Self-Propelled Artillery Mount - Inter-War Period 1930s
[Samokhodnye Artilleriya Ustanovka]

SU stands for "Samohodnaya Ustanovka" (self-propelled mount). It is an index used to designate an artillery system on a self propelled chassis: trucks, tractors, or tanks. The mounted artillery could be anti-aircraft, indirect fire guns, or direct fire guns. American and English doctrine distinguishes between tank destroyers and self propelled artillery, but the Soviets did not make such distinctions. A turretless tank is called SAU: Samohodyana Artilleriyskaya Ustanovka (self-propelled artillery mount). This weapons could be used for direct fire missions such as anti-tank or anti-emplacement. In any event, the numbers that follow the index could mean the caliber of the gun (SU-152), the tank of origin (SU-26), or be a sequential index (SU-5).

The early history of Soviet self-propelled artillery is a story of false starts and set-backs. In November 1932, common sense prevailed, and design work shifted from the futile quest for a "universal guns" to a focus on a "universal chassis". The Artillery Armament System for 1933-1937 was approved, which included the creation of self-propelled guns designed to support mobile army units with fire. It was assumed that the regimental and battalion guns would get armored on the tank chassis; self-propelled guns with 76 mm caliber guns, to support rifle units and cavalry, also on the basis of mass-produced tanks with compulsory protection of crew from bullets and fragments. As for anti-aircraft guns, the 76-mm should have been designed again on a tank or special tracked chassis, and a 25-37-mm caliber on a car.

Tukhachevsky, in a letter addressed to the high command of the Red Army. He directly pointed out that the guns must be manufactured taking into account the future of their application. At the end of April 1933, at a joint meeting of the leaders of the leading People's Commissariats and the high command of the army, a decision was taken to create a single universal chassis for future self-propelled guns, on the basis of which it was necessary to start creating self-propelled guns for various purposes (to support cavalry, infantry, etc.).

In accordance with this decision, the Kirov plant was issued a TTZ, according to which its design bureau in the shortest time developed a project of self-propelled installation on a wheeled chassis. The machine received the SU-12 index and at the end of the summer of 1933 it was already undergoing field tests, with results that were more positive than negative. Therefore, the machine (without alternative option) was adopted by the Red Army and put into the series.

The SU-12A chassis was originally planned as an American three-axle truck "Morland", which was then replaced by a domestic chassis - GAZ-AAA. The machine was serially produced until 1935 and was continuously improved directly during the release (for example: a significant change in the gun shield, the appearance of armor protection of the rear and the driver's cab roof, the upgrading of the mounting platform for the gun, etc.).

the design of the tanks created under Tukhachevsky did not allow creating effective self-propelled guns on their base. In the years 1930-1940. It was made over 50 experienced self-propelled guns, but they all turned out to be unsuccessful. While the Germans used the first self-propelled guns in France in the summer of 1940, normal self-propelled guns appeared only by 1943.

In parallel with the creation of high-powered self-propelled guns in the USSR, work began on creating a “small triplex” for divisional artillery. For mechanical units and strategic cavalry, the design bureau of plant No. 185 developed in 1934 a single small triplex SU-5, which included a universal gun carriage on the T-26 chassis and interchangeable divisions mounted on it: a 76-mm cannon of the model of 1902/30 (SU-5-1); 122-mm howitzer sample 1910/30 year (SU-5-2); 152-mm mortar type 1931 (SU-5-3).

According to the theory that existed at that time, the presence of such a triplex could fully cover the whole spectrum of army tasks. For the development of all three projects, the design bureau of the Kirov Plant of Experimental Machine-Building Plant (No. 185) was supervised by S.A. Ginzburg and P.N.Syachintov. V.Moskvin was appointed responsible designer. Armor was partial, and mounted ammunition was limited, so the complex was supplemented with a special armored patron carrier on the same chassis. Field tests gave positive results. The manufactured 15 vehicles were transferred to the troops.

In 1933, the VOAO design bureau designed a self-propelled A-39 self-propelled gun on the T-26 chassis with a 76-mm cannon in a rotating turret of a special design. But the project was rejected. At the same time, the “Red Putilovets” developed a unified turret with a 76-mm universal regimental cannon for light tanks, which received an index P-BT and P-T26. The development was not implemented due to flaws in the design of the gun. Ultimately, a standard turret was fitted to the installation of the 76mm cannon. Thus, artillery tanks appeared and began to enter the troops: T-26-4 and BT-7A.

In 1933, Plant No. 185 proceeded to design an AT-1 artillery tank with a 76 mm PS-3 tank gun based on the T-26 to escort long-distance infantry support (DPP) tanks and long-range tank groups during the latter’s breakthrough through defense the adversary. This self-propelled gated type had a conning tower with an upper belt in the form of folding shields, which improved the view of the battlefield and the working conditions of the crew with the support of an attack from the second echelon. Documentation was completed in 1935; but work on the AT-1 was stopped in favor of the BT-7A tanks.

In 1935, a prototype of a non-floating low-power SU-37 with a 45-mm cannon in the front leaf was created on the basis of the T-37 as a means of a mobile PTO. Then variants of the non-floating self-propelled 45-mm cannon on the T-38 chassis are developed. One of them - the SU-45 - was manufactured and showed low traction and dynamic qualities and insufficient mobility.

