The Kommandogerät 36 or Kdo-Gerät 36 was an analog fire control computer developed by Carl Zeiss, Jena, and introduced in 1936 to calculate firing trajectories for continuous shooting at moving aerial targets. It operated using a linear calculation method by scaling and geometrically replicating aircraft movement in polar coordinates.
A point in space, the target, was determined using the following three measured values; distance to the measuring point (eₘ), azimuth angle to the measuring point (ωₘ) and the elevation angle to the measuring point (γₘ). These values were determined relative to a fixed reference line on the map plane. The corresponding data was typically collected using the mounted rangefinder and associated sighting telescopes, then continuously fed into the fire control computer. Alternatively, a radar device could be used to determine and transmit the values.
Using this data, the horizontal speed and flight direction of the target were calculated.
Predicted impact point
A gun that is meant to engage an aircraft should not be aimed at its visible position but rather at an anticipated point along its flight path, known as the predicted impact point. This point depends on the loading time of the gun, the flight time of the shell, and the distance the target travels in that time. It is this predicted impact point that is calculated by the Kommandogerät.
For each gun, the necessary firing data was calculated based on the impact point, horizontal and vertical position differences, and the shell’s flight path. These values took into account factors such as shell velocity, spin, powder temperature, initial velocity, wind influence, and air density at various altitudes.
Specifications
The Kommandogerät 36 fire control computer was operated by a crew of 13 personnel and a fire control leader. On its mount the computer weighed 1,375 kg. The Kommandogerat 36 could be transported with a Sd.Ah. 104 trailer.
The device required a rangefinder 4 m R(H)34 for operation and was designed for the “extended range” mode.
Operating Range
- Azimuth rotation range: ±2 × 6,400 mils
- Azimuth angle range: ±800 mils
- Elevation range: -3° to +86°
- Map distance to measuring point: 0 to 15,600 m
- Map distance to impact point: 0 to 13,000 m
- Horizontal target speed: 0 to 250 m/s
- Vertical target speed: 0 to 120 m/s
- Time of flight calculation: up to 50 seconds
- Horizontal position difference: up to 500 m
- Vertical position difference: up to 200 m
- Shell time of flight: up to 30 seconds
- Number of firing positions calculated: 20
Rangefinder 4 m R(H) 36
This stereoscopic rangefinder with a floating mark was also developed by Carl Zeiss (Jena) and introduced in the same year as the Kommandogerät 36. It was used to determine the distance or height of a target, especially for the heavy weapons of anti-aircraft artillery. With a simple switching operation, it could be converted at any height setting from a rangefinder to an altimeter and vice versa. The device featured an inclined viewing angle for aiming direction by 80° and electric illuminated measuring marks. It is also sometimes referred to as a stereo altimeter.
The device includes the Correction Device BGR 36, two aiming telescopes (10×45) for azimuth and elevation, one double observation telescope (10×45), and two finder scopes (6×30).
Specifications
- Measuring principle: Stereoscopic floating mark
- Measuring range: 0.62 to 50 km
- Measuring base (baseline): 4 m
- Magnification: 24x and 12x
- Entrance pupil: 40 mm
- Exit pupil:
- At 24x magnification: 1.7 mm
- At 12x magnification: 3.4 mm
- Field of view:
- At 24x magnification: 29 m at 1000 m
- At 12x magnification: 35 m at 1000 m
- Eyepiece adjustment range: ±6 diopters
- Interpupillary distance adjustment range: 54 to 76 mm
- Year of introduction: 1936
- Weight: 175 kg
- Manufacturer: Carl Zeiss, Jena
Kommandogerät 40
The Kommandogerät 40 analog fire control computer, developed by Zeiss Ikon and introduced in 1937 was the successor to the Kommandogerät 36.
