Mark I Fire Control Computer

The Mark I Fire Control Computer was deployed by the United States Navy on a variety of ships from destroyers (one per ship) to battleships (one per main gun turret, plus one shared by the smaller calibre battery). The Mark I used many inputs, such as range (distance) and bearing (direction) from the radar, the ship's own motion from the gyrocompass, and wind speed and direction from weather instruments. The output is control information to the gun machinery (e.g. turret direction and gun elevation), as well as timing information to the projectile to be fired. While the fire control systems aided greatly with ship-to-ship and ship-to-shore fire control problems, it was in the anti-aircraft warfare mode that a computer made the greatest contribution. However, the usefulness of analog computers such as the Mark I was greatly reduced with the introduction of jet aircraft, when the relative motion of the target aircraft became great enough that the gears and shafts of the computer could not keep up.