Wednesday 28 May 2014

SU-76 Review

A lot of people claim that Soviet evaluators are too harsh on foreign vehicles, such as the Churchill or Chaffee, but that has nothing to do with the origin of the vehicles. For instance, here is a report on the SU-76 (SU-12, not its much more popular successor) that is just as unrelenting.

"VII. Conclusions
  1. Accuracy and practical rate of fire, shooting on the move or stationary from the ZiS-3 gun in the SU-76 SPG are within calculated norms. The aiming mechanisms and Hertz panorama do not provide the gunner with adequate working conditions. The periscopic observation devices are unsatisfactory, and their location does not result in sufficient observation range. The ammunition rack is incompletely developed, shells are not securely affixed and fall out when moving.
  2. The maximum and average speeds are satisfactory. The SPG is less maneuverable than the T-70, and is insufficient. The fuel and oil expenditure is normal.
  3. SU-76 SPGs contain a series of design and production defects, which results in an unreliable vehicle in general and the transmission and suspension components in particular.
    1. The gearbox from the GAZ-AA truck, when subjected to stresses such as those that come from a jammed track, is destroyed due to breaking gear teeth in the first intermediate gear.
    2. The issue of preventing the track from jamming on the drive wheel when turning is not resolved, the teeth on the drive wheel do not match the track openings. The deflectors do not prevent tracks from jamming and become useless within 250-300 km of motion.
    3. The weakened final drives, flexible clutches, and supplemental friction clutch do not save the transmission from breaking.
  4. In order to prevent aforementioned breakdowns, SU-76 SPGs must be driven in accordance with the following rules:
    1. Turn smoothly, without bursts, as turning rapidly will result in gearbox breakages.
    2. After 20-25 km of march and before heading out, adjust tracks, inspect and tighten idler carriers and support idlers.
    3. Before heading out and when stopped on a march, inspect the splinting of gearbox mechanissm and main friction clutches, keep an eye on the condition of the sliding bars and rods in the gearbox, check the work of the blocking mechanism.
VIII: Summary
  1. SU-76 SPGs released in April by factory #38 did not pass warranty trials due to design defects of the transmission and suspension.
  2. A qualified driver that performs careful maintenance can be expected to get 200-400 km of reliable service life our of a SU-76."
CAMD RF 38-11355-1553

Of course, such an unacceptable vehicle did not remain in production. It was discontinued and a new, more reliable SU-76M took its place.

2 comments:

  1. You need to post that archive doc I gave you on the IS-7. Now that is harsh.

    ReplyDelete
  2. wow this tank is awesome.

    ReplyDelete