Continuing the theme of creating in the USSR its own combat vehicles based on captured equipment, we decided to talk about one more vehicle, which was created on the chassis of the German Pz. Kpfw. III tank.
A machine that was produced in fairly small quantities, but still mass-produced. Alas, in Russia such machines have not survived in their original form. In Moscow, on Poklonnaya Hill, there is a hybrid sample. Real chassis and modern tower.
The only such machine, which was actually produced during the Great Patriotic War and which took part in hostilities, is in the form of a monument on a pedestal in the Ukrainian city of Sarny. The car was found at the bottom of the river, raised and became a monument.
So, the hero of today's story is the SU-76i SPG.
A machine that is often undeservedly criticized. A vehicle that in terms of firepower was not inferior to the T-34 tank. A machine that was able to replace the completely Soviet SU-76 at the time of revision. A total of 201 SU-76i. But these are 201 heroes and 201 heroic crews.
You should start not with the history of creation, but with the name. The fact is that for most fans of Soviet technology, there are two self-propelled guns. SU-76i and SU-76 (S-1). There are those who will say that there was another SPG - the SU-76 (T-III). Yes, all these cars were in the Red Army. But, in fact, this is one car. Just at different stages of development.
SU-76 (T-III) is just an intermediate designation of the vehicle, which was used at the beginning of the development of the ACS. SU-S-1, in other documents SU-76 (S-1) is the designation under which the vehicle was put into service. SU-76i is a modern name. The letter "and", by the way, means "foreign". We will use the modern designation for ACS.
In the material about the SG-122 ACS, we touched on the topic of further developments of the A. N. Kashtanov Design Bureau. Already during the development of the self-propelled howitzer, it became clear for the designers that the chassis of the PzIII tank could be used to create heavy self-propelled guns without serious modifications. The same SG-122s were clearly overloaded in front. Which created many problems for the crews.
Already in 1942, Kashtanov came up with a proposal to put a 2-mm ZiS-3Sh cannon on the German chassis 76. It was this gun that was installed on the SU-76. In another version, it was proposed to use the F-22USV. Both options were good and bad in their own way. The guns were reasonably well-assembled and had good fire properties. However, there was a drawback that made their use problematic.
Fastening the machine to the floor when aiming the gun both vertically and horizontally led to the fact that gaps appeared between the armor plate and the case of the cabin. The crew was in danger of being hit not only by shells, but also by shrapnel and even small arms bullets.
Kashtanov also considered a classic solution - the use of a curbstone. But in this version, the fighting compartment was reduced, which led to a decrease in the ammunition load of the ACS. The "American" option of placing one of the crew members during combat work outside the vehicle was not even considered.
The best solution was the installation of the S-1 gun mount, which was developed at TsAKB on the basis of the F-34. The gun was installed not inside the wheelhouse, but on the frontal sheet of the hull. For this, the C-1 had a special gimbal frame. The car received the appearance of a familiar self-propelled gun. And the installation of the C-1 was not a problem for the designers.
1942 was a difficult year for the SU-76. The misuse of the machines resulted in huge losses. The vehicle was intended for direct support of the infantry. Agree, it is difficult to object to the commander of the SU-76 when the commander of a rifle unit said "you have armor and a weapon, but my soldiers have only heaven and earth for defense." So the self-propelled guns were burning, rolling out to direct fire against the tanks.
But especially a lot of complaints and, to be honest, deaths, were from two engines, which periodically out of sync and disabled not only the power plant, but also the chassis. Moreover, this phenomenon was so frequent that the command of the Red Army demanded that the ACS be removed from the front and sent for revision.
It was then that the order for the development of Kashtanov appeared! The beginning of 1943. More precisely, on February 3, 1943, the People's Commissariat of Armaments issued an order on the preparation of mass production of a self-propelled assault gun at a trophy base. Naturally, the development of a new ACS was entrusted to the Kashtanov Design Bureau.
By this time, A. N. Kashtanov already had a full-fledged design bureau in Sverdlovsk. And two factories (No. 37 and No. 592), which were subordinated to the design bureau by the same order, significantly accelerated the work. And, as always, there was no time at all. The first prototype was needed on March 1! It was necessary to remake 200 pieces of equipment! Alas, the prototype was not completed until March 6th. And on the same day, his tests began.
The question of the caliber often arises. Why are there such "mood swings" - from 122mm howitzers to 76mm guns? The answer is again in the purpose of the vehicles and the availability of guns in the Red Army. The SG-122 showed that the large-caliber guns for this chassis are heavy. And it's not the business of the infantry support vehicle to smash tanks and fortifications. And for field guns, bunkers and machine-gun nests 76 mm was enough.
