The SU-152 and Related Vehicles

CHAPTER 3. The Evacuation

The tank programs underwent a fundamental revision immediately after Germany attacked the Soviet Union. The manufacture of armored vehicles already in production was accelerated, and programs that were in the design stage or that did not conform to wartime realities were shut down. The most common theory has it that Project 212 met a similar fate, but its actual history was somewhat different.

Under Order No. 253ss issued by the People’s Commissariat of Heavy Machine Building on June 26, 1941, preparations for production of the KV-3 were transferred from the Kirov Factory to the Chelyabinsk Tractor Factory (ChTZ). Chelyabinsk received a team of designers from the Kirov Factory, as well as production engineers, materials, and the KV-3 prototype minus its turret and a number of other assemblies. As of February 1942, this KV-3 was located in experimental shop OP-2. But Project 212 continued to be listed as a Kirov Factory project until early August 1941, as evidenced by a letter GAU Deputy Director Lt. Gen. V. I. Khokhlov wrote on the 11th to V. A. Malyshev, People’s Commissar of Medium Machine Building:

It was only in late August 1941 that SP gun Project 212 was transferred to the Ural Heavy Machinery Plant (abbreviated UZTM and located in Sverdlovsk, now named Yekaterinburg). The choice of UZTM as the site where work on the bunker buster would continue was no accident. The giant Sverdlovsk factory was the main supplier of KV-1 armored hulls for the Chelyabinsk Tractor Plant. Equally important was that, as the war began, UZTM’s design Bureau had a wealth of experience in the design and manufacture of howitzers and corps-level artillery. The factory’s design bureau under V. N. Sidorenko had developed the U-1 howitzer in 1937, and in 1938, it had developed the U-2. The following year, it developed the U-3 203 mm corps-level heavy howitzer. The decision was made in 1940 to engineer production of the M-30 122 mm howitzer at UZTM, and its creator, Fedor Petrov, traveled to Sverdlovsk for that purpose. Fedor’s business trip lasted 34 years. He became chief of the factory design bureau at his new location. In 1941, UZTM received a number of initiatives from Sverdlovsk that had been discussed in the GAU. For example, a project for a 107 mm antitank gun under the designation UML-20 was discussed in July. Like the M75, this gun was based on the ML-20’s carriage. But as with a number of other similar projects, the UML-20 did not go beyond the conceptual design stage.

Despite the design bureau’s competent team, the new task was a serious challenge for the factory. In a letter to GAU Deputy Chief Gen. V. I. Khokhlov on October 7, 1941, UZTM Chief Engineer A. S. Ryzhkov said the following:

The tank industry was not prepared for the KV-3 in October 1941, much less for the bunker buster based on it. The Kirov Factory had been evacuated to Chelyabinsk (and renamed the Chelyabinsk Kirov Factory, or ChKZ for short), as had the Izhor Factory, which produced the KV’s armor. UZTM was temporarily given the name Izhor Factory. Its original name was only restored on January 4, 1942. An additional item on UZTM’s plate was the evacuation of the Kalinin Factory No. 8 and the Ordzhonikidze Factory No. 37 (Moscow) to the plant’s grounds in the fall of 1941. Factory No. 75 which had developed the V-5 engine, was evacuated to Chelyabinsk, and its main mission was to begin producing the V-2 diesel engine, the need for which was much greater. The situation with production of the BR-2 152 mm guns was no better: the last guns of that type had been manufactured in 1940 by Factory No. 221 (“Barricades” in Stalingrad, now named Volgograd).

The bunker buster project was dropped as a high-priority task, but not for long. The system showed up again in GAU correspondence in November 1941. A report by Military Engineer 2nd Class Getmanov (of the Field Artillery Armament Directorate’s Main Artillery Directorate) discussed work done in Chelyabinsk from November 12 through 24, 1941:

This letter marked the initiation of wartime development of SP guns. Beginning in November 1941, work intensified on many of the SP gun projects named in the draft decree of the Council of People’s Commissars of the USSR and the Central Committee of the All-Union Communist Party (Bolshevik) “On Self-Propelled Artillery” that was issued on May 27, 1941. Operational requirements were still being drawn up prior to 1942; however, conceptual designs were not even being discussed. Most of the factories assigned to develop SP guns were either still in the process of setting up production lines at the sites to which they had been evacuated in the summer and fall of 1941, or they had been loaded down with more urgent orders. Nevertheless, the development plan for 1942 again featured the “KV-3 Tank” project with a completion date of May 1, 1942. The project also included a “1200 hp two-stroke diesel engine” (with a completion date of October 1, 1942) and a “supercharged 1200 hp V-2 diesel engine” (to be completed by July 1, 1942).

The project bearing the title “A 152 mm Self-Propelled Gun Incorporating Assemblies from the KV Tank Chassis” (a bunker buster) surfaced again in March 1942. The KV tank was specified as the base chassis, and the armament was to include the tipping parts from the BR-2 gun. Pilot Plant No. 100 (established in Chelyabinsk in 1942) of the People’s Commissariat of the Tank Industry was given responsibility for the chassis, and Factory No. 8 of the People’s Commissariat of Arms at its new location in Sverdlovsk was to be responsible for the gun. The amount allocated for development was 1.5 million rubles, and a prototype was expected by July 1, 1942. However, the KV-3 project was finally killed in the spring of 1942, and an entirely different vehicle began to be considered as the base chassis for the bunker buster.