THE MASS “SELF-PROPELLED GUN” OF THE GREAT PATRIOTIC

An important component of the armored weapons of the red Army during the great Patriotic war was self-propelled artillery. As you know, the red Army did the heavy (SU-152, ISU-152 and ISU-122), medium (SU-122, SU-85 and SU-100) and light (SU-76 and SU-76M) self-propelled guns. The process of creating the latter was launched on 3 March 1942 after the formation of the special Bureau of self-propelled artillery. It was created on the basis of the 2nd Department of the NKTP (engineering), chief of which S. Ginsburg A., on starting from September, 1941, put forward proposals for an assault and anti-aircraft self-propelled gun on the basis of outdated and light tanks.

Apparently, by the spring of 1942 he was able to reach the management of the Commissariat. The special Bureau was instructed to develop a common chassis for ACS with the use of automobile units and assemblies of tanks T-60. Based on this chassis was intended to establish a 76-mm self-propelled gun support and a 37-mm anti-aircraft self-propelled gun. In may – June 1942 the prototypes of the assault and anti-aircraft self-propelled guns were made by plant n 37 NKTP and enrolled in the trial. Both cars have the same chassis, which was used for assemblies of tanks T-60 and T-70. Tests in General were successful and in June 1942 the GKO ordered the speedy development of machinery and the manufacture of the first production batch for army trials. However, soon unfolded large-scale fighting on the southern flank of the Soviet-German front demanded plants Narkomtyazhprom increasing production of tanks and SAU turned.

Again to develop samopoznavatelnykh installations, or as they were called, Artamonov, returned in the fall of 1942. October 19 GKO adopted a decision on the preparation of serial production of assault and anti-aircraft Artamonov with guns of calibre from 37 mm. to 152 by assault ACS was defined Zavod No. 38 of them. Kuibyshev (Moscow) and GAS. The completion dates were set hard – by 1 December 1942 was required to report in t-bills on the results of tests of new combat vehicles.

In November, experienced instances of assault SPG SU-12 (plant No. 38) and GAZ-71 Gorky automobile plant went to trial. The layout of the machines were generally consistent with the proposed special Bureau NKTP back in the summer of 1942 two parallel twin engine in the front and fighting compartment in the stern. However, there were some nuances. So, the SU-12 engines were on the sides of the vehicle, and the driver was placed between them. The GAZ-71 both engines are shifted to starboard, placing the driver closer to the left. In addition, Gorky was placed the wheels back to them through the whole car was stretched a long propeller shaft, which significantly reduced the reliability of the transmission. The result has not kept itself waiting – November 19, 1942 the Commission, which conducted tests that rejected the sample of the plant and recommended the adoption of the SU-12 plant No. 38 with regard to the elimination of the identified test deficiencies. However, further events developed on a widespread during the war years, a sad scenario.

2 December 1942 the GKO decided on the deployment of serial production of SU-12 and by 1 January 1943 the first batch of 25 cars of the SU-76 (is the army designation was given ACS) were sent to the newly formed learning center of self-propelled artillery. All anything, but the state tests of the new machine began only on 9 December 1942, ie after the start of series production. The state Commission recommended that SAU to adopting, but again, after elimination of shortcomings that few people were interested. For the imperfection of the design of the combat vehicle, as it was not time, his blood paid gunners.

After a 10-day military operation, most of the SU-76 went down because of breakdowns of gearboxes and main shafts. Attempt to improve the situation by strengthening the shafts nor to no avail. Moreover, such machines fail even more often. It became apparent that transmission of the SU-76 has a fundamental design flaw, which was a parallel installation of the two coupled engines operating on a common shaft. This scheme of transmission resulted in the shafts of resonant torsional vibrations. Moreover, the maximum value of the resonance frequency were the most stressful mode of operation of the engine (movement in 2nd gear on the road) that led to their early failure. The elimination of this defect took a lot of time, so on March 21, 1943 production of the SU-76 was suspended.

In the subsequent “debriefing” by the Commission under the chairmanship of I. M. Salzman, the main culprit was the designated head of OGK NKTP S. A. Ginzburg, who was removed from office and sent to the front head of the maintenance Department of one of the tank hulls. Looking ahead, we say that Stalin, having learned about it, did not approve such decision and ordered to revoke talented designer from the front, but it was too late – Ginzburg died.