Yes, and we did not have a larger, for example, 85-mm, gun. D-5 was just being tested. Although, in fairness, it should be noted that Kashtanov proposed to immediately equip the SPG with precisely these weapons. To which he received an answer (September 14, 1943) with a refusal. It was proposed to "freeze" the project for a while.
Let's take a closer look at the car. Externally, the SU-76i is very similar to the SG-122. However, upon closer examination, it becomes clear that the alterations were still significant. Even though the body is practically preserved in its original form. Naturally, with the exception of the cut off superstructure and tower. Therefore, we will not repeat ourselves.
Let's look at the conning tower. The cabin was assembled from sheets of rolled armor steel. The thickness of the sheets varied. Forehead - 35 mm, sides - 25 mm, feed and roof - 15 mm. Moreover, the upper armor plate was solid and bolted to the sides.
The crew of the vehicle had the ability to defend against enemy infantry using special holes on the forehead, in the sides and in the left aft door of the wheelhouse. The holes for firing from the PPSh (included in the self-propelled gun kit) were closed with special armored dampers. Also, the upper double-leaf hatch could be used for firing. In normal times, this hatch was used for embarkation and disembarkation of the crew.
An interesting solution was found by the designers and to increase the visibility of the crew. It's no secret that this moment was a serious drawback of many Soviet self-propelled guns.
Let's start with the driver. Unlike other combat vehicles, the SU-76i mechanic looked not only forward, but also to the sides. Inspection hatches were located in such a way that in the frontal triplex the driver saw the road, in the side ones what was happening on the flanks. Moreover, each triplex was protected from accidental bullets by a special armored shutter.
For the crew in the wheelhouse it was also possible to inspect the area around. Those holes for firing from the PPSh perfectly played the role of slots for viewing the area. In addition, there was also a PTK-5 commander's panorama. On the whole, the SU-76i surpassed other self-propelled guns of that period in terms of this indicator.
Now let's get back to the C-1 setup. The designers, considering the GAZ reservation option, were unhappy with the complexity of this particular element of the C-1 design. The result of this dissatisfaction was a new molded mask, which allows you to aim the gun within the range from -5 to +15 degrees vertically and + (-) 10 degrees horizontally. Here you simply cannot ignore the deadlines for the delivery of the mask. The designers of the plant # 592 and UZTM developed and presented the mask in 5 (!) Days.
With sighting equipment, the issue was resolved in approximately the same way. The designers adapted the TMFD-7 sight from the ZiS-3 field gun for the new vehicle.
The choice of the weapon had its advantages. The SU could use almost the entire range of 76 mm tank shells. The range of SU-76i ammunition included unitary shots with a steel high-explosive long-range grenade (OF-350, O-350A, F-354), an armor-piercing tracer projectile (BR-350A, BR-350B, BR-350SP), a cumulative projectile (BP-353A), subcaliber armor-piercing tracer projectile (BR-354P), bullet shrapnel (Sh-354, Sh-354T and Sh-354G) and buckshot (Sh-350).
The SU had an impressive ammunition load, which made it possible to fight for a long time without additional supplies. 96 shots for a cannon is weighty. The placement of the ammunition was as follows: 48 shots were in the rear right corner of the wheelhouse on a horizontal rack, 38 in vertical struts along the left side and 10 in a vertical rack along the starboard side.
To protect the vehicle, the armament kit included two PPSh submachine guns (994 rounds of ammunition) and 25 F-1 grenades in pouches. And this is in addition to the crew's personal weapons, that is, TT pistols. Quite enough for short close range combat.
The vehicle entered service on March 20, 1943. And already at the beginning of May, the first SU-76i were in the army. From that time on, the factories stopped sending the SU-76 to the active army. All cars were returned to the factories to eliminate the identified deficiencies.
The assembly of self-propelled guns on a German chassis continued until November 1943 inclusive. In total, they managed to assemble 201 S-1 SUs. By month, they were distributed as follows:
March - 1;
April - 25;
May - 15;
June - 20;
July, August and September - 26 each;
October and November - 31.
Moreover, in August, out of 26 issued SUs, 20 were commanders. Difference from ordinary cars in the communication system. The command vehicles were equipped with more powerful radio stations.
How did the new cars fight? The story would be incomplete precisely without the combat episodes of the use of these SUs. But we will start not with Soviet documents, but with German ones. A document from the archives of the Foreign Armies - East Department of the Abwehr Army Intelligence Service. The dispatch is dated October 25, 1943. The sender is the headquarters of the 1st Tank Army of the Wehrmacht.
