Friday, 8 October 2021

T-34 Rate of Fire Trials

 "March 1st, 1941
Approved by Proving Grounds Chief Colonel Romanov

Report on the experimental driver's observation device, ammunition racks, and commander's and loader's seats of the T-34 tank

...

Program of T-34 ammunition rack and rate of fire trials

1. Purpose of trial

  1. To determine the practical rate of fire in various conditions of operation.
  2. To determine the convenience of using the new ammunition rack.
  3. To test the convenience of loading with the loader's seat folded
2. Conditions of trial
  1. Task #1: firing from standstill at a target. The tank's angle from the target is 0 degrees. The elevation is 0-3 degrees. The range is 1000 meters. Ammunition from bin #3 on the right side is used. 9 shots fired.
  2. Task #2: firing from standstill at a target. The tank's angle from the target is 0 degrees. The elevation is 0-3 degrees. The range is 1000 meters. Ammunition from bins #5 and #7 on the left side is used. 9 shots fired.
  3. Task #3: firing from standstill at a target. The tank's angle from the target is 90 degrees. The elevation is 0-3 degrees. The range is 1000 meters. Ammunition from bin #2 on the right side is used. 9 shots fired.
  4. Task #4: firing from short stops at a target. The tank's angle from the target is 0 degrees. The range is 1200 meters. The tank's speed is 8-10 kph. Ammunition from bins ##4, 6, and 8 is used. 24 shots fired.
  5. Task #5: firing from short stops at a target. The tank's angle from the target is 0 degrees. The range is 1000 meters. The tank's speed is 8-10 kph. Ammunition from bins ##3, 4 is used. 15 shots fired.
...

Determination of the rate of fire

Meteorological conditions: cloudy, visibility 1300-1500 meters. Snowfall. Ambient temperature -8 degrees.

Conditions: HE shells loaded in bins are fired. The time is counted from the command "fire" to the last shot. The gun is aimed after every shot.
  1. Task #1
    1. Firing from standstill. Angle 0 degrees. Ammunition in a bin on the right side.
    2. 9 shots fired.
    3. 2 minutes 23 seconds spent.
    4. Misfires: 2.
    5. Trigger jammed: 10 seconds to correct.
    6. Average time to load and fire one shell: 15.9 seconds.
  2. Task #2
    1. Firing from standstill. Angle 0 degrees. Ammunition in a bin on the left side.
    2. 9 shots fired.
    3. 3 minutes 9 seconds spent.
    4. Misfires: none.
    5. Trigger jammed: 5 seconds to correct.
    6. Average time to load and fire one shell: 21 seconds.
  3. Task #3
    1. Firing from standstill. Angle 90 degrees. Ammunition in a bin on the right side.
    2. 9 shots fired.
    3. 2 minutes 18 seconds spent.
    4. Misfires: 1.
    5. Trigger jammed: 5 seconds to correct.
    6. Average time to load and fire one shell: 15.3 second.
  4. Task #4
    1. Firing from short stops. Angle 0 degrees. Ammunition in a bins on the right side.
    2. 24 shots fired.
    3. 9 minutes 25 seconds spent.
    4. Time spent on stops:
      1. First stop: 35 seconds (two misfires because of the trigger mechanism).
      2. Second stop: 15 seconds.
      3. Third stop: 15 seconds.
      4. Fourth stop: 11 seconds.
      5. Fifth stop: 24 seconds (trigger fault, 5 seconds to correct).
      6. Sixth stop: 24 seconds (trigger fault, 5 seconds to correct).
      7. Seventh stop: 45 seconds (two misfires because of the trigger mechanism).
      8. Eighth stop: 55 seconds (misfire, 35-40 seconds to correct).
      9. Ninth stop: 13 seconds.
      10. Tenth stop: 20 seconds.
      11. Eleventh stop: 26 seconds (trigger fault, 5 seconds to correct).
      12. Twelfth stop: 30 seconds (trigger fault, 5 seconds to correct).
        The tank was stopped when the gun was ready to fire. Overall the tank travelled for 350 meters. With the existing ammunition racks it took 12-15 minutes to complete this exercise.
  5. Task #4=5
    1. Firing from short stops. Angle 0 degrees. Ammunition in a bins on the right side.
    2. 16 shots fired.
    3. 5 minutes 2 seconds spent.
    4. Time spent on trigger faults: 5 faults of 5 seconds each
    5. One misfire
    6. Average time per shell: 18.8 seconds
A drawback of this rack is the falling out of liners from the second and third row of bins when ammunition is removed.

The following defects were observed that were not linked to the racks:
  1. The firing pin does not guarantee ignition of the primer.
  2. The lubricant on the trigger mechanism spring guide rod freezes at a temperature of -8 degrees, which delays the movement of the worm gear and delays firing.
  3. The PT-6 sight is quickly covered in snow which reduces visibility and increases the time to fire.
Practical rate of fire from standstill when using up all ammunition is recorded at 4 RPM.
Practical rate of fire on the move from short stops: 3 RPM.
The rate of fire with the existing rack is much lower and does not exceed 2 RPM once ammunition is partially depleted.

...

Conclusions

The experimental ammunition bins for 76 mm rounds on the floor of the fighting compartment of the T-34 tank:
  1. Allows for easier access and increases aimed rate of fire to 4 RPM versus 2 RPM with the existing racks.
  2. Reduces the time to replenish ammunition from 2-2.5 hours to 10 minutes.
  3. Allows spent casings to be stowed quickly even if many are fired.
  4. Allows easy access to the drive couplings and batteries.
Drawback include design defects in the holders of the top row of rounds, lids, and removable liners."

3 comments:

  1. Replies
    1. 4 RPM if your gun is jamming and you can't see because your sight is covered in snow is pretty decent ROF ;)

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  2. I really appreciate your professional approach.These are pieces of very useful information that will be of great use for me in future.
    ប្រដាល់ថៃអនឡាញ

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