working reliably enough, which led to the winding down of the project.
In the same 1959, the OKTB of the Kirov plant developed a project for an improved machine, which received the designation Object 282K. Its combat weight increased to 46.5 tons, and its overall height decreased to 1900 mm. As planned, the car was equipped with two TRS-132 launchers (20 missiles for each), located on the sides. In the stern there was a 152-mm launcher PURS-2 with ammunition for 9 missiles. The fire control system was completely borrowed from the Object 282T. In view of the failure to test Object 282T, work on Object 282 did not leave the design phase.
This concludes the history of designing SPGs based on the T-10.