"The 177th tank regiment of the 64th mechanized brigade has four companies of 11 vehicles each. These combat vehicles are designated Sturmgeschütz (assault gun) 76mm. They are made on the chassis of a German Panzer III tank with a Maybach engine. The new wheelhouse has a thickness of armor. in the frontal part 3-4 cm, on the sides - 1-1.5 cm. The deckhouse is open at the top. The gun has horizontal guidance angles 15 ° in each direction and vertical guidance ± 7 ° ".
This is just about the SU-76i. More than once in German documents the SU-76i was compared in terms of efficiency with the T-34 tank. Agree, the comparison is more than honorable. In general, no wonder, since the machines were equal in firepower, since the weapon was the same.
Soviet documents from that period are often difficult to examine. The fact is that combat vehicles were not divided by name. The SU-76 could be anything. The main thing is the caliber of the machine gun. Nevertheless, there are reliable facts about the units that used the SU-76i. These are three self-propelled artillery regiments in the 5th Guards Tank Army - 1901st, 1902nd and 1903rd. The place where these vehicles fought is also known. South of Russia and north of Ukraine.
A lot of controversy is caused by the participation of these self-propelled guns in the Battle of Kursk. Alas, no reliable facts about this could be found. At least about the battle in the Prokhorovka area. As there are no references to such participation from other authors. Most likely, the Soviet command took into account the weak armor of these vehicles and did not consider them to be real opponents for the tanks and anti-tank equipment of the Germans. Incidentally, this is precisely what subsequent events indicate. SS were used more on the flanks.
So, the 13th Army of the Central Front, which defended the line in the Ponyri region, initially simply did not enter the existing 16 SU-76i into battle. Even on the most difficult days for defense. These vehicles were in reserve. Exactly until the moment when the Germans broke through the defenses. It was then that the SU-76i appeared at the turn.
We will not talk about specific combat episodes. But the results for the SUs themselves are more than difficult. Of the 16 cars, exactly half were knocked out - 8 units. Of which 3 cars burned down.
It is interesting to read the combat reports from the already mentioned 1902 glanders. The regiment arrived at the 5th Guards on August 2, 1943. The regiment included 15 SU-76i. The regiment received its first baptism of fire only 12 days later. The reason for this delay was the lack of vehicles for the delivery of ammunition and fuel. However, on August 14, the regiment began to take part in the battles.
Practically from 14 to 31 August, the regiment was constantly on the front line and participated in battles and skirmishes with the enemy. There were five serious battles. In battles, the regiment destroyed two tanks, nine guns, 12 machine-gun nests and up to 250 enemy soldiers.
On August 20, the Germans began to withdraw. SU-76s began to pursue them. This is where the advantage of the lighter SUs over tanks came into play. The speed of self-propelled guns was higher. As a result, six SU-76i destroyed three more tanks.
However, fierce battles, especially with tanks and self-propelled guns, knocked out self-propelled guns with a very high intensity. Judging by the reports, the main losses of the self-propelled guns were suffered in September 1943. It was then that the machines began to be used for their intended purpose - to support the infantry. Cars were attached to rifle regiments and battalions in quantities of 2-7 pieces. And they went on the attack on the German defense saturated with PTS.
Be that as it may, but these SU made their contribution to the overall victory over the enemy. Yes, they fought for only a year. But it was they who gave our engineers and designers time to eliminate the SU-76's shortcomings and equip our army with good machines. By the way, in terms of the number of units produced, the firm second place (after the T-34) is occupied by the Su-76. Soviet design.
The effectiveness of these self-propelled guns was really great. In one of the sources, we found such an interesting fact, for the reliability of which we cannot vouch, but … in one of the battles of 1944, a German self-propelled gun was destroyed by our troops. After inspection, it turned out to be the SU-76i! It turns out this car was a double trophy. First ours, then German. What does not happen in war …
Well, the traditional performance characteristics of the heroine, the SU-76 and the 1943 model:
Weight: 22,500 kg.
Crew: 4 people.
Dimensions:
Length: 6,900 mm.
Width: 2,910 mm.
Height: 2,375 mm.
Clearance: 350 mm.
Armament:
- 76, 2-mm cannon S-1, 96 rounds of ammunition.
- 2 PPSh submachine guns, 994 ammunition (14 disks).
- 25 F-1 grenades.
Reservation:
body forehead: 30 mm.
cutting forehead: 35 mm.
side of the case: 30 mm.
wheelhouse side: 25 mm.
feed, roof, bottom: 15 mm.
Engine: Maybach HL120TRM, 12-cylinder, liquid-cooled, 300 hp
Speed: 50 km / h on the highway.
In store down the highway: 180 km.
Overcoming obstacles:
Climbing angle: 30 °.
Wall height: 1, 00 m.
Fording depth: 1, 00 m.
Moat width: 2, 10 m.
