Tuesday 10 December 2013

SU-76I

I briefly mentioned various Soviet re-arming projects in the past, so let's take a closer look at a successful one, the SU-76I. As was the tradition at the time, the 76 index stands for the caliber of the gun. The I stands for Inostrannaya (foreign). The vehicle was also referred to as SU-76 (S-1) after its gun assembly index, or Sturmgeschütz 76 in German intelligence documents.

"Mass production model of a SU-76I SPG on the chassis of a captured PzIII, designed by factory #37"
CAMD RF 38-11369-1

The Red Army experienced a need for light SPGs armed with 76 mm guns as early as Fall of 1941, but that need was not met until December of 1942, when production of the SU-76 SPG began. Sadly, production was dragging slowly, and the vehicle ultimately ended up a bust. The need for a light SPG didn't go anywhere. In order to meet the army's needs, factory #37 converted PzIIIs and StuGs to use an F-34 76 mm gun in a fixed casemate.

"According to GOKO decree #2758 from January 18th, 1943, factory #37 and TsAKB NKV designed and built an experimental prototype of a SU-76I SPG on the chassis of a captured StuG SPG and PzIII tank, using a stock 76 mm F-34 tank gun.

In March of 1943, the vehicle was tested at the Sofrino proving grounds over 280 kilometers of travel and 434 rounds.

The experimental prototype passed trials, and was recommended for service in the Red Army. The SU-76I SPG was accepted into the Red Army by GOKO decree #2758ss from January 18th, 1943."
CAMD RF 38-11369-1

The SU-76I was a continuation of the SG-122 design, along with some improvements, like sloped armour. Originally, the project called for a ZiS-3 gun (which was later installed on the SU-76), but the only way to provide proper mantlet protection was to use an F-34 in a special frame (indexed S-1). Armour reached 50 mm in the front. The SPG kept its 300 hp Maybach engine. Due to the fact that vehicles of different makes and models served as a base for the SU-76I, various SPGs of this type can look slightly different. It is not known exactly how many of these vehicles were made from StuGs and how many were made from PzIIIs. According to M. Svirin, the total amount of SU-76I and SG-122 vehicles built with captured StuG hulls only equalled eight.

An interesting point: the decree that accepted the SU-76I into service pre-dates its trials by a month and a half. The Red Army must have really needed those SPGs. 611 SU-76I vehicles were built (compared to 550 of the original SU-76 production run).

By the end of 1943, there were almost no SU-76Is left in the army, and in the beginning of 1944, the last of them were transferred to training units. To this day, two SU-76Is remain: an authentic one at Sarny, Ukraine, and one with a restored casemate at the Poklonnaya Gora museum in Moscow. LiveJournal user starcom68 took very many photos of the former one.

2 comments:

  1. It would be interesting to see if there were any "recaptured" SU-76i by the Germans?

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  2. It happened : http://beutepanzer.ru/Beutepanzer/su/su-76i/su-76i.htm

    Interesting article on a very original TD. Thank you!

    Vautour2b

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