As a means of air defense of combined-arms, mechanized and cavalry formations, self-propelled guns were designed for the 76-mm anti-aircraft gun on the elongated T-26 chassis. (SU-6) and T -28(SU-8). One copy of the SU-6 was manufactured by plant number 185 in 1935, a year earlier, ANIMI completed a project of placing a 45-mm anti-aircraft gun 21K on the T-28 tank, which included alteration of the frontal part of the standard turret. To the production of the development was not accepted. In 1937, on the chassis T-26 made an experimental self-propelled gun with a 37-mm anti-aircraft automatic gun of the 1937 type.

The high rate of combat operations developed by the mobile forces was not possible for the towed artillery of great and special power. In this regard, the creation of self-propelled artillery began in 1934, when the Red Putilovets completed the development on the T-28 chassis of the L-5 gun complex in two versions: system D (125 mm self-propelled gun) and system E (203 mm howitzer). For unloading the chassis when shooting, special additional supports were used. According to calculations, the vehicle could move at a speed of up to 36.6 km / h. The project was not implemented.

In 1933–1934, experimental artillery was created on the basis of the T-28 / T-35 units on the basis of the “Big Duplex” program : the howitzer variant (203 mm) had the index Su-14, the gun version (152 mm) - SU-14A. The prototype was ready in 1935. For the first time in domestic practice, such powerful artillery systems were given the ability of independent movement. After finishing the machine, called the SU-14-1 (152-mm cannon or 203-mm howitzer), passed the second ground testing in June 1938 and showed unsatisfactory results. Due to design flaws, the rate of fire was one shot in 5-6 minutes. The transition from traveling to combat took 6 minutes. The transmission was overloaded. Solitary copies of the SU-14 and SU-14-1 were transferred to the troops for trial operation.

In the framework of the Big Triplex program in 1934, the complex was designed on a single self-propelled double-rollback carriage (base T-28 / T-35) carrying an interchangeable 220/254-mm cannon, or a 305-mm howitzer, or 400-mm mortar. In the process of project justification, the task was changed. The SU-7 self-propelled gun was developed for a 203-mm howitzer or 305-mm howitzer. The huge mass - 106 tons - forced to abandon the project and concentrate on fine-tuning the SU-14.

Among the light escort guns to support reconnaissance and strategic cavalry actions was the installation of a 76-mm DRP on the T-37, which was distinguished by an automatic reloading mechanism. There was also a wheel sample of the 76-mm DRP on the GAZ-TK chassis. In connection with the cessation of work on the guns of the PDD, work on these objects was stopped.

When the Red Army was ready to adopt the new self-propelled artillery [SAU] into service, mass arrests among designers and engineers followed. Thus, on December 31, 1936, P.N.Syachintov was arrested, who was convicted under Article 58 pp. 6, 7, 8 and 11. In other words, the chief designer was accused of spying, undermining state industry, committing terrorist acts, sabotaging and maintaining subversive work in a team. The trial of Syachintov took place on May 5, 1937, and the execution of the sentence (execution) the next day. The same fate befell the creator of the B-4 howitzer, the head of the Bolshevik plant, Magdisiyev, who, during interrogations, fully confessed to his “sabotage” activity and was shot.

Needless to say, what a blow was struck on the creation of self-propelled units in the USSR in the prewar period, because until the end of 1942, the Red Army never received a single specialized self-propelled gun. Having dealt with the “apologists” of self-propelled artillery, the Red Army before the outbreak of the Great Patirotic War turned out to be with a minimum number of self-propelled guns, most of which belonged to regimental or divisional. The new leadership of the Red Army, partly frightened by the previous “purges”, did not practically develop the SAU theme, and if not for the active intervention of the head of the ABTU Pavlov, their further development would completely stop.

The design and development of the self-propelled artillery was abruptly discontinued as a result of the work of the special commission, which, from 12/19/1937 to 04/05/1938, developed a list of weapon samples for the RKKA artillery weapons system. Probably the main reason for this decision was the personnel purge of 1937-1938.

The Soviet Main Artillery Directorate (GAU) showed very little interest in self-propelled artillery during the war. Western observers have frequently mistaken the profusion of assault guns, like the SU-85, SU-100, ISU-122, and ISU-152 for self-propelled artillery. In fact, these assault guns were developed at the bequest of the Main Armor Directorate, manned by tank troops, and employed as surrogate tanks. They were intended primarily for direct fire, and ill-suited for the usual artillery role of indirect fire. They were closest in conception to the German Wehrmacht's Sturmgeschutz assault guns.

The only significant design to vaguely resemble American, German or British self-propelled artillery was the SU-76, a lightly armored vehicle mounting the 76mm divisional field gun. But even this vehicle had been developed as an assault gun, and was used in a role more akin to the pre-war infantry support tanks. The Red Army of the Great Patriotic War had no immediate equivalents of the American M-7 105mm howitzer motor carriage, M-40 155mm gun motor carriage; the Canadian Sexton 25 pound self-propelled howitzer; or the German Wespe 105mm or Hummel 150mm self-propelled howitzers.