The first mention of the design work on the creation of Russian wartime self-propelled guns dates back to September 1941, when the head of the second department of the NKTP (technical department) S.A. Ginzburg put forward a proposal on the development of assault and anti-aircraft armored tracked vehicles on light and obsolete chassis tanks. However, until the end of 1941, this initiative was not widely implemented.
At the meeting NKTP held 26-28 in January and dedicated to the study of the experience of fighting in the offensive S.A. Ginzburg again raised the issue of creating light-weight self-propelled guns with powerful weapons, equalizing them with a medium or heavy tank, and suddenly found support in the person of the People's Commissar and was also present at the meeting of the representative of the People's Commissariat of Defense, who saw in the proposed combat vehicle design a version of a heavily armed tank without a tower and with This is very cheap and easy to manufacture.
“Assault” SAU of the plant №37, 1942g.
3 MARCH 1942 issued an order to the People's Commissariat of the tank industry to prescribe a special self-propelled artillery bureau based on the technical department. As a test, the special bureau was to develop in a short time a unified chassis and power unit from the units of the T-60 light tank and trucks, on which the 76-mm cannon with the ballistics of the divisional weapon could be installed. 1939, (SPM) or tank gun arr. 1940 (F-34). However, S.Ginzburg made a more extensive work plan in this direction. In particular, he proposed to design the following machines with the use of T-60 chassis nodes and GAS and VMS engines in a three-month period together with the Moscow Technical University named after Bauman and NATI:
- 76-mm assault self-propelled gun support;
- 37-mm anti-aircraft self-propelled machine;
- 37-mm anti-aircraft tank with a tower installation design Savin;
- a light tank with a 45-mm high-power cannon and 45 mm armor;
- an armored infantry and ammunition transporter (it is also an ambulance car, a technical assistance vehicle and a self-propelled mortar);
- artillery tractor.
The unified chassis scheme assumed the use of 2-x engines of VMS, GAZ-AA, or GAZ-MM with their checkpoints on the sides in front of the ACS (very attractive from the point of view of compact placement), a spacious fighting compartment (loading platform, or armored cab for riflemen ), located in the stern of the machine and suspension on 5-6 track rollers.
14-15 April 1942 was held a plenum of the art committee of the SAU, which also raised the issues of creating an ACS. The gunners developed their own requirements for self-propelled installations and put forward their own TTTs, which differed from those put forward by the 2 department of the NKTP. In June, 1942, by order of the GFCS, was developed a joint program of the NKV and NKTP to create a "system of self-propelled artillery for arming the Red Army."
At the same time, the People's Commissariat of Armaments (NKV) was assigned the tasks of developing and manufacturing the artillery part of future SAUs, and the People's Commissariat of the tank industry was to deal with their undercarriage and power plants. The overall coordination of work on the ACS was to be carried out by the special bureau of the NKTP under the leadership of S. A. Ginzburg.
Meanwhile, by the end of April, the design of a unified chassis for the ACS program was completed, but funds were allocated for execution only for an assault assault cannon of support in a crazy performance with 7,5-8 t and 37-mm anti-aircraft self-propelled roundabout gun.
76-mm "assault" SAU GAZ-71. 1942
Plant No. 37 NKTP was appointed as the responsible contractor for the manufacture of machines. At the same time, the design bureau of V.G. Grabin on TTZ NKTP developed a "self-propelled" version of its new divisional gun ZIS-3, called ZIS-ZS ("assault"). In May-June 1942, prototypes of “assault” and “anti-aircraft” self-propelled guns were manufactured and entered for testing. Unfortunately, the test report of these interesting self-propelled guns has not yet been found, nor is their troop index known. But the tests, apparently, ended successfully, since in June 1942 was followed by the order of the GO-KO about the prompt completion of the machine and the preparation of a series for conducting military tests. But the large-scale battle for Stalingrad, which began shortly, demanded that Plant No. 37 urgently increase the production of light tanks and the order to manufacture an experimental series of self-propelled guns was canceled.
In the autumn of 1942, the Red Army command planned a series of large offensive operations, the development of which attempted to take into account the lessons of the winter offensive near Moscow, when medium-sized artillery, and especially large-caliber (so necessary for crushing enemy fortifications and countering tanks) constantly lagged behind advancing tank (and infantry) units. October 19 1942, at the request of the GAU RKKA, the State Defense Committee adopted decision No. 2429ss on the development and preparation of the serial production of “artillery self-propelled guns” in caliber from 37-mm to 152-mm. Responsible performers for the "assault SAU" were appointed Kolomna Plant number 38 them. Kuibyshev and GAZ them. Molotov, for anti-aircraft SAU - plant number 37, and for the tractor and conveyors - CB NATI.
SU-76 on the Volkhov front. March 1943 g
When creating an “assault SAU”, it was proposed to stop at the layout scheme proposed by the special bureau of the ACS NKTP (with two engines paired in parallel in front of the car and a spacious fighting compartment in the stern).