However, before sending it to the front Ginzburg proposed a solution that allowed largely to solve the problem. Between the engines and transmissions were installed two elastic coupling, and between the two main gears on a common shaft – a friction slip clutch. This solution managed to reduce the accident rate of combat vehicles to an acceptable level. Such self-propelled guns, which received factory index SU-12M, went into production in may 1943, when resumed production of the SU-76.

Its baptism of fire of the SU-76 was received in February 1943 during the fighting in the area Sordini (Volkhov front). In these battles took part in two self-propelled artillery regiment – 1433 and 1434. These regiments had a mixed composition, armed with four batteries of the regiment consisted of the SU-76 (a total of 17 units, including the car of the commander of the regiment), and two SU-122 (8 units). However, this organization was not justified, and since April 1943, self-propelled artillery regiments moved on to a new organization. Now the shelves were completed with the same type of combat vehicles in the regiment of SU-76 had 21 ACS and 225 personnel.

I must say that the SU-76 was not particularly popular among soldiers. In addition to the permanent damage of the transmission affected and other shortcomings of layout and design. Sitting between the two motors, the driver was poisoned by fumes from the heat even in the winter and cut out by the noise of two asynchronously working transmission controlled by one rocker was quite difficult. It was hard for the crew closed the cockpit armor as the SU-76 had no exhaust ventilation of the fighting compartment. This shortcoming became especially apparent in the hot summer of 1943. Nanocuries gunners in the hearts had called SU-76 “gas chamber”. Already in the first days of July NKTP recommended directly to the troops to dismantle the roof of the conning tower down to the apron periscopic sight. This innovation was universally welcomed by crews. However, the age of the SU-76 was measured, it replaced was more reliable and perfect machine. Total produced 560 SU-76, which met in the army until the middle of 1944.

As for a more reliable machine, it was the result of a competition announced by the NKTP leadership on the creation of a light assault SPG, armed with 76-mm divisional gun. In the competition participated and GAS plant No. 38.

Gorky proposed a draft SAU GAZ-74 chassis of a light tank T-70. The machine was equipped with a single engine VMS-80 or American TEXTS. As the weapons were to be used 76-mm gun s-1, created on the basis of the tank gun f-34.

The plant number 38 decided to use as the power plant of the propulsion unit GAE-203, T-70, which consisted of two engines GAZ-202 connected in series. Earlier, the use of this unit on the ACS was considered unacceptable because of its great length. Now, the problem tried to be solved by a more careful layout of the fighting compartment, change the design of a number of nodes, in particular through the levels.

Unlike SU-12 on a new machine SU-15 gun ZIS-S were installed without the bottom of the machine. The SU-12 instrument was used with minimal changes, not only with the bottom machine, but with a cropped frame (on cars of late releases, they were replaced by special spacers), which goes into the side. The SU-15 from the field gun was only used a swinging part and an upper machine, which was mounted on a transverse U-shaped beam, riveted and welded to the sides of the fighting compartment. Combat tower was still closed.

Except the SU-15 factory No. 38 offered two SU-38 SU-16. Both of them were distinguished using the standard base of the T-70 and SU-16, in addition, fighting compartment, open at the top.

Testing of new Artamonov was conducted at the Gorokhovetsky training ground in July 1943, in the midst of the battle of Kursk. The most successful of the military used SU-15, and recommended for serial production after some modifications. Required to facilitate the car, which was done by removing the roof that at the same time solved all the problems with ventilation and also facilitate embarkation and disembarkation of the crew. In July 1943, the SU-15 army under the designation SU-76M was adopted by the red Army.

In its layout, the SU-76M belonged to the type of semi-self-propelled units. The driver was located in the bow of the hull along its longitudinal axis in the Department of management, which was in the transmission Department.
In the rear of the hull was fixed partially open top and rear armor of the cockpit from the crew compartment. The case of ACS and cockpit welded or skladyvalas from rolled armor plates with thickness 7-35 mm, installed at different angles of inclination. Booking recoil devices of the gun had a thickness of 10 mm. For landing of the driver in the upper front hull there was a hatch, skryvavsheysya cast armor cap with a periscope surveillance device, borrowed from the tank T-70M. In the fighting compartment to the left of the gun is the gunner on the right – the commander of the installation, the loader located in the left rear of the fighting compartment. For planting these crew members and load ammunition was meant for the door at the rear of the fighting compartment. From atmospheric precipitations the fighting compartment was closed with a canvas awning.

