Soviet Union (1942-45)
Self-propelled gun – 181 built

The Red Army’s Panzer III 76mm SPG

The SU-76i was built or re-built by the Soviets because, while speeding up their huge production of tanks, they still faced shortages in certain areas. Furthermore, the original SU-76 model had several flaws. They were unreliable and not a pleasure to drive, so much so the Soviet tankers named it “the Bitch”. During the fall of Stalingrad, the Soviets had captured several StuG and Panzer III tank chassis in relatively good condition. With the thought of rearming them with bigger Soviet guns, they were shipped back to factory 37 at Sverdlovsk.

SU-76i self-propelled gun was armed with a 76.2 mm (3 in) S-1 anti-tank gun
The SU-76i self-propelled gun was armed with a 76.2 mm (3 in) S-1 anti-tank gun

By early 1943, the Soviets had some 300 StuGs and Panzer IIIs and decided to mount 76.2 mm (3 in) Zis-3sh guns into their hulls. The resulting non-turreted tank destroyer was meant to fill in the gaps where SU-76s had been destroyed or sent back for repairs. The initial design was to mount the 76.2 mm on a semi traversable pedestal similar to early Italian TD’s, but this left the crew very exposed, more so than the SU-76, and would have left the tank defenceless against close artillery blasts and shrapnel. The gun was then to be mounted in a fixed casemate with limited traverse and a shorter, but more powerful 76.2 mm S1 gun was chosen.

Hinged pistol holes with an armored cover were inserted in the upper slab sided armor plate. This enabled the crew to fire their hand held weapons at enemy infantry that were getting too close. A vision slit was fitted above the pistol hole.

The hull mounted machine gun found on the Panzer III tank was removed on the SU-76i SPG. The driver sat on the left and had limited vision. He could only see directly ahead and to his left through an armored vision slit.

The prototypes were ready by March 1943 and sent for testing to the Sverdlovsk grounds. Even while the weather was extremely cold, with temperatures at -35 degrees Celsius, the new tanks destroyers, with their durable German components, passed the test. A few modifications were made, including oil heaters to stop the engine from freezing and other minor changes to batteries and sights. They were given the designation SU-76i, with the letter ‘I’ standing for ‘Inostrannaya’ or foreigner. It seems the hatred for Germans was even placed upon their equipment. The new SU-76i would have to prove itself.

This Su-76i SPG does not have the external fuel tanks fitted to on the rear of the vehicle or the armoured engine hatch covers.
This Su-76i SPG does not have the external fuel tanks fitted onto the rear of the vehicle or the armored engine hatch covers.

Some 181 of these tank destroyers and 20 command vehicles were built by November 1943. Production was stopped after that date, mainly because, by then, the original SU-76 had all of its bugs rectified and was running well. The other reason was cost; stripping down and rebuilding a knocked out or captured Panzer III was harder than building a new SU-76, which could now be easily repaired and updated.

The SU-76i self-propelled gun was in some ways better than the SU-76 standard version. It had better armor, with 35 mm (1.38 in) of frontal plate, 25 (1 in) on the sides and about 15 mm (0.59 in) on the back. The SU-76 on the other hand, had only enough armor to stop small arms fire and splinters. The second and more important thing to those that drove it was that the SU-76i was fully enclosed. This made a huge difference to morale in the biting Russian winds and harsh temperatures present during that winter, and SU-76i crews could stay snug inside the vehicle by keeping the engine ticking over.

This Su-76i SPG does not have the external fuel tanks fitted to on the rear
This Su-76i SPG did not have the external fuel tanks fitted onto the rear of the vehicle

The superstructure itself was of a welded design which, while more expensive than bolting, was necessary as the tank was not being made out of pre-fabricated parts, but was rather a chop shop job. Only the roof was bolted on, and this as a single piece to increase its strength. It was not unheard of for crew to remove this roof during the hot summer months and use the vehicle as an open topped tank.

The command tanks did not remove their roof and kept the original German commander cupola in situ. Their left ammunition bank was removed in order to fit an extra radio with improved signal capabilities in place.

Very few modifications were made or needed to the SU-76i. A reinforced shield was added over the mantle to stop stray rounds, and small changes were made to the suspension, as the Soviets had no natural replacement parts for this. The torsion suspension, on the other hand, was durable and lasted well. Despite its radical facelift and altered parts, the SU76i handled very well and was popular with its crews, despite its original heritage.

SU-76i SPGs were used on the Eastern Front during the winter of 1943-44
SU-76i SPGs were used on the Eastern Front during the winter of 1943-44

Active Service

The SU-76i self-propelled guns fought from spring 1943 until early spring 1944. They were part of the Soviet armored forces at the battle of Kursk, where they were attached to the 5th Guards, 13th Army of the Central Front. Eight were lost and three totally burnt out.