In accordance with the specified tactical and technical requirements, in November 1942, Plant No. 38 and GAZ presented their first samples of “assault SAU” armed with 76-mm ZIS-ZSh divisional gun on the chassis with parallel-coupled engines operating on a common shaft. The car of Gorky had the GAZ-71 index, and the car of the plant No. 38 had SU-12.
Despite the fact that GAZ-71 carried two parallel-coupled engines, its layout was different from the recommended SAB NKTP special bureau. If the layout adopted for the standard (which was followed by the engineers of the plant No. 38 under the direction of M. Shchukin) provided for the driver to be placed between the engines along the axis of the machine and the front drive wheel, the Gorky team did things a little differently. The engines in the GAZ-71 crowded at the starboard side, the driver was located to the left of the longitudinal axis of the car, and the drive wheel was moved back. This led to the need to use a long cardan shaft, which sharply worsened the reliability of the transmission.
19 November 1942, the acceptance committee drew up the act according to which the model of the automobile plant was named not meeting the technical requirements of the specification and not having adequate reliability. SU-12 was recommended for use, with the proviso of the need for repeated road tests. The run was carried out in a short time, however, it was driven along the roads and it is possible because no major defects in the design of the cars were noted.
In January, 1943 began mass production of the SU-12, which received the military index SU-76. The first cars were handed over to the customer 14 in January and soon passed to the formation of two regiments of the ACS of a mixed organization. The NKTP Commission, chaired by S.A. Ginzburg, also went to the front with the vehicles. After training military teams, 1433 and 1434 regiments, which included both SU-76 (SU-12) and SU-122 (U-35), went to the Volkhov front, where the battles on the de-blockade of Leningrad were going on.
SU-76 on the Volkhov front. March 1943 g
The first combat tests did not last long - only ten days, during which the most successful tactics of supporting the advancing infantry and tank units were worked out. The tactic was that the self-propelled guns, moving behind the advancing infantry chains, or tanks at a distance of 300-600 m, suppressed the firing points from the stops with fire, and after breaking through the line of defense, guarded the attacking orders from counterattacks of enemy tanks.
It was very rare to have to shoot self-propelled positions from closed positions, since in the conditions of a stationary front, the troops completely managed with cheaper divisional artillery available.
At the end of the first ten days of troop days, the factory teams were mostly replaced by front-line crews, and the self-propelled guns were involved in the planned battles that took place on February 13-15 in the Smerdyn region.
However, by the time these battles began, most of the SU-76 had already failed, due to breakdowns in gearboxes and main shafts that could not withstand the conditions of front-line operation. But at that time it did not cause concern.
It seemed that the simplest solution lay on the surface - to reinforce the design of the shafts, which was easily done. But such “reinforced” cars began to fail even more often than the previous ones. It became clear that the machines have a global design defect. Therefore 21 March 1943g. Su-12 production was stopped until the causes of defects and ways of their possible elimination were clarified.
Tests of SU-76М (SU-12М) at the NIBT training ground. Spring 1943
To compensate for the forced decrease in the production volumes of the SU-76, which were urgently required at the front and fill up their number, until an effective solution was found, 37, evacuated to Sverdlovsk, was given an order for the production of 20 pcs. 1943-mm SU-С-200 (SU-76 (И)) based on the PzKpfw III trophy tank. In total, until the autumn of 1, the customer accepted 76 pcs. such SAUs, after which their production was no longer resumed, since the constructive defect in the domestic light SAUs was overcome.
However, it was not as easy as it might seem at first glance. The fact is that during the operation of two engines on a common shaft, it was necessary to synchronize their revolutions, since otherwise torsional oscillations occurred on the shaft, the resonant frequency of which was in the operating range of the engine revolutions. The worst thing is that its peak value accounted for just the most loaded mode of operation, corresponding to the movement of ACS in second gear in deep snow and mud. It was necessary to urgently find a way to eliminate the resonances of torsional vibrations, and this was done by the special bureau of the ACS and OGK NKTP as a whole. The work was carried out in two directions: damping of the torsional vibrations of the working shaft, or synchronization of the motors.
Synchronization of motors located at a distance from each other, especially when the driver was sitting between them, resulted in a separate problem. This was fundamentally possible only if the path of Gorky tank builders repeated - the maximum convergence of the motor units, which led to a serious alteration of the SAU design as a whole, and therefore a real and long stop of their production at the time they were urgently needed for the upcoming 1943 in the summer. offensive operations.
Tests of SU-76М (SU-12М) at the NIBT training ground. Spring 1943
Therefore, S.A. Ginzburg and M. Schukin chose another way - the quenching of torsional vibration resonances on the shaft. In March-April, the SU-1943М, which was distinguished from the SU-12 by a number of improvements, passed tests in Kirov in Kirov. Between the engines and the gearbox, two spring elastic couplings were installed, and between the two main gears on the common shaft - a friction slipping clutch. Motors supplemented with submotor shock absorbers. The measures taken have dramatically reduced the accident rate of the main gear SU-12М. The need for light SAU was so great that in May 12 of the SU-1943М went into series under the index SU-12М.