In front of the fighting compartment was welded to the cross member box shape, which is attached to support the top of the machine 76-mm gun ZIS-S Gun mod. 1942 had the V-vertical shutter and lavomatic opernogo type. The length of the gun barrel was 42 calibres. Angles pointing guns ranged from -5° to +15° vertically and 15° to the left and right horizontally. For direct fire and from the closed position used regular periscope sight guns (Hertz panorama). Rate gun with the correction of interferences was 10 RDS./min., when doing a quick fire – up to 20 RDS./min. Maximum firing range was 12 to 100 m, range direct fire – 4,000 m, the direct fire range 600 m. Trim bookings swinging gun parts was carried out by installing a 110-kg counterweight, fastened to the cradle back hem.

Gun ammunition consisted of 60 unitary shots.

Armor-piercing tracer projectile with a mass of 6.5 kg had an initial speed of 680 m/s At distances of 500 and 1000 meters, he fired a normal armor thickness 70 and 61 mm, respectively. Armor-piercing projectile with a mass of 3 kg and an initial velocity of 960 m/s at distances of 300 and 500 m past 105 – and 90-mm armor.

Auxiliary armament of the SU-76M consisted of 7.62-mm machine gun DT, which is carried in the fighting compartment. For firing the gun used armor flaps close the loopholes in the sides of the wheelhouse, and in her right front armor plate of the gun. Ammunition gun consisted of 945 rounds (15 disks). In addition, in the fighting compartment fit two pistols-machine guns PPSH and 426 cartridges (6 disc), and 10 hand grenades f-1.
In the middle of the hull in the engine compartment closer to the starboard side was installed the power unit GAE-203 consisting of two connected in series 6-cylinder gasoline engines GAZ-202 with a total capacity of 140 HP Crank shafts of the engines were connected by a coupling with elastic sleeves. Ignition system, lubrication system and power supply system (except tanks) for each motor was independent. In the cleaning system engine used two dual inertial air cleaner-oil bath type. Capacity two fuel tanks, located in the Department of management, was 412 L.

Transmission of ACS consisted of double-disc main clutch dry friction, four-speed transmission ZIS-5, main gear, two side multi-disc clutch with floating band brakes and two final drives.

In the undercarriage of the vehicle in relation to the same Board consisted of six rubber-coated rollers, three rollers, drive sprocket at the front with a removable ring gear and guide wheel, a similar device for supporting the rink. Suspension – personal torsion. Melkosofta caterpillar cycloid gear included 93 track width 300 mm.

Self-propelled gun SU-76M:

1 – 76 mm gun ZIS-S; 2 – us swinging gun parts; 3 – cutting; 4 – valve loopholes for firing personal weapons; 5 – a steering wheel; 6 – support roller; 7 – supporting the rink; 8 – driving wheel; 9 – the muffler; 10 – shutters; 11 – transmission of the hatch cover; 12 – Luke air flow units; 13 – cover newmotor-tion of the hatch; 14 – cover for access to the stopper of the gun in its stowed position; 15 – cover of the front of the gas tank 16 – cover the rear of the fuel tank; 17-valve of the loopholes of the commander; 18 – the commander’s seat; 19 – seat gunner and loader (on the March); 20 – a stopper of a cannon on the March; 21 – plug the loopholes for firing from a revolver; 22 – headlight; 23 – cover of the driver’s hatch; 24 – valve hole for hand crank; 25 – the breech of the gun; 26 – feed door; 27 – rear lamp; 28 – a window air. On the bottom view chassis components conventionally not shown.

Combat weight of the machine was 10.5 t Maximum speed limited to 30 km/h instead of the estimated 41 km/h, since the greater the speed began beating the left axle main gear. The reserve fuel was 320 km by road and 190 km by a dirt road.

In the fall of 1943, after the complete cessation of the production of light tanks T-70, SU-76M is connected GAS and factory No. 40 in Mytishchi near Moscow. From 1 January 1944, the parent company of the SU-76M was the Gorky automobile plant and the chief designer of ACS were assigned to H. A. Astrov. Under his leadership, the Gas already in the autumn of 1943, work was conducted on improving self-propelled and adapted her design to mass production. Changes were made in the design of the SU-76M in the future. So, cars of late releases received high rear sheet of the fighting compartment with two embrasures and a larger door, for mounting a machine gun in the aft part of the cabin appeared a pipe welded to its right and left sides, began to use the loopholes of the new form, more adapted for firing from a machine gun, etc.

