Friday, 4 October 2013

Night Vision

Many people may have read about German night vision devices, built in the late war. Far fewer people read about the Soviet equivalents, which started development in 1941.

CAMD RF 38-11355-644: "To the chief of the 3rd Division of GABTU KA

Here are the project description and blueprints, for your confirmation, of the aiming device for night-time fire from a tank, built as a result of contract #BZ-415 from May 29th, 1941...."

Some tedious bureaucracy comes after, but then, blueprints:

Nighttime gun sight. The maximum range is 200 meters.

IR projector for the gun sight.

The developments weren't entirely theoretical. Two tank brigades received night vision devices on the Stalingrad front in the fall of 1942.

CAMD RF 38-11355-801

This device was not for the gunner, but for the driver, enabling Soviet tanks to move at night. The following document, dated November 9th, 1942, describes it and its function.

"Tactical-Technical Requirements of the Prism type night driving device for the T-34

Purpose: the Prism type night driving device is designed to enable driving a T-34 tank during a dark night with closed hatches.

Positioning: the device is installed on a T-34 tank instead of the driver's observation device.

Principle of Operation: the device operates by illuminating the terrain in front of the tank with invisible infra-red light. The light beams reflect off objects, and are caught by the Prism device. The device converts the invisible light to visible green light. The observer, looking into the device, can see items in front of him.

Tactical-Technical Characteristics: 
  1. The Prism device has the following dimensions: 180 mm in height, 120 mm in width, 135 mm in depth, and is shaped the same as a T-34 driver observation device.
  2. Main elements of the device:
    1. Driver's observation device "Prism" with a cover.
    2. Power supply for the electro-optical converter.
    3. Two headlights with light filters.
  3. Main elements of the observation device:
    1. Two lenses with a 90 degree optical axis.
    2. Refractor system with a 90 degree optical axis.
    3. Two eyepieces with an 8 mm pupil.
    4. Optics with 1:1.25 magnification, 20 degree observation angle, and 1:1.2 light amplification.
  4. Inside of the Prism are two electro-optical converters with the resolution of 10 lines per millimeter, and sensitivity of 10 microamperes per lumen.
  5. For a high voltage power supply for the electro-optical transformers, a 20 kilovolt power supply is used. The main elements of the power supply are:
    1. Two base 2NKN-10 batteries.
    2. Inductor coil.
    3. [I can't translate this component. The original says безнакальный кинотронный выпрямитель. Some kind of heat-less straightener.]
    4. Elements of the power supply fit into a container 165 mm by 145 mm by 110 mm in size.
  6. The device enables the driving of a T-34 column at night, with a closed driver's hatch, with a speed of 10-12 kph.
  7. While stationary, the device can show a person and his movements, trees, bushes, and buildings, at a distance of 20-25 meters, in an area 8-10 meters wide.
  8. While moving, the device can show 20-25 of road without a well defined boundary.
  9. The device is simple to use and does not inconvenience the driver.
  10. The lights have a constant focus. Each bulb consumes 100 watts, at 12 volts. The lightbulbs draw power from the tank's battery. The bulbs should last 25 hours.
  11. Projectors can shine both IR and visible light.
  12. The device and all of its spare parts fit in a special container."
CAMD RF 38-11355-650

"Prism" was much more elegant than the "Flute" (Dudka) system from 1941, which looked like this:



5 comments:

  1. This owns so hard. I wonder if there are any working examples remaining? It's be interesting to see how it compares not only to the German systems from later in the war, but also postwar Soviet and Western systems, as well as modern ones. My experiences using modern NV were somewhat marred by my shitty eyesight and the impracticality of wearing them over regular glasses, but I was rather surprised at how the world really looked through them.

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  2. The "flute" is not elegant ? THIS THING IS SO BADASS.

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  3. The "Some kind of heat-less straightener" is an image intensifier tube. The coil delivering 20 kV suggest that it would need a source of IR light where as a 4000 kV tube whould not need need any light source. However given the state of the art at the time it is quite good.

    Herman der German

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  4. Herman der German21 October 2013 at 04:21

    The first drawing looks like different equipment from that in the photographs and more like equipment attached to the tank. The lower to sections shows that it is switchable between binocular optical and mixed optical and image intensifier.

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  5. Soviet engineering at its finest I see, Socialist technology prevails once again

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