During the assault on Orel, in late July 1943, sixteen SU-76i SPGs were deployed in operations. The Voronezh front saw the same number in action. Many were destroyed in the German counter attack near Prokhorovka. They saw action in South Russia and northern Ukraine.

After 1944, unlike many captured German tanks that were scrapped immediately when they were of no further combat use, the SU-76i had earned a warm place in the hearts of a few and as such the surviving 10-15 vehicles went on to be training vehicles at tank and artillery schools.

SU-76i Command Vehicle with Panzer III cupola fitted to the roof
SU-76i Command Vehicle with Panzer III cupola fitted to the roof

The SU-76i command vehicle version

Twenty SU-76i self-propelled guns were constructed as command vehicles. They had an improved high powered radio and a Panzer III commander’s copula fixed on the roof. Less ammunition was carried to give extra room for the radio and maps.

The Gun

The 76.2 mm (3 in) S1 gun could fire high explosive HE shells, as well as armor piercing rounds. Firing as an artillery gun using HE shells, it had a maximum range of 13.29 km (8.25 miles). Its armor piercing rounds could penetrate 75 mm (2.95 in) of armor plate at a distance of 500 m and 82 mm (3.23 in) at 100 m range, when the armour was at a 90 degree angle. It could not penetrate the front armor of a Tiger tank, but could knock out a Panzer III or IV tank.

An article by Ed Francis

Specifications

Dimensions (L-W-H) 5.56 x 2.90 x 2.5 m
( 18’3″ x 9’6″ x 8’2″)
Crew 4 (driver, commander, gunner loader)
Propulsion 12-cylinder Maybach HL120 TRM, 296 bhp
Top road speed 40 km/h (25 mph)
Operational Range 165 km (103 miles)
Armament 76.2 mm (3 in) S-1 gun with 48 shells
Hull Armor Front 30 mm, sides 30 mm, rear 20 mm (1.18, 1.18, 0.8 in)
Upper Armor Front 35 mm, sides 25 mm, rear and roof 15 mm (1.38, 1 ,0.59 in)
Production Around 181 SU-76i
+20 Command Vehicles

Sources

aviarmor.net
valka.cz
Pejčoch: Obrněná Technika
The SU-76i on Tank-Hunter.com
The SU-76M on Wikipedia
Battlefield.ru
The SU-76 on WWIIVehicles.net

Battle of Kursk SU-76i attached to the 5th Guards.
Battle of Kursk SU-76i attached to the 5th Guards.

SU-76i in winter camouflage, Eastern Front, 1943.
SU-76i in winter camouflage, Eastern Front, 1943.

SU-76i command tank variant with Panzer III tank cupola fixed to the roof.
SU-76i command tank variant with Panzer III tank cupola fixed to the roof.

Gallery

Soviet SU-76i SPG, Eastern Front, Winter 1943-44
Soviet SU-76i SPG, Eastern Front, Winter 1943-44

Only the command version of the SU-76i SPG was fitted with a cupola - Eastern Front, Winter 1943-44
Only the command version of the SU-76i SPG was fitted with a cupola – Eastern Front, Winter 1943-44

Rear view of a SU-76i SPG. Notice the large crew hatch, armored engine hatch covers and external fuel containers.
Rear view of a SU-76i SPG. Notice the large crew hatch, armored engine hatch covers and external fuel containers.

Surviving SU-76i SPGs

This SU-76i Soviet SPG can be found in the Central Museum of the Great Patriotic War 1941 - 1945, Park Pobedy, Moscow Russia
This SU-76i Soviet SPG can be found in the Central Museum of the Great Patriotic War 1941 – 1945, Park Pobedy, Moscow Russia.

The SU-76i driver could only see straight ahead and to his left. Notice the vision slit above the covered pistol hole on the left side of the armored casement.
The SU-76i driver could only see straight ahead and to his left. Notice the vision slit above the covered pistol hole on the left side of the armored casement.

The SU-76i Soviet SPG was armed with a 76.2 mm (3 in) anti-tank gun. It is missing the additional gun shield and dust cover.
The SU-76i Soviet SPG was armed with a 76.2 mm (3 in) anti-tank gun. It is missing the additional gun shield and dust cover.

Surviving SU-76i self-propelled gun used as a war memorial in Sarny, Rivne Oblast, Ukraine.
Surviving SU-76i self-propelled gun used as a war memorial in Sarny, Rivne Oblast, Ukraine.

SU-76i Command Tank replica at the Museum of Military Equipment Battle Glory of the Urals, Verkhnyaya Pyshma, Sverdlovsk, Russia
SU-76i Command Tank replica at the Museum of Military Equipment Battle Glory of the Urals, Verkhnyaya Pyshma, Sverdlovsk, Russia

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2 Responses to SU-76i

  1. Corentin says:

    At the begining you say that only 121 were built and after 181 were built, is it an error ?

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