Serial production of SU-76M continued until 1946. In all there were 13 732 self-propelled guns of this type, including in the great Patriotic war, -11 494 units.

Like its predecessor SU-76, SU-76M has arrived on arms of light self-propelled artillery regiments, which during the war was formed by a few dozen. In early 1944 began the formation of self-propelled artillery battalions. The staff of the division consisted of 12 (later 16) SU-76M. Such divisions were included in the several dozen infantry divisions instead of separate istrebitelnitsy divisions. Since January 1944 began the formation and light self-propelled artillery brigade (SU-76) RVGK. In this brigade there were 60 sets of the SU-76M, five tanks T-70 and three us armored scout МЗА1.
Only formed four teams.

The layout of self-propelled guns SU-76M:

1 – transmission hatch cover; 2 – cleaners; 3 – transmission; 4 – main gear with side clutches and brakes; 5 – levers; 6 – engine; 7 – driving wheel; 8 – tank; 9 – boxes of ZIP; 10 – feed door; 11 – the flywheel the rotary mechanism; 12 – flywheel lifting mechanism; 13 – panoramic sight; 14 – lakatnik; 15 – recoil brake; 16 – compensating mechanism; 17 – crossmember

Speaking about the combat use of the SU-76M, it should be emphasized that at the initial stage these ACS, as well as all the others, was used quite illiterate, mostly as tanks. Most of the commanders of tank and combined arms had no idea about the tactics of self-propelled artillery and was often sent these shelves literally to the slaughter. Misuse, and the fact that at first the crews of the ACS recruited former tankers (comparison between tanks and light armored vehicles, self-propelled guns was clearly not in favor of the latter) caused a negative attitude to the SU-76, which found its expression in soldiers ‘ folklore.

Over time, however, the attitude of the car changed.

First, changed the application of tactics, and second, the crews had not had a tank of the past, very different looked at their cars. They are not considered a disadvantage, for example, the lack of a roof. On the contrary, due to this facilitated observation of the terrain, it was possible to breathe normally (ventilation, is known to have been a big problem for Soviet tanks and enclosed ACS), it was possible to conduct long-term intensive fire without the risk of choking. Thus, in contrast to the field gun ZIS-W, the calculation of the SU-76M was closed on the sides and partially behind bullets and shrapnel. In addition, the lack of a roof gave the opportunity to the crew, in any case, that part of it which was in the fighting compartment, quickly leave the car in the event of its failure. A hostage in such a situation, alas, remained the driver. Best of all protected, he was killed more often than other gunners.

The advantages of SU-76M include good maneuverability and low noise, speed, reliability (unit GAE-203 confidently worked 350 hours without serious damage), and most importantly – a wide versatility. Light self-propelled gun brought to counter-battery, support the infantry in defense and attack, combat tanks, etc. all these tasks self-propelled guns to cope. Reliability and good handling characteristics of the SU-76M were particularly in demand in the final stages of the war. Quick and nimble, bristling with captured machine guns, the SU-76M is often included in the composition of the forward detachments in pursuit of the retreating enemy.

SU-76M late production during a parade in Riga November 7, 1947

Together with the attitude has changed and folklore, reflected in the names and in the names of military vehicles: “Swallow”, “Bold”, “snowflake”. SU-76M became known as “crackers” and very viscoelatic “Colombina”.

SU-76M was the second mass Soviet armoured fighting vehicle of the period of the great Patriotic war. More there were only “thirty”!

Light artillery was in service with the Soviet Army until the beginning of 1950-ies. The last scene of their combat use was Korea. A few dozen of SU-76M was in service with the Korean people’s army the beginning of the war. There were these machines, and in parts of the Chinese people’s volunteers. However, the use of these machines in the Korean war not been a great success. Low level of training of personnel, the enemy’s superiority in tanks, artillery and aircraft led to the fact that the SU-76M was quickly knocked out. Losses, however, were met through supplies from the Soviet Union and the end of the war the North Korean troops had 127 self-propelled guns of this type.

However, the age of these vehicles have been measured as age of the divisional artillery 76 mm caliber.