Here it is necessary to make some sad retreat from stories cars to the fate of man. The fact is that in the spring of 1943, on the orders of the Bid, to investigate the reasons for non-fulfillment of NPO's orders for 76-mm SU-76 (SU-12) and. Commissar of Tank Industry I. Saltsman formed a special commission under his own chairmanship. The commission worked quickly and quickly, but found no other reason for non-fulfillment of orders other than the perpetrators. Those were announced by S.А. Ginzburg (by that time - the Head of the Department of the Chief Designer of the NKTP), as well as the Director of the Plant No. 38 Yakovlev and the former Chief Designer of the Plant No. 37.
The transfer of SU-76M representatives of the army. May 1943.
But if the latter were subjected to fairly light punishment (temporary suspension from management and reprimands), then the head of the OGK NKTP, as the “main culprit”, was sent to 1943 in April by the head of the repair service of one of the tank corps. Soon I.Stalin inquired what was done to eliminate the SU-76 defects, and how their shortage was repaired. And having learned that the activity of the people's commissariat was limited to punishments, he brought his anger outlined in two letters and a telegram to the heads of the NKTP leadership, where "... such a punishment of the USSR’s talented designer and tank builder, Comrade Ginzburg ..." a crime! ”, and“ ... the actual inaction of the leadership of the Commissariat ... ”in his opinion,“ ... left the Red Army without any self-propelled artillery. ”
S.A. Ginzburg was recalled from the front by the order of the Headquarters, but it was too late, as the recall, according to the memoirs of L. Gorlitsky, came only one or two days after his tragic death.
Anyway, by the summer of 1943, the SU-76М (SU-12М) went to the troops and training units. Their massive combat use took place at the Kursk Bulge, and it was here that sustained rumors about the unreliability of the SU-76 mechanisms that lasted through the war were born and immediately appeared the first derogatory nicknames addressed to this combat vehicle, in particular, the “common grave of four tankers” and “bitch” and the "gas chamber".
SU-76М (SU-12М) on the Belgorod direction. Battle of Kursk, July 1943
This was partly explained by the fact that the SAU was given to the submission of tank forces, and this was fraught with the fact that most of them were used mostly as tanks without a tower. And because the tactics worked out at the very beginning of the year often changed to the exact opposite - relatively thick-armored tanks went under the cover of SU-76 / SU-76М protected by anti-bullet armor. But there were other reasons.
The summer was hot and SU-12М, which practically did not have normal ventilation of the crew compartment, was called a “decelerator”, as well as SU-76 (I), which was experiencing similar problems at that time. Already in the first days of July, the People's Commissariat recommended to dismantle the roof of the conning tower “up to the periscope sight apron”, or install an additional exhaust fan on the roof of the SU-76М. The car with the roof removed was liked by the troops, despite the fact that the rain poured on the crew heads, and it was not easy to fix the tarp.
The driver mechanics also did not particularly like SU-12M, since it was rather unpleasant to sit in the middle between the engines, as it was not very convenient to operate the ACU with one handle, serving two transmissions, which emitted multiple extraneous noises due to asynchronous operation. The failure of the mechanisms also did not add love to these machines.
And although the reliability of work, they almost did not differ from the average ACS, they still had to be repaired with more blood, since the repair almost always came down to replacing the gearbox, main shaft or main gears.
A radical modernization of the SU-76M, as they say, is overdue and soon took place. However, individual machines such as the SU-12M survived in the troops until the middle of 1944 g, when by order of early. The armored control of the spacecraft, were withdrawn in training units.
SU-12M with a cut off roof. July 1943
SHORT TTX SU-76М (SU-12М)
Combat Weight ............... 11,2
Loading weight .......... 9,7 t
Full length ............... 5000 mm
Full width ............ 2740 mm
Overall height .............. 2200 mm
Track width ............. 2390 mm
Clearance .................... 300 mm
Wed specific pressure ..... 0,57 kg / cm2
Max speed ........... 44 km / h
Speed over the country road ....... 15 km / h
Ground speed ......... 10 km / h
Extreme lift .......... 30 °
Limit roll .......... 35 °
Maximum descent ........... 30 °
The width of the pit ................. 2,0 m
Wade depth ............. 0,9 m
Vertical wall ........ 0,6 m
Cruising on the highway ....... 250 km
Cruising on the country road ..... 175 km
76,2-mm gun ZIS-ZSH ....... 1 pcs.
Panorama Hertz ............ 2 pcs
Periscope intelligence ........ 1 pcs
Viewing Instruments ........ 4 pcs
Submachine gun .......... 2 pcs
Cartridges .................. 1065 (15 drives)
Engine GAZ-202 .......... 2 pcs.
Gearbox type GAZ-AA ............ 2 pcs
Mover .................. tracked
Driving wheel ............. ahead
Number of tracks ............... 2 x 93 pcs
Suspension ................... torsion bar
Number of track rollers ....... 12 pcs
Number of support / rollers ..... 6 pcs
Radio station type .......... 9-РМ, 12-РТ
Lviv direction, Chernov, 1944